National Electric Code Handbook

✍ Scribed by NFPA - National Fire Protection Association

• Year: 2020
• Tongue: English
• Leaves: 1369
• Edition: 14
• Category: Library

✦ Table of Contents

National Electrical Code® Handbook
Copyright
Dedication
Contents
Preface
Acknowledgments
Richard G. Biermann Award
About the Editors
Technical Changes
90 Introduction
ARTICLE 90 Introduction
90.1 Purpose.
(A) Practical Safeguarding.
(B) Adequacy.
(C) Relation to Other International Standards.
90.2 Scope.
(A) Covered.
(B) Not Covered.
(C) Special Permission.
90.3 Code Arrangement.
90.4 Enforcement.
90.5 Mandatory Rules, Permissive Rules, and Explanatory Material.
(A) Mandatory Rules.
(B) Permissive Rules.
(C) Explanatory Material.
(D) Informative Annexes.
90.6 Formal Interpretations.
90.7 Examination of Equipment for Safety.
90.8 Wiring Planning.
(A) Future Expansion and Convenience.
(B) Number of Circuits in Enclosures.
90.9 Units of Measurement.
(A) Measurement System of Preference.
(B) Dual System of Units.
(C) Permitted Uses of Soft Conversion.
(D) Compliance.
Chapter 1 General
ARTICLE 100 Definitions
Part I. General
Part II. Over 1000 Volts, Nominal
ARTICLE 110 Requirements for Electrical Installations
Part I. General
110.1 Scope.
110.2 Approval.
110.3 Examination, Identification, Installation, Use, and Listing (Product Certification) of Equipment.
(A) Examination.
(B) Installation and Use.
(C) Listing.
110.4 Voltages.
110.5 Conductors.
110.6 Conductor Sizes.
110.7 Wiring Integrity.
110.8 Wiring Methods.
110.9 Interrupting Rating.
110.10 Circuit Impedance, Short-Circuit Current Ratings, and Other Characteristics.
110.11 Deteriorating Agents.
110.12 Mechanical Execution of Work.
(A) Unused Openings.
(B) Integrity of Electrical Equipment and Connections
110.13 Mounting and Cooling of Equipment.
(A) Mounting.
(B) Cooling.
110.14 Electrical Connections.
(A) Terminals.
(B) Splices.
(C) Temperature Limitations.
(D) Installation.
110.15 High-Leg Marking.
110.16 Arc-Flash Hazard Warning.
(A) General.
(B) Service Equipment.
110.18 Arcing Parts.
110.19 Light and Power from Railway Conductors.
110.21 Marking.
(A) Equipment Markings.
(B) Field-Applied Hazard Markings.
110.22 Identification of Disconnecting Means.
(A) General.
(B) Engineered Series Combination Systems.
(C) Tested Series Combination Systems.
110.23 Current Transformers.
110.24 Available Fault Current.
(A) Field Marking.
(B) Modifications.
110.25 Lockable Disconnecting Means.
Part II. 1000 Volts, Nominal, or Less
110.26 Spaces About Electrical Equipment.
(A) Working Space.
(B) Clear Spaces.
(C) Entrance to and Egress from Working Space.
(D) Illumination.
(E) Dedicated Equipment Space.
(F) Locked Electrical Equipment Rooms or Enclosures.
110.27 Guarding of Live Parts.
(A) Live Parts Guarded Against Accidental Contact.
(B) Prevent Physical Damage.
(C) Warning Signs.
110.28 Enclosure Types.
Part III. Over 1000 Volts, Nominal
110.30 General.
110.31 Enclosure for Electrical Installations.
(A) Electrical Vaults.
(B) Indoor Installations.
(C) Outdoor Installations.
(D) Enclosed Equipment Accessible to Unqualified Persons.
110.32 Work Space About Equipment.
110.33 Entrance to Enclosures and Access to Working Space.
(A) Entrance.
(B) Access.
110.34 Work Space and Guarding.
(A) Working Space.
(B) Separation from Low-Voltage Equipment.
(C) Locked Rooms or Enclosures.
(D) Illumination.
(E) Elevation of Unguarded Live Parts.
(F) Protection of Service Equipment, Switchgear, and Industrial Control Assemblies.
110.36 Circuit Conductors.
110.40 Temperature Limitations at Terminations.
110.41 Inspections and Tests.
(A) Pre-energization and Operating Tests.
(B) Test Report.
Part IV. Tunnel Installations over 1000 Volts, Nominal
110.51 General.
(A) Covered.
(B) Other Articles.
(C) Protection Against Physical Damage.
110.52 Overcurrent Protection.
110.53 Conductors.
110.54 Bonding and Equipment Grounding Conductors.
(A) Grounded and Bonded.
(B) Equipment Grounding Conductors.
110.55 Transformers, Switches, and Electrical Equipment
110.56 Energized Parts.
110.57 Ventilation System Controls.
110.58 Disconnecting Means.
110.59 Enclosures.
Part V. Manholes and Other Electrical Enclosures Intended for Personnel Entry
110.70 General.
110.71 Strength.
110.72 Cabling Work Space.
110.73 Equipment Work Space.
110.74 Conductor Installation.
(A) 1000 Volts, Nominal, or Less.
(B) Over 1000 Volts, Nominal.
110.75 Access to Manholes.
(A) Dimensions.
(B) Obstructions.
(C) Location.
(D) Covers.
(E) Marking.
110.76 Access to Vaults and Tunnels.
(A) Location.
(B) Locks.
110.77 Ventilation.
110.78 Guarding.
110.79 Fixed Ladders.
Chapter 2 Wiring and Protection
ARTICLE 200 Use and Identification of Grounded Conductors
200.1 Scope.
200.2 General.
(A) Insulation.
(B) Continuity.
200.3 Connection to Grounded System.
200.4 Neutral Conductors.
(A) Installation.
(B) Multiple Circuits.
200.6 Means of Identifying Grounded Conductors.
(A) Sizes 6 AWG or Smaller.
(B) Sizes 4 AWG or Larger.
(C) Flexible Cords.
(D) Grounded Conductors of Different Systems.
(E) Grounded Conductors of Multiconductor Cables.
200.7 Use of Insulation of a White or Gray Color or with Three Continuous White or Gray Stripes.
(A) General.
(B) Circuits of Less Than 50 Volts.
(C) Circuits of 50 Volts or More.
200.9 Means of Identification of Terminals.
200.10 Identification of Terminals.
(A) Device Terminals.
(B) Receptacles, Plugs, and Connectors.
(C) Screw Shells.
(D) Screw Shell Devices with Leads.
(E) Appliances.
200.11 Polarity of Connections.
ARTICLE 210 Branch Circuits
Part I. General Provisions
210.1 Scope.
210.3 Other Articles for Specific-Purpose Branch Circuits.
210.4 Multiwire Branch Circuits.
(A) General.
(B) Disconnecting Means.
(C) Line-to-Neutral Loads.
(D) Grouping.
210.5 Identification for Branch Circuits.
(A) Grounded Conductor.
(B) Equipment Grounding Conductor.
(C) Identification of Ungrounded Conductors.
210.6 Branch-Circuit Voltage Limitations.
(A) Occupancy Limitation.
(B) 120 Volts Between Conductors.
(C) 277 Volts to Ground.
(D) 600 Volts Between Conductors.
(E) Over 600 Volts Between Conductors.
210.7 Multiple Branch Circuits.
210.8 Ground-Fault Circuit-Interrupter Protection for Personnel.
(A) Dwelling Units.
(B) Other Than Dwelling Units.
(C) Boat Hoists.
(D) Kitchen Dishwasher Branch Circuit.
(E) Crawl Space Lighting Outlets.
210.9 Circuits Derived from Autotransformers.
210.10 Ungrounded Conductors Tapped from Grounded Systems.
210.11 Branch Circuits Required.
(A) Number of Branch Circuits.
(B) Load Evenly Proportioned Among Branch Circuits.
(C) Dwelling Units.
210.12 Arc-Fault Circuit-Interrupter Protection.
(A) Dwelling Units.
(B) Dormitory Units.
(C) Guest Rooms and Guest Suites.
(D) Branch Circuit Extensions or Modifications — Dwelling
210.13 Ground-Fault Protection of Equipment.
210.17 Guest Rooms and Guest Suites.
Part II. Branch-Circuit Ratings
210.18 Rating.
210.19 Conductors — Minimum Ampacity and Size.
(A) Branch Circuits Not More Than 600 Volts.
(B) Branch Circuits Over 600 Volts.
210.20 Overcurrent Protection.
(A) Continuous and Noncontinuous Loads.
(B) Conductor Protection.
(C) Equipment.
(D) Outlet Devices.
210.21 Outlet Devices.
(A) Lampholders.
(B) Receptacles.
210.22 Permissible Loads, Individual Branch Circuits.
210.23 Permissible Loads, Multiple-Outlet Branch Circuits.
(A) 15- and 20- Ampere Branch Circuits.
(B) 30- Ampere Branch Circuits.
(C) 40- and 50- Ampere Branch Circuits.
(D) Branch Circuits Larger Than 50 Amperes.
210.24 Branch-Circuit Requirements — Summary.
210.25 Branch Circuits in Buildings with More Than One Occupancy.
(A) Dwelling Unit Branch Circuits.
(B) Common Area Branch Circuits.
Part III. Required Outlets
210.50 General.
(A) Cord Pendants.
(B) Cord Connections.
(C) Appliance Receptacle Outlets.
210.52 Dwelling Unit Receptacle Outlets.
(A) General Provisions.
(B) Small Appliances.
(C) Countertops and Work Surfaces.
(D) Bathrooms.
(E) Outdoor Outlets.
(F) Laundry Areas.
(G) Basements, Garages, and Accessory Buildings.
(H) Hallways.
(I) Foyers.
210.60 Guest Rooms, Guest Suites, Dormitories, and Similar Occupancies.
(A) General.
(B) Receptacle Placement.
210.62 Show Windows.
210.63 Heating, Air-Conditioning, and Refrigeration Equipment Outlet.
210.64 Electrical Service Areas.
210.70 Lighting Outlets Required.
(A) Dwelling Units.
(B) Guest Rooms or Guest Suites.
(C) All Occupancies.
210.71 Meeting Rooms.
(A) General.
(B) Receptacle Outlets Required.
ARTICLE 215 Feeders
215.1 Scope.
215.2 Minimum Rating and Size.
(A) Feeders Not More Than 600 Volts.
(B) Feeders over 600 Volts.
215.3 Overcurrent Protection.
215.4 Feeders with Common Neutral Conductor.
(A) Feeders with Common Neutral.
(B) In Metal Raceway or Enclosure.
215.5 Diagrams of Feeders.
215.6 Feeder Equipment Grounding Conductor.
215.7 Ungrounded Conductors Tapped from Grounded Systems.
215.9 Ground-Fault Circuit-Interrupter Protection for Personnel
215.10 Ground-Fault Protection of Equipment.
215.11 Circuits Derived from Autotransformers.
215.12 Identification for Feeders.
(A) Grounded Conductor.
(B) Equipment Grounding Conductor.
(C) Identification of Ungrounded Conductors.
ARTICLE 220 Branch-Circuit, Feeder, and Service Load Calculations
Part I. General
220.1 Scope.
220.3 Other Articles for Specific-Purpose Calculations.
220.5 Calculations.
(A) Voltages.
(B) Fractions of an Ampere.
Part II. Branch-Circuit Load Calculations
220.10 General.
220.12 Lighting Load for Specified Occupancies.
220.14 Other Loads — All Occupancies.
(A) Specific Appliances or Loads.
(B) Electric Dryers and Electric Cooking Appliances in Dwellings and Household Cooking Appliances Used in Instructional Programs.
(C) Motor Outlets.
(D) Luminaires.
(E) Heavy-Duty Lampholders.
(F) Sign and Outline Lighting.
(G) Show Windows.
(H) Fixed Multioutlet Assemblies.
(I) Receptacle Outlets.
(J) Dwelling Occupancies.
(K) Banks and Office Buildings.
(L) Other Outlets.
220.16 Loads for Additions to Existing Installations.
(A) Dwelling Units.
(B) Other Than Dwelling Units.
220.18 Maximum Loads.
(A) Motor-Operated and Combination Loads.
(B) Inductive and LED Lighting Loads.
(C) Range Loads.
Part III. Feeder and Service Load Calculations
220.40 General.
220.42 General Lighting.
220.43 Show-Window and Track Lighting.
(A) Show Windows.
(B) Track Lighting.
(B) Laundry Circuit Load.
220.44 Receptacle Loads — Other Than Dwelling Units.
220.50 Motors.
220.51 Fixed Electric Space Heating.
220.52 Small-Appliance and Laundry Loads — Dwelling Unit.
(A) Small-Appliance Circuit Load.
(B) Laundry Circuit Load
220.53 Appliance Load — Dwelling Unit(s).
220.54 Electric Clothes Dryers — Dwelling Unit(s).
220.55 Electric Cooking Appliances in Dwelling Units and Household Cooking Appliances Used in Instructional Programs.
220.56 Kitchen Equipment — Other Than Dwelling Unit(s).
220.60 Noncoincident Loads.
220.61 Feeder or Service Neutral Load.
(A) Basic Calculation.
(B) Permitted Reductions.
(C) Prohibited Reductions.
Part IV. Optional Feeder and Service Load Calculations
220.80 General.
220.82 Dwelling Unit.
(A) Feeder and Service Load.
(B) General Loads.
(C) Heating and Air-Conditioning Load.
220.83 Existing Dwelling Unit.
(A) Where Additional Air-Conditioning Equipment or Electric Space-Heating Equipment Is Not to Be Installed.
(B) Where Additional Air-Conditioning Equipment or Electric Space-Heating Equipment Is to Be Installed.
220.84 Multifamily Dwelling.
(A) Feeder or Service Load.
(B) House Loads.
(C) Calculated Loads.
220.85 Two Dwelling Units.
220.86 Schools
220.87 Determining Existing Loads.
220.88 New Restaurants.
Part V. Farm Load Calculations
220.100 General.
220.102 Farm Loads — Buildings and Other Loads.
(A) Dwelling Unit
(B) Other Than Dwelling Unit.
220.103 Farm Loads — Total.
ARTICLE 225 Outside Branch Circuits and Feeders
225.1 Scope
225.3 Other Articles
Part I. General
225.4 Conductor Covering.
225.5 Size of Conductors 600 Volts, Nominal, or Less.
225.6 Conductor Size and Support.
(A) Overhead Spans.
(B) Festoon Lighting.
225.7 Lighting Equipment Installed Outdoors.
(A) General.
(B) Common Neutral.
(C) 277 Volts to Ground.
(D) 1000 Volts Between Conductors.
225.8 Calculation of Loads 1000 Volts, Nominal, or Less.
(A) Branch Circuits.
(B) Feeders.
225.10 Wiring on Buildings (or Other Structures).
225.11 Feeder and Branch-Circuit Conductors Entering, Exiting, or Attached to Buildings or Structures.
225.12 Open-Conductor Supports.
225.14 Open-Conductor Spacings.
(A) 1000 Volts, Nominal, or Less.
(B) Over 1000 Volts, Nominal.
(C) Separation from Other Circuits.
(D) Conductors on Poles.
225.15 Supports over Buildings.
225.16 Attachment to Buildings.
(A) Point of Attachment.
(B) Means of Attachment.
225.17 Masts as Supports.
(A) Strength.
(B) Attachment.
225.18 Clearance for Overhead Conductors and Cables.
225.19 Clearances from Buildings for Conductors of Not over 1000 Volts, Nominal.
(A) Above Roofs.
(B) From Nonbuilding or Nonbridge Structures.
(C) Horizontal Clearances.
(D) Final Spans.
(E) Zone for Fire Ladders.
225.20 Protection Against Physical Damage.
225.21 Multiconductor Cables on Exterior Surfaces of Buildings (or Other Structures).
225.22 Raceways on Exterior Surfaces of Buildings or Other Structures.
225.24 Outdoor Lampholders.
225.25 Location of Outdoor Lamps.
225.26 Vegetation as Support.
225.27 Raceway Seal.
Part II. Buildings or Other Structures Supplied by a Feeder(s) or Branch Circuit(s)
225.30 Number of Supplies.
(A) Special Conditions.
(B) Special Occupancies.
(C) Capacity Requirements.
(D) Different Characteristics.
(E) Documented Switching Procedures.
225.31 Disconnecting Means.
225.32 Location.
225.33 Maximum Number of Disconnects.
(A) General.
(B) Single-Pole Units.
225.34 Grouping of Disconnects.
(A) General.
(B) Additional Disconnecting Means.
225.35 Access to Occupants.
225.36 Type of Disconnecting Means.
225.37 Identification.
225.38 Disconnect Construction.
(A) Manually or Power Operable.
(B) Simultaneous Opening of Poles.
(C) Disconnection of Grounded Conductor.
(D) Indicating.
225.39 Rating of Disconnect.
(A) One-Circuit Installation.
(B) Two-Circuit Installations.
(C) One-Family Dwelling.
(D) All Others.
225.40 Access to Overcurrent Protective Devices.
Part III. Over 1000 Volts
225.50 Sizing of Conductors.
225.51 Isolating Switches.
225.52 Disconnecting Means.
(A) Location.
(B) Type.
(C) Locking.
(D) Indicating.
(E) Uniform Position.
(F) Identification.
225.56 Inspections and Tests.
(A) Pre-Energization and Operating Tests.
(B) Test Report.
225.60 Clearances over Roadways, Walkways, Rail, Water, and Open Land.
(A) 22 kV, Nominal, to Ground or Less.
(B) Over 22 kV Nominal to Ground.
(C) Special Cases.
225.61 Clearances over Buildings and Other Structures.
(A) 22 kV Nominal to Ground or Less.
(B) Over 22 kV Nominal to Ground.
ARTICLE 230 Services
Part I. General
230.2 Number of Services.
(A) Special Conditions.
(B) Special Occupancies.
(C) Capacity Requirements.
(D) Different Characteristics.
(E) Identification.
230.3 One Building or Other Structure Not to Be Supplied Through Another.
230.6 Conductors Considered Outside the Building.
230.7 Other Conductors in Raceway or Cable.
230.8 Raceway Seal.
230.9 Clearances on Buildings.
(A) Clearances.
(B) Vertical Clearance.
(C) Building Openings.
230.10 Vegetation as Support.
Part II. Overhead Service Conductors
230.22 Insulation or Covering.
230.23 Size and Rating.
(A) General.
(B) Minimum Size.
(C) Grounded Conductors.
230.24 Clearances.
(A) Above Roofs.
(B) Vertical Clearance for Overhead Service Conductors.
(C) Clearance from Building Openings.
(D) Clearance from Swimming Pools.
(E) Clearance from Communication Wires and Cables.
230.26 Point of Attachment.
230.27 Means of Attachment.
230.28 Service Masts as Supports.
(A) Strength.
(B) Attachment.
230.29 Supports over Buildings.
Part III. Underground Service Conductors
230.30 Installation.
(A) Insulation.
(B) Wiring Methods.
230.31 Size and Rating.
(A) General.
(B) Minimum Size.
(C) Grounded Conductors.
230.32 Protection Against Damage.
230.33 Spliced Conductors.
Part IV. Service-Entrance Conductors
230.40 Number of Service-Entrance Conductor Sets.
230.41 Insulation of Service-Entrance Conductors.
230.42 Minimum Size and Rating.
(A) General.
(B) Specific Installations.
(C) Grounded Conductors.
230.43 Wiring Methods for 1000 Volts, Nominal, or Less.
230.44 Cable Trays.
230.46 Spliced Conductors.
230.50 Protection Against Physical Damage.
(A) Underground Service-Entrance Conductors.
(B) All Other Service-Entrance Conductors.
230.51 Mounting Supports.
(A) Service-Entrance Cables.
(B) Other Cables.
(C) Individual Open Conductors.
230.52 Individual Conductors Entering Buildings or Other Structures.
230.53 Raceways to Drain.
230.54 Overhead Service Locations.
(A) Service Head.
(B) Service-Entrance Cables Equipped with Service Head
(C) Service Heads and Goosenecks Above Service-Drop or Overhead Service Attachment.
(D) Secured.
(E) Separately Bushed Openings.
(F) Drip Loops.
(G) Arranged That Water Will Not Enter Service Raceway
230.56 Service Conductor with the Higher Voltage to Ground.
Part V. Service Equipment — General
230.62 Service Equipment — Enclosed or Guarded.
(A) Enclosed.
(B) Guarded.
230.66 Marking.
Part VI. Service Equipment — Disconnecting Means
230.70 General.
(A) Location.
(B) Marking.
(C) Suitable for Use.
230.71 Maximum Number of Disconnects.
(A) General.
(B) Single-Pole Units.
230.72 Grouping of Disconnects.
(A) General.
(B) Additional Service Disconnecting Means.
(C) Access to Occupants.
230.74 Simultaneous Opening of Poles.
230.75 Disconnection of Grounded Conductor.
230.76 Manually or Power Operable.
230.77 Indicating.
230.79 Rating of Service Disconnecting Means.
(A) One-Circuit Installations.
(B) Two-Circuit Installations.
(C) One-Family Dwellings.
(D) All Others.
230.80 Combined Rating of Disconnects.
230.81 Connection to Terminals.
230.82 Equipment Connected to the Supply Side of Service Disconnect.
Part VII. Service Equipment — Overcurrent Protection
230.90 Where Required.
(A) Ungrounded Conductor.
(B) Not in Grounded Conductor.
230.91 Location.
230.92 Locked Service Overcurrent Devices.
230.93 Protection of Specific Circuits.
230.94 Relative Location of Overcurrent Device and Other Service Equipment.
230.95 Ground-Fault Protection of Equipment.
(A) Setting.
(B) Fuses.
(C) Performance Testing.
Part VIII. Services Exceeding 1000 Volts, Nominal
230.200 General.
230.202 Service-Entrance Conductors.
(A) Conductor Size.
(B) Wiring Methods.
230.204 Isolating Switches.
(A) Where Required.
(B) Fuses as Isolating Switch.
(C) Accessible to Qualified Persons Only.
(D) Connection to Ground.
230.205 Disconnecting Means.
(A) Location.
(B) Type.
(C) Remote Control.
230.206 Overcurrent Devices as Disconnecting Means.
230.208 Protection Requirements.
(A) Equipment Type.
(B) Enclosed Overcurrent Devices.
230.209 Surge Arresters.
230.210 Service Equipment — General Provisions.
230.211 Switchgear.
230.212 Over 35,000 Volts.
ARTICLE 240 Overcurrent Protection
Part I. General
240.1 Scope.
240.2 Definitions.
240.3 Other Articles.
240.4 Protection of Conductors.
(A) Power Loss Hazard.
(B) Overcurrent Devices Rated 800 Amperes or Less.
(C) Overcurrent Devices Rated over 800 Amperes.
(D) Small Conductors.
(E) Tap Conductors.
(F) Transformer Secondary Conductors.
(G) Overcurrent Protection for Specific Conductor Applications
240.5 Protection of Flexible Cords, Flexible Cables, and Fixture Wires.
(A) Ampacities.
(B) Branch-Circuit Overcurrent Device.
240.6 Standard Ampere Ratings.
(A) Fuses and Fixed-Trip Circuit Breakers.
(B) Adjustable-Trip Circuit Breakers.
(C) Restricted Access Adjustable-Trip Circuit Breakers.
240.8 Fuses or Circuit Breakers in Parallel.
240.9 Thermal Devices.
240.10 Supplementary Overcurrent Protection.
240.12 Electrical System Coordination.
240.13 Ground-Fault Protection of Equipment.
240.15 Ungrounded Conductors.
(A) Overcurrent Device Required.
(B) Circuit Breaker as Overcurrent Device.
Part II. Location
240.21 Location in Circuit.
(A) Branch-Circuit Conductors.
(B) Feeder Taps.
(C) Transformer Secondary Conductors.
(D) Service Conductors.
(E) Busway Taps.
(F) Motor Circuit Taps.
(G) Conductors from Generator Terminals.
(H) Battery Conductors.
240.22 Grounded Conductor.
240.23 Change in Size of Grounded Conductor.
240.24 Location in or on Premises.
(A) Accessibility.
(B) Occupancy.
(C) Not Exposed to Physical Damage.
(D) Not in Vicinity of Easily Ignitible Material.
(E) Not Located in Bathrooms.
(F) Not Located over Steps.
Part III. Enclosures
240.30 General.
(A) Protection from Physical Damage.
(B) Operating Handle.
240.32 Damp or Wet Locations.
240.33 Vertical Position.
Part IV. Disconnecting and Guarding
240.40 Disconnecting Means for Fuses.
240.41 Arcing or Suddenly Moving Parts.
(A) Location.
(B) Suddenly Moving Parts.
Part V. Plug Fuses, Fuseholders, and Adapters
240.50 General.
(A) Maximum Voltage.
(B) Marking.
(C) Hexagonal Configuration.
(D) No Energized Parts.
(E) Screw Shell.
240.51 Edison-Base Fuses.
(A) Classification.
(B) Replacement Only.
240.52 Edison-Base Fuseholders.
240.53 Type S Fuses.
(A) Classification.
(B) Noninterchangeable.
240.54 Type S Fuses, Adapters, and Fuseholders.
(A) To Fit Edison-Base Fuseholders.
(B) To Fit Type S Fuses Only.
(C) Nonremovable.
(D) Nontamperable.
(E) Interchangeability.
Part VI. Cartridge Fuses and Fuseholders
240.60 General.
(A) Maximum Voltage — 300-Volt Type.
(B) Noninterchangeable — 0–6000-Ampere Cartridge Fuseholders
(C) Marking.
(D) Renewable Fuses.
240.61 Classification.
240.67 Arc Energy Reduction.
(A) Documentation.
(B) Method to Reduce Clearing Time.
Part VII. Circuit Breakers
240.80 Method of Operation.
240.81 Indicating.
240.82 Nontamperable.
240.83 Marking.
(A) Durable and Visible.
(B) Location.
(C) Interrupting Rating.
(D) Used as Switches.
(E) Voltage Marking.
240.85 Applications.
240.86 Series Ratings.
(A) Selected Under Engineering Supervision in Existing Installations.
(B) Tested Combinations.
(C) Motor Contribution.
240.87 Arc Energy Reduction.
(A) Documentation.
(B) Method to Reduce Clearing Time.
Part VIII. Supervised Industrial Installations
240.90 General.
240.91 Protection of Conductors.
(A) General.
(B) Devices Rated Over 800 Amperes.
240.92 Location in Circuit.
(A) Feeder and Branch-Circuit Conductors.
(B) Feeder Taps.
(C) Transformer Secondary Conductors of Separately Derived Systems.
(D) Outside Feeder Taps.
(E) Protection by Primary Overcurrent Device.
Part IX. Overcurrent Protection over 1000 Volts, Nominal
240.100 Feeders and Branch Circuits.
(A) Location and Type of Protection.
(B) Protective Devices.
(C) Conductor Protection.
240.101 Additional Requirements for Feeders.
(A) Rating or Setting of Overcurrent Protective Devices.
(B) Feeder Taps.
ARTICLE 250 Grounding and Bonding
Part I. General
250.1 Scope.
250.2 Definition.
250.3 Application of Other Articles.
250.4 General Requirements for Grounding and Bonding.
(A) Grounded Systems.
(B) Ungrounded Systems.
250.6 Objectionable Current.
(A) Arrangement to Prevent Objectionable Current.
(B) Alterations to Stop Objectionable Current.
(C) Temporary Currents Not Classified as Objectionable Currents.
(D) Limitations to Permissible Alterations.
(E) Isolation of Objectionable Direct-Current Ground Currents
250.8 Connection of Grounding and Bonding Equipment.
(A) Permitted Methods.
(B) Methods Not Permitted.
250.10 Protection of Ground Clamps and Fittings.
250.12 Clean Surfaces.
Part II. System Grounding
250.20 Alternating-Current Systems to Be Grounded.
(A) Alternating-Current Systems of Less Than 50 Volts.
(B) Alternating-Current Systems of 50 Volts to 1000 Volts.
(C) Alternating-Current Systems of over 1000 Volts.
(D) Impedance Grounded Neutral Systems.
250.21 Alternating-Current Systems of 50 Volts to 1000 Volts Not Required to Be Grounded.
(A) General.
(B) Ground Detectors.
(C) Marking.
250.22 Circuits Not to Be Grounded.
250.24 Grounding Service-Supplied Alternating-Current Systems.
(A) System Grounding Connections.
(B) Main Bonding Jumper.
(C) Grounded Conductor Brought to Service Equipment.
(D) Grounding Electrode Conductor.
(E) Ungrounded System Grounding Connections.
250.26 Conductor to Be Grounded — Alternating-Current Systems.
250.28 Main Bonding Jumper and System Bonding Jumper.
(A) Material.
(B) Construction.
(C) Attachment.
(D) Size.
250.30 Grounding Separately Derived Alternating-Current Systems.
(A) Grounded Systems.
(B) Ungrounded Systems.
(C) Outdoor Source.
250.32 Buildings or Structures Supplied by a Feeder(s) or Branch Circuit(s).
(A) Grounding Electrode.
(B) Grounded Systems.
(C) Ungrounded Systems.
(D) Disconnecting Means Located in Separate Building or Structure on the Same Premises.
(E) Grounding Electrode Conductor.
250.34 Portable and Vehicle-Mounted Generators.
(A) Portable Generators.
(B) Vehicle-Mounted Generators.
(C) Grounded Conductor Bonding.
250.35 Permanently Installed Generators.
(A) Separately Derived System.
(B) Nonseparately Derived System.
250.36 High-Impedance Grounded Neutral Systems.
(A) Location.
(B) Conductor Insulation and Ampacity.
(C) System Grounding Connection.
(D) Conductor Routing.
(E) Equipment Bonding Jumper.
(F) Grounding Electrode Conductor Connection Location.
(G) Equipment Bonding Jumper Size.
Part III. Grounding Electrode System and Grounding Electrode Conductor
250.50 Grounding Electrode System.
250.52 Grounding Electrodes.
(A) Electrodes Permitted for Grounding.
(B) Not Permitted for Use as Grounding Electrodes.
250.53 Grounding Electrode System Installation.
(A) Rod, Pipe, and Plate Electrodes.
(B) Electrode Spacing.
(C) Bonding Jumper.
(D) Metal Underground Water Pipe.
(E) Supplemental Electrode Bonding Connection Size.
(F) Ground Ring.
(G) Rod and Pipe Electrodes.
(H) Plate Electrode.
250.54 Auxiliary Grounding Electrodes.
250.58 Common Grounding Electrode.
250.60 Use of Strike Termination Devices.
250.62 Grounding Electrode Conductor Material.
250.64 Grounding Electrode Conductor Installation.
(A) Aluminum or Copper-Clad Aluminum Conductors.
(B) Securing and Protection Against Physical Damage
(C) Continuous.
(D) Building or Structure with Multiple Disconnecting Means in Separate Enclosures.
(E) Raceways and Enclosures for Grounding Electrode Conductors.
(F) Installation to Electrode(s).
250.66 Size of Alternating-Current Grounding Electrode Conductor.
(A) Connections to a Rod, Pipe, or Plate Electrode(s).
(B) Connections to Concrete-Encased Electrodes.
(C) Connections to Ground Rings.
250.68 Grounding Electrode Conductor and Bonding Jumper Connection to Grounding Electrodes.
(A) Accessibility.
(B) Effective Grounding Path.
(C) Grounding Electrode Conductor Connections.
250.70 Methods of Grounding and Bonding Conductor Connection to Electrodes.
Part IV. Enclosure, Raceway, and Service Cable Connections
250.80 Service Raceways and Enclosures.
250.84 Underground Service Cable or Raceway.
(A) Underground Service Cable.
(B) Underground Service Raceway Containing Cable.
250.86 Other Conductor Enclosures and Raceways.
Part V. Bonding
250.90 General.
250.92 Services.
(A) Bonding of Equipment for Services.
(B) Method of Bonding at the Service.
250.94 Bonding for Communication Systems.
(A) The Intersystem Bonding Termination Device.
(B) Other Means.
250.96 Bonding Other Enclosures.
(A) General.
(B) Isolated Grounding Circuits.
250.97 Bonding for Over 250 Volts.
250.98 Bonding Loosely Jointed Metal Raceways.
250.100 Bonding in Hazardous (Classified) Locations.
250.102 Grounded Conductor, Bonding Conductors, and Jumpers.
(A) Material.
(B) Attachment.
(C) Size — Supply-Side Bonding Jumper.
(D) Size — Equipment Bonding Jumper on Load Side of an Overcurrent Device.
(E) Installation.
250.104 Bonding of Piping Systems and Exposed Structural Metal.
(A) Metal Water Piping.
(B) Other Metal Piping.
(C) Structural Metal.
(D) Separately Derived Systems.
250.106 Lightning Protection Systems.
Part VI. Equipment Grounding and Equipment Grounding Conductors
250.110 Equipment Fastened in Place (Fixed) or Connected by Permanent Wiring Methods.
250.112 Specific Equipment Fastened in Place (Fixed) or Connected by Permanent Wiring Methods.
(A) Switchgear and Switchboard Frames and Structures.
(B) Pipe Organs.
(C) Motor Frames.
(D) Enclosures for Motor Controllers.
(E) Elevators and Cranes.
(F) Garages, Theaters, and Motion Picture Studios.
(G) Electric Signs.
(H) Motion Picture Projection Equipment.
(I) Remote-Control, Signaling, and Fire Alarm Circuits.
(J) Luminaires.
(K) Skid-Mounted Equipment.
(L) Motor-Operated Water Pumps.
(M) Metal Well Casings.
250.114 Equipment Connected by Cord and Plug.
250.116 Nonelectrical Equipment.
250.118 Types of Equipment Grounding Conductors.
250.119 Identification of Equipment Grounding Conductors
(A) Conductors 4 AWG and Larger.
(B) Multiconductor Cable.
(C) Flexible Cord.
250.120 Equipment Grounding Conductor Installation.
(A) Raceway, Cable Trays, Cable Armor, Cablebus, or Cable Sheaths.
(B) Aluminum and Copper-Clad Aluminum Conductors.
(C) Equipment Grounding Conductors Smaller Than 6 AWG.
250.121 Use of Equipment Grounding Conductors.
250.122 Size of Equipment Grounding Conductors.
(A) General.
(B) Increased in Size.
(C) Multiple Circuits.
(D) Motor Circuits.
(E) Flexible Cord and Fixture Wire.
(F) Conductors in Parallel.
(G) Feeder Taps.
250.124 Equipment Grounding Conductor Continuity.
(A) Separable Connections.
(B) Switches.
250.126 Identification of Wiring Device Terminals.
Part VII. Methods of Equipment Grounding
250.130 Equipment Grounding Conductor Connections.
(A) For Grounded Systems.
(B) For Ungrounded Systems.
(C) Nongrounding Receptacle Replacement or Branch Circuit Extensions.
250.132 Short Sections of Raceway.
250.134 Equipment Fastened in Place or Connected by Permanent Wiring Methods (Fixed) — Grounding.
(A) Equipment Grounding Conductor Types.
(B) With Circuit Conductors.
250.136 Equipment Considered Grounded.
(A) Equipment Secured to Grounded Metal Supports.
(B) Metal Car Frames.
250.138 Cord-and-Plug-Connected Equipment.
(A) By Means of an Equipment Grounding Conductor.
(B) By Means of a Separate Flexible Wire or Strap.
250.140 Frames of Ranges and Clothes Dryers.
250.142 Use of Grounded Circuit Conductor for Grounding Equipment.
(A) Supply-Side Equipment.
(B) Load-Side Equipment.
250.144 Multiple Circuit Connections.
250.146 Connecting Receptacle Grounding Terminal to Box.
(A) Surface-Mounted Box.
(B) Contact Devices or Yokes.
(C) Floor Boxes.
(D) Isolated Ground Receptacles.
250.148 Continuity and Attachment of Equipment Grounding Conductors to Boxes.
(A) Connections.
(B) Grounding Continuity.
(C) Metal Boxes.
(D) Nonmetallic Boxes.
(E) Solder.
Part VIII. Direct-Current Systems
250.160 General.
250.162 Direct-Current Circuits and Systems to Be Grounded.
(A) Two-Wire, Direct-Current Systems.
(B) Three-Wire, Direct-Current Systems.
250.164 Point of Connection for Direct-Current Systems.
(A) Off-Premises Source.
(B) On-Premises Source.
250.166 Size of the Direct-Current Grounding Electrode Conductor.
(A) Not Smaller Than the Neutral Conductor.
(B) Not Smaller Than the Largest Conductor.
(C) Connected to Rod, Pipe, or Plate Electrodes.
(D) Connected to a Concrete-Encased Electrode.
(E) Connected to a Ground Ring.
250.167 Direct-Current Ground-Fault Detection.
(A) Ungrounded Systems.
(B) Grounded Systems.
(C) Marking.
250.168 Direct-Current System Bonding Jumper.
250.169 Ungrounded Direct-Current Separately Derived Systems.
Part IX. Instruments, Meters, and Relays
250.170 Instrument Transformer Circuits.
250.172 Instrument Transformer Cases.
250.174 Cases of Instruments, Meters, and Relays Operating at 1000 Volts or Less.
(A) Not on Switchgear or Switchboards.
(B) On Switchgear or Dead-Front Switchboards.
(C) On Live-Front Switchboards.
250.176 Cases of Instruments, Meters, and Relays — Operating at 1000 Volts and Over.
250.178 Instrument Equipment Grounding Conductor.
Part X. Grounding of Systems and Circuits of over 1000 Volts
250.180 General.
250.182 Derived Neutral Systems.
250.184 Solidly Grounded Neutral Systems.
(A) Neutral Conductor.
(B) Single-Point Grounded Neutral System.
(C) Multigrounded Neutral Systems.
250.186 Grounding Service-Supplied Alternating-Current Systems.
(A) Systems with a Grounded Conductor at the Service Point.
(B) Systems Without a Grounded Conductor at the Service Point.
250.187 Impedance Grounded Neutral Systems.
(A) Location.
(B) Identified and Insulated.
(C) System Neutral Conductor Connection.
(D) Equipment Grounding Conductors.
250.188 Grounding of Systems Supplying Portable or Mobile Equipment.
(A) Portable or Mobile Equipment.
(B) Exposed Non–Current-Carrying Metal Parts.
(C) Ground-Fault Current.
(D) Ground-Fault Detection and Relaying.
(E) Isolation.
(F) Trailing Cable and Couplers.
250.190 Grounding of Equipment.
(A) Equipment Grounding.
(B) Grounding Electrode Conductor.
(C) Equipment Grounding Conductor.
250.191 Grounding System at Alternating-Current Substations
250.194 Grounding and Bonding of Fences and Other Metal Structures.
(A) Metal Fences.
(B) Metal Structures.
ARTICLE 280 Surge Arresters, Over 1000 Volts
Part I. General
280.1 Scope.
280.3 Number Required.
280.4 Surge Arrester Selection.
(A) Rating.
(B) Silicon Carbide Types.
Part II. Installation
280.11 Location.
280.12 Uses Not Permitted.
280.14 Routing of Surge Arrester Grounding Conductors.
Part III. Connecting Surge Arresters
280.21 Connection.
280.23 Surge-Arrester Conductors.
280.24 Interconnections.
(A) Metal Interconnections.
(B) Through Spark Gap or Device.
(C) By Special Permission.
280.25 Grounding Electrode Conductor Connections and Enclosures.
ARTICLE 285 Surge-Protective Devices (SPDs), 1000 Volts or Less
Part I. General
285.1 Scope.
285.3 Uses Not Permitted.
285.4 Number Required.
285.6 Listing.
285.7 Short-Circuit Current Rating.
Part II. Installation
285.11 Location.
285.12 Routing of Connections.
285.13 Type 4 and Other Component Type SPDs.
Part III. Connecting SPDs
285.21 Connection.
285.23 Type 1 SPDs.
(A) Installation.
(B) At the Service.
285.24 Type 2 SPDs.
(A) Service-Supplied Building or Structure.
(B) Feeder-Supplied Building or Structure.
(C) Separately Derived System.
285.25 Type 3 SPDs.
285.26 Conductor Size.
285.27 Connection Between Conductors.
285.28 Grounding Electrode Conductor Connections and Enclosures.
Chapter 3 Wiring Methods and Materials
ARTICLE 300 General Requirements for Wiring Methods and Materials
Part I. General Requirements
300.1 Scope.
(A) All Wiring Installations.
(B) Integral Parts of Equipment.
(C) Metric Designators and Trade Sizes.
300.2 Limitations.
(A) Voltage.
(B) Temperature.
300.3 Conductors.
(A) Single Conductors.
(B) Conductors of the Same Circuit.
(C) Conductors of Different Systems.
300.4 Protection Against Physical Damage.
(A) Cables and Raceways Through Wood Members.
(B) Nonmetallic-Sheathed Cables and Electrical
(C) Cables Through Spaces Behind Panels Designed to Allow Access.
(D) Cables and Raceways Parallel to Framing Members and Furring Strips.
(E) Cables, Raceways, or Boxes Installed in or Under Roof Decking.
(F) Cables and Raceways Installed in Shallow Grooves.
(G) Insulated Fittings.
(H) Structural Joints.
300.5 Underground Installations.
(A) Minimum Cover Requirements.
(B) Wet Locations.
(C) Underground Cables and Conductors Under Buildings.
(D) Protection from Damage.
(E) Splices and Taps.
(F) Backfill.
(G) Raceway Seals.
(H) Bushing.
(I) Conductors of the Same Circuit.
(J) Earth Movement.
(K) Directional Boring.
300.6 Protection Against Corrosion and Deterioration.
(A) Ferrous Metal Equipment.
(B) Aluminum Metal Equipment.
(C) Nonmetallic Equipment.
300.7 Raceways Exposed to Different Temperatures.
(A) Sealing.
(B) Expansion, Expansion-Deflection, and Deflection Fittings.
300.8 Installation of Conductors with Other Systems.
300.9 Raceways in Wet Locations Abovegrade.
300.10 Electrical Continuity of Metal Raceways and Enclosures.
300.11 Securing and Supporting.
(A) Secured in Place.
(B) Wiring Systems Installed Above Suspended Ceilings.
(C) Raceways Used as Means of Support.
(D) Cables Not Used as Means of Support.
300.12 Mechanical Continuity — Raceways and Cables.
300.13 Mechanical and Electrical Continuity — Conductors.
(A) General.
(B) Device Removal.
300.14 Length of Free Conductors at Outlets, Junctions, and Switch Points.
300.15 Boxes, Conduit Bodies, or Fittings — Where Required.
(A) Wiring Methods with Interior Access.
(B) Equipment.
(C) Protection.
(D) Type MI Cable.
(E) Integral Enclosure.
(F) Fitting.
(G) Direct-Buried Conductors.
(H) Insulated Devices.
(I) Enclosures.
(J) Luminaires.
(K) Embedded.
(L) Manholes and Handhole Enclosures.
300.16 Raceway or Cable to Open or Concealed Wiring.
(A) Box, Conduit Body, or Fitting.
(B) Bushing.
300.17 Number and Size of Conductors in Raceway.
300.18 Raceway Installations.
(A) Complete Runs.
(B) Welding.
300.19 Supporting Conductors in Vertical Raceways.
(A) Spacing Intervals — Maximum.
(B) Fire-Rated Cables and Conductors.
(C) Support Methods.
300.20 Induced Currents in Ferrous Metal Enclosures or Ferrous Metal Raceways.
(A) Conductors Grouped Together.
(B) Individual Conductors.
300.21 Spread of Fire or Products of Combustion.
300.22 Wiring in Ducts Not Used for Air Handling, Fabricated Ducts for Environmental Air, and Other Spaces for Ducts for Environmental Air, and Other Spaces for Environmental Air (Plenums).
(A) Ducts for Dust, Loose Stock, or Vapor Removal.
(B) Ducts Specifically Fabricated for Environmental Air.
(C) Other Spaces Used for Environmental Air (Plenums).
(D) Information Technology Equipment.
300.23 Panels Designed to Allow Access.
Part II. Requirements for over 1000 Volts, Nominal
300.31 Covers Required.
300.32 Conductors of Different Systems.
300.34 Conductor Bending Radius.
300.35 Protection Against Induction Heating.
300.37 Aboveground Wiring Methods.
300.38 Raceways in Wet Locations Above Grade.
300.39 Braid-Covered Insulated Conductors — Exposed Installation.
300.40 Insulation Shielding.
300.42 Moisture or Mechanical Protection for Metal-Sheathed Cables.
300.45 Warning Signs.
300.50 Underground Installations.
(A) General.
(B) Wet Locations.
(C) Protection from Damage.
(D) Splices.
(E) Backfill.
(F) Raceway Seal.
ARTICLE 310 Conductors for General Wiring
Part I. General
310.1 Scope.
310.2 Definitions.
Part II. Installation
310.10 Uses Permitted.
(A) Dry Locations.
(B) Dry and Damp Locations.
(C) Wet Locations.
(D) Locations Exposed to Direct Sunlight.
(E) Shielding.
(F) Direct-Burial Conductors.
(G) Corrosive Conditions.
(H) Conductors in Parallel.
310.15 Ampacities for Conductors Rated 0–2000 Volts.
(A) General.
(B) Tables.
(C) Engineering Supervision.
310.60 Conductors Rated 2001 to 35,000 Volts.
(A) Ampacities of Conductors Rated 2001 to 35,000 Volts.
(B) Engineering Supervision.
(C) Tables.
Part III. Construction Specifications
310.104 Conductor Constructions and Applications.
310.106 Conductors.
(A) Minimum Size of Conductors.
(B) Conductor Material.
(C) Stranded Conductors.
(D) Insulated.
310.110 Conductor Identification.
(A) Grounded Conductors.
(B) Equipment Grounding Conductors.
(C) Ungrounded Conductors.
310.120 Marking.
(A) Required Information.
(B) Method of Marking.
(C) Suffixes to Designate Number of Conductors.
(D) Optional Markings.
ARTICLE 312 Cabinets, Cutout Boxes, and Meter Socket Enclosures
Part I. Scope and Installation
312.1 Scope.
312.2 Damp and Wet Locations.
312.3 Position in Wall.
312.4 Repairing Noncombustible Surfaces.
312.5 Cabinets, Cutout Boxes, and Meter Socket Enclosures.
(A) Openings to Be Closed.
(B) Metal Cabinets, Cutout Boxes, and Meter Socket Enclosures
(C) Cables.
312.6 Deflection of Conductors.
(A) Width of Wiring Gutters.
(B) Wire-Bending Space at Terminals.
(C) Conductors 4 AWG or Larger.
312.7 Space in Enclosures.
312.8 Switch and Overcurrent Device Enclosures.
(A) Splices, Taps, and Feed-Through Conductors.
(B) Power Monitoring Equipment.
312.9 Side or Back Wiring Spaces or Gutters.
Part II. Construction Specifications
312.10 Material.
(A) Metal Cabinets and Cutout Boxes.
(B) Strength.
(C) Nonmetallic Cabinets.
312.11 Spacing.
(A) General.
(B) Switch Clearance.
(C) Wiring Space.
(D) Wiring Space — Enclosure.
ARTICLE 314 Outlet, Device, Pull, and Junction Boxes; Conduit Bodies; Fittings; and Handhole Enclosures
Part I. Scope and General
314.1 Scope.
314.2 Round Boxes.
314.3 Nonmetallic Boxes.
314.4 Metal Boxes.
Part II. Installation
314.15 Damp or Wet Locations.
314.16 Number of Conductors in Outlet, Device, and Junction Boxes, and Conduit Bodies.
(A) Box Volume Calculations.
(B) Box Fill Calculations.
(C) Conduit Bodies.
314.17 Conductors Entering Boxes, Conduit Bodies, or Fittings
(A) Openings to Be Closed.
(B) Metal Boxes and Conduit Bodies.
(C) Nonmetallic Boxes and Conduit Bodies.
(D) Conductors 4 AWG or Larger.
314.19 Boxes Enclosing Flush Devices.
314.20 Flush-Mounted Installations.
314.21 Repairing Noncombustible Surfaces.
314.22 Surface Extensions.
314.23 Supports.
(A) Surface Mounting.
(B) Structural Mounting.
(C) Mounting in Finished Surfaces.
(D) Suspended Ceilings.
(E) Raceway-Supported Enclosure, Without Devices, Luminaires or Lampholders.
(F) Raceway-Supported Enclosures, with Devices, Luminaires or Lampholders.
(G) Enclosures in Concrete or Masonry.
(H) Pendant Boxes.
314.24 Depth of Boxes.
(A) Outlet Boxes Without Enclosed Devices or Utilization Equipment.
(B) Outlet and Device Boxes with Enclosed Devices or Utilization Equipment.
314.25 Covers and Canopies.
(A) Nonmetallic or Metal Covers and Plates.
(B) Exposed Combustible Wall or Ceiling Finish.
(C) Flexible Cord Pendants.
314.27 Outlet Boxes.
(A) Boxes at Luminaire or Lampholder Outlets.
(B) Floor Boxes.
(C) Boxes at Ceiling-Suspended (Paddle) Fan Outlets.
(D) Utilization Equipment.
(E) Separable Attachment Fittings.
314.28 Pull and Junction Boxes and Conduit Bodies.
(A) Minimum Size.
(B) Conductors in Pull or Junction Boxes.
(C) Covers.
(D) Permanent Barriers.
(E) Power Distribution Blocks.
314.29 Boxes, Conduit Bodies, and Handhole Enclosures to Be Accessible.
314.30 Handhole Enclosures.
(A) Size.
(B) Wiring Entries.
(C) Enclosed Wiring.
(D) Covers.
Part III. Construction Specifications
314.40 Metal Boxes, Conduit Bodies, and Fittings.
(A) Corrosion Resistant.
(B) Thickness of Metal.
(C) Metal Boxes Over 1650 cm3 (100 in.
(D) Grounding Provisions.
314.41 Covers.
314.42 Bushings.
314.43 Nonmetallic Boxes.
314.44 Marking.
Part IV. Pull and Junction Boxes, Conduit Bodies, and Handhole Enclosures for Use on Systems over 1000 Volts, Nominal
314.70 General.
(A) Pull and Junction Boxes.
(B) Conduit Bodies.
(C) Handhole Enclosures.
314.71 Size of Pull and Junction Boxes, Conduit Bodies, and Handhole Enclosures.
(A) For Straight Pulls.
(B) For Angle or U Pulls.
(C) Removable Sides.
314.72 Construction and Installation Requirements.
(A) Corrosion Protection.
(B) Passing Through Partitions.
(C) Complete Enclosure.
(D) Wiring Is Accessible.
(E) Suitable Covers.
(F) Suitable for Expected Handling.
ARTICLE 320 Armored Cable: Type AC
Part I. General
320.1 Scope.
320.2 Definition.
320.6 Listing Requirements.
Part II. Installation
320.10 Uses Permitted.
320.12 Uses Not Permitted.
320.15 Exposed Work.
320.17 Through or Parallel to Framing Members.
320.23 In Accessible Attics.
(A) Cables Run Across the Top of Floor Joists.
(B) Cable Installed Parallel to Framing Members.
320.24 Bending Radius.
320.30 Securing and Supporting.
(A) General.
(B) Securing.
(C) Supporting.
(D) Unsupported Cables.
320.40 Boxes and Fittings.
320.80 Ampacity.
(A) Thermal Insulation.
(B) Cable Tray.
Part III. Construction Specifications
320.100 Construction.
320.104 Conductors.
320.108 Equipment Grounding Conductor.
320.120 Marking.
ARTICLE 320 Flat Cable Assemblies: Type FC
Part I. General
322.1 Scope.
322.2 Definition.
322.6 Listing Requirements.
Part II. Installation
322.10 Uses Permitted.
322.12 Uses Not Permitted.
322.30 Securing and Supporting.
322.40 Boxes and Fittings.
(A) Dead Ends.
(B) Luminaire Hangers.
(C) Fittings.
(D) Extensions.
322.56 Splices and Taps.
(A) Splices.
(B) Taps.
Part III. Construction Specifications
322.100 Construction.
322.104 Conductors.
322.112 Insulation.
322.120 Marking.
(A) Temperature Rating.
(B) Identification of Grounded Conductor.
(C) Terminal Block Identification.
ARTICLE 324 Flat Conductor Cable: Type FCC
Part I. General
324.1 Scope.
324.2 Definitions.
324.6 Listing Requirements.
Part II. Installation
324.10 Uses Permitted.
(A) Branch Circuits.
(B) Branch-Circuit Ratings.
(C) Floors.
(D) Walls.
(E) Damp Locations.
(F) Heated Floors.
(G) System Height.
324.12 Uses Not Permitted.
324.18 Crossings.
324.30 Securing and Supporting.
324.40 Boxes and Fittings.
(A) Cable Connections and Insulating Ends.
(B) Polarization of Connections.
(C) Shields.
(D) Connection to Other Systems.
(E) Metal-Shield Connectors.
324.41 Floor Coverings.
324.42 Devices.
(A) Receptacles.
(B) Receptacles and Housings.
324.56 Splices and Taps.
(A) FCC Systems Alterations.
(B) Transition Assemblies.
324.60 Grounding.
Part III. Construction Specifications
324.100 Construction.
(A) Type FCC Cable.
(B) Shields.
324.101 Corrosion Resistance.
324.112 Insulation.
324.120 Markings.
(A) Cable Marking.
(B) Conductor Identification.
ARTICLE 326 Integrated Gas Spacer Cable: Type IGS
Part I. General
326.1 Scope.
326.2 Definition.
Part II. Installation
326.10 Uses Permitted.
326.12 Uses Not Permitted.
326.24 Bending Radius.
326.26 Bends.
326.40 Fittings.
326.80 Ampacity.
Part III. Construction Specifications
326.104 Conductors.
326.112 Insulation.
326.116 Conduit.
326.120 Marking.
ARTICLE 328 Medium Voltage Cable: Type MV
Part I. General
328.1 Scope.
328.2 Definition.
328.6 Listing Requirements.
Part II. Installation
328.10 Uses Permitted.
328.12 Uses Not Permitted.
328.14 Installation.
328.30 Support.
328.80 Ampacity.
Part III. Construction Specifications
328.100 Construction.
328.120 Marking.
ARTICLE 330 Metal-Clad Cable: Type MC
Part I. General
330.1 Scope.
330.2 Definition.
330.6 Listing Requirements.
Part II. Installation
330.10 Uses Permitted.
(A) General Uses.
(B) Specific Uses.
330.12 Uses Not Permitted.
330.15 Exposed Work.
330.17 Through or Parallel to Framing Members.
330.23 In Accessible Attics.
330.24 Bending Radius.
(A) Smooth Sheath.
(B) Interlocked-Type Armor or Corrugated Sheath.
(C) Shielded Conductors.
330.30 Securing and Supporting.
(A) General.
(B) Securing.
(C) Supporting.
(D) Unsupported Cables.
330.31 Single Conductors.
330.80 Ampacity.
(A) Type MC Cable Installed in Cable Tray.
(B) Single Type MC Conductors Grouped Together.
Part III. Construction Specifications
330.104 Conductors.
330.108 Equipment Grounding Conductor.
330.112 Insulation.
(A) 1000 Volts or Less.
(B) Over 1000 Volts.
330.116 Sheath.
ARTICLE 332 Mineral-Insulated, Metal-Sheathed Cable: Type MI
Part I. General
332.1 Scope.
332.2 Definition.
332.6 Listing Requirements.
Part II. Installation
332.10 Uses Permitted.
332.12 Uses Not Permitted.
332.17 Through or Parallel to Framing Members.
332.24 Bending Radius.
(B) Unsupported Cable.
(C) Cable Trays.
332.31 Single Conductors.
332.40 Boxes and Fittings.
(A) Fittings.
332.30 Securing and Supporting.
(A) Horizontal Runs Through Holes and Notches.
(B) Terminal Seals.
332.80 Ampacity.
(A) Type MI Cable Installed in Cable Tray.
(B) Single Type MI Conductors Grouped Together.
Part III. Construction Specifications
332.104 Conductors.
332.108 Equipment Grounding Conductor.
332.112 Insulation.
332.116 Sheath.
ARTICLE 334 Nonmetallic-Sheathed Cable: Types NM, NMC, and NMS
Part I. General
334.1 Scope.
334.2 Definitions.
334.6 Listing Requirements.
Part II. Installation
334.10 Uses Permitted.
(A) Type NM.
(B) Type NMC.
(C) Type NMS.
334.12 Uses Not Permitted.
(A) Types NM, NMC, and NMS.
(B) Types NM and NMS.
334.15 Exposed Work.
(A) To Follow Surface.
(B) Protection from Physical Damage.
(C) In Unfinished Basements and Crawl Spaces.
334.17 Through or Parallel to Framing Members.
334.23 In Accessible Attics.
334.24 Bending Radius.
334.30 Securing and Supporting.
(A) Horizontal Runs Through Holes and Notches.
(B) Unsupported Cables.
(C) Wiring Device Without a Separate Outlet Box.
334.40 Boxes and Fittings.
(A) Boxes of Insulating Material.
(B) Devices of Insulating Material.
(C) Devices with Integral Enclosures.
334.80 Ampacity.
Part III. Construction Specifications
334.100 Construction.
334.104 Conductors.
334.108 Equipment Grounding Conductor.
334.112 Insulation.
334.116 Sheath.
(A) Type NM.
(B) Type NMC.
(C) Type NMS.
ARTICLE 336 Power and Control Tray Cable: Type TC
Part I. General
336.1 Scope.
336.2 Definition.
336.6 Listing Requirements.
Part II. Installation
336.10 Uses Permitted.
336.12 Uses Not Permitted.
336.24 Bending Radius.
336.80 Ampacity.
Part III. Construction Specifications
336.100 Construction.
336.104 Conductors.
(A) Fire Alarm Systems.
(B) Thermocouple Circuits.
(C) Class 1 Circuit Conductors.
336.116 Jacket.
336.120 Marking.
ARTICLE 338 Service-Entrance Cable: Types SE and USE
Part I. General
338.1 Scope.
338.2 Definitions.
338.6 Listing Requirements.
Part II. Installation
338.10 Uses Permitted.
(A) Service-Entrance Conductors.
(B) Branch Circuits or Feeders.
338.12 Uses Not Permitted.
(A) Service-Entrance Cable.
(B) Underground Service-Entrance Cable.
338.24 Bending Radius.
Part III. Construction Specifications
338.100 Construction.
338.120 Marking.
ARTICLE 340 Underground Feeder and Branch-Circuit Cable: Type UF
Part I. General
340.1 Scope.
340.2 Definition.
340.6 Listing Requirements.
Part II. Installation
340.10 Uses Permitted.
340.12 Uses Not Permitted.
340.24 Bending Radius.
340.80 Ampacity.
Part III. Construction Specifications
340.104 Conductors.
340.108 Equipment Grounding Conductor.
340.112 Insulation.
340.116 Sheath.
ARTICLE 342 Intermediate Metal Conduit: Type IMC
Part I. General
342.1 Scope.
342.2 Definition.
342.6 Listing Requirements.
Part II. Installation
342.10 Uses Permitted.
(A) All Atmospheric Conditions and Occupancies.
(B) Corrosion Environments.
(C) Cinder Fill.
(D) Wet Locations.
342.14 Dissimilar Metals.
342.20 Size.
(A) Minimum.
(B) Maximum.
342.22 Number of Conductors.
342.24 Bends — How Made.
342.26 Bends — Number in One Run.
342.28 Reaming and Threading.
342.30 Securing and Supporting.
(A) Securely Fastened.
(B) Supports.
342.42 Couplings and Connectors.
(A) Threadless.
(B) Running Threads.
342.46 Bushings.
342.56 Splices and Taps.
342.60 Grounding.
342.100 Construction.
Part III. Construction Specifications
342.120 Marking.
342.130 Standard Lengths.
ARTICLE 344 Rigid Metal Conduit: Type RMC
Part I. General
344.1 Scope.
344.2 Definition.
344.6 Listing Requirements.
Part II. Installation
344.10 Uses Permitted.
(A) Atmospheric Conditions and Occupancies.
(B) Corrosive Environments.
(C) Cinder Fill.
(D) Wet Locations.
344.14 Dissimilar Metals.
344.20 Size.
(A) Minimum.
(B) Maximum.
344.22 Number of Conductors.
344.24 Bends — How Made.
344.26 Bends — Number in One Run.
344.28 Reaming and Threading.
344.30 Securing and Supporting.
(A) Securely Fastened.
(B) Supports.
344.42 Couplings and Connectors.
(A) Threadless.
(B) Running Threads.
344.46 Bushings.
344.56 Splices and Taps.
344.60 Grounding.
Part III. Construction Specifications
344.100 Construction.
344.120 Marking.
344.130 Standard Lengths.
ARTICLE 348 Flexible Metal Conduit: Type FMC
Part I. General
348.1 Scope.
348.2 Definition.
348.6 Listing Requirements.
Part II. Installation
348.10 Uses Permitted.
348.12 Uses Not Permitted.
348.20 Size.
(A) Minimum.
(B) Maximum.
348.22 Number of Conductors.
348.24 Bends — How Made.
348.26 Bends — Number in One Run.
348.28 Trimming.
348.30 Securing and Supporting.
(A) Securely Fastened.
(B) Supports.
348.42 Couplings and Connectors.
348.56 Splices and Taps.
348.60 Grounding and Bonding.
ARTICLE 350 Liquidtight Flexible Metal Conduit: Type LFMC
Part I. General
350.1 Scope.
350.2 Definition.
350.6 Listing Requirements.
Part II. Installation
350.10 Uses Permitted.
350.12 Uses Not Permitted.
350.20 Size.
(A) Minimum.
(B) Maximum.
350.22 Number of Conductors or Cables.
(A) Metric Designators 16 through 103 (Trade Sizes through 4).
(B) Metric Designator 12 (Trade Size
350.24 Bends — How Made.
350.26 Bends — Number in One Run.
350.28 Trimming.
350.30 Securing and Supporting.
(A) Securely Fastened.
(B) Supports.
350.42 Couplings and Connectors.
350.56 Splices and Taps.
350.60 Grounding and Bonding.
Part III. Construction Specifications
350.120 Marking.
ARTICLE 352 Rigid Polyvinyl Chloride Conduit: Type PVC
Part I. General
352.1 Scope.
352.2 Definition.
352.6 Listing Requirements.
Part II. Installation
352.10 Uses Permitted.
(A) Concealed.
(B) Corrosive Influences.
(C) Cinders.
(D) Wet Locations.
(E) Dry and Damp Locations.
(F) Exposed.
(G) Underground Installations.
(H) Support of Conduit Bodies.
(I) Insulation Temperature Limitations.
352.12 Uses Not Permitted.
(A) Hazardous (Classified) Locations.
(B) Support of Luminaires.
(C) Physical Damage.
(D) Ambient Temperatures.
(E) Theaters and Similar Locations.
352.20 Size.
(A) Minimum.
(B) Maximum.
352.22 Number of Conductors.
352.24 Bends — How Made.
352.26 Bends — Number in One Run.
352.28 Trimming.
352.30 Securing and Supporting.
(A) Securely Fastened.
(B) Supports.
352.44 Expansion Fittings.
352.46 Bushings.
352.48 Joints.
352.56 Splices and Taps.
352.60 Grounding.
Part III. Construction Specifications
352.100 Construction.
352.120 Marking.
ARTICLE 353 High Density Polyethylene Conduit: Type HDPE Conduit
Part I. General
353.1 Scope.
353.2 Definition.
353.6 Listing Requirements.
Part II. Installation
353.10 Uses Permitted.
353.12 Uses Not Permitted.
353.20 Size.
(A) Minimum.
(B) Maximum.
353.22 Number of Conductors.
353.24 Bends — How Made.
353.26 Bends — Number in One Run.
353.28 Trimming.
353.46 Bushings.
353.48 Joints.
353.56 Splices and Taps.
353.60 Grounding.
Part III. Construction Specifications
353.100 Construction.
353.120 Marking.
ARTICLE 354 Nonmetallic Underground Conduit with Conductors: Type NUCC
Part I. General
354.1 Scope.
354.2 Definition.
354.6 Listing Requirements.
Part II. Installation
354.10 Uses Permitted.
354.12 Uses Not Permitted.
354.20 Size.
(A) Minimum.
(B) Maximum.
354.22 Number of Conductors.
354.24 Bends — How Made.
354.26 Bends — Number in One Run.
354.28 Trimming.
354.46 Bushings.
354.48 Joints.
354.50 Conductor Terminations.
354.56 Splices and Taps.
354.60 Grounding.
Part III. Construction Specifications
354.100 Construction.
(A) General.
(B) Nonmetallic Underground Conduit.
(C) Conductors and Cables.
(D) Conductor Fill.
354.120 Marking.
ARTICLE 355 Reinforced Thermosetting Resin Conduit: Type RTRC
Part I. General
355.1 Scope.
355.2 Definition.
355.6 Listing Requirements.
Part II. Installation
355.10 Uses Permitted.
(A) Concealed.
(B) Corrosive Influences.
(C) Cinders.
(D) Wet Locations.
(E) Dry and Damp Locations.
(F) Exposed.
(G) Underground Installations.
(H) Support of Conduit Bodies.
(I) Insulation Temperature Limitations.
355.12 Uses Not Permitted.
(A) Hazardous (Classified) Locations.
(B) Support of Luminaires.
(C) Physical Damage.
(D) Ambient Temperatures.
(E) Theaters and Similar Locations.
355.20 Size.
(A) Minimum.
(B) Maximum.
355.22 Number of Conductors.
355.24 Bends — How Made.
355.26 Bends — Number in One Run.
355.28 Trimming.
355.30 Securing and Supporting.
(A) Securely Fastened.
(B) Supports.
355.44 Expansion Fittings.
355.46 Bushings.
355.48 Joints.
355.56 Splices and Taps
355.60 Grounding.
Part III. Construction Specifications
355.100 Construction.
355.120 Marking.
ARTICLE 356 Liquidtight Flexible Nonmetallic Conduit: Type LFNC
Part I. General
356.1 Scope.
356.2 Definition.
356.6 Listing Requirements.
Part II. Installation
356.10 Uses Permitted.
356.12 Uses Not Permitted.
356.20 Size.
(A) Minimum.
(B) Maximum.
356.22 Number of Conductors.
356.24 Bends — How Made.
356.26 Bends — Number in One Run.
356.28 Trimming.
356.30 Securing and Supporting.
356.42 Couplings and Connectors.
356.56 Splices and Taps.
356.60 Grounding.
Part III. Construction Specifications
356.100 Construction.
356.120 Marking.
ARTICLE 358 Electrical Metallic Tubing: Type EMT
Part I. General
358.1 Scope.
358.2 Definition.
358.6 Listing Requirements.
Part II. Installation
358.10 Uses Permitted.
(A) Exposed and Concealed.
(B) Corrosive Environments.
(C) Cinder Fill.
(D) Wet Locations.
358.12 Uses Not Permitted.
358.14 Dissimilar Metals.
358.20 Size.
(A) Minimum.
(B) Maximum.
358.22 Number of Conductors.
358.24 Bends — How Made.
358.26 Bends — Number in One Run.
358.28 Reaming and Threading.
(A) Reaming.
(B) Threading.
358.30 Securing and Supporting.
(A) Securely Fastened.
(B) Supports.
358.42 Couplings and Connectors.
358.56 Splices and Taps.
358.60 Grounding.
Part III. Construction Specifications
358.100 Construction.
358.120 Marking.
ARTICLE 360 Flexible Metallic Tubing: Type FMT
Part I. General
360.1 Scope.
360.2 Definition.
360.6 Listing Requirements.
Part II. Installation
360.10 Uses Permitted.
360.12 Uses Not Permitted.
360.20 Size.
(A) Minimum.
(B) Maximum.
360.22 Number of Conductors.
(A) FMT — Metric Designators 16 and 21
(B) FMT — Metric Designator 12
360.24 Bends.
(A) Infrequent Flexing Use.
(B) Fixed Bends.
360.56 Splices and Taps.
360.60 Grounding.
Part III. Construction Specifications
360.120 Marking.
ARTICLE 362 Electrical Nonmetallic Tubing: Type ENT
Part I. General
362.1 Scope.
362.2 Definition.
362.6 Listing Requirements.
Part II. Installation
362.10 Uses Permitted.
362.12 Uses Not Permitted.
362.20 Size.
(A) Minimum.
(B) Maximum.
362.22 Number of Conductors.
362.24 Bends — How Made.
362.26 Bends — Number in One Run.
362.28 Trimming.
362.30 Securing and Supporting.
(A) Securely Fastened.
(B) Supports.
362.46 Bushings.
362.48 Joints.
362.56 Splices and Taps.
362.60 Grounding.
Part III. Construction Specifications
362.100 Construction.
362.120 Marking.
ARTICLE 366 Auxiliary Gutters
Part I. General
366.1 Scope.
366.2 Definitions.
366.6 Listing Requirements.
(A) Outdoors.
(B) Indoors.
Part II. Installation
366.10 Uses Permitted.
(A) Sheet Metal Auxiliary Gutters.
(B) Nonmetallic Auxiliary Gutters.
366.12 Uses Not Permitted.
366.20 Conductors Connected in Parallel.
366.22 Number of Conductors.
(A) Sheet Metal Auxiliary Gutters.
(B) Nonmetallic Auxiliary Gutters.
366.23 Ampacity of Conductors.
(A) Sheet Metal Auxiliary Gutters.
(B) Nonmetallic Auxiliary Gutters.
366.30 Securing and Supporting.
(A) Sheet Metal Auxiliary Gutters.
(B) Nonmetallic Auxiliary Gutters.
366.44 Expansion Fittings.
366.56 Splices and Taps.
(A) Within Gutters.
(B) Bare Conductors.
(C) Suitably Identified.
(D) Overcurrent Protection.
366.58 Insulated Conductors.
(A) Deflected Insulated Conductors.
(B) Auxiliary Gutters Used as Pull Boxes.
366.60 Grounding.
Part III. Construction Specifications
366.100 Construction.
(A) Electrical and Mechanical Continuity.
(B) Substantial Construction.
(C) Smooth Rounded Edges.
(D) Covers.
(E) Clearance of Bare Live Parts.
366.120 Marking.
(A) Outdoors.
(B) Indoors.
ARTICLE 368 Busways
Part I. General Requirements
368.1 Scope.
368.2 Definition.
Part II. Installation
368.10 Uses Permitted.
(A) Exposed.
(B) Behind Access Panels.
(C) Through Walls and Floors.
368.12 Uses Not Permitted.
(A) Physical Damage.
(B) Hoistways.
(C) Hazardous Locations.
(D) Wet Locations.
(E) Working Platform.
368.17 Overcurrent Protection.
(A) Rating of Overcurrent Protection — Feeders.
(B) Reduction in Ampacity Size of Busway.
(C) Feeder or Branch Circuits.
(D) Rating of Overcurrent Protection — Branch Circuits.
368.30 Support.
368.56 Branches from Busways.
(A) General.
(B) Cord and Cable Assemblies.
(C) Branches from Trolley-Type Busways.
368.58 Dead Ends.
368.60 Grounding.
Part III. Construction
368.120 Marking.
Part IV. Requirements for Over 1000 Volts, Nominal
368.214 Adjacent and Supporting Structures.
368.234 Barriers and Seals.
(A) Vapor Seals.
(B) Fire Barriers.
368.236 Drain Facilities.
368.237 Ventilated Bus Enclosures.
368.238 Terminations and Connections.
368.239 Switches.
368.240 Wiring 1000 Volts or Less, Nominal.
368.244 Expansion Fittings.
368.258 Neutral Conductor.
368.260 Grounding.
368.320 Marking.
ARTICLE 370 Cablebus
Part I. General
370.1 Scope.
370.2 Definition.
Part II. Installation
370.10 Uses Permitted.
370.12 Uses Not Permitted.
370.18 Cablebus Installation.
(A) Transversely Routed.
(B) Through Dry Floors and Platforms.
(C) Through Floors and Platforms in Wet Locations.
370.20 Conductor Size and Termination.
(A) Conductors.
(B) Termination.
370.22 Number of Conductors.
370.23 Overcurrent Protection.
370.30 Securing and Supporting.
(A) Cablebus Supports.
(B) Conductor Supports.
370.42 Fittings.
370.60 Grounding.
370.80 Ampacity of Conductors.
Part III. Construction Specifications
370.120 Marking.
ARTICLE 372 Cellular Concrete Floor Raceways
Part I. General
372.1 Scope.
372.2 Definitions.
Part II. Installations
372.12 Uses Not Permitted.
372.18 Cellular Concrete Floor Raceways Installation.
(A) Header.
(B) Connection to Cabinets and Other Enclosures.
(C) Junction Boxes.
(D) Inserts.
(E) Markers.
372.20 Size of Conductors.
372.22 Maximum Number of Conductors.
372.23 Ampacity of Conductors.
372.56 Splices and Taps.
372.58 Discontinued Outlets.
ARTICLE 374 Cellular Metal Floor Raceways
Part I. General
374.1 Scope.
374.2 Definitions.
Part II. Installation
374.12 Uses Not Permitted.
374.18 Cellular Metal Floor Raceways Installations.
(A) Connection to Cabinets and Extensions from Cells.
(B) Junction Boxes.
(C) Inserts.
(D) Markers.
374.20 Size of Conductors.
374.22 Maximum Number of Conductors in Raceway.
374.23 Ampacity of Conductors.
374.56 Splices and Taps.
374.58 Discontinued Outlets.
Part III. Construction Specifications
374.100 General.
ARTICLE 376 Metal Wireways
Part I. General
376.1 Scope.
376.2 Definition.
Part II. Installation
376.10 Uses Permitted.
376.12 Uses Not Permitted.
376.20 Conductors Connected in Parallel.
376.21 Size of Conductors.
376.22 Number of Conductors and Ampacity.
(A) Cross-Sectional Areas of Wireway.
(B) Adjustment Factors.
376.23 Insulated Conductors.
(A) Deflected Insulated Conductors.
(B) Metal Wireways Used as Pull Boxes.
376.30 Securing and Supporting.
(A) Horizontal Support.
(B) Vertical Support.
376.56 Splices, Taps, and Power Distribution Blocks.
(A) Splices and Taps.
(B) Power Distribution Blocks.
376.58 Dead Ends.
376.70 Extensions from Metal Wireways.
Part III. Construction Specifications
376.100 Construction.
(A) Electrical and Mechanical Continuity.
(B) Substantial Construction.
(C) Smooth Rounded Edges.
(D) Covers.
376.120 Marking.
ARTICLE 378 Nonmetallic Wireways
Part I. General
378.1 Scope.
378.2 Definition.
378.6 Listing Requirements.
Part II. Installation
378.10 Uses Permitted.
378.12 Uses Not Permitted.
378.20 Conductors Connected in Parallel.
378.21 Size of Conductors.
378.22 Number of Conductors.
378.23 Insulated Conductors.
(A) Deflected Insulated Conductors.
(B) Nonmetallic Wireways Used as Pull Boxes.
378.30 Securing and Supporting.
(A) Horizontal Support.
(B) Vertical Support.
378.44 Expansion Fittings.
378.56 Splices and Taps.
378.58 Dead Ends.
378.60 Grounding.
378.70 Extensions from Nonmetallic Wireways.
Part III. Construction Specifications
378.120 Marking.
ARTICLE 380 Multioutlet Assembly
Part I. General
380.1 Scope.
Part II. Installation
380.10 Uses Permitted.
380.12 Uses Not Permitted.
380.23 Insulated Conductors.
(A) Deflected Insulated Conductors.
(B) Multioutlet Assemblies Used as Pull Boxes.
380.76 Metal Multioutlet Assembly Through Dry Partitions.
ARTICLE 382 Nonmetallic Extensions
Part I. General
382.1 Scope.
382.2 Definitions.
382.6 Listing Requirements.
Part II. Installation
382.10 Uses Permitted.
(A) From an Existing Outlet.
(B) Exposed and in a Dry Location.
(C) Residential or Offices.
382.12 Uses Not Permitted.
382.15 Exposed.
(A) Nonmetallic Extensions.
(B) Concealable Nonmetallic Extensions.
382.26 Bends.
(A) Nonmetallic Extensions.
(B) Concealable Nonmetallic Extensions.
382.30 Securing and Supporting.
(A) Nonmetallic Extensions.
(B) Concealable Nonmetallic Extensions.
382.40 Boxes and Fittings.
382.42 Devices.
(A) Receptacles.
(B) Receptacles and Housings.
382.56 Splices and Taps.
Part III. Construction Specifications (Concealable Nonmetallic Extensions Only)
382.100 Construction.
382.104 Flat Conductors.
(A) Ungrounded Conductor (Center Layer).
(B) Grounded Conductor (Inner Sectioned Layers).
(C) Grounding Conductor (Outer Sectioned Layers).
382.112 Insulation.
382.120 Marking.
(A) Cable.
(B) Conductor Identification.
ARTICLE 384 Strut-Type Channel Raceway
Part I. General
384.1 Scope.
384.2 Definition.
384.6 Listing Requirements.
Part II. Installation
384.10 Uses Permitted.
384.12 Uses Not Permitted.
384.21 Size of Conductors.
384.22 Number of Conductors.
384.30 Securing and Supporting
(A) Surface Mount
(B) Suspension Mount.
384.56 Splices and Taps.
384.60 Grounding.
Part III. Construction Specifications
384.100 Construction.
(A) Material.
(B) Corrosion Protection.
(C) Cover.
384.120 Marking.
ARTICLE 386 Surface Metal Raceways
Part I. General
386.1 Scope.
386.2 Definition.
386.6 Listing Requirements.
Part II. Installation
386.10 Uses Permitted.
386.12 Uses Not Permitted.
386.21 Size of Conductors.
386.22 Number of Conductors or Cables.
386.30 Securing and Supporting.
386.56 Splices and Taps.
386.60 Grounding.
386.70 Combination Raceways.
Part III. Construction Specifications
386.100 Construction.
386.120 Marking.
ARTICLE 388 Surface Nonmetallic Raceways
Part I. General
388.1 Scope.
388.2 Definition.
388.6 Listing Requirements.
Part II. Installation
388.10 Uses Permitted.
388.12 Uses Not Permitted.
388.21 Size of Conductors.
388.22 Number of Conductors or Cables.
388.30 Securing and Supporting.
388.56 Splices and Taps.
388.60 Grounding.
388.70 Combination Raceways.
Part III. Construction Specifications
388.100 Construction.
388.120 Marking.
ARTICLE 390 Underfloor Raceways
390.1 Scope.
390.2 Definition.
390.3 Use.
(A) Permitted.
(B) Not Permitted.
390.4 Covering.
(A) Raceways Not over 100 mm (4 in.) Wide.
(B) Raceways over 100 mm (4 in.) Wide But Not over 200 mm (8 in.) Wide.
(C) Trench-Type Raceways Flush with Concrete.
(D) Other Raceways Flush with Concrete.
390.5 Size of Conductors.
390.6 Maximum Number of Conductors in Raceway.
390.7 Splices and Taps.
390.8 Discontinued Outlets.
390.9 Laid in Straight Lines.
390.10 Markers at Ends.
390.11 Dead Ends.
390.13 Junction Boxes.
390.14 Inserts.
390.15 Connections to Cabinets and Wall Outlets.
390.17 Ampacity of Conductors.
ARTICLE 392 Cable Trays
Part I. General
392.1 Scope.
392.2 Definition.
Part II. Installation
392.10 Uses Permitted.
(A) Wiring Methods.
(B) In Industrial Establishments.
(C) Hazardous (Classified) Locations.
(D) Nonmetallic Cable Tray.
(E) Airfield Lighting Cable Tray.
392.12 Uses Not Permitted.
392.18 Cable Tray Installation.
(A) Complete System.
(B) Completed Before Installation.
(C) Covers.
(D) Through Partitions and Walls.
(E) Exposed and Accessible.
(F) Adequate Access.
(G) Raceways, Cables, Boxes, and Conduit Bodies Supported from Cable Tray Systems.
(H) Marking.
392.20 Cable and Conductor Installation.
(A) Multiconductor Cables Operating at 1000 Volts or Less.
(B) Cables Operating at Over 1000 Volts.
(C) Connected in Parallel.
(D) Single Conductors.
392.22 Number of Conductors or Cables.
(A) Number of Multiconductor Cables, Rated 2000 Volts or Less, in Cable Trays.
(B) Number of Single-Conductor Cables, Rated 2000 Volts or Less, in Cable Trays.
(C) Number of Type MV and Type MC Cables (2001 Volts or Over) in Cable Trays.
392.30 Securing and Supporting.
(A) Cable Trays.
(B) Cables and Conductors.
392.46 Bushed Conduit and Tubing.
392.56 Cable Splices.
392.60 Grounding and Bonding.
(A) Metal Cable Trays.
(B) Steel or Aluminum Cable Tray Systems.
(C) Transitions.
392.80 Ampacity of Conductors.
(A) Ampacity of Cables, Rated 2000 Volts or Less, in Cable Trays.
(1) Multiconductor Cables.
(2) Single-Conductor Cables.
(3) Combinations of Multiconductor and Single-Conductor Cables.
(B) Ampacity of Type MV and Type MC Cables (2001 Volts or Over) in Cable Trays.
Part III. Construction Specifications
392.100 Construction.
(A) Strength and Rigidity.
(B) Smooth Edges.
(C) Corrosion Protection.
(D) Side Rails.
(E) Fittings.
(F) Nonmetallic Cable Tray.
ARTICLE 393 Low-Voltage Suspended Ceiling Power Distribution Systems
Part I. General
393.1 Scope.
393.2 Definitions.
393.6 Listing Requirements.
(A) Listed System.
(B) Assembly of Listed Parts.
Part II. Installation
393.10 Uses Permitted.
393.12 Uses Not Permitted.
393.14 Installation.
(A) General Requirements.
(B) Insulated Conductors.
393.21 Disconnecting Means.
(A) Location.
(B) Multiwire Branch Circuits.
393.30 Securing and Supporting.
(A) Attached to Building Structure.
(B) Attachment of Power Grid Rails.
393.40 Connectors and Enclosures.
(A) Connectors.
(B) Enclosures.
393.45 Overcurrent and Reverse Polarity (Backfeed) Protection.
(A) Overcurrent Protection.
(B) Interconnection of Power Sources.
(C) Reverse Polarity (Backfeed) Protection of Direct-Current Systems.
393.56 Splices.
393.57 Connections.
393.60 Grounding.
(A) Grounding of Supply Side of Class 2 Power Source.
(B) Grounding of Load Side of Class 2 Power Source.
Part III. Construction Specifications
393.104 Sizes and Types of Conductors.
(A) Load Side Utilization Conductor Size.
(B) Power Feed Bus Rail Conductor Size.
ARTICLE 394 Concealed Knob-and-Tube Wiring
Part I. General
394.1 Scope.
394.2 Definition.
Part II. Installation
394.10 Uses Permitted.
394.12 Uses Not Permitted.
394.17 Through or Parallel to Framing Members.
394.19 Clearances.
(A) General.
(B) Limited Conductor Space.
(C) Clearance from Piping, Exposed Conductors, and So Forth.
394.23 In Accessible Attics.
(A) Accessible by Stairway or Permanent Ladder.
(B) Not Accessible by Stairway or Permanent Ladder.
394.30 Securing and Supporting.
(A) Supporting.
(B) Securing.
394.42 Devices.
394.56 Splices and Taps.
Part III. Construction Specifications
394.104 Conductors.
ARTICLE 396 Messenger-Supported Wiring
Part I. General
396.1 Scope.
396.2 Definitions.
Part II. Installation
396.10 Uses Permitted.
(A) Cable Types.
(B) In Industrial Establishments.
(C) Hazardous (Classified) Locations.
396.12 Uses Not Permitted.
396.30 Messenger.
(A) Support.
(B) Neutral Conductor.
(C) Equipment Grounding Conductor.
396.56 Conductor Splices and Taps.
396.60 Grounding.
ARTICLE 398 Open Wiring on Insulators
Part I. General
398.1 Scope.
398.2 Definition.
Part II. Installation
398.10 Uses Permitted.
398.12 Uses Not Permitted.
398.15 Exposed Work.
(A) Dry Locations.
(B) Entering Spaces Subject to Dampness, Wetness, or Corrosive Vapors.
(C) Exposed to Physical Damage.
398.17 Through or Parallel to Framing Members.
398.19 Clearances.
398.23 In Accessible Attics.
(A) Accessible by Stairway or Permanent Ladder.
(B) Not Accessible by Stairway or Permanent Ladder.
398.30 Securing and Supporting.
(A) Conductor Sizes Smaller Than 8 AWG.
(B) Conductor Sizes 8 AWG and Larger.
(C) Industrial Establishments.
(D) Mounting of Conductor Supports.
(E) Tie Wires.
398.42 Devices.
Part III. Construction Specifications
398.104 Conductors.
ARTICLE 399 Outdoor Overhead Conductors over 1000 Volts
399.1 Scope.
399.2 Definition.
399.10 Uses Permitted.
399.30 Support.
(A) Conductors.
(B) Structures.
(C) Insulators.
Chapter 4 Equipment for General Use
ARTICLE 400 Flexible Cords and Flexible Cables
Part I. General
400.1 Scope.
400.2 Other Articles.
400.3 Suitability.
400.4 Types.
400.5 Ampacities for Flexible Cords and Flexible Cables.
(A) Ampacity Tables.
(B) Ultimate Insulation Temperature.
(C) Engineering Supervision.
400.6 Markings.
(A) Standard Markings.
(B) Optional Markings.
400.10 Uses Permitted.
(A) Uses.
(B) Attachment Plugs.
400.12 Uses Not Permitted.
400.13 Splices.
400.14 Pull at Joints and Terminals.
400.15 In Show Windows and Showcases.
400.16 Overcurrent Protection.
400.17 Protection from Damage.
Part II. Construction Specifications
400.20 Labels.
400.21 Construction.
(A) Conductors.
(B) Nominal Insulation Thickness.
400.22 Grounded-Conductor Identification.
(A) Colored Braid.
(B) Tracer in Braid.
(C) Colored Insulation.
(D) Colored Separator.
(E) Tinned Conductors.
(F) Surface Marking.
400.23 Equipment Grounding Conductor Identification.
(A) Colored Braid.
(B) Colored Insulation or Covering.
400.24 Attachment Plugs.
Part III. Portable Cables Over 600 Volts, Nominal
400.30 Scope.
400.31 Construction.
(A) Conductors.
(B) Equipment Grounding Conductor(s).
400.32 Shielding.
400.33 Equipment Grounding Conductors.
400.34 Minimum Bending Radii.
400.35 Fittings.
400.36 Splices and Terminations.
ARTICLE 402 Fixture Wires
402.1 Scope.
402.2 Other Articles.
402.3 Types.
402.5 Allowable Ampacities for Fixture Wires.
402.6 Minimum Size.
402.7 Number of Conductors in Conduit or Tubing.
402.8 Grounded Conductor Identification.
402.9 Marking.
(A) Method of Marking.
(B) Optional Marking.
402.10 Uses Permitted.
402.12 Uses Not Permitted.
402.14 Overcurrent Protection.
ARTICLE 404 Switches
Part I. Installation
404.1 Scope.
404.2 Switch Connections.
(A) Three-Way and Four-Way Switches.
(B) Grounded Conductors.
(C) Switches Controlling Lighting Loads.
404.3 Enclosure.
(A) General.
(B) Used as a Raceway.
404.4 Damp or Wet Locations.
(A) Surface-Mounted Switch or Circuit Breaker.
(B) Flush-Mounted Switch or Circuit Breaker.
(C) Switches in Tub or Shower Spaces.
404.5 Time Switches, Flashers, and Similar Devices.
404.6 Position and Connection of Switches.
(A) Single-Throw Knife Switches.
(B) Double-Throw Knife Switches.
(C) Connection of Switches.
404.7 Indicating.
404.8 Accessibility and Grouping.
(A) Location.
(B) Voltage Between Adjacent Devices.
(C) Multipole Snap Switches.
404.9 Provisions for General-Use Snap Switches.
(A) Faceplates.
(B) Grounding.
(C) Construction.
404.10 Mounting of Snap Switches.
(A) Surface Type.
(B) Box Mounted.
404.11 Circuit Breakers as Switches.
404.12 Grounding of Enclosures.
404.13 Knife Switches.
(A) Isolating Switches.
(B) To Interrupt Currents.
(C) General-Use Switches.
(D) Motor-Circuit Switches.
404.14 Rating and Use of Switches.
(A) Alternating-Current General-Use Snap Switch.
(B) Alternating-Current or Direct-Current General-Use Snap Switch
(C) CO/ALR Snap Switches.
(D) Alternating-Current Specific-Use Snap Switches Rated for 347 Volts.
(E) Dimmer Switches.
(F) Cordand Plug-Connected Loads.
Part II. Construction Specifications
404.20 Marking.
(A) Ratings.
(B) Off Indication.
404.22 Electronic Lighting Control Switches.
404.26 Knife Switches Rated 600 to 1000 Volts.
404.27 Fused Switches.
404.28 Wire-Bending Space.
ARTICLE 406 Receptacles, Cord Connectors, and Attachment Plugs (Caps)
406.1 Scope.
406.2 Definitions.
406.3 Receptacle Rating and Type.
(A) Receptacles.
(B) Rating.
(C) Receptacles for Aluminum Conductors.
(D) Isolated Ground Receptacles.
(E) Controlled Receptacle Marking.
(F) Receptacle with USB Charger.
406.4 General Installation Requirements.
(A) Grounding Type.
(B) To Be Grounded.
(C) Methods of Grounding.
(D) Replacements.
(E) Cord- and Plug-Connected Equipment.
(F) Noninterchangeable Types.
406.5 Receptacle Mounting.
(A) Boxes That Are Set Back.
(B) Boxes That Are Flush.
(C) Receptacles Mounted on Covers.
(D) Position of Receptacle Faces.
(E) Receptacles in Countertops.
(F) Receptacles in Work Surfaces.
(G) Receptacle Orientation.
(H) Receptacles in Seating Areas and Other Similar Surfaces
(I) Exposed Terminals.
(J) Voltage Between Adjacent Devices.
406.6 Receptacle Faceplates (Cover Plates).
(A) Thickness of Metal Faceplates.
(B) Grounding.
(C) Faceplates of Insulating Material.
(D) Receptacle Faceplate (Cover Plates) with Integral Night Light and/or USB Charger.
406.7 Attachment Plugs, Cord Connectors, and Flanged Surface Devices.
(A) Construction of Attachment Plugs and Cord Connectors.
(B) Connection of Attachment Plugs.
(C) Attachment Plug Ejector Mechanisms.
(D) Flanged Surface Inlet.
406.8 Noninterchangeability.
406.9 Receptacles in Damp or Wet Locations.
(A) Damp Locations.
(B) Wet Locations.
(C) Bathtub and Shower Space.
(D) Protection for Floor Receptacles.
(E) Flush Mounting with Faceplate.
406.10 Grounding-Type Receptacles, Adapters, Cord Connectors, and Attachment Plugs.
(A) Grounding Poles.
(B) Grounding-Pole Identification.
(C) Grounding Terminal Use.
(D) Grounding-Pole Requirements.
(E) Use.
406.11 Connecting Receptacle Grounding Terminal to Box.
406.12 Tamper-Resistant Receptacles.
ARTICLE 408 Switchboards, Switchgear, and Panelboards
Part I. General
408.1 Scope.
408.2 Other Articles.
408.3 Support and Arrangement of Busbars and Conductors.
(A) Conductors and Busbars on a Switchboard, Switchgear, or Panelboard.
(B) Overheating and Inductive Effects.
(C) Used as Service Equipment.
(D) Terminals.
(E) Bus Arrangement.
(F) Switchboard, Switchgear, or Panelboard Identification.
(G) Minimum Wire-Bending Space.
408.4 Field Identification Required.
(A) Circuit Directory or Circuit Identification.
(B) Source of Supply.
408.5 Clearance for Conductor Entering Bus Enclosures.
408.7 Unused Openings.
Part II. Switchboards and Switchgear
408.16 Switchboards and Switchgear in Damp or Wet Locations
408.17 Location Relative to Easily Ignitible Material.
408.18 Clearances.
(A) From Ceiling.
(B) Around Switchboards and Switchgear.
408.19 Conductor Insulation.
408.20 Location of Switchboards and Switchgear.
408.22 Grounding of Instruments, Relays, Meters, and Instrument Transformers on Switchboards and Switchgear.
Part III. Panelboards
408.30 General.
408.36 Overcurrent Protection.
(A) Snap Switches Rated at 30 Amperes or Less.
(B) Supplied Through a Transformer.
(C) Delta Breakers.
(D) Back-Fed Devices.
408.37 Panelboards in Damp or Wet Locations.
408.38 Enclosure.
408.39 Relative Arrangement of Switches and Fuses.
408.40 Grounding of Panelboards.
408.41 Grounded Conductor Terminations.
Part IV. Construction Specifications
408.50 Panels.
408.51 Busbars.
408.52 Protection of Instrument Circuits.
408.53 Component Parts.
408.54 Maximum Number of Overcurrent Devices.
408.55 Wire-Bending Space Within an Enclosure Containing a Panelboard.
(A) Top and Bottom Wire-Bending Space.
(B) Side Wire-Bending Space.
(C) Back Wire-Bending Space.
408.56 Minimum Spacings.
408.58 Panelboard Marking.
ARTICLE 409 Industrial Control Panels
Part I. General
409.1 Scope.
409.3 Other Articles.
Part II. Installation
409.20 Conductor — Minimum Size and Ampacity.
409.21 Overcurrent Protection.
(A) General.
(B) Location.
(C) Rating.
409.22 Short-Circuit Current Rating.
(A) Installation.
(B) Documentation.
409.30 Disconnecting Means.
409.60 Grounding.
Part III. Construction Specifications
409.100 Enclosures.
409.102 Busbars and Conductors.
(A) Support and Arrangement.
(B) Phase Arrangement.
409.104 Wiring Space.
(A) General.
(B) Wire Bending Space.
409.106 Spacings.
409.108 Service Equipment.
409.110 Marking.
ARTICLE 410 Luminaires, Lampholders, and Lamps
Part I. General
410.1 Scope.
410.2 Definition.
410.5 Live Parts.
410.6 Listing Required.
410.8 Inspection.
Part II. Luminaire Locations
410.10 Luminaires in Specific Locations.
(A) Wet and Damp Locations.
(B) Corrosive Locations.
(C) In Ducts or Hoods.
(D) Bathtub and Shower Areas.
(E) Luminaires in Indoor Sports, Mixed-Use, and All-Purpose Facilities.
(F) Luminaires Installed in or Under Roof Decking.
410.11 Luminaires Near Combustible Material.
410.12 Luminaires over Combustible Material.
410.14 Luminaires in Show Windows.
410.16 Luminaires in Clothes Closets.
(A) Luminaire Types Permitted.
(B) Luminaire Types Not Permitted.
(C) Location.
410.18 Space for Cove Lighting.
Part III. Provisions at Luminaire Outlet Boxes, Canopies, and Pans
410.20 Space for Conductors.
410.21 Temperature Limit of Conductors in Outlet Boxes.
410.22 Outlet Boxes to Be Covered.
410.23 Covering of Combustible Material at Outlet Boxes.
410.24 Connection of Electric-Discharge and LED Luminaires.
(A) Independent of the Outlet Box.
(B) Access to Boxes.
Part IV. Luminaire Supports
410.30 Supports.
(A) General.
(B) Metal or Nonmetallic Poles Supporting Luminaires
410.36 Means of Support.
(A) Outlet Boxes.
(B) Suspended Ceilings.
(C) Luminaire Studs.
(D) Insulating Joints.
(E) Raceway Fittings.
(F) Busways.
(G) Trees.
Part V. Grounding
410.40 General.
410.42 Luminaire(s) with Exposed Conductive Parts.
410.44 Methods of Grounding.
410.46 Equipment Grounding Conductor Attachment.
Part VI. Wiring of Luminaires
410.48 Luminaire Wiring — General.
410.50 Polarization of Luminaires.
410.52 Conductor Insulation.
410.54 Pendant Conductors for Incandescent Filament Lamps.
(A) Support.
(B) Size.
(C) Twisted or Cabled.
410.56 Protection of Conductors and Insulation.
(A) Properly Secured.
(B) Protection Through Metal.
(C) Luminaire Stems.
(D) Splices and Taps.
(E) Stranding.
(F) Tension.
410.59 Cord-Connected Showcases.
(A) Cord Requirements.
(B) Receptacles, Connectors, and Attachment Plugs.
(C) Support.
(D) No Other Equipment.
(E) Secondary Circuit(s).
410.62 Cord-Connected Lampholders and Luminaires.
(A) Lampholders.
(B) Adjustable Luminaires.
(C) Electric-Discharge and LED Luminaires.
410.64 Luminaires as Raceways.
(A) Listed.
(B) Through-Wiring.
(C) Luminaires Connected Together.
410.68 Feeder and Branch-Circuit Conductors and Ballasts.
Part VII. Construction of Luminaires
410.70 Combustible Shades and Enclosures.
410.74 Luminaire Rating.
(A) Marking.
(B) Electrical Rating.
410.82 Portable Luminaires.
(A) General.
(B) Portable Handlamps.
410.84 Cord Bushings.
Part VIII. Installation of Lampholders
410.90 Screw Shell Type.
410.93 Double-Pole Switched Lampholders.
410.96 Lampholders in Wet or Damp Locations.
410.97 Lampholders Near Combustible Material.
Part IX. Lamps and Auxiliary Equipment
410.103 Bases, Incandescent Lamps.
410.104 Electric-Discharge Lamp Auxiliary Equipment.
(A) Enclosures.
(B) Switching.
Part X. Special Provisions for Flush and Recessed Luminaires
410.110 General.
410.115 Temperature.
(A) Combustible Material.
(B) Fire-Resistant Construction.
(C) Recessed Incandescent Luminaires.
410.116 Clearance and Installation.
(A) Clearance.
(B) Installation.
410.117 Wiring.
(A) General.
(B) Circuit Conductors.
(C) Tap Conductors.
Part XI. Construction of Flush and Recessed Luminaires
410.118 Temperature.
410.120 Lamp Wattage Marking.
410.121 Solder Prohibited.
410.122 Lampholders.
Part XII. Special Provisions for ElectricDischarge Lighting Systems of 1000 Volts or Less
410.130 General.
(A) Open-Circuit Voltage of 1000 Volts or Less.
(B) Considered as Energized.
(C) Transformers of the Oil-Filled Type.
(D) Additional Requirements.
(E) Thermal Protection — Fluorescent Luminaires.
(F) High-Intensity Discharge Luminaires.
(G) Disconnecting Means.
410.134 Direct-Current Equipment.
410.135 Open-Circuit Voltage Exceeding 300 Volts.
410.136 Luminaire Mounting.
(A) Exposed Components.
(B) Combustible Low-Density Cellulose Fiberboard.
410.137 Equipment Not Integral with Luminaire.
(A) Metal Cabinets.
(B) Separate Mounting.
(C) Wired Luminaire Sections.
410.138 Autotransformers.
410.139 Switches.
Part XIII. Special Provisions for Electric-Discharge Lighting Systems of More Than 1000 Volts
410.140 General.
(A) Listing.
(B) Dwelling Occupancies.
(C) Live Parts.
(D) Additional Requirements.
410.141 Control.
(A) Disconnection.
(B) Within Sight or Locked Type.
410.142 Lamp Terminals and Lampholders.
410.143 Transformers.
(A) Type.
(B) Voltage.
(C) Rating.
(D) Secondary Connections.
410.144 Transformer Locations.
(A) Accessible.
(B) Secondary Conductors.
(C) Adjacent to Combustible Materials.
410.145 Exposure to Damage.
410.146 Marking.
Part XIV. Lighting Track
410.151 Installation.
(A) Lighting Track.
(B) Connected Load.
(C) Locations Not Permitted.
(D) Support.
410.153 Heavy-Duty Lighting Track.
410.154 Fastening.
410.155 Construction Requirements.
(A) Construction.
(B) Grounding.
Part XV. Decorative Lighting and Similar Accessories
410.160 Listing of Decorative Lighting.
ARTICLE 411 Low-Voltage Lighting
411.1 Scope.
411.3 Low-Voltage Lighting Systems.
411.4 Listing Required.
(A) Listed System.
(B) Assembly of Listed Parts.
411.5 Specific Location Requirements.
(A) Walls, Floors, and Ceilings.
(B) Pools, Spas, Fountains, and Similar Locations.
411.6 Secondary Circuits.
(A) Grounding.
(B) Isolation.
(C) Bare Conductors.
(D) Insulated Conductors.
411.7 Branch Circuit.
411.8 Hazardous (Classified) Locations.
ARTICLE 422 Appliances
Part I. General
422.1 Scope.
422.3 Other Articles.
422.4 Live Parts.
422.5 Ground-Fault Circuit-Interrupter (GFCI) Protection for Personnel.
(A) General.
(B) Type.
422.6 Listing Required.
Part II. Installation
422.10 Branch-Circuit Rating.
(A) Individual Circuits.
(B) Circuits Supplying Two or More Loads.
422.11 Overcurrent Protection.
(A) Branch-Circuit Overcurrent Protection.
(B) Household-Type Appliances with Surface Heating Elements
(C) Infrared Lamp Commercial and Industrial Heating Appliances.
(D) Open-Coil or Exposed Sheathed-Coil Types of Surface Heating Elements in Commercial-Type Heating Appliances
(E) Single Non–Motor-Operated Appliance.
(F) Electric Heating Appliances Employing Resistance-Type Heating Elements Rated More Than 48 Amperes.
(G) Motor-Operated Appliances.
422.12 Central Heating Equipment.
422.13 Storage-Type Water Heaters.
422.15 Central Vacuum Outlet Assemblies.
422.16 Flexible Cords.
(A) General.
(B) Specific Appliances.
422.17 Protection of Combustible Material.
422.18 Support of Ceiling-Suspended (Paddle) Fans.
422.19 Space for Conductors.
422.20 Outlet Boxes to Be Covered.
422.21 Covering of Combustible Material at Outlet Boxes.
422.22 Other Installation Methods.
Part III. Disconnecting Means
422.30 General.
422.31 Disconnection of Permanently Connected Appliances.
(A) Rated at Not over 300 Volt-Amperes or Horsepower
(B) Appliances Rated over 300 Volt-Amperes.
(C) Motor-Operated Appliances Rated over Horsepower
422.33 Disconnection of Cord-and-Plug-Connected or Attachment Fitting–Connected Appliances.
(A) Separable Connector or an Attachment Plug (or Attachment Fitting) and Receptacle.
(B) Connection at the Rear Base of a Range.
(C) Rating.
422.34 Unit Switch(es) as Disconnecting Means.
(A) Multifamily Dwellings.
(B) Two-Family Dwellings.
(C) One-Family Dwellings.
(D) Other Occupancies.
422.35 Switch and Circuit Breaker to Be Indicating.
Part IV. Construction
422.40 Polarity in Cord-and Plug-Connected Appliances.
422.41 Cord-and Plug-Connected Appliances Subject to Immersion.
422.42 Signals for Heated Appliances.
422.43 Flexible Cords.
(A) Heater Cords.
(B) Other Heating Appliances.
422.44 Cord-and Plug-Connected Immersion Heaters.
422.45 Stands for Cord-and Plug-Connected Appliances.
422.46 Flatirons.
422.47 Water Heater Controls.
422.48 Infrared Lamp Industrial Heating Appliances.
(A) 300 Watts or Less.
(B) Over 300 Watts.
422.50 Cord-and-Plug-Connected Pipe Heating Assemblies
Part V. Marking
422.60 Nameplate.
(A) Nameplate Marking.
(B) To Be Visible.
422.61 Marking of Heating Elements.
422.62 Appliances Consisting of Motors and Other Loads.
(A) Nameplate Horsepower Markings.
(B) Additional Nameplate Markings.
ARTICLE 424 Fixed Electric Space-Heating Equipment
Part I. General
424.1 Scope.
424.2 Other Articles.
424.3 Branch Circuits.
(A) Branch-Circuit Requirements.
(B) Branch-Circuit Sizing.
424.6 Listed Equipment.
Part II. Installation
424.9 General.
424.10 Special Permission.
424.11 Supply Conductors.
424.12 Locations.
(A) Exposed to Physical Damage.
(B) Damp or Wet Locations.
424.13 Spacing from Combustible Materials.
Part III. Control and Protection of Fixed Electric Space-Heating Equipment
424.19 Disconnecting Means.
(A) Heating Equipment with Supplementary Overcurrent Protection.
(B) Heating Equipment Without Supplementary Overcurrent Protection.
(C) Unit Switch(es) as Disconnecting Means.
424.20 Thermostatically Controlled Switching Devices.
(A) Serving as Both Controllers and Disconnecting Means.
(B) Thermostats That Do Not Directly Interrupt All Ungrounded Conductors.
424.21 Switch and Circuit Breaker to Be Indicating.
424.22 Overcurrent Protection.
(A) Branch-Circuit Devices.
(B) Resistance Elements.
(C) Overcurrent Protective Devices.
(D) Branch-Circuit Conductors.
(E) Conductors for Subdivided Loads.
Part IV. Marking of Heating Equipment
424.28 Nameplate.
(A) Marking Required.
(B) Location.
424.29 Marking of Heating Elements.
Part V. Electric Space-Heating Cables
424.34 Heating Cable Construction.
424.35 Marking of Heating Cables.
424.36 Clearances of Wiring in Ceilings.
424.38 Area Restrictions.
(A) Extending Beyond the Room or Area.
(B) Uses Not Permitted.
(C) In Closet Ceilings as Low-Temperature Heat Sources to Control Relative Humidity.
424.39 Clearance from Other Objects and Openings.
424.40 Splices.
424.41 Ceiling Installation of Heating Cables on Dry Board, in Plaster, and on Concrete.
(A) In Walls.
(B) Adjacent Runs.
(C) Surfaces to Be Applied.
(D) Splices.
(E) Ceiling Surface.
(F) Secured.
(G) Dry Board Installations.
(H) Free from Contact with Conductive Surfaces.
(I) Joists.
(J) Crossing Joists.
424.42 Finished Ceilings.
424.43 Installation of Nonheating Leads of Cables.
(A) Free Nonheating Leads.
(B) Leads in Junction Box.
(C) Excess Leads.
424.44 Installation of Cables in Concrete or Poured Masonry Floors.
(A) Adjacent Runs.
(B) Secured in Place.
(C) Leads Protected.
(D) Bushings or Approved Fittings.
(E) Ground-Fault Circuit-Interrupter Protection.
424.45 Installation of Cables Under Floor Coverings.
(A) Identification.
(B) Expansion Joints.
(C) Connection to Conductors.
(D) Anchoring.
(E) Ground-Fault Circuit-Interrupter Protection.
(F) Grounding Braid or Sheath.
424.46 Inspection and Tests.
424.47 Label Provided by Manufacturer.
Part VI. Duct Heaters
424.57 General.
424.58 Identification.
424.59 Airflow.
424.60 Elevated Inlet Temperature.
424.61 Installation of Duct Heaters with Heat Pumps and Air Conditioners.
424.62 Condensation.
424.63 Fan Circuit Interlock.
424.64 Limit Controls.
424.65 Location of Disconnecting Means.
424.66 Installation.
Part VII. Resistance-Type Boilers
424.70 Scope.
424.71 Identification.
424.72 Overcurrent Protection.
(A) Boiler Employing Resistance-Type Immersion Heating Elements in an ASME-Rated and Stamped Vessel.
(B) Boiler Employing Resistance-Type Heating Elements Rated More Than 48 Amperes and Not Contained in an ASME-Rated and Stamped Vessel.
(C) Supplementary Overcurrent Protective Devices.
(D) Conductors Supplying Supplementary Overcurrent Protective Devices.
(E) Conductors for Subdivided Loads.
424.73 Overtemperature Limit Control.
424.74 Overpressure Limit Control.
Part VIII. Electrode-Type Boilers
424.80 Scope.
424.81 Identification.
424.82 Branch-Circuit Requirements.
424.83 Overtemperature Limit Control.
424.84 Overpressure Limit Control.
424.85 Grounding.
424.86 Markings.
Part IX. Electric Radiant Heating Panels and Heating Panel Sets
424.90 Scope.
424.91 Definitions.
424.92 Markings.
(A) Location.
(B) Identified as Suitable.
(C) Required Markings.
424.93 Installation.
(A) General.
(B) Heating Panel Sets.
424.94 Clearances of Wiring in Ceilings.
424.95 Location of Branch-Circuit and Feeder Wiring in Walls.
(A) Exterior Walls.
(B) Interior Walls.
424.96 Connection to Branch-Circuit Conductors.
(A) General.
(B) Heating Panels.
(C) Heating Panel Sets.
424.97 Nonheating Leads.
424.98 Installation in Concrete or Poured Masonry.
(A) Secured in Place and Identified as Suitable.
(B) Expansion Joints.
(C) Spacings.
(D) Protection of Leads.
(E) Bushings or Fittings Required.
424.99 Installation Under Floor Covering.
(A) Identification.
(B) Installation.
Part X. Low-Voltage Fixed Electric Space-Heating Equipment
424.100 Scope.
424.101 Energy Source.
(A) Power Unit.
(B) Alternate Energy Sources.
424.102 Listed Equipment.
424.103 Installation.
(A) General.
(B) Ground.
(C) Ground-Fault Protection.
424.104 Branch Circuit.
ARTICLE 425 Fixed Resistance and Electrode Industrial Process Heating Equipment
Part I. General
425.1 Scope.
425.2 Other Articles.
425.3 Branch Circuits.
(A) Branch-Circuit Requirements.
(B) Branch-Circuit Sizing.
425.6 Listed Equipment.
Part II. Installation
425.8 General.
(A) Location.
(B) Working Space.
(C) Above Grade Level, Floor, or Work Platform.
425.9 Approval.
425.10 Special Permission.
425.11 Supply Conductors.
425.12 Locations.
(A) Exposed to Physical Damage.
(B) Damp or Wet Locations.
425.13 Spacing from Combustible Materials.
425.14 Infrared Lamp Industrial Heating Equipment.
Part III. Control and Protection of Fixed Industrial Process Heating Equipment
425.19 Disconnecting Means.
(A) Heating Equipment with Supplementary Overcurrent Protection.
(B) Heating Equipment Without Supplementary Overcurrent Protection.
(C) Unit Switch(es) as Disconnecting Means.
425.21 Switch and Circuit Breaker to Be Indicating.
425.22
(A) Branch-Circuit Devices.
(B) Resistance Elements.
(C) Overcurrent Protective Devices.
(D) Branch-Circuit Conductors.
(E) Conductors for Subdivided Loads.
Part IV. Marking of Heating Equipment
425.28 Nameplate.
(A) Marking Required.
(B) Location.
425.29 Marking of Heating Elements.
425.45 Concealed Fixed Industrial Heating Equipment — Inspection and Tests.
Part V. Fixed Industrial Process Duct Heaters
425.57 General.
425.58 Identification.
425.59 Airflow.
425.60 Elevated Inlet Temperature.
425.63 Fan Circuit Interlock.
425.64 Limit Controls.
425.65 Location of Disconnecting Means.
Part VI. Fixed Industrial Process Resistance-Type Boilers
425.70 Scope.
425.71 Identification.
425.72 Overcurrent Protection.
(A) Boiler Employing Resistance-Type Immersion Heating Elements in an ASME-Rated and Stamped Vessel.
(B) Boiler Employing Resistance-Type Heating Elements Rated More than 48 Amperes and Not Contained in an Rated More than 48 Amperes and Not Contained in an ASME-Rated and Stamped Vessel.
(C) Supplementary Overcurrent Protective Devices.
(D) Suitable for Branch-Circuit Protection.
(E) Conductors Supplying Supplementary Overcurrent Protective Devices.
(F) Conductors for Subdivided Loads.
425.73 Overtemperature Limit Control.
425.74 Overpressure Limit Control.
Part VII. Fixed Industrial Process Electrode-Type Boilers
425.80 Scope.
425.81 Identification.
425.82 Branch-Circuit Requirements.
425.83 Overtemperature Limit Control.
425.84 Overpressure Limit Control.
425.85 Grounding.
425.86 Markings.
ARTICLE 426 Fixed Outdoor Electric Deicing and Snow-Melting Equipment
Part I. General
426.1 Scope.
(A) Embedded.
(B) Exposed.
426.2 Definitions.
426.3 Application of Other Articles.
426.4 Continuous Load.
Part II. Installation
426.10 General.
426.11 Use.
426.12 Thermal Protection.
426.13 Identification.
426.14 Special Permission.
Part III. Resistance Heating Elements
426.20 Embedded Deicing and Snow-Melting Equipment.
(A) Watt Density.
(B) Spacing.
(C) Cover.
(D) Secured.
(E) Expansion and Contraction.
426.21 Exposed Deicing and Snow-Melting Equipment.
(A) Secured.
(B) Overtemperature.
(C) Expansion and Contraction.
(D) Flexural Capability.
426.22 Installation of Nonheating Leads for Embedded Equipment.
(A) Grounding Sheath or Braid.
(B) Raceways.
(C) Bushings.
(D) Expansion and Contraction.
(E) Leads in Junction Boxes.
426.23 Installation of Nonheating Leads for Exposed Equipment.
(A) Nonheating Leads.
(B) Protection.
426.24 Electrical Connection.
(A) Heating Element Connections.
(B) Circuit Connections.
426.25 Marking.
426.26 Corrosion Protection.
426.27 Grounding Braid or Sheath.
426.28 Ground-Fault Protection of Equipment.
Part IV. Impedance Heating
426.30 Personnel Protection.
426.31 Isolation Transformer.
426.32 Voltage Limitations.
426.33 Induced Currents.
426.34 Grounding.
Part V. Skin-Effect Heating
426.40 Conductor Ampacity.
426.41 Pull Boxes.
426.42 Single Conductor in Enclosure.
426.43 Corrosion Protection.
426.44 Grounding.
Part VI. Control and Protection
426.50 Disconnecting Means.
(A) Disconnection.
(B) Cord-and-Plug-Connected Equipment.
426.51 Controllers.
(A) Temperature Controller with “Off” Position.
(B) Temperature Controller Without “Off ” Position.
(C) Remote Temperature Controller.
(D) Combined Switching Devices.
426.54 Cord-and-Plug-Connected Deicing and Snow-Melting Equipment.
ARTICLE 427 Fixed Electric Heating Equipment for Pipelines and Vessels
Part I. General
427.1 Scope.
427.2 Definitions.
427.3 Application of Other Articles.
427.4 Continuous Load.
Part II. Installation
427.10 General.
427.11 Use.
427.12 Thermal Protection.
427.13 Identification.
Part III. Resistance Heating Elements
427.14 Secured.
427.15 Not in Direct Contact.
427.16 Expansion and Contraction.
427.17 Flexural Capability.
427.18 Power Supply Leads.
(A) Nonheating Leads.
(B) Power Supply Leads Protection.
(C) Interconnecting Leads.
427.19 Electrical Connections.
(A) Nonheating Interconnections.
(B) Circuit Connections.
427.20 Marking.
427.22 Ground-Fault Protection of Equipment.
427.23 Grounded Conductive Covering.
(A) Heating Wires or Cables.
(B) Heating Panels.
Part IV. Impedance Heating
427.25 Personnel Protection.
427.26 Isolation Transformer.
427.27 Voltage Limitations.
427.28 Induced Currents.
427.29 Grounding.
427.30 Secondary Conductor Sizing.
Part V. Induction Heating
427.35 Scope.
427.36 Personnel Protection.
427.37 Induced Current.
Part VI. Skin-Effect Heating
427.45 Conductor Ampacity.
427.46 Pull Boxes.
427.47 Single Conductor in Enclosure.
427.48 Grounding.
Part VII. Control and Protection
427.55 Disconnecting Means.
(A) Switch or Circuit Breaker.
(B) Cord-and-Plug-Connected Equipment.
427.56 Controls.
(A) Temperature Control with “Off ” Position.
(B) Temperature Control Without “Off” Position.
(C) Remote Temperature Controller.
(D) Combined Switching Devices.
427.57 Overcurrent Protection.
ARTICLE 430 Motors, Motor Circuits, and Controllers
Part I. General
430.1 Scope.
430.2 Definitions.
430.4 Part-Winding Motors.
430.5 Other Articles.
430.6 Ampacity and Motor Rating Determination.
(A) General Motor Applications.
(B) Torque Motors.
(C) Alternating-Current Adjustable Voltage Motors.
(D) Valve Actuator Motor Assemblies.
430.7 Marking on Motors and Multimotor Equipment.
(A) Usual Motor Applications.
(B) Locked-Rotor Indicating Code Letters.
(C) Torque Motors.
(D) Multimotor and Combination-Load Equipment.
430.8 Marking on Controllers.
430.9 Terminals.
(A) Markings.
(B) Conductors.
(C) Torque Requirements.
430.10 Wiring Space in Enclosures.
(A) General.
(B) Wire-Bending Space in Enclosures.
430.11 Protection Against Liquids.
430.12 Motor Terminal Housings.
(A) Material.
(B) Dimensions and Space — Wire-to-Wire Connections.
(C) Dimensions and Space — Fixed Terminal Connections.
(D) Large Wire or Factory Connections.
(E) Equipment Grounding Connections.
430.13 Bushing.
430.14 Location of Motors.
(A) Ventilation and Maintenance.
(B) Open Motors.
430.16 Exposure to Dust Accumulations.
430.17 Highest Rated or Smallest Rated Motor.
430.18 Nominal Voltage of Rectifier Systems.
Part II. Motor Circuit Conductors
430.21 General.
430.22 Single Motor.
(A) Direct-Current Motor-Rectifier Supplied.
(B) Multispeed Motor.
(C) Wye-Start, Delta-Run Motor.
(D) Part-Winding Motor.
(E) Other Than Continuous Duty.
(F) Separate Terminal Enclosure.
(G) Conductors for Small Motors.
430.23 Wound-Rotor Secondary.
(A) Continuous Duty.
(B) Other Than Continuous Duty.
(C) Resistor Separate from Controller.
430.24 Several Motors or a Motor(s) and Other Load(s).
430.25 Multimotor and Combination-Load Equipment.
430.26 Feeder Demand Factor.
430.27 Capacitors with Motors.
430.28 Feeder Taps.
430.29 Constant Voltage Direct-Current Motors — Power Resistors.
Part III. Motor and Branch-Circuit Overload Protection
430.31 General.
430.32 Continuous-Duty Motors.
(A) More Than 1 Horsepower.
(B) One Horsepower or Less, Automatically Started.
(C) Selection of Overload Device.
(D) One Horsepower or Less, Nonautomatically Started.
(E) Wound-Rotor Secondaries.
430.33 Intermittent and Similar Duty.
430.35 Shunting During Starting Period.
(A) Nonautomatically Started.
(B) Automatically Started.
430.36 Fuses — In Which Conductor.
430.37 Devices Other Than Fuses — In Which Conductor.
430.38 Number of Conductors Opened by Overload Device.
430.39 Motor Controller as Overload Protection.
430.40 Overload Relays.
430.42 Motors on General-Purpose Branch Circuits.
(A) Not over 1 Horsepower.
(B) Over 1 Horsepower.
(C) Cord-and Plug-Connected.
(D) Time Delay.
430.43 Automatic Restarting.
430.44 Orderly Shutdown.
Part IV. Motor Branch-Circuit Short-Circuit and Ground-Fault Protection
430.51 General.
430.52 Rating or Setting for Individual Motor Circuit.
(A) General.
(B) All Motors.
(C) Rating or Setting.
(D) Torque Motors.
430.53 Several Motors or Loads on One Branch Circuit.
(A) Not Over 1 Horsepower.
(B) If Smallest Rated Motor Protected.
(C) Other Group Installations.
(D) Single Motor Taps.
430.54 Multimotor and Combination-Load Equipment.
430.55 Combined Overcurrent Protection.
430.56 Branch-Circuit Protective Devices — In Which Conductor.
430.57 Size of Fuseholder.
430.58 Rating of Circuit Breaker.
Part V. Motor Feeder Short-Circuit and Ground-Fault Protection
430.61 General.
430.62 Rating or Setting — Motor Load.
(A) Specific Load.
(B) Other Installations.
430.63 Rating or Setting — Motor Load and Other Load(s)
Part VI. Motor Control Circuits
430.71 General.
430.72 Overcurrent Protection.
(A) General.
(B) Conductor Protection.
(C) Control Circuit Transformer.
430.73 Protection of Conductors from Physical Damage.
430.74 Electrical Arrangement of Control Circuits.
430.75 Disconnection.
(A) General.
(B) Control Transformer in Controller Enclosure.
Part VII. Motor Controllers
430.81 General.
(A) Stationary Motor of 1 8 Horsepower or Less.
(B) Portable Motor of 1 3 Horsepower or Less.
430.82 Controller Design.
(A) Starting and Stopping.
(B) Autotransformer.
(C) Rheostats.
430.83 Ratings.
(A) General.
(B) Small Motors.
(C) Stationary Motors of 2 Horsepower or Less.
(D) Torque Motors.
(E) Voltage Rating.
430.84 Need Not Open All Conductors.
430.85 In Grounded Conductors.
430.87 Number of Motors Served by Each Controller.
430.88 Adjustable-Speed Motors.
430.89 Speed Limitation.
430.90 Combination Fuseholder and Switch as Controller.
Part VIII. Motor Control Centers
430.92 General.
430.94 Overcurrent Protection.
430.95 Service Equipment.
430.96 Grounding.
430.97 Busbars and Conductors.
(A) Support and Arrangement.
(B) Phase Arrangement.
(C) Minimum Wire-Bending Space.
(D) Spacings.
(E) Barriers.
430.98 Marking.
(A) Motor Control Centers.
(B) Motor Control Units.
430.99 Available Fault Current.
Part IX. Disconnecting Means
430.101 General.
430.102 Location.
(A) Controller.
(B) Motor.
430.103 Operation.
430.104 To Be Indicating.
430.105 Grounded Conductors.
430.107 Readily Accessible.
430.108 Every Disconnecting Means.
430.109 Type.
(A) General.
(B) Stationary Motors of 1 8 Horsepower or Less.
(C) Stationary Motors of 2 Horsepower or Less.
(D) Autotransformer-Type Controlled Motors.
(E) Isolating Switches.
(F) Cord-and-Plug-Connected Motors.
(G) Torque Motors.
430.110 Ampere Rating and Interrupting Capacity.
(A) General.
(B) For Torque Motors.
(C) For Combination Loads.
430.111 Switch or Circuit Breaker as Both Controller and Disconnecting Means.
(A) General.
(B) Type.
430.112 Motors Served by Single Disconnecting Means.
430.113 Energy from More Than One Source.
Part X. Adjustable-Speed Drive Systems
430.120 General.
430.122 Conductors — Minimum Size and Ampacity.
(A) Branch/Feeder Circuit Conductors.
(B) Bypass Device.
430.124 Overload Protection.
(A) Included in Power Conversion Equipment.
(B) Bypass Circuits.
(C) Multiple Motor Applications.
430.126 Motor Overtemperature Protection.
(A) General.
(B) Multiple Motor Applications.
(C) Automatic Restarting and Orderly Shutdown.
430.128 Disconnecting Means.
430.130 Branch-Circuit Short-Circuit and Ground-Fault Protection for Single Motor Circuits Containing Power Conversion Equipment.
(A) Circuits Containing Power Conversion Equipment.
(B) Bypass Circuit/Device.
430.131 Several Motors or Loads on One Branch Circuit Including Power Conversion Equipment.
Part XI. Over 1000 Volts, Nominal
430.221 General.
430.222 Marking on Controllers.
430.223 Raceway Connection to Motors.
430.224 Size of Conductors.
430.225 Motor-Circuit Overcurrent Protection.
(A) General.
(B) Overload Protection.
(C) Fault-Current Protection.
430.226 Rating of Motor Control Apparatus.
430.227 Disconnecting Means.
Part XII. Protection of Live Parts — All Voltages
430.231 General.
430.232 Where Required.
430.233 Guards for Attendants.
Part XIII. Grounding — All Voltages
430.241 General.
430.242 Stationary Motors.
430.243 Portable Motors.
430.244 Controllers.
430.245 Method of Grounding.
(A) Grounding Through Terminal Housings.
(B) Separation of Junction Box from Motor.
(C) Grounding of Controller-Mounted Devices.
Part XIV. Tables
ARTICLE 440 Air-Conditioning and Refrigerating Equipment
Part I. General
440.1 Scope.
440.2 Definitions.
440.3 Other Articles.
(A) Article 430.
(B) Articles 422, 424, or 430.
(C) Article 422.
(D) Other Applicable Articles.
440.4 Marking on Hermetic Refrigerant Motor-Compressors and Equipment.
(A) Hermetic Refrigerant Motor-Compressor Nameplate.
(B) Multimotor and Combination-Load Equipment.
(C) Branch-Circuit Selection Current.
440.5 Marking on Controllers.
440.6 Ampacity and Rating.
(A) Hermetic Refrigerant Motor-Compressor.
(B) Multimotor Equipment.
440.7 Highest Rated (Largest) Motor.
440.8 Single Machine.
440.9 Grounding and Bonding.
440.10 Short-Circuit Current Rating.
(A) Installation.
(B) Documentation.
Part II. Disconnecting Means
440.11 General.
440.12 Rating and Interrupting Capacity.
(A) Hermetic Refrigerant Motor-Compressor.
(B) Combination Loads.
(C) Small Motor-Compressors.
(D) Disconnecting Means.
(E) Disconnecting Means Rated in Excess of 100 Horsepower
440.13 Cord-Connected Equipment.
440.14 Location.
Part III. Branch-Circuit Short-Circuit and Ground-Fault Protection
440.21 General.
440.22 Application and Selection.
(A) Rating or Setting for Individual Motor-Compressor.
(B) Rating or Setting for Equipment.
(C) Protective Device Rating Not to Exceed the Manufacturer’s Values.
Part IV. Branch-Circuit Conductors
440.31 General.
440.32 Single Motor-Compressor.
440.33 Motor-Compressor(s) With or Without Additional Motor Loads.
440.34 Combination Load.
440.35 Multimotor and Combination-Load Equipment.
Part V. Controllers for Motor-Compressors
440.41 Rating.
(A) Motor-Compressor Controller.
(B) Controller Serving More Than One Load.
Part VI. Motor-Compressor and Branch-Circuit Overload Protection
440.51 General.
440.52 Application and Selection.
(A) Protection of Motor-Compressor.
(B) Protection of Motor-Compressor Control Apparatus and Branch-Circuit Conductors.
440.53 Overload Relays.
440.54 Motor-Compressors and Equipment on 15 or 20-Ampere Branch Circuits — Not Cordand Attachment-Plug-Connected.
(A) Overload Protection.
(B) Time Delay.
440.55 Cordand Attachment-Plug-Connected Motor-Compressors and Equipment on 15 or 20-Ampere Branch Circuits.
(A) Overload Protection.
(B) Attachment Plug and Receptacle or Cord Connector Rating.
(C) Time Delay.
Part VII. Provisions for Room Air Conditioners
440.60 General.
440.61 Grounding.
440.62 Branch-Circuit Requirements.
(A) Room Air Conditioner as a Single Motor Unit.
(B) Where No Other Loads Are Supplied.
(C) Where Lighting Units or Other Appliances Are Also Supplied.
440.63 Disconnecting Means.
440.64 Supply Cords.
440.65 Protection Devices.
ARTICLE 445 Generators
445.1 Scope.
445.10 Location.
445.11 Marking.
445.12 Overcurrent Protection.
(A) Constant-Voltage Generators.
(B) Two-Wire Generators.
(C) 65 Volts or Less.
(D) Balancer Sets.
(E) Three-Wire, Direct-Current Generators.
445.13 Ampacity of Conductors.
(A) General.
(B) Overcurrent Protection Provided.
445.14 Protection of Live Parts.
445.15 Guards for Attendants.
445.16 Bushings.
445.17 Generator Terminal Housings.
445.18 Disconnecting Means and Shutdown of Prime Mover.
(A) Disconnecting Means.
(B) Shutdown of Prime Mover.
(C) Generators Installed in Parallel.
445.20 Ground-Fault Circuit-Interrupter Protection for Receptacles on 15-kW or Smaller Portable Generators.
(A) Unbonded (Floating Neutral) Generators.
(B) Bonded Neutral Generators.
ARTICLE 450 Transformers and Transformer Vaults (Including Secondary Ties)
Part I. General Provisions
450.1 Scope.
450.2 Definition.
450.3 Overcurrent Protection.
(A) Transformers Over 1000 Volts, Nominal.
(B) Transformers 1000 Volts, Nominal, or Less.
(C) Voltage (Potential) Transformers.
450.4 Autotransformers 1000 Volts, Nominal, or Less.
(A) Overcurrent Protection.
(B) Transformer Field-Connected as an Autotransformer.
450.5 Grounding Autotransformers.
(A) Three-Phase, 4-Wire System.
(B) Ground Reference for Fault Protection Devices.
(C) Ground Reference for Damping Transitory Overvoltages
450.6 Secondary Ties.
(A) Tie Circuits.
(B) Overcurrent Protection for Secondary Connections.
(C) Grounding.
450.7 Parallel Operation.
450.8 Guarding.
(A) Mechanical Protection.
(B) Case or Enclosure.
(C) Exposed Energized Parts.
(D) Voltage Warning.
450.9 Ventilation.
450.10 Grounding.
(A) Dry-Type Transformer Enclosures.
(B) Other Metal Parts.
450.11 Marking.
(A) General.
(B) Source Marking.
450.12 Terminal Wiring Space.
450.13 Accessibility.
(A) Open Installations.
(B) Hollow Space Installations.
450.14 Disconnecting Means.
Part II. Specific Provisions Applicable to Different Types of Transformers
450.21 Dry-Type Transformers Installed Indoors.
(A) Not Over 1121 2 kVA.
(B) Over 1121 2 kVA.
(C) Over 35,000 Volts.
450.22 Dry-Type Transformers Installed Outdoors.
450.23 Less-Flammable Liquid-Insulated Transformers.
(A) Indoor Installations.
(B) Outdoor Installations.
450.24 Nonflammable Fluid-Insulated Transformers.
450.25 Askarel-Insulated Transformers Installed Indoors.
450.26 Oil-Insulated Transformers Installed Indoors.
450.27 Oil-Insulated Transformers Installed Outdoors.
450.28 Modification of Transformers.
Part III. Transformer Vaults
450.41 Location.
450.42 Walls, Roofs, and Floors.
450.43 Doorways.
(A) Type of Door.
(B) Sills.
(C) Locks.
450.45 Ventilation Openings.
(A) Location.
(B) Arrangement.
(C) Size.
(D) Covering.
(E) Dampers.
(F) Ducts.
450.46 Drainage.
450.47 Water Pipes and Accessories.
450.48 Storage in Vaults.
ARTICLE 455 Phase Converters
Part I. General
455.1 Scope.
455.2 Definitions.
455.3 Other Articles.
455.4 Marking.
455.5 Equipment Grounding Connection.
455.6 Conductors.
(A) Ampacity.
(B) Manufactured Phase Marking.
455.7 Overcurrent Protection.
(A) Variable Loads.
(B) Fixed Loads.
455.8 Disconnecting Means.
(A) Location.
(B) Type.
(C) Rating.
(D) Voltage Ratios.
455.9 Connection of Single-Phase Loads.
455.10 Terminal Housings.
Part II. Specific Provisions Applicable to Different Types of Phase Converters
455.20 Disconnecting Means.
455.21 Start-Up.
455.22 Power Interruption.
455.23 Capacitors.
ARTICLE 460 Capacitors
460.1 Scope.
460.2 Enclosing and Guarding.
(A) Containing More Than 11 L (3 gal) of Flammable Liquid.
(B) Accidental Contact.
Part I. 1000 Volts, Nominal, and Under
460.6 Discharge of Stored Energy.
(A) Time of Discharge.
(B) Means of Discharge.
460.8 Conductors.
(A) Ampacity.
(B) Overcurrent Protection.
(C) Disconnecting Means.
460.9 Rating or Setting of Motor Overload Device.
460.10 Grounding.
460.12 Marking.
Part II. Over 1000 Volts, Nominal
460.24 Switching.
(A) Load Current.
(B) Isolation.
(C) Additional Requirements for Series Capacitors.
460.25 Overcurrent Protection.
(A) Provided to Detect and Interrupt Fault Current.
(B) Single Pole or Multipole Devices.
(C) Protected Individually or in Groups.
(D) Protective Devices Rated or Adjusted.
460.26 Identification.
460.27 Grounding.
460.28 Means for Discharge.
(A) Means to Reduce the Residual Voltage.
(B) Connection to Terminals.
ARTICLE 470 Resistors and Reactors
Part I. 1000 Volts, Nominal, and Under
470.1 Scope.
470.2 Location.
470.3 Space Separation.
470.4 Conductor Insulation.
Part II. Over 1000 Volts, Nominal
470.18 General.
(A) Protected Against Physical Damage.
(B) Isolated by Enclosure or Elevation.
(C) Combustible Materials.
(D) Clearances.
(E) Temperature Rise from Induced Circulating Currents
470.19 Grounding.
470.20 Oil-Filled Reactors.
ARTICLE 480 Storage Batteries
480.1 Scope.
480.2 Definitions.
480.3 Equipment.
480.4 Battery and Cell Terminations.
(A) Corrosion Prevention.
(B) Intercell and Intertier Conductors and Connections.
(C) Battery Terminals.
480.5 Wiring and Equipment Supplied from Batteries.
480.6 Overcurrent Protection for Prime Movers.
480.7 DC Disconnect Methods.
(A) Disconnecting Means.
(B) Remote Actuation.
(C) Busway.
(D) Notification.
480.8 Insulation of Batteries.
480.9 Battery Support Systems.
480.10 Battery Locations.
(A) Ventilation.
(B) Live Parts.
(C) Spaces About Battery Systems.
(D) Top Terminal Batteries.
(E) Egress.
(F) Piping in Battery Rooms.
(G) Illumination.
480.11 Vents.
(A) Vented Cells.
(B) Sealed Cells.
ARTICLE 490 Equipment Over 1000 Volts, Nominal
Part I. General
490.1 Scope.
490.2 Definition.
490.3 Other Articles.
(A) Oil-Filled Equipment.
(B) Enclosures in Damp or Wet Locations.
Part II. Equipment — Specific Provisions
490.21 Circuit-Interrupting Devices.
(A) Circuit Breakers.
(B) Power Fuses and Fuseholders.
(C) Distribution Cutouts and Fuse Links — Expulsion Type.
(D) Oil-Filled Cutouts.
(E) Load Interrupters.
490.22 Isolating Means.
490.23 Voltage Regulators.
490.24 Minimum Space Separation.
490.25 Backfeed.
Part III. Equipment — Switchgear and Industrial Control Assemblies
490.30 General.
490.31 Arrangement of Devices in Assemblies.
490.32 Guarding of High-Voltage Energized Parts Within a Compartment.
490.33 Guarding of Energized Parts Operating at 1000 Volts, Nominal, or Less Within Compartments.
490.34 Clearance for Cable Conductors Entering Enclosure
490.35 Accessibility of Energized Parts.
(A) High-Voltage Equipment.
(B) Control Equipment.
(C) High-Voltage Instruments or Control Transformers and Space Heaters.
490.36 Grounding.
490.37 Grounding of Devices.
490.38 Door Stops and Cover Plates.
490.39 Gas Discharge from Interrupting Devices.
490.40 Visual Inspection Windows.
490.41 Location of Industrial Control Equipment.
(A) Control and Instrument Transfer Switch Handles or Push Buttons.
(B) Infrequently Operated Devices.
490.42 Interlocks — Interrupter Switches.
490.43 Stored Energy for Opening.
490.44 Fused Interrupter Switches.
(A) Supply Terminals.
(B) Backfeed.
(C) Switching Mechanism.
490.45 Circuit Breakers — Interlocks.
(A) Circuit Breakers.
(B) Mechanical Interlocks.
490.46 Circuit Breaker Locking.
490.47 Switchgear Used as Service Equipment.
490.48 Substation Design, Documentation, and Required Diagram.
(A) Design and Documentation.
(B) Diagram.
Part IV. Mobile and Portable Equipment
490.51 General.
(A) Covered.
(B) Other Requirements.
(C) Protection.
(D) Disconnecting Means.
490.52 Overcurrent Protection.
490.53 Enclosures.
490.54 Collector Rings.
490.55 Power Cable Connections to Mobile Machines.
490.56 High-Voltage Portable Cable for Main Power Supply.
Part V. Electrode-Type Boilers
490.70 General.
490.71 Electrical Supply System.
490.72 Branch-Circuit Requirements.
(A) Rating.
(B) Common-Trip Fault-Interrupting Device.
(C) Phase-Fault Protection.
(D) Ground Current Detection.
(E) Grounded Neutral Conductor.
490.73 Pressure and Temperature Limit Control.
490.74 Bonding.
Chapter 5 Special Occupancies
ARTICLE 500 Hazardous (Classified) Locations, Classes I, II, and III, Divisions 1 and 2
500.1 Scope — Articles 500 Through 504.
500.3 Other Articles.
500.4 General.
(A) Documentation.
(B) Reference Standards.
500.5 Classifications of Locations.
(A) General.
(B) Class I Locations.
(C) Class II Locations.
(D) Class III Locations.
500.6 Material Groups.
(A) Class I Group Classifications.
(B) Class II Group Classifications.
500.7 Protection Techniques.
(A) Explosionproof Equipment.
(B) Dust Ignitionproof.
(C) Dusttight.
(D) Purged and Pressurized.
(E) Intrinsic Safety.
(F) Nonincendive Circuit.
(G) Nonincendive Equipment.
(H) Nonincendive Component.
(I) Oil Immersion.
(J) Hermetically Sealed.
(K) Combustible Gas Detection System.
(L) Other Protection Techniques.
500.8 Equipment.
(A) Suitability.
(B) Approval for Class and Properties.
(C) Marking.
(D) Temperature.
(E) Threading.
(F) Optical Fiber Cables.
500.9 Specific Occupancies.
ARTICLE 501 Class I Locations
Part I. General
501.1 Scope.
501.5 Zone Equipment.
Part II. Wiring
501.10 Wiring Methods.
(A) Class I, Division 1.
(B) Class I, Division 2.
501.15 Sealing and Drainage.
(A) Conduit Seals, Class I, Division 1.
(B) Conduit Seals, Class I, Division 2.
(C) Class I, Divisions 1 and 2.
(D) Cable Seals, Class I, Division 1.
(E) Cable Seals, Class I, Division 2.
(F) Drainage.
501.17 Process Sealing.
501.20 Conductor Insulation, Class I, Divisions 1 and 2.
501.25 Uninsulated Exposed Parts, Class I, Divisions 1 and 2.
501.30 Grounding and Bonding, Class I, Divisions 1 and 2.
(A) Bonding.
(B) Types of Equipment Grounding Conductors.
501.35 Surge Protection.
(A) Class I, Division 1.
(B) Class I, Division 2.
Part III. Equipment
501.100 Transformers and Capacitors.
(A) Class I, Division 1.
(B) Class I, Division 2.
501.105 Meters, Instruments, and Relays.
(A) Class I, Division 1.
(B) Class I, Division 2.
501.115 Switches, Circuit Breakers, Motor Controllers, and Fuses.
(A) Class I, Division 1.
(B) Class I, Division 2.
501.120 Control Transformers and Resistors.
(A) Class I, Division 1.
(B) Class I, Division 2.
501.125 Motors and Generators.
(A) Class I, Division 1.
(B) Class I, Division 2.
501.130 Luminaires.
(A) Class I, Division 1.
(B) Class I, Division 2.
501.135 Utilization Equipment.
(A) Class I, Division 1.
(B) Class I, Division 2.
501.140 Flexible Cords, Class I, Divisions 1 and 2.
(A) Permitted Uses.
(B) Installation.
501.145 Receptacles and Attachment Plugs, Class I, Divisions 1 and 2.
(A) Receptacles.
(B) Attachment Plugs.
501.150 Signaling, Alarm, Remote-Control, and Communications Systems.
(A) Class I, Division 1.
(B) Class I, Division 2.
ARTICLE 502 Class II Locations
Part I. General
502.1 Scope.
502.5 Explosionproof Equipment.
502.6 Zone Equipment.
Part II. Wiring
502.10 Wiring Methods.
(A) Class II, Division 1.
(B) Class II, Division 2.
502.15 Sealing, Class II, Divisions 1 and 2.
502.25 Uninsulated Exposed Parts, Class II, Divisions 1 and 2.
502.30 Grounding and Bonding, Class II, Divisions 1 and 2.
(A) Bonding.
(B) Types of Equipment Grounding Conductors.
502.35 Surge Protection — Class II, Divisions 1 and 2.
Part III. Equipment
502.100 Transformers and Capacitors.
(A) Class II, Division 1.
(B) Class II, Division 2.
502.115 Switches, Circuit Breakers, Motor Controllers, and Fuses.
(A) Class II, Division 1.
(B) Class II, Division 2.
502.120 Control Transformers and Resistors.
(A) Class II, Division 1.
(B) Class II, Division 2.
502.125 Motors and Generators.
(A) Class II, Division 1.
(B) Class II, Division 2.
502.128 Ventilating Piping.
(A) Class II, Division 1.
(B) Class II, Division 2.
502.130 Luminaires.
(A) Class II, Division 1.
(B) Class II, Division 2.
502.135 Utilization Equipment.
(A) Class II, Division 1.
(B) Class II, Division 2.
502.140 Flexible Cords — Class II, Divisions 1 and 2.
(A) Permitted Uses.
(B) Installation.
502.145 Receptacles and Attachment Plugs.
(A) Class II, Division 1.
(B) Class II, Division 2.
502.150 Signaling, Alarm, Remote-Control, and Communications Systems; and Meters, Instruments, and Relays.
(A) Class II, Division 1.
(B) Class II, Division 2.
ARTICLE 503 Class III Locations
Part I. General
503.1 Scope.
503.5 General.
503.6 Zone Equipment.
Part II. Wiring
503.10 Wiring Methods.
(A) Class III, Division 1.
(B) Class III, Division 2.
503.25 Uninsulated Exposed Parts, Class III, Divisions 1 and 2.
503.30 Grounding and Bonding — Class III, Divisions 1 and 2.
(A) Bonding.
(B) Types of Equipment Bonding Conductors.
Part III. Equipment
503.100 Transformers and Capacitors — Class III, Divisions 1 and 2.
503.115 Switches, Circuit Breakers, Motor Controllers, and Fuses — Class III, Divisions 1 and 2.
503.120 Control Transformers and Resistors — Class III, Divisions 1 and 2.
503.125 Motors and Generators — Class III, Divisions 1 and 2.
503.128 Ventilating Piping — Class III, Divisions 1 and 2.
503.130 Luminaires — Class III, Divisions 1 and 2.
(A) Fixed Lighting.
(B) Physical Damage.
(C) Pendant Luminaires.
(D) Portable Lighting Equipment.
503.135 Utilization Equipment — Class III, Divisions 1 and 2.
(A) Heaters.
(B) Motors.
(C) Switches, Circuit Breakers, Motor Controllers, and Fuses.
503.140 Flexible Cords — Class III, Divisions 1 and 2.
503.145 Receptacles and Attachment Plugs — Class III, Divisions 1 and 2.
503.150 Signaling, Alarm, Remote-Control, and Local Loudspeaker Intercommunications Systems — Class III, Divisions 1 and 2
503.155 Electric Cranes, Hoists, and Similar Equipment — Class III, Divisions 1 and 2.
(A) Power Supply.
(B) Contact Conductors.
(C) Current Collectors.
(D) Control Equipment.
503.160 Storage Battery Charging Equipment — Class III, Divisions 1 and 2.
ARTICLE 504 Intrinsically Safe Systems
504.1 Scope.
504.2 Definitions.
504.3 Application of Other Articles.
504.4 Equipment.
504.10 Equipment Installation.
(A) Control Drawing.
(B) Location.
(C) Enclosures.
(D) Simple Apparatus.
504.20 Wiring Methods.
504.30 Separation of Intrinsically Safe Conductors.
(A) From Nonintrinsically Safe Circuit Conductors.
(B) From Different Intrinsically Safe Circuit Conductors.
(C) From Grounded Metal.
504.50 Grounding.
(A) Intrinsically Safe Apparatus, Enclosures, and Raceways
(B) Associated Apparatus and Cable Shields.
(C) Connection to Grounding Electrodes.
504.60 Bonding.
(A) Intrinsically Safe Apparatus.
(B) Metal Raceways.
504.70 Sealing.
504.80 Identification.
(A) Terminals.
(B) Wiring.
(C) Color Coding.
ARTICLE 505 Zone 0, 1, and 2 Locations
505.1 Scope.
505.2 Definitions.
505.3 Other Articles.
505.4 General.
(A) Documentation for Industrial Occupancies.
(B) Reference Standards.
505.5 Classifications of Locations.
(A) General.
(B) Class I, Zone 0, 1, and 2 Locations.
505.6 Material Groups.
(A) Group IIC.
(B) Group IIB.
(C) Group IIA.
505.7 Special Precaution.
(A) Implementation of Zone Classification System.
(B) Dual Classification.
(C) Reclassification Permitted.
(D) Solid Obstacles.
(E) Simultaneous Presence of Flammable Gases and Combustible Dusts or Fibers/Flyings.
(F) Available Short-Circuit Current for Type of Protection “e”.
505.8 Protection Techniques.
(A) Flameproof “d”.
(B) Pressurization “p”.
(C) Intrinsic Safety “i”.
(D) Type of Protection “n”.
(E) Oil Immersion “o”.
(F) Increased Safety “e”.
(G) Encapsulation “m”.
(H) Powder Filling “q”.
505.9 Equipment.
(A) Suitability.
(B) Listing.
(C) Marking.
(D) Class I Temperature.
(E) Threading.
(F) Optical Fiber Cables.
505.15 Wiring Methods.
(A) Class I, Zone 0.
(B) Class I, Zone 1.
(C) Class I, Zone 2.
505.16 Sealing and Drainage.
(A) Zone 0.
(B) Zone 1.
(C) Zone 2.
(D) Class I, Zones 0, 1, and 2.
(E) Drainage.
505.17 Flexible Cables, Cords and Connections.
(A) Flexible Cords, Class I, Zones 1 and 2.
(B) Instrumentation Connections for Zone 2.
505.18 Conductors and Conductor Insulation.
(A) Conductors.
(B) Conductor Insulation.
505.19 Uninsulated Exposed Parts.
505.20 Equipment Requirements.
(A) Zone 0.
(B) Zone 1.
(C) Zone 2.
(D) Materials.
(E) Manufacturer’s Instructions.
505.22 Increased Safety “e” Motors and Generators.
505.25 Grounding and Bonding.
(A) Bonding.
(B) Types of Equipment Grounding Conductors.
505.26 Process Sealing.
ARTICLE 506 Zone 20, 21, and 22 Locations for Combustible Dusts or Ignitible Fibers/Flyings
506.1 Scope.
506.2 Definitions.
506.3 Other Articles.
506.4 General.
(A) Documentation for Industrial Occupancies.
(B) Reference Standards.
506.5 Classification of Locations.
(A) Classifications of Locations.
(B) Zone 20, Zone 21, and Zone 22 Locations.
506.6 Material Groups.
(A) Group IIIC.
(B) Group IIIB.
(C) Group IIIA.
506.7 Special Precaution.
(A) Implementation of Zone Classification System.
(B) Dual Classification.
(C) Reclassification Permitted.
(D) Simultaneous Presence of Flammable Gases and Combustible Dusts or Fibers/Flyings.
506.8 Protection Techniques.
(A) Dust Ignitionproof.
(B) Pressurized.
(C) Intrinsic Safety.
(D) Dusttight.
(E) Protection by Encapsulation “m”.
(F) Nonincendive Equipment.
(G) Protection by Enclosure “t”.
(H) Protection by Pressurization “pD”.
(I) Protection by Intrinsic Safety “iD”.
506.9 Equipment Requirements.
(A) Suitability.
(B) Listing.
(C) Marking.
(D) Temperature Classifications.
(E) Threading.
(F) Optical Fiber Cables.
506.15 Wiring Methods.
(A) Zone 20.
(B) Zone 21.
(C) Zone 22.
506.16 Sealing.
506.17 Flexible Cords.
506.20 Equipment Installation.
(A) Zone 20.
(B) Zone 21.
(C) Zone 22.
(D) Material Group.
(E) Manufacturer’s Instructions.
(F) Temperature.
506.25 Grounding and Bonding.
(A) Bonding.
(B) Types of Equipment Grounding Conductors.
ARTICLE 510 Hazardous (Classified) Locations — Specific
510.1 Scope.
510.2 General.
ARTICLE 511 Commercial Garages, Repair and Storage
511.1 Scope.
511.2 Definitions.
511.3 Area Classification, General.
(A) Parking Garages.
(B) Repair Garages, with Dispensing.
(C) Repair Garages, Major and Minor.
(D) Repair Garages, Major.
(E) Modifications to Classification.
511.4 Wiring and Equipment in Class I Locations.
(A) Wiring Located in Class I Locations.
(B) Equipment Located in Class I Locations.
511.7 Wiring and Equipment Installed Above Class I Locations.
(A) Wiring in Spaces Above Class I Locations.
(B) Electrical Equipment Installed Above Class I Locations.
511.8 Underground Wiring.
511.9 Sealing.
511.10 Special Equipment.
(A) Battery Charging Equipment.
(B) Electric Vehicle Charging Equipment.
511.12 Ground-Fault Circuit-Interrupter Protection for Personnel.
511.16 Grounding and Bonding Requirements.
(A) General Grounding Requirements.
(B) Supplying Circuits with Grounded and Grounding Conductors in Class I Locations.
ARTICLE 513 Aircraft Hangars
513.1 Scope.
513.2 Definitions.
Aircraft Painting Hangar.
513.3 Classification of Locations.
(A) Below Floor Level.
(B) Areas Not Cut Off or Ventilated.
(C) Vicinity of Aircraft.
(D) Areas Suitably Cut Off and Ventilated.
513.4 Wiring and Equipment in Class I Locations.
(A) General.
(B) Stanchions, Rostrums, and Docks.
513.7 Wiring and Equipment Not Installed in Class I Locations.
(A) Fixed Wiring.
(B) Pendants.
(C) Arcing Equipment.
(D) Lampholders.
(E) Stanchions, Rostrums, or Docks.
(F) Mobile Stanchions.
513.8 Underground Wiring.
(A) Wiring and Equipment Embedded, Under Slab, or Underground.
(B) Uninterrupted Raceways, Embedded, Under Slab, or Underground.
513.9 Sealing.
513.10 Special Equipment.
(A) Aircraft Electrical Systems.
(B) Aircraft Battery Charging and Equipment.
(C) External Power Sources for Energizing Aircraft.
(D) Mobile Servicing Equipment with Electrical
Components.
(E) Portable Equipment.
513.12 Ground-Fault Circuit-Interrupter Protection for Personnel
513.16 Grounding and Bonding Requirements.
(A) General Grounding Requirements.
(B) Supplying Circuits with Grounded and Grounding Conductors in Class I Locations.
ARTICLE 514 Motor Fuel Dispensing Facilities
514.1 Scope.
514.2 Definition.
514.3 Classification of Locations.
(A) Unclassified Locations.
(B) Classified Locations.
(C) Motor Fuel Dispensing Stations in Boatyards and Marinas.
(D) Closed Construction.
(E) Open Construction.
514.4 Wiring and Equipment Installed in Class I Locations
514.7 Wiring and Equipment Above Class I Locations.
514.8 Underground Wiring.
514.9 Sealing.
(A) At Dispenser.
(B) At Boundary.
514.11 Circuit Disconnects.
(A) Emergency Electrical Disconnects.
(B) Attended Self-Service Motor Fuel Dispensing Facilities
(C) Unattended Self-Service Motor Fuel Dispensing Facilities
514.13 Provisions for Maintenance and Service of Dispensing Equipment.
514.16 Grounding and Bonding.
ARTICLE 515 Bulk Storage Plants
515.1 Scope.
515.3 Class I Locations.
515.4 Wiring and Equipment Located in Class I Locations.
515.7 Wiring and Equipment Above Class I Locations.
(A) Fixed Wiring.
(B) Fixed Equipment.
(C) Portable Luminaires or Other Utilization Equipment.
515.8 Underground Wiring.
(A) Wiring Method.
(B) Insulation.
(C) Nonmetallic Wiring.
515.9 Sealing.
515.10 Special Equipment — Gasoline Dispensers.
515.16 Grounding and Bonding.
ARTICLE 516 Spray Application, Dipping, Coating, and Printing Processes Using Flammable or Combustible Materials
Part I. General
516.1 Scope.
516.2 Definitions.
Part II. Open Containers
516.4 Area Classification.
Part III. Spray Application Processes
516.5 Area Classification.
(A) Zone Classification of Locations.
(B) Class I, Division 1 or Class I, Zone 0 Locations.
(C) Class I, Division 1; Class I, Zone 1; Class II, Division 1; or Zone 21 Locations.
(D) Class I, Division 2; Class I, Zone 2; Class II, Division 2; or Zone 22 Locations.
516.6 Wiring and Equipment in Class I Locations.
(A) Wiring and Equipment — Vapors.
(B) Wiring and Equipment — Vapors and Residues.
(C) Illumination.
(D) Portable Equipment.
(E) Electrostatic Equipment.
(F) Static Electric Discharges.
516.7 Wiring and Equipment Not Within Classified Locations.
(A) Wiring.
(B) Equipment.
516.10 Special Equipment.
(A) Fixed Electrostatic Equipment.
(B) Hand-Spraying Electrostatic Equipment.
(C) Powder Coating.
516.16 Grounding.
Part IV. Spray Application Operations in Membrane Enclosures
516.18 Area Classification for Temporary Membrane Enclosures
516.23 Electrical and Other Sources of Ignition.
Part V. Printing, Dipping, and Coating Processes
516.29 Classification of Locations.
516.35 Areas Adjacent to Enclosed Dipping and Coating Processes
516.36 Equipment and Containers in Ventilated Areas.
516.37 Luminaires.
516.38 Wiring and Equipment Not Within Classified Locations.
(A) Wiring.
(B) Equipment.
516.40 Static Electric Discharges.
ARTICLE 517 Health Care Facilities
Part I. General
517.1 Scope.
517.2 Definitions.
Part II. Wiring and Protection
517.10 Applicability.
(A) Applicability.
(B) Not Covered.
517.11 General Installation — Construction Criteria.
517.12 Wiring Methods.
517.13 Grounding of Receptacles and Fixed Electrical Equipment in Patient Care Spaces.
(A) Wiring Methods.
(B) Insulated Equipment Grounding Conductors and Insulated Equipment Bonding Jumpers.
517.14 Panelboard Bonding.
517.16 Use of Isolated Ground Receptacles.
(A) Inside of a Patient Care Vicinity.
(B) Outside of a Patient Care Vicinity.
517.17 Ground-Fault Protection.
(A) Applicability.
(B) Feeders.
(C) Selectivity.
(D) Testing.
517.18 General Care (Category 2) Spaces.
(A) Patient Bed Location.
(B) Patient Bed Location Receptacles.
(C) Designated General Care (Category 2) Pediatric Locations
517.19 Critical Care (Category 1) Spaces.
(A) Patient Bed Location Branch Circuits.
(B) Patient Bed Location Receptacles.
(C) Operating Room Receptacles.
(D) Patient Care Vicinity Grounding and Bonding (Optional).
(E) Equipment Grounding and Bonding.
(F) Additional Protective Techniques in Critical Care (Category 1) Spaces (Optional).
(G) Isolated Power System Equipment Grounding.
(H) Special-Purpose Receptacle Grounding.
517.20 Wet Procedure Locations.
(A) Receptacles and Fixed Equipment.
(B) Isolated Power Systems.
517.21 Ground-Fault Circuit-Interrupter Protection for Personnel.
Part III. Essential Electrical System
517.25 Scope.
517.26 Application of Other Articles.
517.29 Essential Electrical Systems for Hospitals and Other Health Care Facilities.
(A) Applicability.
(B) Critical care (Category 1)
517.30 Sources of Power.
(A) Two Independent Power Sources.
(B) Types of Power Sources.
(C) Location of Essential Electrical System Components.
517.31 Requirements for the Essential Electrical System.
(A) Separate Branches.
(B) Transfer Switches.
(C) Wiring Requirements.
(D) Capacity of Systems.
(E) Receptacle Identification.
(F) Feeders from Alternate Power Source.
(G) Coordination.
517.32 Branches Requiring Automatic Connection.
517.33 Life Safety Branch.
(A) Illumination of Means of Egress.
(B) Exit Signs.
(C) Alarm and Alerting Systems.
(D) Communications Systems.
(E) Generator Set Locations.
(F) Generator Set Accessories.
(G) Elevators.
(H) Automatic Doors.
517.34 Critical Branch.
(A) Task Illumination and Selected Receptacles.
(B) Switching.
(C) Subdivision of the Critical Branch.
517.35 Equipment Branch Connection to Alternate Power Source.
(A) Equipment for Delayed Automatic Connection.
(B) Equipment for Delayed Automatic or Manual Connection
(C) AC Equipment for Nondelayed Automatic Connection.
517.40 Type 2 Essential Electrical Systems for Nursing
Homes and Limited Care Facilities.
(A) Applicability.
(B) Inpatient Hospital Care Facilities.
(C) Facilities Contiguous or Located on the Same Site with Hospitals.
517.41 Required Power Sources.
(A) Two Independent Power Sources.
(B) Types of Power Sources.
(C) Location of Essential Electrical System Components.
517.42 Essential Electrical Systems.
(A) General.
(B) Transfer Switches.
(C) Capacity of System.
(D) Separation from Other Circuits.
(E) Receptacle Identification.
517.43 Automatic Connection to Life Safety Branch.
(A) Illumination of Means of Egress.
(B) Exit Signs.
(C) Alarm and Alerting Systems.
(D) Communications Systems.
(E) Dining and Recreation Areas.
(F) Generator Set Location.
(G) Elevators.
517.44 Connection to Equipment Branch.
(A) Delayed Automatic Connections to Equipment Branch.
(B) Delayed Automatic or Manual Connection to the Equipment Branch.
517.45 Essential Electrical Systems for Other Health Care Facilities.
(A) Essential Electrical Distribution.
(B) Electrical Life Support Equipment.
(C) Critical Care (Category 1) Patient Care Spaces.
(D) General Care (Category 2) Patent Care Spaces.
(E) Power Systems.
Part IV. Inhalation Anesthetizing Locations
517.60 Anesthetizing Location Classification.
(A) Hazardous (Classified) Location.
(B) Other-Than-Hazardous (Classified) Location.
517.61 Wiring and Equipment.
(A) Within Hazardous (Classified) Anesthetizing Locations.
(B) Above Hazardous (Classified) Anesthetizing Locations.
(C) Other-Than-Hazardous (Classified) Anesthetizing Locations.
517.62 Grounding.
517.63 Grounded Power Systems in Anesthetizing Locations.
(A) Battery-Powered Lighting Units.
(B) Branch-Circuit Wiring.
(C) Fixed Lighting Branch Circuits.
(D) Remote-Control Stations.
(E) Location of Isolated Power Systems.
(F) Circuits in Anesthetizing Locations.
517.64 Low-Voltage Equipment and Instruments.
(A) Equipment Requirements.
(B) Power Supplies.
(C) Isolated Circuits.
(D) Controls.
(E) Battery-Powered Appliances.
(F) Receptacles or Attachment Plugs.
Part V. X-Ray Installations
517.70 Applicability.
517.71 Connection to Supply Circuit.
(A) Fixed and Stationary Equipment.
(B) Portable, Mobile, and Transportable Equipment.
(C) Over 1000-Volt Supply.
517.72 Disconnecting Means.
(A) Capacity.
(B) Location.
(C) Portable Equipment.
517.73 Rating of Supply Conductors and Overcurrent Protection.
(A) Diagnostic Equipment.
(B) Therapeutic Equipment.
517.74 Control Circuit Conductors.
(A) Number of Conductors in Raceway.
(B) Minimum Size of Conductors.
517.75 Equipment Installations.
517.76 Transformers and Capacitors.
517.77 Installation of High-Tension X-Ray Cables.
517.78 Guarding and Grounding.
(A) High-Voltage Parts.
(B) Low-Voltage Cables.
(C) Non–Current-Carrying Metal Parts.
Part VI. Communications, Signaling Systems, Data Systems, Fire Alarm Systems, and Systems Less Than 120 Volts, Nominal
517.80 Patient Care Spaces.
517.81 Other-Than-Patient-Care Areas.
517.82 Signal Transmission Between Appliances.
(A) General.
(B) Common Signal Grounding Wire.
Part VII. Isolated Power Systems
517.160 Isolated Power Systems.
(A) Installations.
(B) Line Isolation Monitor.
ARTICLE 518 Assembly Occupancies
518.1 Scope.
518.2 General Classification.
(A) Examples.
(B) Multiple Occupancies.
(C) Theatrical Areas.
518.3 Other Articles.
(A) Hazardous (Classified) Areas.
(B) Temporary Wiring.
(C) Emergency Systems.
518.4 Wiring Methods.
(A) General.
(B) Nonrated Construction.
(C) Spaces with Finish Rating.
518.5 Supply.
ARTICLE 520 Theaters, Audience Areas of Motion Picture and Television Studios, Performance Areas, and Similar Locations
Part I. General
520.1 Scope.
520.2 Definitions.
520.3 Motion Picture Projectors.
520.4 Audio Signal Processing, Amplification, and Reproduction Equipment.
520.5 Wiring Methods.
(A) General.
(B) Portable Equipment.
(C) Nonrated Construction.
520.6 Number of Conductors in Raceway.
520.7 Enclosing and Guarding Live Parts.
520.8 Emergency Systems.
520.9 Branch Circuits.
520.10 Portable Equipment Used Outdoors.
Part II. Fixed Stage Switchboards
520.21 General.
520.25 Dimmers.
(A) Disconnection and Overcurrent Protection.
(B) Resistanceor Reactor-Type Dimmers.
(C) Autotransformer-Type Dimmers.
(D) Solid-State-Type Dimmers.
520.26 Type of Switchboard.
(A) Manual.
(B) Remotely Controlled.
(C) Intermediate.
(D) Constant Power.
520.27 Stage Switchboard Feeders.
(A) Type of Feeder.
(B) Neutral Conductor.
(C) Supply Capacity.
Part III. Fixed Stage Equipment Other Than Switchboards
520.40 Stage Lighting Hoists.
520.41 Circuit Loads.
(A) Circuits Rated 20 Amperes or Less.
(B) Circuits Rated Greater Than 20 Amperes.
520.42 Conductor Insulation.
520.43 Footlights.
(A) Metal Trough Construction.
(B) Other-Than-Metal Trough Construction.
(C) Disappearing Footlights.
520.44 Borders, Proscenium Sidelights, Drop Boxes, and Connector Strips.
(A) General.
(B) Connector Strips and Drop Boxes.
(C) Cords and Cables for Border Lights, Drop Boxes, and Connector Strips.
520.45 Receptacles.
520.46 Connector Strips, Drop Boxes, Floor Pockets, and Other Outlet Enclosures.
520.47 Backstage Lamps (Bare Bulbs).
520.48 Curtain Machines.
520.49 Smoke Ventilator Control.
Part IV. Portable Switchboards on Stage
520.50 Road Show Connection Panel (A Type of Patch Panel).
(A) Load Circuits.
(B) Circuit Transfer.
(C) Overcurrent Protection.
(D) Enclosure.
520.51 Supply.
520.52 Overcurrent Protection for Branch Circuits.
520.53 Construction.
(A) Pilot Light.
(B) Neutral Terminal.
(C) Single-Pole Separable Connectors.
(D) Supply Feed-Through.
(E) Interior Conductors.
520.54 Supply Conductors.
(A) General.
(B) Conductor Sizing.
(C) Single-Conductor Cables.
(D) Supply Conductors Not Over 3 m (10 ft) Long.
(E) Supply Conductors Not Over 6 m (20 ft) Long.
(F) Supply Conductors Not Reduced in Size.
(G) Protection of Supply Conductors and Connectors.
(H) Number of Supply Interconnections.
(I) Single-Pole Separable Connectors.
(J) Supply Neutral Conductor.
(K) Qualified Personnel.
Part V. Portable Stage Equipment Other Than Switchboards
520.61 Arc Lamps.
520.62 Portable Power Distribution Units.
(A) Enclosure.
(B) Receptacles and Overcurrent Protection.
(C) Busbars and Terminals.
(D) Flanged Surface Inlets.
(E) Cable Arrangement.
(F) Single-Conductor Feeders.
520.63 Bracket Fixture Wiring.
(A) Bracket Wiring.
(B) Mounting.
520.64 Portable Strips.
520.65 Festoons.
520.66 Special Effects.
520.67 Multipole Branch-Circuit Cable Connectors.
520.68 Conductors for Portables.
(A) Conductor Type.
(B) Conductor Ampacity.
(C) Overcurrent Protection.
520.69 Adapters.
(A) No Reduction in Current Rating.
(B) Connectors.
(C) Conductor Type.
Part VI. Dressing Rooms, Dressing Areas, and Makeup Areas
520.71 Pendant Lampholders.
520.72 Lamp Guards.
520.73 Switches Required.
520.74 Pilot Lights Required.
Part VII. Grounding
520.81 Grounding.
ARTICLE 522 Control Systems for Permanent Amusement Attractions
Part I. General
522.1 Scope.
522.2 Definitions.
522.5 Voltage Limitations.
522.7 Maintenance.
Part II. Control Circuits
522.10 Power Sources for Control Circuits.
(A) Power-Limited Control Circuits.
(B) Non–Power-Limited Control Circuits.
Part III. Control Circuit Wiring Methods
522.20 Conductors, Busbars, and Slip Rings.
522.21 Conductor Sizing.
(A) Conductors Within a Listed Component or Assembly.
(B) Conductors Within an Enclosure or Operator Station.
(C) Conductors Outside of an Enclosure or Operator Station
522.22 Conductor Ampacity.
522.23 Overcurrent Protection for Conductors.
522.24 Conductors of Different Circuits in the Same Cable, Cable Tray, Enclosure, or Raceway.
(A) Two or More Control Circuits.
(B) Control Circuits with Power Circuits.
522.25 Ungrounded Control Circuits.
522.28 Control Circuits in Wet Locations.
ARTICLE 525 Carnivals, Circuses, Fairs, and Similar Events
Part I. General Requirements
525.1 Scope.
525.2 Definitions.
525.3 Other Articles.
(A) Portable Wiring and Equipment.
(B) Permanent Structures.
(C) Audio Signal Processing, Amplification, and Reproduction Equipment.
(D) Attractions Utilizing Pools, Fountains, and Similar Installations with Contained Volumes of Water.
525.5 Overhead Conductor Clearances.
(A) Vertical Clearances.
(B) Clearance to Portable Structures.
525.6 Protection of Electrical Equipment.
Part II. Power Sources
525.10 Services.
(A) Guarding.
(B) Mounting and Location.
525.11 Multiple Sources of Supply.
Part III. Wiring Methods
525.20 Wiring Methods.
(A) Type.
(B) Single-Conductor.
(C) Open Conductors.
(D) Splices.
(E) Cord Connectors.
(F) Support.
(G) Protection.
(H) Boxes and Fittings.
525.21 Rides, Tents, and Concessions.
(A) Disconnecting Means.
(B) Portable Wiring Inside Tents and Concessions.
525.22 Portable Distribution or Termination Boxes.
(A) Construction.
(B) Busbars and Terminals.
(C) Receptacles and Overcurrent Protection.
(D) Single-Pole Connectors.
525.23 Ground-Fault Circuit-Interrupter (GFCI) Protection.
(A) Where GFCI Protection Is Required.
(B) Where GFCI Protection Is Not Required.
(C) Where GFCI Protection Is Not Permitted.
(D) Receptacles Supplied by Portable Cords.
Part IV. Grounding and Bonding
525.30 Equipment Bonding.
525.31 Equipment Grounding.
525.32 Equipment Grounding Conductor Continuity Assurance
ARTICLE 530 Motion Picture and Television Studios and Similar Locations
Part I. General
530.1 Scope.
530.2 Definitions.
530.6 Portable Equipment.
Part II. Stage or Set
530.11 Permanent Wiring.
530.12 Portable Wiring.
(A) Stage Set Wiring.
(B) Stage Effects and Electrical Equipment Used as Stage Properties.
(C) Other Electrical Equipment.
530.13 Stage Lighting and Effects Control.
530.14 Plugging Boxes.
530.15 Enclosing and Guarding Live Parts.
(A) Live Parts.
(B) Switches.
(C) Rheostats.
(D) Current-Carrying Parts.
530.16 Portable Luminaires.
530.17 Portable Arc Lamps.
(A) Portable Carbon Arc Lamps.
(B) Portable Noncarbon Arc Electric-Discharge Lamps.
530.18 Overcurrent Protection — General.
(A) Stage Cables.
(B) Feeders.
(C) Cable Protection.
(D) Location Boards.
(E) Plugging Boxes.
(F) Alternating-Current Power Distribution Boxes.
(G) Lighting.
530.19 Sizing of Feeder Conductors for Television Studio Sets.
(A) General.
(B) Portable Feeders.
530.20 Grounding.
530.21 Plugs and Receptacles.
(A) Rating.
(B) Interchangeability.
530.22 Single-Pole Separable Connectors.
(A) General.
(B) Interchangeability.
530.23 Branch Circuits.
Part III. Dressing Rooms
530.31 Dressing Rooms.
Part IV. Viewing, Cutting, and Patching Tables
530.41 Lamps at Tables.
Part V. Cellulose Nitrate Film Storage Vaults
530.51 Lamps in Cellulose Nitrate Film Storage Vaults.
530.52 Electrical Equipment in Cellulose Nitrate Film Storage Vaults.
Part VI. Substations
530.61 Substations.
530.62 Portable Substations.
530.63 Overcurrent Protection of Direct-Current Generators
530.64 Direct-Current Switchboards.
(A) General.
(B) Circuit Breaker Frames.
ARTICLE 540 Motion Picture Projection Rooms
Part I. General
540.1 Scope.
540.2 Definitions.
Part II. Equipment and Projectors of the Professional Type
540.10 Motion Picture Projection Room Required.
540.11 Location of Associated Electrical Equipment.
(A) Motor Generator Sets, Transformers, Rectifiers, Rheostats and Similar Equipment.
(B) Switches, Overcurrent Devices, or Other Equipment.
(C) Emergency Systems.
540.12 Work Space.
540.13 Conductor Size.
540.14 Conductors on Lamps and Hot Equipment.
540.15 Flexible Cords.
540.20 Listing Requirements.
540.21 Marking.
Part III. Nonprofessional Projectors
540.31 Motion Picture Projection Room Not Required.
540.32 Listing Requirements.
Part IV. Audio Signal Processing, Amplification, and Reproduction Equipment
540.50 Audio Signal Processing, Amplification, and Reproduction Equipment.
ARTICLE 545 Manufactured Buildings
545.1 Scope.
545.2 Definitions.
545.4 Wiring Methods.
(A) Methods Permitted.
(B) Securing Cables.
545.5 Supply Conductors.
545.6 Installation of Service-Entrance Conductors.
545.7 Service Equipment.
545.8 Protection of Conductors and Equipment.
545.9 Boxes.
(A) Other Dimensions.
(B) Not Over 1650 cm3 (100 in.3).
545.10 Receptacle or Switch with Integral Enclosure.
545.11 Bonding and Grounding.
545.12 Grounding Electrode Conductor.
545.13 Component Interconnections.
ARTICLE 547 Agricultural Buildings
547.1 Scope.
(A) Excessive Dust and Dust with Water.
(B) Corrosive Atmosphere.
547.2 Definitions.
547.3 Other Articles.
547.4 Surface Temperatures.
547.5 Wiring Methods.
(A) Wiring Systems.
(B) Mounting.
(C) Equipment Enclosures, Boxes, Conduit Bodies, and Fittings.
(D) Flexible Connections.
(E) Physical Protection.
(F) Separate Equipment Grounding Conductor.
(G) Receptacles.
547.6 Switches, Receptacles, Circuit Breakers, Controllers, and Fuses.
547.7 Motors.
547.8 Luminaires.
(A) Minimize the Entrance of Dust.
(B) Exposed to Physical Damage.
(C) Exposed to Water.
547.9 Electrical Supply to Building(s) or Structure(s) from a Distribution Point.
(A) Site-Isolating Device.
(B) Service Disconnecting Means and Overcurrent Protection at the Building(s) or Structure(s).
(C) Service Disconnecting Means and Overcurrent Protection at the Distribution Point.
(D) Identification.
547.10 Equipotential Planes and Bonding of Equipotential Planes.
(A) Where Required.
(B) Bonding.
ARTICLE 550 Mobile Homes, Manufactured Homes, and Mobile Home Parks
Part I. General
550.1 Scope.
550.2 Definitions.
550.4 General Requirements.
(A) Mobile Home Not Intended as a Dwelling Unit.
(B) In Other Than Mobile Home Parks.
(C) Connection to Wiring System.
(D) Listed and Labeled.
Part II. Mobile and Manufactured Homes
550.10 Power Supply.
(A) Feeder.
(B) Power-Supply Cord.
(C) Attachment Plug Cap.
(D) Overall Length of a Power-Supply Cord.
(E) Marking.
(F) Point of Entrance.
(G) Protected.
(H) Protection Against Corrosion and Mechanical Damage.
(I) Mast Weatherhead or Raceway.
550.11 Disconnecting Means and Branch-Circuit Protective Equipment.
(A) Disconnecting Means.
(B) Branch-Circuit Protective Equipment.
(C) Two-Pole Circuit Breakers.
(D) Electrical Nameplates.
550.12 Branch Circuits.
(A) Lighting.
(B) Small Appliances.
(C) Laundry Area.
(D) General Appliances.
(E) Bathrooms.
550.13 Receptacle Outlets.
(A) Grounding-Type Receptacle Outlets.
(B) Ground-Fault Circuit Interrupters (GFCI).
(C) Cord-Connected Fixed Appliance.
(D) Receptacle Outlets Required.
(E) Pipe Heating Cable(s) Outlet.
(F) Receptacle Outlets Not Permitted.
(G) Receptacle Outlets Not Required.
550.14 Luminaires and Appliances.
(A) Fasten Appliances in Transit.
(B) Accessibility.
(C) Pendants.
(D) Bathtub and Shower Luminaires.
550.15 Wiring Methods and Materials.
(A) Nonmetallic Boxes.
(B) Nonmetallic Cable Protection.
(C) Metal-Covered and Nonmetallic Cable Protection.
(D) Metal Faceplates.
(E) Installation Requirements.
(F) Raceways.
(G) Switches.
(H) Under-Chassis Wiring (Exposed to Weather).
(I) Boxes, Fittings, and Cabinets.
(J) Appliance Terminal Connections.
(K) Component Interconnections.
550.16 Grounding.
(A) Grounded Conductor.
(B) Equipment Grounding Means.
(C) Bonding of Non–Current-Carrying Metal Parts.
550.17 Testing.
(A) Dielectric Strength Test.
(B) Continuity and Operational Tests and Polarity Checks.
550.18 Calculations.
(A) Lighting, Small-Appliance, and Laundry Load.
(B) Total Load for Determining Power Supply.
(C) Optional Method of Calculation for Lighting and Appliance Load.
550.19 Interconnection of Multiple-Section Mobile or Manufactured Home Units.
(A) Wiring Methods.
(B) Disconnecting Means.
550.20 Outdoor Outlets, Luminaires, Air-Cooling Equipment, and So Forth.
(A) Listed for Outdoor Use.
(B) Outside Heating Equipment, Air-Conditioning Equipment or Both.
550.25 Arc-Fault Circuit-Interrupter Protection.
(A) Definition.
(B) Mobile Homes and Manufactured Homes.
Part III. Services and Feeders
550.30 Distribution System.
550.31 Allowable Demand Factors.
550.32 Service Equipment.
(A) Mobile Home Service Equipment.
(B) Manufactured Home Service Equipment.
(C) Rating.
(D) Additional Outside Electrical Equipment.
(E) Additional Receptacles.
(F) Mounting Height.
(G) Marking.
550.33 Feeder.
(A) Feeder Conductors.
(B) Feeder Capacity.
ARTICLE 551 Recreational Vehicles and Recreational Vehicle Parks
Part I. General
551.1 Scope.
551.2 Definitions.
551.4 General Requirements.
(A) Not Covered.
(B) Systems.
(C) Labels.
Part II. Combination Electrical Systems
551.20 Combination Electrical Systems.
(A) General.
(B) Voltage Converters (120-Volt Alternating Current to Low-Voltage Direct Current).
(C) Bonding Voltage Converter Enclosures.
(D) Dual-Voltage Fixtures, Including Luminaires or Appliances
(E) Autotransformers.
(F) Receptacles and Plug Caps.
Part III. Other Power Sources
551.30 Generator Installations.
(A) Mounting.
(B) Generator Protection.
(C) Installation of Storage Batteries and Generators.
(D) Ventilation of Generator Compartments.
(E) Supply Conductors.
551.31 Multiple Supply Source.
(A) Multiple Supply Sources.
(B) Multiple Supply Sources Capacity.
(C) Alternate Power Sources Exceeding 30 Amperes.
(D) Power-Supply Assembly Not Less Than 30 Amperes.
551.32 Other Sources.
551.33 Alternate Source Restrictions.
Part IV. Nominal 120-Volt or 120/240-Volt Systems
551.40 120-Volt or 120/240-Volt, Nominal, Systems.
(A) General Requirements.
(B) Materials and Equipment.
(C) Ground-Fault Circuit-Interrupter Protection.
551.41 Receptacle Outlets Required.
(A) Spacing.
(B) Location.
(C) Ground-Fault Circuit-Interrupter Protection.
(D) Face-Up Position.
551.42 Branch Circuits Required.
(A) One 15-Ampere Circuit.
(B) One 20-Ampere Circuit.
(C) Two to Five 15or 20-Ampere Circuits.
(D) More Than Five Circuits Without a Listed Energy Management System.
551.43 Branch-Circuit Protection.
(A) Rating.
(B) Protection for Smaller Conductors.
(C) Fifteen-Ampere Receptacles Considered Protected by 20 Amperes.
551.44 Power-Supply Assembly.
(A) Fifteen-Ampere Main Power-Supply Assembly.
(B) Twenty-Ampere Main Power-Supply Assembly.
(C) Thirty-Ampere Main Power-Supply Assembly.
(D) Fifty-Ampere Power-Supply Assembly.
551.45 Panelboard.
(A) Listed and Appropriately Rated.
(B) Location.
(C) Dead-Front Type.
551.46 Means for Connecting to Power Supply.
(A) Assembly.
(B) Cord.
(C) Attachment Plugs.
(D) Labeling at Electrical Entrance.
(E) Location.
551.47 Wiring Methods.
(A) Wiring Systems.
(B) Conduit and Tubing.
(C) Nonmetallic Boxes.
(D) Boxes.
(E) Mounting.
(F) Raceway and Cable Continuity.
(G) Protected.
(H) Bends.
(I) Cable Supports.
(J) Nonmetallic Box Without Cable Clamps.
(K) Physical Damage.
(L) Receptacle Faceplates.
(M) Metal Faceplates Grounded.
(N) Moisture or Physical Damage.
(O) Component Interconnections.
(P) Method of Connecting Expandable Units.
(Q) Prewiring for Air-Conditioning Installation.
(R) Prewiring for Generator Installation.
(S) Prewiring for Other Circuits.
551.48 Conductors and Boxes.
551.49 Grounded Conductors.
551.50 Connection of Terminals and Splices.
551.51 Switches.
(A) Rating.
(B) Location.
551.52 Receptacles.
551.53 Luminaires and Other Equipment.
(A) General.
(B) Shower Luminaires.
(C) Outdoor Outlets, Luminaires, Air-Cooling Equipment, and So On.
551.54 Grounding.
(A) Power-Supply Grounding.
(B) Panelboard.
(C) Insulated Grounded Conductor (Neutral Conductor).
551.55 Interior Equipment Grounding.
(A) Exposed Metal Parts.
(B) Equipment Grounding and Bonding Conductors.
(C) Grounding of Electrical Equipment.
(D) Grounding Connection in Nonmetallic Box.
(E) Grounding Continuity.
(F) Cord-Connected Appliances.
551.56 Bonding of Non–Current-Carrying Metal Parts.
(A) Required Bonding.
(B) Bonding Chassis.
(C) Bonding Conductor Requirements.
(D) Metallic Roof and Exterior Bonding.
(E) Gas, Water, and Waste Pipe Bonding
(F) Furnace and Metal Air Duct Bonding.
551.57 Appliance Accessibility and Fastening.
Part V. Factory Tests
551.60 Factory Tests (Electrical).
Part VI. Recreational Vehicle Parks
551.71 Type Receptacles Provided.
(A) 20-Ampere.
(B) 30-Ampere.
(C) 50-Ampere.
(D) Tent Sites.
(E) Additional Receptacles.
(F) GFCI Protection.
551.72 Distribution System.
(A) Systems.
(B) Three-Phase Systems.
(C) Receptacles.
(D) Neutral Conductors.
551.73 Calculated Load.
(A) Basis of Calculations.
(B) Demand Factors.
551.74 Overcurrent Protection.
551.75 Grounding.
(A) General.
(B) Grounding Electrode.
551.76 Grounding — Recreational Vehicle Site Supply Equipment.
(A) Exposed Non–Current-Carrying Metal Parts.
(B) Secondary Distribution System.
(C) Grounded Conductor Not to Be Used as an Equipment Ground.
(D) No Connection on the Load Side.
551.77 Recreational Vehicle Site Supply Equipment.
(A) Location.
(B) Disconnecting Means.
(C) Access.
(D) Mounting Height.
(E) Working Space.
(F) Marking.
551.78 Protection of Outdoor Equipment.
(A) Wet Locations.
(B) Meters.
551.79 Clearance for Overhead Conductors.
551.80 Underground Service, Feeder, Branch-Circuit, and Recreational Vehicle Site Feeder-Circuit Conductors.
(A) General.
(B) Protection Against Physical Damage.
551.81 Receptacles.
ARTICLE 552 Park Trailers
Part I. General
552.1 Scope.
552.2 Definition.
552.4 General Requirements.
552.5 Labels.
Part II. Low-Voltage Systems
552.10 Low-Voltage Systems.
(A) Low-Voltage Circuits.
(B) Low-Voltage Wiring.
(C) Low-Voltage Wiring Methods.
(D) Battery Installations.
(E) Overcurrent Protection.
(F) Switches.
(G) Luminaires.
Part III. Combination Electrical Systems
552.20 Combination Electrical Systems.
(A) General.
(B) Voltage Converters (120-Volt Alternating Current to Low-Voltage Direct Current).
(C) Bonding Voltage Converter Enclosures.
(D) Dual-Voltage Fixtures Including Luminaires or Appliances
(E) Autotransformers.
(F) Receptacles and Plug Caps.
Part IV. Nominal 120-Volt or 120/240-Volt Systems
552.40 120-Volt or 120/240-Volt, Nominal, Systems.
(A) General Requirements.
(B) Materials and Equipment.
552.41 Receptacle Outlets Required.
(A) Spacing.
(B) Location.
(C) Ground-Fault Circuit-Interrupter Protection.
(D) Pipe Heating Cable Outlet.
(E) Outdoor Receptacle Outlets.
(F) Receptacle Outlets Not Permitted.
552.42 Branch-Circuit Protection.
(A) Rating.
(B) Protection for Smaller Conductors.
(C) Fifteen-Ampere Receptacle Considered Protected by 20 Amperes.
552.43 Power Supply.
(A) Feeder.
(B) Power-Supply Cord.
(C) Mast Weatherhead or Raceway.
552.44 Cord.
(A) Permanently Connected.
(B) Cord Length.
(C) Attachment Plugs.
(D) Labeling at Electrical Entrance.
(E) Location.
552.45 Panelboard.
(A) Listed and Appropriately Rated.
(B) Location.
(C) Dead-Front Type.
552.46 Branch Circuits.
(A) Two to Five 15or 20-Ampere Circuits.
(B) More Than Five Circuits.
552.47 Calculations.
(A) Lighting and Small-Appliance Load.
(B) Total Load for Determining Power Supply.
(C) Optional Method of Calculation for Lighting and Appliance Load.
552.48 Wiring Methods.
(A) Wiring Systems.
(B) Conduit and Tubing.
(C) Nonmetallic Boxes.
(D) Boxes.
(E) Mounting.
(F) Cable Sheath.
(G) Protected.
(H) Cable Supports.
(I) Nonmetallic Box Without Cable Clamps.
(J) Physical Damage.
(K) Receptacle Faceplates.
(L) Metal Faceplates Grounded.
(M) Moisture or Physical Damage.
(N) Component Interconnections.
(O) Method of Connecting Expandable Units.
(P) Prewiring for Air-Conditioning Installation.
(Q) Prewiring for Other Circuits.
552.49 Maximum Number of Conductors in Boxes.
552.50 Grounded Conductors.
552.51 Connection of Terminals and Splices.
552.52 Switches.
(A) Lighting Circuits.
(B) Motors or Other Loads.
(C) Location.
552.53 Receptacles.
552.54 Luminaires.
(A) General.
(B) Shower Luminaires.
(C) Outdoor Outlets, Luminaires, Air-Cooling Equipment, and So On.
552.55 Grounding.
(A) Power-Supply Grounding.
(B) Panelboard.
(C) Insulated Grounded Conductor.
552.56 Interior Equipment Grounding.
(A) Exposed Metal Parts.
(B) Equipment Grounding Conductors.
(C) Grounding of Electrical Equipment.
(D) Grounding Connection in Nonmetallic Box.
(E) Grounding Continuity.
(F) Cord-Connected Appliances.
552.57 Bonding of Non–Current-Carrying Metal Parts.
(A) Required Bonding.
(B) Bonding Chassis.
(C) Bonding Conductor Requirements.
(D) Metallic Roof and Exterior Bonding.
(E) Gas, Water, and Waste Pipe Bonding.
(F) Furnace and Metal Air Duct Bonding.
552.58 Appliance Accessibility and Fastening.
552.59 Outdoor Outlets, Fixtures, Including Luminaires,
(A) Listed for Outdoor Use.
(B) Outside Heating Equipment, Air-Conditioning Equipment or Both.
Part V. Factory Tests
552.60 Factory Tests (Electrical).
(A) Circuits of 120 Volts or 120/240 Volts.
(B) Low-Voltage Circuits.
ARTICLE 553 Floating Buildings
Part I. General
553.1 Scope.
553.2 Definition.
Part II. Services and Feeders
553.4 Location of Service Equipment.
553.5 Service Conductors.
553.6 Feeder Conductors.
553.7 Installation of Services and Feeders.
(A) Flexibility.
(B) Wiring Methods.
Part III. Grounding
553.8 General Requirements.
(A) Grounding of Electrical and Nonelectrical Parts.
(B) Installation and Connection of Equipment Grounding Conductor.
(C) Identification of Equipment Grounding Conductor.
(D) Grounding Electrode Conductor Connection.
553.9 Insulated Neutral.
553.10 Equipment Grounding.
(A) Electrical Systems.
(B) Cord-Connected Appliances.
553.11 Bonding of Non–Current-Carrying Metal Parts.
ARTICLE 555 Marinas, Boatyards, and Commercial and Noncommercial Docking Facilities
555.1 Scope.
555.2 Definitions.
555.3 Ground-Fault Protection.
555.4 Distribution System.
555.5 Transformers.
555.7 Location of Service Equipment.
555.9 Electrical Connections.
555.10 Electrical Equipment Enclosures.
(A) Securing and Supporting.
(B) Location.
555.11 Circuit Breakers, Switches, Panelboards, and Marine Power Outlets.
555.12 Load Calculations for Service and Feeder Conductors
555.13 Wiring Methods and Installation.
(A) Wiring Methods.
(B) Installation.
555.15 Grounding.
(A) Equipment to Be Grounded.
(B) Type of Equipment Grounding Conductor.
(C) Size of Equipment Grounding Conductor.
(D) Branch-Circuit Equipment Grounding Conductor.
(E) Feeder Equipment Grounding Conductors.
555.17 Disconnecting Means for Shore Power Connection(s).
(A) Type.
(B) Location.
555.19 Receptacles.
(A) Shore Power Receptacles.
(B) Other Than Shore Power.
555.21 Motor Fuel Dispensing Stations — Hazardous (Classified Locations.
555.22 Repair Facilities — Hazardous (Classified) Locations
555.23 Marine Hoists, Railways, Cranes, and Monorails.
555.24 Signage.
ARTICLE 590 Temporary Installations
590.1 Scope.
590.2 All Wiring Installations.
(A) Other Articles.
(B) Approval.
590.3 Time Constraints.
(A) During the Period of Construction.
(B) 90 Days.
(C) Emergencies and Tests.
(D) Removal.
590.4 General.
(A) Services.
(B) Feeders.
(C) Branch Circuits.
(D) Receptacles.
(E) Disconnecting Means.
(F) Lamp Protection.
(G) Splices.
(H) Protection from Accidental Damage.
(I) Termination(s) at Devices.
(J) Support.
590.5 Listing of Decorative Lighting.
590.6 Ground-Fault Protection for Personnel.
(A) Receptacle Outlets.
(B) Use of Other Outlets.
590.7 Guarding.
Chapter 6 Special Equipment
ARTICLE 600 Electric Signs and Outline Lighting
Part I. General
600.1 Scope.
600.2 Definitions.
600.3 Listing.
(A) Field-Installed Skeleton Tubing.
(B) Outline Lighting.
600.4 Markings.
(A) Signs and Outline Lighting Systems.
(B) Signs with a Retrofitted Illumination System.
(C) Signs with Lampholders for Incandescent Lamps.
(D) Visibility.
(E Durability.
(F) Installation Instructions.
600.5 Branch Circuits.
(A) Required Branch Circuit.
(B) Rating.
(C) Wiring Methods.
600.6 Disconnects.
(A) Location.
(B) Control Switch Rating.
600.7 Grounding and Bonding.
(A) Grounding.
(B) Bonding.
600.8 Enclosures.
(A) Strength.
(B) Material.
(C) Minimum Thickness of Enclosure Metal.
(D) Protection of Metal.
600.9 Location.
(A) Vehicles.
(B) Pedestrians.
(C) Adjacent to Combustible Materials.
(D) Wet Location.
600.10 Portable or Mobile Signs.
(A) Support.
(B) Attachment Plug.
(C) Wet or Damp Location.
(D) Dry Location.
600.12 Field-Installed Secondary Wiring.
(A) 1000 Volts or Less.
(B) Over 1000 Volts.
(C) Class 2.
600.21 Ballasts, Transformers, Electronic Power Supplies, and Class 2 Power Sources.
(A) Accessibility.
(B) Location.
(C) Wet Location.
(D) Working Space.
(E) Attic and Soffit Locations.
(F) Suspended Ceilings.
600.22 Ballasts.
(A) Type.
(B) Thermal Protection.
600.23 Transformers and Electronic Power Supplies.
(A) Type.
(B) Secondary-Circuit Ground-Fault Protection.
(C) Voltage.
(D) Rating.
(E) Secondary Connections.
(F) Marking.
600.24 Class 2 Power Sources.
(A) Listing.
(B) Grounding.
(C) Wiring Methods on the Supply Side of the Class 2 Power Supply.
(D) Secondary Wiring.
Part II. Field-Installed Skeleton Tubing, Outline Lighting, and Secondary Wiring
600.30 Applicability.
600.31 Neon Secondary-Circuit Wiring, 1000 Volts or Less, Nominal.
(A) Wiring Method.
(B) Insulation and Size.
(C) Number of Conductors in Raceway.
(D) Installation.
(E) Protection of Leads.
600.32 Neon Secondary-Circuit Wiring, over 1000 Volts, Nominal.
(A) Wiring Methods.
(B) Insulation and Size.
(C) Installation.
(D) Bends in Conductors.
(E) Spacing.
(F) Insulators and Bushings.
(G) Conductors in Raceways.
(H) Between Neon Tubing and Midpoint Return.
(I) Dwelling Occupancies.
(J) Length of Secondary Circuit Conductors.
(K) Splices.
600.33 Class 2 Sign Illumination Systems, Secondary Wiring.
(A) Insulation and Sizing of Class 2 Conductors.
(B) Installation.
(C) Protection Against Physical Damage.
(D) Grounding and Bonding.
600.34 Photovoltaic (PV) Powered Sign.
(A) Equipment.
(B) Wiring.
(C) Flexible Cords and Cables.
(D) Grounding.
(E) Disconnecting Means.
(F) Battery Compartments.
600.41 Neon Tubing.
(A) Design.
(B) Support.
(C) Spacing.
(D) Protection.
600.42 Electrode Connections.
(A) Points of Transition.
(B) Accessibility.
(C) Electrode Connections.
(D) Support.
(E) Receptacles.
(F) Bushings.
(G) Wet Locations.
(H) Electrode Enclosures.
ARTICLE 604 Manufactured Wiring Systems
604.1 Scope.
604.2 Definition.
604.6 Listing Requirements.
604.7 Installation.
604.10 Uses Permitted.
604.12 Uses Not Permitted.
604.100 Construction.
(A) Cable or Conduit Types.
(B) Marking.
(C) Receptacles and Connectors.
(D) Other Component Parts.
ARTICLE 605 Office Furnishings
605.1 Scope.
605.2 Definition.
605.3 General.
(A) Use.
(B) Hazardous (Classified) Locations.
605.4 Wireways.
605.5 Office Furnishing Interconnections.
605.6 Lighting Accessories.
(A) Support.
(B) Connection.
(C) Receptacle Outlet.
605.7 Fixed-Type Office Furnishings.
605.8 Freestanding-Type Office Furnishings.
605.9 Freestanding-Type Office Furnishings, Cordand Plug-Connected.
(A) Flexible Power-Supply Cord.
(B) Receptacle Supplying Power.
(C) Receptacle, Maximum.
(D) Multiwire Circuits, Not Permitted.
ARTICLE 610 Cranes and Hoists
Part I. General
610.1 Scope.
610.2 Definition.
610.3 Special Requirements for Particular Locations.
(A) Hazardous (Classified) Locations.
(B) Combustible Materials.
(C) Electrolytic Cell Lines.
Part II. Wiring
610.11 Wiring Method.
(A) Contact Conductor.
(B) Exposed Conductors.
(C) Flexible Connections to Motors and Similar Equipment
(D) Pushbutton Station Multiconductor Cable.
(E) Flexibility to Moving Parts.
610.12 Raceway or Cable Terminal Fittings.
(A) Separately Bushed Hole.
(B) Bushing in Lieu of a Box.
610.13 Types of Conductors.
(A) Exposed to External Heat or Connected to Resistors.
(B) Contact Conductors.
(C) Flexibility.
(D) Class 1, Class 2, and Class 3 Circuits.
610.14 Rating and Size of Conductors.
(A) Ampacity.
(B) Secondary Resistor Conductors.
(3) Multiple Cranes or Hoists on a Common Conductor System
(C) Minimum Size.
(D) Contact Conductors.
(E) Calculation of Motor Load.
(F) Other Loads.
(G) Nameplate.
610.15 Common Return.
Part III. Contact Conductors
610.21 Installation of Contact Conductors.
(A) Locating or Guarding Contact Conductors.
(B) Contact Wires.
(C) Supports Along Runways.
(D) Supports on Bridges.
(E) Supports for Rigid Conductors.
(F) Track as Circuit Conductor.
(G) Electrical Continuity of Contact Conductors.
(H) Not to Supply Other Equipment.
610.22 Collectors.
Part IV. Disconnecting Means
610.31 Runway Conductor Disconnecting Means.
610.32 Disconnecting Means for Cranes and Monorail Hoists.
610.33 Rating of Disconnecting Means.
Part V. Overcurrent Protection
610.41 Feeders, Runway Conductors.
(A) Single Feeder.
(B) More Than One Feeder Circuit.
610.42 Branch-Circuit Short-Circuit and Ground-Fault Protection.
(A) Fuse or Circuit Breaker Rating.
(B) Taps.
610.43 Overload Protection.
(A) Motor and Branch-Circuit Overload Protection.
(B) Manually Controlled Motor.
(C) Multimotor.
(D) Hoists and Monorail Hoists.
Part VI. Control
610.51 Separate Controllers.
(A) Motions with More Than One Motor.
(B) Multiple Motion Controller.
610.53 Overcurrent Protection.
(A) Taps to Control Transformers.
(B) Continuity of Power.
610.57 Clearance.
Part VII. Grounding
610.61 Grounding.
ARTICLE 620 Elevators, Dumbwaiters, Escalators, Moving Walks, Platform Lifts, and Stairway Chairlifts
Part I. General
620.1 Scope.
620.2 Definitions.
620.3 Voltage Limitations.
(A) Power Circuits.
(B) Lighting Circuits.
(C) Heating and Air-Conditioning Circuits.
620.4 Live Parts Enclosed.
620.5 Working Clearances.
(A) Flexible Connections to Equipment.
(B) Guards.
(C) Examination, Adjusting, and Servicing.
(D) Low Voltage.
Part II. Conductors
620.11 Insulation of Conductors.
(A) Hoistway Door Interlock Wiring.
(B) Traveling Cables.
(C) Other Wiring.
(D) Insulation.
620.12 Minimum Size of Conductors.
(A) Traveling Cables.
(B) Other Wiring.
620.13 Feeder and Branch-Circuit Conductors.
(A) Conductors Supplying Single Motor.
(B) Conductors Supplying a Single Motor Controller.
(C) Conductors Supplying a Single Power Transformer.
(D) Conductors Supplying More Than One Motor, Motor Controller, or Power Transformer
620.14 Feeder Demand Factor.
620.15 Motor Controller Rating.
620.16 Short-Circuit Current Rating.
(A) Marking.
(B) Installation.
Part III. Wiring
620.21 Wiring Methods.
(A) Elevators.
(B) Escalators.
(C) Platform Lifts and Stairway Chairlift Raceways.
620.22 Branch Circuits for Car Lighting, Receptacle(s), Ventilation, Heating, and Air-Conditioning.
(A) Car Light Source.
(B) Air-Conditioning and Heating Source.
620.23 Branch Circuits for Machine Room or Control Room/Machinery Space or Control Space Lighting and Receptacle(s).
(A) Separate Branch Circuits.
(B) Lighting Switch.
(C) Duplex Receptacle.
620.24 Branch Circuit for Hoistway Pit Lighting and Receptacles.
(A) Separate Branch Circuits.
(B) Lighting Switch.
(C) Duplex Receptacle.
620.25 Branch Circuits for Other Utilization Equipment.
(A) Additional Branch Circuits.
(B) Overcurrent Devices.
Part IV. Installation of Conductors
620.32 Metal Wireways and Nonmetallic Wireways.
620.33 Number of Conductors in Raceways.
620.34 Supports.
620.35 Auxiliary Gutters.
620.36 Different Systems in One Raceway or Traveling Cable.
620.37 Wiring in Hoistways, Machine Rooms, Control Rooms, Machinery Spaces, and Control Spaces.
(A) Uses Permitted.
(B) Lightning Protection.
(C) Main Feeders.
620.38 Electrical Equipment in Garages and Similar Occupancies
Part V. Traveling Cables
620.41 Suspension of Traveling Cables.
620.42 Hazardous (Classified) Locations.
620.43 Location of and Protection for Cables.
620.44 Installation of Traveling Cables.
Part VI. Disconnecting Means and Control
620.51 Disconnecting Means.
(A) Type.
(B) Operation.
(C) Location.
(D) Identification and Signs.
(E) Surge Protection.
620.52 Power from More Than One Source.
(A) Single-Car and Multicar Installations.
(B) Warning Sign for Multiple Disconnecting Means.
(C) Interconnection Multicar Controllers.
620.53 Car Light, Receptacle(s), and Ventilation Disconnecting Means.
620.54 Heating and Air-Conditioning Disconnecting Means.
620.55 Utilization Equipment Disconnecting Means.
Part VII. Overcurrent Protection
620.61 Overcurrent Protection.
(A) Operating Devices and Control and Signaling Circuits
(B) Overload Protection for Motors.
Generator Sets Driving Motors.
(C) Motor Feeder Short-Circuit and Ground-Fault Protection
(D) Motor Branch-Circuit Short-Circuit and Ground-Fault Protection.
620.62 Selective Coordination.
Part VIII. Machine Rooms, Control Rooms, Machinery Spaces, and Control Spaces
620.71 Guarding Equipment.
(A) Motor Controllers.
(B) Driving Machines.
Part IX. Grounding
620.81 Metal Raceways Attached to Cars.
620.82 Electric Elevators.
620.83 Nonelectric Elevators.
620.84 Escalators, Moving Walks, Platform Lifts, and Stairway Chairlifts.
620.85 Ground-Fault Circuit-Interrupter Protection for Personnel.
Part X. Emergency and Standby Power Systems
620.91 Emergency and Standby Power Systems.
(A) Regenerative Power.
(B) Other Building Loads.
(C) Disconnecting Means.
ARTICLE 625 Electric Vehicle Charging System
Part I. General
625.1 Scope.
625.2 Definitions.
625.4 Voltages.
625.5 Listed.
Part II. Equipment Construction
625.10 Electric Vehicle Coupler.
(A) Construction and Installation.
(B) Unintentional Disconnection.
(C) Grounding Pole.
(D) Grounding Pole Requirements.
625.15 Markings.
(A) General.
(B) Ventilation Not Required.
(C) Ventilation Required.
625.16 Means of Coupling.
625.17 Cords and Cables.
(A) Power-Supply Cord.
(B) Output Cable to the Electric Vehicle.
(C) Overall Cord and Cable Length.
625.18 Interlock.
625.19 Automatic De-Energization of Cable.
625.22 Personnel Protection System.
Part III. Installation
625.40 Electric Vehicle Branch Circuit.
625.41 Overcurrent Protection.
625.42 Rating.
625.43 Disconnecting Means.
625.44 Equipment Connection.
(A) Portable Equipment.
(B) Stationary Equipment.
(C) Fixed Equipment.
625.46 Loss of Primary Source.
625.47 Multiple Feeder or Branch Circuits.
625.48 Interactive Systems.
625.50 Location.
625.52 Ventilation.
(A) Ventilation Not Required.
(B) Ventilation Required.
Part IV. Wireless Power Transfer Equipment
625.101 Grounding.
625.102 Construction.
(A) Type.
(B) Installation.
(C) Primary Pad.
(D) Protection of the Output Cable.
(E) Other Wiring Systems.
ARTICLE 626 Electrified Truck Parking Spaces
Part I. General
626.1 Scope.
626.2 Definitions.
626.3 Other Articles.
(A) Vehicle Repair and Storage Facilities.
(B) Motor Fuel Dispensing Stations.
626.4 General Requirements.
(A) Not Covered.
(B) Distribution System Voltages.
(C) Connection to Wiring System.
Part II. Electrified Truck Parking Space Electrical Wiring Systems
626.10 Branch Circuits.
626.11 Feeder and Service Load Calculations.
(A) Parking Space Load.
(B) Demand Factors.
(C) Two or More Electrified Truck Parking Spaces.
(D) Conductor Rating.
Part III. Electrified Truck Parking Space Supply Equipment
626.22 Wiring Methods and Materials.
(A) Electrified Truck Parking Space Supply Equipment Type.
(B) Mounting Height.
(C) Access to Working Space.
(D) Disconnecting Means.
626.23 Overhead Gantry or Cable Management System.
(A) Cable Management.
(B) Strain Relief.
626.24 Electrified Truck Parking Space Supply Equipment Connection Means.
(A) General.
(B) Receptacle.
(C) Disconnecting Means, Parking Space.
(D) Ground-Fault Circuit-Interrupter Protection for Personnel
626.25 Separable Power-Supply Cable Assembly.
(A) Rating(s).
(B) Power-Supply Cord.
626.26 Loss of Primary Power.
626.27 Interactive Systems.
Part IV. Transport Refrigerated Units (TRUs)
626.30 Transport Refrigerated Units.
(A) Branch Circuits.
(B) Electrified Truck Parking Space Supply Equipment.
626.31 Disconnecting Means and Receptacles.
(A) Disconnecting Means.
(B) Location.
(C) Receptacles.
626.32 Separable Power Supply Cable Assembly.
(A) Rating(s).
(B) Cord Assemblies.
(C) Attachment Plug(s) and Cord Connector(s).
ARTICLE 630 Electric Welders
Part I. General
630.1 Scope.
630.6 Listing.
Part II. Arc Welders
630.11 Ampacity of Supply Conductors.
(A) Individual Welders.
(B) Group of Welders.
630.12 Overcurrent Protection.
(A) For Welders.
(B) For Conductors.
630.13 Disconnecting Means.
630.14 Marking.
630.15 Grounding of Welder Secondary Circuit.
Part III. Resistance Welders
630.31 Ampacity of Supply Conductors.
(A) Individual Welders.
630.32 Overcurrent Protection.
(A) For Welders.
(B) Groups of Welders.
(B) For Conductors.
630.33 Disconnecting Means.
630.34 Marking.
Part IV. Welding Cable
630.41 Conductors.
630.42 Installation.
(A) Cable Support.
(B) Spread of Fire and Products of Combustion.
(C) Signs.
ARTICLE 640 Audio Signal Processing, Amplification, and Reproduction Equipment
Part I. General
640.1 Scope.
(A) Covered.
(B) Not Covered.
640.2 Definitions.
640.3 Locations and Other Articles.
(A) Spread of Fire or Products of Combustion.
(B) Ducts, Plenums, and Other Air-Handling Spaces.
(C) Cable Trays.
(D) Hazardous (Classified) Locations.
(E) Assembly Occupancies.
(F) Theaters, Audience Areas of Motion Picture and Television Studios, and Similar Locations.
(G) Carnivals, Circuses, Fairs, and Similar Events.
(H) Motion Picture and Television Studios.
(I) Swimming Pools, Fountains, and Similar Locations.
(J) Combination Systems.
(K) Antennas.
(L) Generators.
(M) Organ Pipes.
640.4 Protection of Electrical Equipment.
640.5 Access to Electrical Equipment Behind Panels Designed to Allow Access.
640.6 Mechanical Execution of Work.
(A) Installation of Audio Distribution Cables.
(B) Abandoned Audio Distribution Cables.
(C) Installed Audio Distribution Cable Identified for Future Use.
640.7 Grounding.
(A) General.
(B) Separately Derived Systems with 60 Volts to Ground.
(C) Isolated Ground Receptacles.
640.8 Grouping of Conductors.
640.9 Wiring Methods.
(A) Wiring to and Between Audio Equipment.
(B) Auxiliary Power Supply Wiring.
(C) Output Wiring and Listing of Amplifiers.
(D) Use of Audio Transformers and Autotransformers.
640.10 Audio Systems Near Bodies of Water.
(A) Equipment Supplied by Branch-Circuit Power.
(B) Equipment Not Supplied by Branch-Circuit Power.
Part II. Permanent Audio System Installations
640.21 Use of Flexible Cords and Cables.
(A) Between Equipment and Branch-Circuit Power.
(B) Between Loudspeakers and Amplifiers or Between Loudspeakers
(C) Between Equipment.
(D) Between Equipment and Power Supplies Other Than Branch-Circuit Power.
(E) Between Equipment Racks and Premises Wiring System
640.22 Wiring of Equipment Racks and Enclosures.
640.23 Conduit or Tubing.
(A) Number of Conductors.
(B) Nonmetallic Conduit or Tubing and Insulating Bushings
640.24 Wireways, Gutters, and Auxiliary Gutters.
640.25 Loudspeaker Installation in Fire Resistance–Rated Partitions, Walls, and Ceilings.
Part III. Portable and Temporary Audio System Installations
640.41 Multipole Branch-Circuit Cable Connectors.
640.42 Use of Flexible Cords and Cables.
(A) Between Equipment and Branch-Circuit Power.
(B) Between Loudspeakers and Amplifiers, or Between Loudspeakers.
(C) Between Equipment and/or Between Equipment Racks.
(D) Between Equipment, Equipment Racks, and Power Supplies Other Than Branch-Circuit Power.
(E) Between Equipment Racks and Branch-Circuit Power.
640.43 Wiring of Equipment Racks.
640.44 Environmental Protection of Equipment.
640.45 Protection of Wiring.
640.46 Equipment Access.
ARTICLE 645 Information Technology Equipment
645.1 Scope.
645.2 Definitions.
645.3 Other Articles.
(A) Spread of Fire or Products of Combustion.
(B) Wiring and Cabling in Other Spaces Used for Environmental Air (Plenums).
(C) Bonding and Grounding.
(D) Electrical Classification of Data Circuits.
(E) Fire Alarm Cables and Equipment.
(F) Cable Routing Assemblies, Communications Wires, Cables, Raceways, and Equipment.
(G) Community Antenna Television and Radio Distribution Systems Cables and Equipment.
(H) Optical Fiber Cables.
(I) Cables Not in Information Technology Equipment Room.
645.4 Special Requirements for Information Technology Equipment Room.
645.5 Supply Circuits and Interconnecting Cables.
(A) Branch-Circuit Conductors.
(B) Power-Supply Cords.
(C) Interconnecting Cables.
(D) Physical Protection.
(E) Under Raised Floors.
(F) Securing in Place.
(G) Abandoned Supply Circuits and Interconnecting Cables.
(H) Installed Supply Circuits and Interconnecting Cables Identified for Future Use.
645.10 Disconnecting Means.
(A) Remote Disconnect Controls.
(B) Critical Operations Data Systems.
645.11 Uninterruptible Power Supplies (UPSs).
645.14 System Grounding.
645.15 Equipment Grounding and Bonding.
645.16 Marking.
645.17 Power Distribution Units.
645.18 Surge Protection for Critical Operations Data Systems
645.25 Engineering Supervision.
645.27 Selective Coordination.
ARTICLE 646 Modular Data Centers
Part I. General
646.1 Scope.
646.2 Definitions.
646.3 Other Articles.
(A) Spread of Fire or Products of Combustion.
(B) Wiring and Cabling in Other Spaces Used for Environmental Air (Plenums).
(C) Grounding.
(D) Electrical Classification of Data Circuits.
(E) Fire Alarm Equipment.
(F) Cable Routing Assemblies and Communications Wires, Cables, Raceways, and Equipment.
(G) Community Antenna Television and Radio Distribution Systems Cables and Equipment.
(H) Storage Batteries.
(I) Surge-Protective Devices (SPDs).
(J) Lighting.
(K) Power Distribution Wiring and Wiring Protection.
(L) Wiring Methods and Materials.
(M) Service Equipment.
(N) Disconnecting Means.
646.4 Applicable Requirements.
646.5 Nameplate Data.
646.6 Supply Conductors and Overcurrent Protection.
(A) Size.
(B) Overcurrent Protection.
(1) Service Equipment — Overcurrent Protection.
(2) Taps and Feeders.
646.7 Short-Circuit Current Rating.
(A) Service Equipment.
(B) MDCs Connected to Branch Circuits and Feeders.
(C) MDCs Powered from Separate MDC System Enclosures
646.8 Field-Wiring Compartments.
646.9 Flexible Power Cords and Cables for Connecting Equipment Enclosures of an MDC System.
(A) Uses Permitted.
(B) Uses Not Permitted.
(C) Listing.
(D) Single-Conductor Cable.
Part II. Equipment
646.10 Electrical Supply and Distribution.
646.11 Distribution Transformers.
(A) Utility-Owned Transformers.
(B) Non-Utility-Owned Premises Transformers.
(C) Power Transformers.
646.12 Receptacles.
646.13 Other Electrical Equipment.
646.14 Installation and Use.
Part III. Lighting
646.15 General Illumination.
646.16 Emergency Lighting.
646.17 Emergency Lighting Circuits.
Part IV. Workspace
646.18 General.
646.19 Entrance to and Egress from Working Space.
(A) Unobstructed Egress.
(B) Extra Working Space.
646.20 Working Space for ITE.
(A) Low-Voltage Circuits.
(B) Other Circuits.
646.21 Work Areas and Working Space About Batteries.
646.22 Workspace for Routine Service and Maintenance.
ARTICLE 647 Sensitive Electronic Equipment
647.1 Scope.
647.3 General.
647.4 Wiring Methods.
(A) Panelboards and Overcurrent Protection.
(B) Junction Boxes.
(C) Conductor Identification.
(D) Voltage Drop.
647.5 Three-Phase Systems.
647.6 Grounding.
(A) General.
(B) Grounding Conductors Required.
647.7 Receptacles.
(A) General.
(B) Isolated Ground Receptacles.
647.8 Lighting Equipment.
(A) Disconnecting Means.
(B) Luminaires.
(C) Screw Shell.
ARTICLE 650 Pipe Organs
650.1 Scope.
650.2 Definitions.
650.3 Other Articles.
(A) Electronic Organ Equipment.
(B) Optical Fiber Cable.
650.4 Source of Energy.
650.5 Grounding or Double Insulation of the DC Power Supply
650.6 Conductors.
(A) Size.
(B) Insulation.
(C) Conductors to Be Cabled.
(D) Cable Covering.
650.7 Installation of Conductors.
650.8 Overcurrent Protection.
650.9 Protection from Accidental Contact.
ARTICLE 660 X-Ray Equipment
Part I. General
660.1 Scope.
660.2 Definitions.
660.3 Hazardous (Classified) Locations.
660.4 Connection to Supply Circuit.
(A) Fixed and Stationary Equipment.
(B) Portable, Mobile, and Transportable Equipment.
(C) Over 1000 Volts, Nominal.
660.5 Disconnecting Means.
660.6 Rating of Supply Conductors and Overcurrent Protection.
(A) Branch-Circuit Conductors.
(B) Feeder Conductors.
660.7 Wiring Terminals.
660.9 Minimum Size of Conductors.
660.10 Equipment Installations.
Part II. Control
660.20 Fixed and Stationary Equipment.
(A) Separate Control Device.
(B) Protective Device.
660.21 Portable and Mobile Equipment.
660.23 Industrial and Commercial Laboratory Equipment.
(A) Radiographic and Fluoroscopic Types.
(B) Diffraction and Irradiation Types.
660.24 Independent Control.
Part III. Transformers and Capacitors
660.35 General.
660.36 Capacitors.
Part IV. Guarding and Grounding
660.47 General.
(A) High-Voltage Parts.
(B) Low-Voltage Cables.
660.48 Grounding.
ARTICLE 665 Induction and Dielectric Heating Equipment
Part I. General
665.1 Scope.
665.2 Definitions.
665.4 Hazardous (Classified) Locations.
665.5 Output Circuit.
665.7 Remote Control.
(A) Multiple Control Points.
(B) Foot Switches.
665.10 Ampacity of Supply Conductors.
(A) Nameplate Rating.
(B) Motor-Generator Equipment.
665.11 Overcurrent Protection.
665.12 Disconnecting Means.
Part II. Guarding, Grounding, and Labeling
665.19 Component Interconnection.
665.20 Enclosures.
665.21 Control Panels.
665.22 Access to Internal Equipment.
665.23 Warning Labels or Signs.
665.24 Capacitors.
665.25 Dielectric Heating Applicator Shielding.
665.26 Grounding and Bonding.
665.27 Marking.
ARTICLE 668 Electrolytic Cells
668.1 Scope.
668.2 Definitions.
668.3 Other Articles.
(A) Lighting, Ventilating, Material Handling.
(B) Systems Not Electrically Connected.
(C) Electrolytic Cell Lines.
668.10 Cell Line Working Zone.
(A) Area Covered.
(B) Area Not Covered.
668.11 Direct-Current Cell Line Process Power Supply.
(A) Not Grounded.
(B) Metal Enclosures Grounded.
(C) Grounding Requirements.
668.12 Cell Line Conductors.
(A) Insulation and Material.
(B) Size.
(C) Connections.
668.13 Disconnecting Means.
(A) More Than One Process Power Supply.
(B) Removable Links or Conductors.
668.14 Shunting Means.
(A) Partial or Total Shunting.
(B) Shunting One or More Cells.
668.15 Grounding.
668.20 Portable Electrical Equipment.
(A) Portable Electrical Equipment Not to Be Grounded.
(B) Isolating Transformers.
(C) Marking.
668.21 Power-Supply Circuits and Receptacles for Portable Electrical Equipment.
(A) Isolated Circuits.
(B) Noninterchangeability.
(C) Marking.
668.30 Fixed and Portable Electrical Equipment.
(A) Electrical Equipment Not Required to Be Grounded.
(B) Exposed Conductive Surfaces Not Required to Be Grounded.
(C) Wiring Methods.
(D) Circuit Protection.
(E) Bonding.
668.31 Auxiliary Nonelectrical Connections.
668.32 Cranes and Hoists.
(A) Conductive Surfaces to Be Insulated from Ground.
(B) Hazardous Electrical Conditions.
668.40 Enclosures.
ARTICLE 669 Electroplating
669.1 Scope.
669.3 General.
669.5 Branch-Circuit Conductors.
669.6 Wiring Methods.
(A) Systems Not Exceeding 60 Volts Direct Current.
(B) Systems Exceeding 60 Volts Direct Current.
669.7 Warning Signs.
669.8 Disconnecting Means.
(A) More Than One Power Supply.
(B) Removable Links or Conductors.
669.9 Overcurrent Protection.
ARTICLE 670 Industrial Machinery
670.1 Scope.
670.2 Definition.
670.3 Machine Nameplate Data.
(A) Permanent Nameplate.
(B) Overcurrent Protection.
670.4 Supply Conductors and Overcurrent Protection.
(A) Size.
(B) Disconnecting Means.
(C) Overcurrent Protection.
670.5 Short-Circuit Current Rating.
670.6 Surge Protection.
ARTICLE 675 Electrically Driven or Controlled Irrigation Machines
Part I. General
675.1 Scope.
675.2 Definitions.
675.4 Irrigation Cable.
(A) Construction.
(B) Alternate Wiring Methods.
(C) Supports.
(D) Fittings.
675.5 More Than Three Conductors in a Raceway or Cable.
675.6 Marking on Main Control Panel.
675.7 Equivalent Current Ratings.
(A) Continuous-Current Rating.
(B) Locked-Rotor Current.
675.8 Disconnecting Means.
(A) Main Controller.
(B) Main Disconnecting Means.
(C) Disconnecting Means for Individual Motors and Controllers
675.9 Branch-Circuit Conductors.
675.10 Several Motors on One Branch Circuit.
(A) Protection Required.
(B) Individual Protection Not Required.
675.11 Collector Rings.
(A) Transmitting Current for Power Purposes.
(B) Control and Signal Purposes.
(C) Grounding.
(D) Protection.
675.12 Grounding.
675.13 Methods of Grounding.
675.14 Bonding.
675.15 Lightning Protection.
675.16 Energy from More Than One Source.
675.17 Connectors.
Part II. Center Pivot Irrigation Machines
675.21 General.
675.22 Equivalent Current Ratings.
(A) Continuous-Current Rating.
(B) Locked-Rotor Current.
ARTICLE 680 Swimming Pools, Fountains, and Similar Installations
Part I. General
680.1 Scope.
680.2 Definitions.
680.4 Approval of Equipment.
680.5 Ground-Fault Circuit Interrupters.
680.6 Grounding.
680.7 Grounding and Bonding Terminals.
680.8 Cord-and-Plug-Connected Equipment.
(A) Length.
(B) Equipment Grounding.
(C) Construction.
680.9 Overhead Conductor Clearances.
(A) Power.
(B) Communications Systems.
(C) Network-Powered Broadband Communications Systems
680.10 Electric Pool Water Heaters.
680.11 Underground Wiring Location.
680.12 Equipment Rooms and Pits.
680.13 Maintenance Disconnecting Means.
680.14 Corrosive Environment.
(A) General.
(B) Wiring Methods.
Part II. Permanently Installed Pools
680.20 General.
680.21 Motors.
(A) Wiring Methods.
(B) Double Insulated Pool Pumps.
(C) GFCI Protection.
680.22 Lighting, Receptacles, and Equipment.
(A) Receptacles.
(B) Luminaires, Lighting Outlets, and Ceiling-Suspended (Paddle) Fans.
(C) Switching Devices.
(D) Other Outlets.
680.23 Underwater Luminaires.
(A) General.
(B) Wet-Niche Luminaires.
(C) Dry-Niche Luminaires.
(D) No-Niche Luminaires.
(E) Through-Wall Lighting Assembly.
(F) Branch-Circuit Wiring.
680.24 Junction Boxes and Electrical Enclosures for
Transformers or Ground-Fault Circuit Interrupters.
(A) Junction Boxes.
(B) Other Enclosures.
(C) Protection.
(D) Grounding Terminals.
(E) Strain Relief.
(F) Grounding.
680.25 Feeders.
(A) Feeders.
(B) Aluminum Conduit.
680.26 Equipotential Bonding.
(A) Performance.
(B) Bonded Parts.
(C) Pool Water.
680.27 Specialized Pool Equipment.
(A) Underwater Audio Equipment.
(B) Electrically Operated Pool Covers.
(C) Deck Area Heating.
680.28 Gas-Fired Water Heater.
Part III. Storable Pools, Storable Spas, and Storable Hot Tubs
680.30 General.
680.31 Pumps.
680.32 Ground-Fault Circuit Interrupters Required.
680.33 Luminaires.
(A) Within the Low Voltage Contact Limit.
(B) Over the Low Voltage Contact Limit But Not over 150 Volts.
680.34 Receptacle Locations.
Part IV. Spas and Hot Tubs
680.40 General.
680.41 Emergency Switch for Spas and Hot Tubs.
680.42 Outdoor Installations.
(A) Flexible Connections.
(B) Bonding.
(C) Interior Wiring to Outdoor Installations.
680.43 Indoor Installations.
(A) Receptacles.
(B) Installation of Luminaires, Lighting Outlets, and Ceiling-Suspended (Paddle) Fans.
(C) Switches.
(D) Bonding.
(E) Methods of Bonding.
(F) Grounding.
(G) Underwater Audio Equipment.
680.44 Protection.
(A) Listed Units.
(B) Other Units.
Part V. Fountains
680.50 General.
680.51 Luminaires, Submersible Pumps, and Other Submersible Equipment.
(A) Ground-Fault Circuit Interrupter.
(B) Operating Voltage.
(C) Luminaire Lenses.
(D) Overheating Protection.
(E) Wiring.
(F) Servicing.
(G) Stability.
680.52 Junction Boxes and Other Enclosures.
(A) General.
(B) Underwater Junction Boxes and Other Underwater Enclosures.
680.53 Bonding.
680.54 Grounding.
680.55 Methods of Grounding.
(A) Applied Provisions.
(B) Supplied by a Flexible Cord.
680.56 Cord-and-Plug-Connected Equipment.
(A) Ground-Fault Circuit Interrupter.
(B) Cord Type.
(C) Sealing.
(D) Terminations.
680.57 Signs.
(A) General.
(B) Ground-Fault Circuit-Interrupter Protection for Personnel
(C) Location.
(D) Disconnect.
(E) Bonding and Grounding.
680.58 GFCI Protection for Adjacent Receptacle Outlets.
Part VI. Pools and Tubs for Therapeutic Use
680.60 General.
680.61 Permanently Installed Therapeutic Pools.
680.62 Therapeutic Tubs (Hydrotherapeutic Tanks).
(A) Protection.
(B) Bonding.
(C) Methods of Bonding.
(D) Grounding.
(E) Receptacles.
(F) Luminaires.
Part VII. Hydromassage Bathtubs
680.70 General.
680.71 Protection.
680.72 Other Electrical Equipment.
680.73 Accessibility.
680.74 Bonding.
(A) General.
(B)
Part VIII. Electrically Powered Pool Lifts
680.80 General.
680.81 Equipment Approval.
680.82 Protection.
680.83 Bonding.
680.84 Switching Devices.
680.85 Nameplate Marking.
ARTICLE 682 Natural and Artificially Made Bodies of Water
Part I. General
682.1 Scope.
682.2 Definitions.
682.3 Other Articles.
Part II. Installation
682.10 Electrical Equipment and Transformers.
682.11 Location of Service Equipment.
682.12 Electrical Connections.
682.13 Wiring Methods and Installation
682.14 Submersible or Floating Equipment Power Connection(s).
(A) Type and Marking.
(B) Location.
682.15 Ground-Fault Circuit-Interrupter (GFCI) Protection.
Part III. Grounding and Bonding
682.30 Grounding.
682.31 Equipment Grounding Conductors.
(A) Type.
(B) Feeders.
(C) Branch Circuits.
(D) Cord-and-Plug-Connected Appliances.
682.32 Bonding of Non–Current-Carrying Metal Parts.
682.33 Equipotential Planes and Bonding of Equipotential Planes.
(A) Areas Requiring Equipotential Planes.
(B) Areas Not Requiring Equipotential Planes.
(C) Bonding.
ARTICLE 685 Integrated Electrical Systems
Part I. General
685.1 Scope.
685.3 Application of Other Articles.
Part II. Orderly Shutdown
685.10 Location of Overcurrent Devices in or on Premises.
685.12 Direct-Current System Grounding.
685.14 Ungrounded Control Circuits.
ARTICLE 690 Solar Photovoltaic (PV) Systems
Part I. General
690.1 Scope.
690.2 Definitions.
690.4 General Requirements.
(A) Photovoltaic Systems.
(B) Equipment.
(C) Qualified Personnel.
(D) Multiple PV Systems.
(E) Locations Not Permitted.
690.6 Alternating-Current (ac) Modules.
(A) Photovoltaic Source Circuits.
(B) Inverter Output Circuit.
Part II. Circuit Requirements
690.7 Maximum Voltage.
(A) Photovoltaic Source and Output Circuits.
(B) DC-to-DC Converter Source and Output Circuits.
(C) Bipolar Source and Output Circuits.
690.8 Circuit Sizing and Current.
(A) Calculation of Maximum Circuit Current.
(B) Conductor Ampacity.
(C) Systems with Multiple Direct-Current Voltages.
(D) Sizing of Module Interconnection Conductors.
690.9 Overcurrent Protection.
(A) Circuits and Equipment.
(B) Overcurrent Device Ratings.
(C) Photovoltaic Source and Output Circuits.
(D) Power Transformers.
690.10 Stand-Alone Systems.
690.11 Arc-Fault Circuit Protection (Direct Current).
690.12 Rapid Shutdown of PV Systems on Buildings.
(A) Controlled Conductors.
(B) Controlled Limits.
(C) Initiation Device.
(D) Equipment.
Part III. Disconnecting Means
690.13 Photovoltaic System Disconnecting Means.
(A) Location
(B) Marking.
(C) Suitable for Use.
(D) Maximum Number of Disconnects.
(E) Ratings.
(F) Type of Disconnect.
690.15 Disconnection of Photovoltaic Equipment.
(A) Location.
(B) Interrupting Rating.
(C) Isolating Device.
(D) Equipment Disconnecting Means.
Part IV. Wiring Methods
690.31 Methods Permitted.
(A) Wiring Systems.
(B) Identification and Grouping.
(C) Single-Conductor Cable.
(D) Multiconductor Cable.
(E) Flexible Cords and Cables Connected to Tracking PV Arrays.
(F) Small-Conductor Cables.
(G) Photovoltaic System Direct Current Circuits on or in a Building.
(H) Flexible, Fine-Stranded Cables.
(I) Bipolar Photovoltaic Systems.
690.32 Component Interconnections.
690.33 Connectors.
(A) Configuration.
(B) Guarding.
(C) Type.
(D) Grounding Member.
(E) Interruption of Circuit.
690.34 Access to Boxes.
Part V. Grounding and Bonding
690.41 System Grounding.
(A) PV System Grounding Configurations.
(B) Ground-Fault Protection.
690.42 Point of System Grounding Connection.
690.43 Equipment Grounding and Bonding.
(A) Photovoltaic Module Mounting Systems and Devices.
(B) Equipment Secured to Grounded Metal Supports.
(C) With Circuit Conductors.
690.45 Size of Equipment Grounding Conductors.
690.46 Array Equipment Grounding Conductors.
690.47 Grounding Electrode System.
(A) Buildings or Structures Supporting a PV Array.
(B) Additional Auxiliary Electrodes for Array Grounding.
690.50 Equipment Bonding Jumpers.
Part VI. Marking
690.51 Modules.
690.52 Alternating-Current Photovoltaic Modules.
690.53 Direct-Current Photovoltaic Power Source.
690.54 Interactive System Point of Interconnection.
690.55 Photovoltaic Systems Connected to Energy Storage Systems.
690.56 Identification of Power Sources.
(A) Facilities with Stand-Alone Systems.
(B) Facilities with Utility Services and Photovoltaic Systems
(C) Buildings with Rapid Shutdown.
Part VII. Connection to Other Sources
690.59 Connection to Other Sources.
Part VIII. Energy Storage Systems
690.71 General.
690.72 Self-regulated PV Charge Control.
ARTICLE 691 Large-Scale Photovoltaic (PV) Electric Power Production Facility
691.1 Scope.
691.2 Definitions.
691.4 Special Requirements for Large-Scale PV Electric Supply Stations.
691.5 Equipment Approval.
691.6 Engineered Design.
691.7 Conformance of Construction to Engineered Design.
691.8 Direct Current Operating Voltage.
691.9 Disconnection of Photovoltaic Equipment.
691.10 Arc-Fault Mitigation.
691.11 Fence Grounding.
ARTICLE 692 Fuel Cell Systems
Part I. General
692.1 Scope.
692.2 Definitions.
692.4 Installation.
(A) Fuel Cell System.
(B) Identification.
(C) System Installation.
692.6 Listing Requirement.
Part II. Circuit Requirements
692.8 Circuit Sizing and Current.
(A) Nameplate Rated Circuit Current.
(B) Conductor Ampacity and Overcurrent Device Ratings.
(C) Ampacity of Grounded or Neutral Conductor.
692.9 Overcurrent Protection.
(A) Circuits and Equipment.
(B) Accessibility.
692.10 Stand-Alone Systems.
(A) Fuel Cell System Output.
(B) Sizing and Protection.
(C) Single 120-Volt Nominal Supply.
Part III. Disconnecting Means
692.13 All Conductors.
692.17 Switch or Circuit Breaker.
Part IV. Wiring Methods
692.31 Wiring Systems.
Part V. Grounding
692.41 System Grounding.
(A) AC Systems.
(B) DC Systems.
(C) Systems with Alternating-Current and Direct-Current Grounding Requirements.
692.44 Equipment Grounding Conductor.
692.45 Size of Equipment Grounding Conductor.
692.47 Grounding Electrode System.
Part VI. Marking
692.53 Fuel Cell Power Sources.
692.54 Fuel Shut-Off.
692.56 Stored Energy.
Part VII. Connection to Other Circuits
692.59 Transfer Switch.
692.60 Identified Interactive Equipment.
692.61 Output Characteristics.
692.62 Loss of Interactive System Power.
692.64 Unbalanced Interconnections.
692.65 Utility-Interactive Point of Connection.
ARTICLE 694 Wind Electric Systems
Part I. General
694.1 Scope.
694.2 Definitions.
694.7 Installation.
(A) Wind Electric Systems.
(B) Equipment.
(C) Diversion Load Controllers.
(D) Surge Protective Devices (SPD).
(E) Receptacles.
(F) Poles or Towers Supporting Wind Turbines Used as a Raceway.
(G) Working Clearances.
Part II. Circuit Requirements
694.10 Maximum Voltage.
(A) Wind Turbine Output Circuits.
(B) Direct-Current Utilization Circuits.
(C) Circuits over 150 Volts to Ground.
694.12 Circuit Sizing and Current.
(A) Calculation of Maximum Circuit Current.
(B) Ampacity and Overcurrent Device Ratings.
694.15 Overcurrent Protection.
(A) Circuits and Equipment.
(B) Power Transformers.
(C) Direct-Current Rating.
Part III. Disconnecting Means
694.20 All Conductors.
694.22 Additional Provisions.
(A) Disconnecting Means.
(B) Equipment.
(C) Requirements for Disconnecting Means.
(D) Equipment That Is Not Readily Accessible.
694.23 Turbine Shutdown.
(A) Manual Shutdown.
(B) Shutdown Procedure.
694.24 Disconnection of Wind Electric System Equipment.
694.26 Fuses.
694.28 Installation and Service of a Wind Turbine.
Part IV. Wiring Methods
694.30 Permitted Methods.
(A) Wiring Systems.
(B) Flexible Cords and Cables.
(C) Direct-Current Turbine Output Circuits Inside a Building
Part V. Grounding and Bonding
694.40 Equipment Grounding and Bonding.
(A) General.
(B) Tower Grounding and Bonding.
Part VI. Marking
694.50 Interactive System Point of Interconnection.
694.52 Power Systems Employing Energy Storage.
694.54 Identification of Power Sources.
(A) Facilities with Stand-Alone Systems.
(B) Facilities with Utility Services and Wind Electric Systems.
694.56 Instructions for Disabling Turbine.
Part VII. Connection to Other Sources
694.60 Identified Interactive Equipment.
694.62 Installation.
694.66 Operating Voltage Range.
694.68 Point of Connection.
ARTICLE 695 Fire Pumps
695.1 Scope.
(A) Covered.
(B) Not Covered.
695.2 Definitions.
695.3 Power Source(s) for Electric Motor-Driven Fire Pumps.
(A) Individual Sources.
(B) Multiple Sources.
(C) Multibuilding Campus-Style Complexes.
(D) On-Site Standby Generator as Alternate Source.
(E) Arrangement.
(F) Transfer of Power.
(G) Power Source Selection.
(H) Overcurrent Device Selection.
(I) Phase Converters.
695.4 Continuity of Power.
(A) Direct Connection.
(B) Connection Through Disconnecting Means and Overcurrent Device.
695.5 Transformers.
(A) Size.
(B) Overcurrent Protection.
(C) Feeder Source.
695.6 Power Wiring.
(A) Supply Conductors.
(B) Conductor Size.
(C) Overload Protection.
(D) Pump Wiring.
(E) Loads Supplied by Controllers and Transfer Switches.
(F) Mechanical Protection.
(G) Ground-Fault Protection of Equipment.
(H) Listed Electrical Circuit Protective System to Controller Wiring.
(I) Junction Boxes.
(J) Raceway Terminations.
695.7 Voltage Drop.
(A) Starting.
(B) Running.
695.10 Listed Equipment.
695.12 Equipment Location.
(A) Controllers and Transfer Switches.
(B) Engine-Drive Controllers.
(C) Storage Batteries.
(D) Energized Equipment.
(E) Protection Against Pump Water.
(F) Mounting.
695.14 Control Wiring.
(A) Control Circuit Failures.
(B) Sensor Functioning.
(C) Remote Device(s).
(D) Engine-Drive Control Wiring.
(E) Electric Fire Pump Control Wiring Methods.
(F) Generator Control Wiring Methods.
695.15 Surge Protection.
Chapter 7 Special Conditions
ARTICLE 700 Emergency Systems
Part I. General
700.1 Scope.
700.2 Definitions.
700.3 Tests and Maintenance.
(A) Conduct or Witness Test.
(B) Tested Periodically.
(C) Maintenance.
(D) Written Record.
(E) Testing Under Load.
(F) Temporary Source of Power for Maintenance or Repair of the Alternate Source of Power.
700.4 Capacity.
(A) Capacity and Rating.
(B) Selective Load Pickup, Load Shedding, and Peak Load Shaving.
700.5 Transfer Equipment.
(A) General.
(B) Bypass Isolation Switches.
(C) Automatic Transfer Switches.
(D) Use.
(E) Documentation.
700.6 Signals.
(A) Malfunction.
(B) Carrying Load.
(C) Not Functioning.
(D) Ground Fault.
700.7 Signs.
(A) Emergency Sources.
(B) Grounding.
700.8 Surge Protection.
Part II. Circuit Wiring
700.10 Wiring, Emergency System.
(A) Identification.
(B) Wiring.
(C) Wiring Design and Location.
(D) Fire Protection.
Part III. Sources of Power
700.12 General Requirements.
(A) Storage Battery.
(B) Generator Set.
(C) Uninterruptible Power Supplies.
(D) Separate Service.
(E) Fuel Cell System.
(F) Unit Equipment.
Part IV. Emergency System Circuits for Lighting and Power
700.15 Loads on Emergency Branch Circuits.
700.16 Emergency Illumination.
700.17 Branch Circuits for Emergency Lighting.
700.18 Circuits for Emergency Power.
700.19 Multiwire Branch Circuits.
Part V. Control — Emergency Lighting Circuits
700.20 Switch Requirements.
700.21 Switch Location.
700.22 Exterior Lights.
700.23 Dimmer and Relay Systems.
700.24 Directly Controlled Luminaires.
700.25 Branch Circuit Emergency Lighting Transfer Switch.
700.26 Automatic Load Control Relay.
Part VI. Overcurrent Protection
700.30 Accessibility.
700.31 Ground-Fault Protection of Equipment.
700.32 Selective Coordination.
ARTICLE 701 Legally Required Standby Systems
Part I. General
701.1 Scope.
701.2 Definition.
701.3 Tests and Maintenance.
(A) Conduct or Witness Test.
(B) Tested Periodically.
(C) Maintenance.
(D) Written Record.
(E) Testing Under Load.
701.4 Capacity and Rating.
701.5 Transfer Equipment.
(A) General.
(B) Bypass Isolation Switches.
(C) Automatic Transfer Switches.
(D) Documentation.
701.6 Signals.
(A) Malfunction.
(B) Carrying Load.
(C) Not Functioning.
(D) Ground Fault.
701.7 Signs.
(A) Mandated Standby.
(B) Grounding.
Part II. Circuit Wiring
701.10 Wiring Legally Required Standby Systems.
Part III. Sources of Power
701.12 General Requirements.
(A) Storage Battery.
(B) Generator Set.
(C) Uninterruptible Power Supplies.
(D) Separate Service.
(E) Connection Ahead of Service Disconnecting Means.
(F) Fuel Cell System.
(G) Unit Equipment.
Part IV. Overcurrent Protection
701.25 Accessibility.
701.26 Ground-Fault Protection of Equipment.
701.27 Selective Coordination.
ARTICLE 702 Optional Standby Systems
Part I. General
702.1 Scope.
702.2 Definition.
702.4 Capacity and Rating.
(A) Available Short-Circuit Current.
(B) System Capacity.
702.5 Transfer Equipment.
702.6 Signals.
(A) Malfunction.
(B) Carrying Load.
702.7 Signs.
(A) Standby.
(B) Grounding.
(C) Power Inlet.
Part II. Wiring
702.10 Wiring Optional Standby Systems.
702.11 Portable Generator Grounding.
(A) Separately Derived System.
(B) Nonseparately Derived System.
702.12 Outdoor Generator Sets.
(A) Portable Generators Greater Than 15 kW and Permanently Installed Generators.
(B) Portable Generators 15 kW or Less.
(C) Power Inlets Rated at 100 Amperes or Greater, for Portable Generators.
ARTICLE 705 Interconnected Electric Power Production Sources
Part I. General
705.1 Scope.
705.2 Definitions.
705.3 Other Articles.
705.6 Equipment Approval.
705.8 System Installation.
705.10 Directory.
705.12 Point of Connection.
(A) Supply Side.
(B) Load Side.
705.14 Output Characteristics.
705.16 Interrupting and Short-Circuit Current Rating.
705.20 Disconnecting Means, Sources.
705.21 Disconnecting Means, Equipment.
705.22 Disconnect Device.
705.23 Interactive System Disconnecting Means.
705.30 Overcurrent Protection.
(A) Solar Photovoltaic Systems.
(B) Transformers.
(C) Fuel Cell Systems.
(D) Interactive Inverters.
(E) Generators.
705.31 Location of Overcurrent Protection.
705.32 Ground-Fault Protection.
705.40 Loss of Primary Source.
705.42 Loss of 3-Phase Primary Source.
705.50 Grounding.
Part II. Interactive Inverters
705.60 Circuit Sizing and Current.
(A) Calculation of Maximum Circuit Current.
(B) Ampacity and Overcurrent Device Ratings.
705.65 Overcurrent Protection.
(A) Circuits and Equipment.
(B) Power Transformers.
(C) Conductor Ampacity.
705.70 Interactive Inverters Mounted in Not Readily Accessible Locations.
705.80 Utility-Interactive Power Systems Employing Energy Storage.
705.82 Hybrid Systems.
705.95 Ampacity of Neutral Conductor.
(A) Neutral Conductor for Single Phase, 2-Wire Inverter Output.
(B) Neutral Conductor for Instrumentation, Voltage, Detection or Phase Detection.
705.100 Unbalanced Interconnections.
(A) Single Phase.
(B) Three Phase.
Part III. Generators
705.130 Overcurrent Protection.
705.143 Synchronous Generators.
Part IV. Microgrid Systems
705.150 System Operation.
705.160 Primary Power Source Connection.
705.165 Reconnection to Primary Power Source.
705.170 Microgrid Interconnect Devices (MID).
ARTICLE 706 Energy Storage Systems
Part I. General
706.1 Scope.
706.2 Definitions.
706.3 Other Articles.
706.4 System Classification.
706.5 Equipment.
706.6 Multiple Systems.
706.7 Disconnecting Means.
(A) ESS Disconnecting Means.
(B) Remote Actuation.
(C) Busway.
(D) Notification.
(E) Partitions and Distance.
706.8 Connection to Other Energy Sources.
(A) Load Disconnect.
(B) Identified Interactive Equipment.
(C) Loss of Interactive System Power.
(D) Unbalanced Interconnections.
(E) Point of Connection.
706.10 Energy Storage System Locations.
(A) Ventilation.
(B) Guarding of Live Parts.
(C) Spaces About ESS Components.
(D) Egress.
(E) Illumination.
706.11 Directory.
(A) Directory.
(B) Facilities with Stand-Alone Systems.
Part II. Circuit Requirements
706.20 Circuit Sizing and Current.
(A) Maximum Rated Current for a Specific Circuit.
(B) Conductor Ampacity and Overcurrent Device Ratings.
(C) Ampacity of Grounded or Neutral Conductor.
706.21 Overcurrent Protection.
(A) Circuits and Equipment.
(B) Overcurrent Device Ampere Ratings.
(C) Direct Current Rating.
(D) Current Limiting.
(E) Fuses.
(F) Location.
706.23 Charge Control.
(A) General.
(B) Diversion Charge Controller.
(C) Charge Controllers and DC-to-DC Converters.
Part III. Electrochemical Energy Storage Systems
706.30 Installation of Batteries.
(A) Dwelling Units.
(B) Disconnection of Series Battery Circuits.
(C) Storage System Maintenance Disconnecting Means.
(D) Storage Systems of More Than 100 Volts.
706.31 Battery and Cell Terminations.
(A) Corrosion Prevention.
(B) Intercell and Intertier Conductors and Connections.
(C) Battery Terminals.
706.32 Battery Interconnections.
706.33 Accessibility.
706.34 Battery Locations.
(A) Live Parts.
(B) Top Terminal Batteries.
(C) Gas Piping.
Part IV. Flow Battery Energy Storage Systems
706.40 General.
706.41 Electrolyte Classification.
706.42 Electrolyte Containment.
706.43 Flow Controls.
706.44 Pumps and Other Fluid Handling Equipment.
Part V. Other Energy Storage Technologies
706.50 General.
ARTICLE 708 Critical Operations Power Systems (COPS)
Part I. General
708.1 Scope.
708.2 Definitions.
708.4 Risk Assessment.
(A) Conducting Risk Assessment.
(B) Identification of Hazards.
(C) Developing Mitigation Strategy.
708.5 Physical Security.
(A) Risk Assessment.
(B) Restricted Access.
708.6 Testing and Maintenance.
(A) Conduct or Witness Test.
(B) Tested Periodically.
(C) Maintenance.
(D) Written Record.
(E) Testing Under Load.
708.8 Commissioning.
(A) Commissioning Plan.
(B) Component and System Tests.
(C) Baseline Test Results.
(D) Functional Performance Tests.
Part II. Circuit Wiring and Equipment
708.10 Feeder and Branch Circuit Wiring.
(A) Identification.
(B) Wiring.
(C) COPS Feeder Wiring Requirements.
(D) COPS Branch Circuit Wiring.
708.11 Branch Circuit and Feeder Distribution Equipment.
(A) Branch Circuit Distribution Equipment.
(B) Feeder Distribution Equipment.
708.12 Feeders and Branch Circuits Supplied by COPS.
708.14 Wiring of HVAC, Fire Alarm, Security, Emergency Communications, and Signaling Systems.
Part III. Power Sources and Connection
708.20 Sources of Power.
(A) General Requirements.
(B) Fire Protection.
(C) Grounding.
(D) Surge Protection Devices.
(E) Storage Battery.
(F) Generator Set.
(G) Uninterruptible Power Supplies.
(H) Fuel Cell System.
708.21 Ventilation.
708.22 Capacity of Power Sources.
(A) Capacity and Rating.
(B) Selective Load Pickup, Load Shedding, and Peak Load Shaving.
(C) Duration of COPS Operation.
708.24 Transfer Equipment.
(A) General.
(B) Bypass Isolation Switches.
(C) Automatic Transfer Switches.
(D) Use.
(E) Documentation.
708.30 Branch Circuits Supplied by COPS.
Part IV. Overcurrent Protection
708.50 Accessibility.
708.52 Ground-Fault Protection of Equipment.
(A) Applicability.
(B) Feeders.
(C) Testing.
(D) Selectivity.
708.54 Selective Coordination.
Part V. System Performance and Analysis
708.64 Emergency Operations Plan.
ARTICLE 710 Stand-Alone Systems
710.1 Scope.
710.6 Equipment Approval.
710.15 General.
(A) Supply Output.
(B) Sizing and Protection.
(C) Single 120-Volt Supply.
(D) Energy Storage or Backup Power System Requirements.
(E) Back-Fed Circuit Breakers.
(F) Voltage and Frequency Control.
ARTICLE 712 Direct Current Microgrids
Part I. General
712.1 Scope.
712.2 Definitions.
712.3 Other Articles.
712.4 Listing and Labeling.
712.10 Directory.
Part II. Circuit Requirements
712.25 Identification of Circuit Conductors
712.30 System Voltage.
Part III. Disconnecting Means
712.34 DC Source Disconnecting Means.
712.35 Disconnection of Ungrounded Conductors.
712.37 Directional Current Devices.
Part IV. Wiring Methods
712.52 System Grounding.
(A) General.
(B) Over 300 Volts.
712.55 Ground Fault Detection Equipment.
712.57 Arc Fault Protection.
Part V. Marking
712.62 Distribution Equipment and Conductors.
712.65 Available DC Short-Circuit Current.
(A) Field Marking.
(B) Modifications.
Part VI. Protection
712.70 Overcurrent Protection.
712.72 Interrupting and Short-Circuit Current Ratings.
Part VII. Systems over 1000 Volts
712.80 General.
ARTICLE 720 Circuits and Equipment Operating at Less Than 50 Volts
720.1 Scope.
720.2 Other Articles.
720.3 Hazardous (Classified) Locations.
720.4 Conductors.
720.5 Lampholders.
720.6 Receptacle Rating.
720.7 Receptacles Required.
720.9 Batteries.
720.11 Mechanical Execution of Work.
ARTICLE 725 Class 1, Class 2, and Class 3 Remote-Control, Signaling, and Power-Limited Circuits
Part I. General
725.1 Scope.
725.2 Definitions.
725.3 Other Articles.
(A) Number and Size of Conductors in Raceway.
(B) Spread of Fire or Products of Combustion.
(C) Ducts, Plenums, and Other Air-Handling Spaces.
(D) Hazardous (Classified) Locations.
(E) Cable Trays.
(F) Motor Control Circuits.
(G) Instrumentation Tray Cable.
(H) Raceways Exposed to Different Temperatures.
(I) Vertical Support for Fire-Rated Cables and Conductors.
(J) Bushing.
(K) Installation of Conductors with Other Systems.
(L) Corrosive, Damp, or Wet Locations.
(M) Cable Routing Assemblies.
(N) Communications Raceways.
725.21 Access to Electrical Equipment Behind Panels Designed to Allow Access.
725.24 Mechanical Execution of Work.
725.25 Abandoned Cables.
725.30 Class 1, Class 2, and Class 3 Circuit Identification.
725.31 Safety-Control Equipment.
(A) Remote-Control Circuits.
(B) Physical Protection.
725.35 Class 1, Class 2, and Class 3 Circuit Requirements.
Part II. Class 1 Circuits
725.41 Class 1 Circuit Classifications and Power Source Requirements.
(A) Class 1 Power-Limited Circuits.
(B) Class 1 Remote-Control and Signaling Circuits.
725.43 Class 1 Circuit Overcurrent Protection.
725.45 Class 1 Circuit Overcurrent Device Location.
(A) Point of Supply.
(B) Feeder Taps.
(C) Branch-Circuit Taps.
(D) Primary Side of Transformer.
(E) Input Side of Electronic Power Source.
725.46 Class 1 Circuit Wiring Methods.
725.48 Conductors of Different Circuits in the Same Cable, Cable Tray, Enclosure, or Raceway.
(A) Two or More Class 1 Circuits.
(B) Class 1 Circuits with Power-Supply Circuits.
725.49 Class 1 Circuit Conductors.
(A) Sizes and Use.
(B) Insulation.
725.51 Number of Conductors in Cable Trays and Raceway, and Ampacity Adjustment.
(A) Class 1 Circuit Conductors.
(B) Power-Supply Conductors and Class 1 Circuit Conductors
(C) Class 1 Circuit Conductors in Cable Trays.
725.52 Circuits Extending Beyond One Building.
Part III. Class 2 and Class 3 Circuits
725.121 Power Sources for Class 2 and Class 3 Circuits.
(A) Power Source.
(B) Interconnection of Power Sources.
(C) Marking.
725.124 Circuit Marking.
725.127 Wiring Methods on Supply Side of the Class 2 or Class 3 Power Source.
725.130 Wiring Methods and Materials on Load Side of the Class 2 or Class 3 Power Source.
(A) Class 1 Wiring Methods and Materials.
(B) Class 2 and Class 3 Wiring Methods.
725.133 Installation of Conductors and Equipment in Cables, Compartments, Cable Trays, Enclosures, Manholes, Outlet Boxes, Device Boxes, Raceways, and Cable Routing Assemblies for Class 2 and Class 3 Circuits.
725.135 Installation of Class 2, Class 3, and PLTC Cables.
(A) Listing.
(B) Ducts Specifically Fabricated for Environmental Air.
(C) Other Spaces Used for Environmental Air (Plenums).
(D) Risers — Cables in Vertical Runs.
(E) Risers — Cables in Metal Raceways.
(F) Risers — Cables in Fireproof Shafts.
(G) Risers — Oneand Two-Family Dwellings.
(H) Cable Trays.
(I) Cross-Connect Arrays.
(J) Industrial Establishments.
(K) Other Building Locations.
(L) Multifamily Dwellings.
(M) Oneand Two-Family Dwellings.
725.136 Separation from Electric Light, Power, Class 1, Non–Power-Limited Fire Alarm Circuit Conductors, and Medium-Power Network-Powered Broadband Communications Cables.
(A) General.
(B) Separated by Barriers.
(C) Raceways Within Enclosures.
(D) Associated Systems Within Enclosures.
(E) Enclosures with Single Opening.
(F) Manholes.
(G) Cable Trays.
(H) In Hoistways.
(I) Other Applications.
725.139 Installation of Conductors of Different Circuits in the Same Cable, Enclosure, Cable Tray, Raceway, or Cable Routing Assembly.
(A) Two or More Class 2 Circuits.
(B) Two or More Class 3 Circuits.
(C) Class 2 Circuits with Class 3 Circuits.
(D) Class 2 and Class 3 Circuits with Communications Circuits.
(E) Class 2 or Class 3 Cables with Other Circuit Cables.
(F) Class 2 or Class 3 Conductors or Cables and Audio System Circuits.
725.141 Installation of Circuit Conductors Extending Beyond One Building.
725.143 Support of Conductors.
725.144 Transmission of Power and Data.
(A) Use of Class 2 or Class 3 Cables to Transmit Power and Data.
(B) Use of Class 2-LP or Class 3-LP Cables to Transmit Power and Data.
725.154 Applications of Listed Class 2, Class 3, and PLTC Cables.
(A) Class 2 and Class 3 Cable Substitutions.
(B) Class 2, Class 3, PLTC Circuit Integrity (CI) Cable or Electrical Circuit Protective System.
(C) Thermocouple Circuits.
Part IV. Listing Requirements
725.170 Listing and Marking of Equipment for Power and Data Transmission.
725.179 Listing and Marking of Class 2, Class 3, and Type PLTC Cables.
(A) Types CL2P and CL3P.
(B) Types CL2R and CL3R.
(C) Types CL2 and CL3.
(D) Types CL2X and CL3X.
(E) Type PLTC.
(F) Circuit Integrity (CI) Cable or Electrical Circuit Protective System.
(1) Circuit Integrity (CI) Cables.
(2) Electrical Circuit Protective System.
(G) Class 2 and Class 3 Cable Voltage Ratings.
(H) Class 3 Single Conductors.
(I) Limited Power (LP) Cables.
(J) Marking.
ARTICLE 727 Instrumentation Tray Cable: Type ITC
727.1 Scope.
727.2 Definition.
727.3 Other Articles.
727.4 Uses Permitted.
727.5 Uses Not Permitted.
727.6 Construction.
727.7 Marking.
727.8 Allowable Ampacity.
727.9 Overcurrent Protection.
727.10 Bends.
ARTICLE 728 Fire-Resistive Cable Systems
728.1 Scope.
728.2 Definition.
728.3 Other Articles.
728.4 General.
728.5 Installations.
(A) Mounting.
(B) Supports.
(C) Raceways and Couplings.
(D) Cable Trays.
(E) Boxes.
(F) Pulling Lubricants.
(G) Vertical Supports.
(H) Splices.
728.60 Grounding.
728.120 Marking.
ARTICLE 750 Energy Management Systems
750.1 Scope.
750.2 Definitions.
750.20 Alternate Power Sources.
750.30 Load Management.
(A) Load Shedding Controls.
(B) Disconnection of Power.
(C) Capacity of Branch Circuit, Feeder, or Service.
750.50 Field Markings.
ARTICLE 760 Fire Alarm Systems
Part I. General
760.1 Scope.
760.3 Other Articles.
(A) Spread of Fire or Products of Combustion.
(B) Ducts, Plenums, and Other Air-Handling Spaces.
(C) Hazardous (Classified) Locations.
(D) Corrosive, Damp, or Wet Locations.
(E) Building Control Circuits.
(F) Optical Fiber Cables.
(G) Installation of Conductors with Other Systems.
(H) Raceways or Sleeves Exposed to Different Temperatures
(I) Vertical Support for Fire Rated Cables and Conductors.
(J) Number and Size of Cables and Conductors in Raceway.
(K) Bushing.
(L) Cable Routing Assemblies.
(M) Communications Raceways.
760.21 Access to Electrical Equipment Behind Panels Designed to Allow Access.
760.24 Mechanical Execution of Work.
(A) General.
(B) Circuit Integrity (CI) Cable.
760.25 Abandoned Cables.
760.30 Fire Alarm Circuit Identification.
760.32 Fire Alarm Circuits Extending Beyond One Building
760.35 Fire Alarm Circuit Requirements.
(A) Non–Power-Limited Fire Alarm (NPLFA) Circuits.
(B) Power-Limited Fire Alarm (PLFA) Circuits.
Part II. Non–Power-Limited Fire Alarm (NPLFA) Circuits
760.41 NPLFA Circuit Power Source Requirements.
(A) Power Source.
(B) Branch Circuit.
760.43 NPLFA Circuit Overcurrent Protection.
760.45 NPLFA Circuit Overcurrent Device Location.
760.46 NPLFA Circuit Wiring.
760.48 Conductors of Different Circuits in Same Cable, Enclosure, or Raceway.
(A) Class 1 with NPLFA Circuits.
(B) Fire Alarm with Power-Supply Circuits.
760.49 NPLFA Circuit Conductors.
(A) Sizes and Use.
(B) Insulation.
(C) Conductor Materials.
760.51 Number of Conductors in Cable Trays and Raceways, and Ampacity Adjustment Factors.
(A) NPLFA Circuits and Class 1 Circuits.
(B) Power-Supply Conductors and NPLFA Circuit Conductors
(C) Cable Trays.
760.53 Multiconductor NPLFA Cables.
(A) NPLFA Wiring Method.
(B) Applications of Listed NPLFA Cables.
Part III. Power-Limited Fire Alarm (PLFA) Circuits
760.121 Power Sources for PLFA Circuits.
(A) Power Source.
(B) Branch Circuit.
760.124 Circuit Marking.
760.127 Wiring Methods on Supply Side of the PLFA Power Source.
760.130 Wiring Methods and Materials on Load Side of the PLFA Power Source.
(A) NPLFA Wiring Methods and Materials.
(B) PLFA Wiring Methods and Materials.
760.133 Installation of Conductors and Equipment in Cables, Compartments, Cable Trays, Enclosures, Manholes, OutletBoxes, Device Boxes, Raceways, and Cable Routing Assemblies for Power-Limited Fire Alarm Circuits.
760.135 Installation of PLFA Cables in Buildings.
(A) Listing.
(B) Ducts Specifically Fabricated for Environmental Air.
(C) Other Spaces Used For Environmental Air (Plenums).
(D) Risers — Cables in Vertical Runs.
(E) Risers — Cables in Metal Raceways.
(F) Risers — Cables in Fireproof Shafts.
(G) Risers — Oneand Two-Family Dwellings.
(H) Other Building Locations.
(I) Nonconcealed Spaces.
(J) Portable Fire Alarm System.
760.136 Separation from Electric Light, Power, Class 1, NPLFA, and Medium-Power Network-Powered Broadband Communications Circuit Conductors.
(A) General.
(B) Separated by Barriers.
(C) Raceways Within Enclosures.
(D) Associated Systems Within Enclosures.
(E) Enclosures with Single Opening.
(F) In Hoistways.
(G) Other Applications.
760.139 Installation of Conductors of Different PLFA Circuits, Class 2, Class 3, and Communications Circuits in the Same Cable, Enclosure, Cable Tray, Raceway, or Cable Routing Assembly.
(A) Two or More PLFA Circuits.
(B) Class 2 Circuits with PLFA Circuits.
(C) Low-Power Network-Powered Broadband Communications Cables and PLFA Cables.
(D) Audio System Circuits and PLFA Circuits.
760.142 Conductor Size.
760.143 Support of Conductors.
760.145 Current-Carrying Continuous Line-Type Fire Detectors.
(A) Application.
(B) Installation.
760.154 Applications of Listed PLFA Cables.
(A) Fire Alarm Cable Substitutions.
Part IV. Listing Requirements
760.176 Listing and Marking of NPLFA Cables.
(A) NPLFA Conductor Materials.
(B) Insulated Conductors.
(C) Type NPLFP.
(D) Type NPLFR.
(E) Type NPLF.
(F) Fire Alarm Circuit Integrity (CI) Cable or Electrical Circuit Protective System.
(G) NPLFA Cable Markings.
760.179 Listing and Marking of PLFA Cables and Insulated Continuous Line-Type Fire Detectors.
(A) Conductor Materials.
(B) Conductor Size.
(C) Ratings.
(D) Type FPLP.
(E) Type FPLR.
(J) Insulated Continuous Line-Type Fire Detectors.
(F) Type FPL.
(G) Fire Alarm Circuit Integrity (CI) Cable or Electrical Circuit Protective System.
(H) Coaxial Cables.
(I) Cable Marking.
ARTICLE 770 Optical Fiber Cables
Part I. General
770.1 Scope.
770.2 Definitions.
770.3 Other Articles.
(A) Hazardous (Classified) Locations.
(B) Cables in Ducts for Dust, Loose Stock, or Vapor Removal.
(C) Composite Cables.
770.21 Access to Electrical Equipment Behind Panels Designed to Allow Access.
770.24 Mechanical Execution of Work.
770.25 Abandoned Cables.
770.26 Spread of Fire or Products of Combustion.
Part II. Cables Outside and Entering Buildings
770.44 Overhead (Aerial) Optical Fiber Cables.
(A) On Poles and In-Span.
(B) Above Roofs.
770.47 Underground Optical Fiber Cables Entering Buildings
(A) Underground Systems with Electric Light, Power, Class 1, or Non–Power-Limited Fire Alarm Circuit Conductors
(B) Direct-Buried Cables and Raceways.
770.48 Unlisted Cables Entering Buildings.
(A) Conductive and Nonconductive Cables.
(B) Nonconductive Cables in Raceway.
770.49 Metallic Entrance Conduit Grounding.
Part III. Protection
770.93 Grounding or Interruption of Non–Current-Carrying Metallic Members of Optical Fiber Cables.
(A) Entering Buildings.
(B) Terminating on the Outside of Buildings.
Part IV. Grounding Methods
770.100 Entrance Cable Bonding and Grounding.
(A) Bonding Conductor or Grounding Electrode Conductor.
(B) Electrode.
(C) Electrode Connection.
(D) Bonding of Electrodes.
770.106 Grounding and Bonding of Entrance Cables at Mobile Homes.
(A) Grounding.
(B) Bonding.
Part V. Installation Methods Within Buildings
770.110 Raceways and Cable Routing Assemblies for Optical Fiber Cables.
(A) Types of Raceways.
(B) Raceway Fill for Optical Fiber Cables.
(C) Cable Routing Assemblies.
770.113 Installation of Optical Fiber Cables.
(A) Listing.
(B) Ducts Specifically Fabricated for Environmental Air.
(C) Other Spaces Used for Environmental Air (Plenums).
(D) Risers — Cables in Vertical Runs.
(E) Risers — Cables and Innerducts in Metal Raceways.
(F) Risers — Cables in Fireproof Shafts.
(G) Risers — Oneand Two-Family Dwellings.
(H) Cable Trays.
(I) Distributing Frames and Cross-Connect Arrays.
(J) Other Building Locations.
770.114 Grounding.
770.133 Installation of Optical Fibers and Electrical Conductors.
(A) With Conductors for Electric Light, Power, Class 1, Non–Power-Limited Fire Alarm, or Medium Power Network- Powered Broadband Communications Circuits.
(B) With Other Circuits.
(C) Support of Optical Fiber Cables.
770.154 Applications of Listed Optical Fiber Cables.
Part VI. Listing Requirements
770.179 Optical Fiber Cables.
(A) Types OFNP and OFCP.
(B) Types OFNR and OFCR.
(C) Types OFNG and OFCG.
(D) Types OFN and OFC.
(E) Circuit Integrity (CI) Cable or Electrical Circuit Protective System.
(F) Field-Assembled Optical Fiber Cables.
770.180 Grounding Devices.
Chapter 8 Communications Systems
ARTICLE 800 Communications Circuits
Part I. General
800.1 Scope.
800.2 Definitions.
800.3 Other Articles.
(A) Hazardous (Classified) Locations.
(B) Wiring in Ducts for Dust, Loose Stock, or Vapor Removal.
(C) Equipment in Other Space Used for Environmental Air.
(D) Installation and Use.
(E) Network-Powered Broadband Communications Systems
(F) Premises-Powered Broadband Communications Systems
(G) Optical Fiber Cable.
(H) Temperature Limitation of Conductors.
800.18 Installation of Equipment.
800.21 Access to Electrical Equipment Behind Panels Designed to Allow Access.
800.24 Mechanical Execution of Work.
800.25 Abandoned Cables.
800.26 Spread of Fire or Products of Combustion.
Part II. Wires and Cables Outside and Entering Buildings
800.44 Overhead (Aerial) Communications Wires and Cables.
(A) On Poles and In-Span.
(B) Above Roofs.
800.47 Underground Communications Wires and Cables Entering Buildings.
(A) Underground Systems with Electric Light, Power, Class 1, or Non–Power-Limited Fire Alarm Circuit Conductors.
(B) Underground Block Distribution.
800.48 Unlisted Cables Entering Buildings.
800.49 Metallic Entrance Conduit Grounding.
800.50 Circuits Requiring Primary Protectors.
(A) Insulation, Wires, and Cables.
(B) On Buildings.
(C) Entering Buildings.
800.53 Lightning Conductors.
Part III. Protection
800.90 Protective Devices.
(A) Application.
(B) Location.
(C) Hazardous (Classified) Locations.
(D) Secondary Protectors.
800.93 Grounding or Interruption of Non–Current-Carrying Metallic Sheath Members of Communications Cables.
(A) Entering Buildings.
(B) Terminating on the Outside of Buildings.
Part IV. Grounding Methods
800.100 Cable and Primary Protector Bonding and Grounding
(A) Bonding Conductor or Grounding Electrode Conductor.
(B) Electrode.
(C) Electrode Connection.
(D) Bonding of Electrodes.
800.106 Primary Protector Grounding and Bonding at Mobile Homes.
(A) Grounding.
(B) Bonding.
Part V. Installation Methods Within Buildings
800.110 Raceways and Cable Routing Assemblies for Communications Wires and Cables.
(A) Types of Raceways.
(B) Raceway Fill for Communications Wires and Cables.
(C) Cable Routing Assemblies.
800.113 Installation of Communications Wires, Cables and Raceways, and Cable Routing Assemblies.
(A) Listing.
(B) Ducts Specifically Fabricated for Environmental Air.
(C) Other Spaces Used for Environmental Air (Plenums).
(D) Risers — Cables, Raceways, and Cable Routing Assemblies in Vertical Runs.
(E) Risers — Cables and Innerducts in Metal Raceways.
(F) Risers — Cables, Raceways, and Cable Routing Assemblies in Fireproof Shafts.
(G) Risers — Oneand Two-Family Dwellings.
(H) Cable Trays.
(I) Distributing Frames and Cross-Connect Arrays.
(J) Other Building Locations.
(K) Multifamily Dwellings.
(L) Oneand Two-Family Dwellings.
800.133 Installation of Communications Wires, Cables, and Equipment.
(A) Separation from Other Conductors.
(B) Support of Communications Wires and Cables.
800.154 Applications of Listed Communications Wires, Cables, and Raceways, and Listed Cable Routing Assemblies
800.156 Dwelling Unit Communications Outlet.
Part VI. Listing Requirements
800.170 Equipment.
(A) Primary Protectors.
(B) Secondary Protectors.
(C) Plenum Grade Cable Ties.
800.173 Drop Wire and Cable.
800.179 Communications Wires and Cables.
(A) Type CMP.
(B) Type CMR.
(C) Type CMG.
(D) Type CM.
(E) Type CMX.
(F) Type CMUC Undercarpet Wires and Cables.
(G) Circuit Integrity (CI) Cable or Electrical Circuit Protective System.
(H) Communications Wires.
(I) Hybrid Power and Communications Cables.
800.180 Grounding Devices.
800.182 Cable Routing Assemblies and Communications Raceways.
(A) Plenum Cable Routing Assemblies and Plenum Communications Raceways.
(B) Riser Cable Routing Assemblies and Riser Communications Raceways.
(C) General-Purpose Cable Routing Assemblies and General-Purpose Communication Raceways.
ARTICLE 810 Radio and Television Equipment
Part I. General
810.1 Scope.
810.2 Definitions.
810.3 Other Articles.
810.4 Community Television Antenna.
810.5 Radio Noise Suppressors.
810.6 Antenna Lead-In Protectors.
810.7 Grounding Devices.
Part II. Receiving Equipment — Antenna Systems
810.11 Material.
810.12 Supports.
810.13 Avoidance of Contacts with Conductors of Other Systems.
810.14 Splices.
810.15 Grounding.
810.16 Size of Wire-Strung Antenna — Receiving Station.
(A) Size of Antenna Conductors.
(B) Self-Supporting Antennas.
810.17 Size of Lead-in — Receiving Station.
810.18 Clearances — Receiving Stations.
(A) Outside of Buildings.
(B) Antennas and Lead-ins — Indoors.
(C) In Boxes or Other Enclosures.
810.19 Electrical Supply Circuits Used in Lieu of Antenna — Receiving Stations.
810.20 Antenna Discharge Units — Receiving Stations.
(A) Where Required.
(B) Location.
(C) Grounding.
810.21 Bonding Conductors and Grounding Electrode Conductors — Receiving Stations.
(A) Material.
(B) Insulation.
(C) Supports.
(D) Physical Protection.
(E) Run in Straight Line.
(F) Electrode.
(G) Inside or Outside Building.
(H) Size.
(I) Common Ground.
(J) Bonding of Electrodes.
(K) Electrode Connection.
Part III. Amateur and Citizen Band Transmitting and Receiving Stations — Antenna Systems
810.51 Other Sections.
810.52 Size of Antenna.
810.53 Size of Lead-in Conductors.
810.54 Clearance on Building.
810.55 Entrance to Building.
810.56 Protection Against Accidental Contact.
810.57 Antenna Discharge Units — Transmitting Stations.
810.58 Bonding Conductors and Grounding Electrode Conductors — Amateur and Citizen Band Transmitting and Receiving Stations.
(A) Other Sections.
(B) Size of Protective Bonding Conductor or Grounding Electrode Conductor.
(C) Size of Operating Bonding Conductor or Grounding Electrode Conductor.
Part IV. Interior Installation — Transmitting Stations
810.70 Clearance from Other Conductors.
810.71 General.
(A) Enclosing.
(B) Grounding of Controls.
(C) Interlocks on Doors.
ARTICLE 820 Community Antenna Television and Radio Distribution Systems
Part I. General
820.1 Scope.
820.2 Definitions.
820.3 Other Articles.
(A) Hazardous (Classified) Locations.
(B) Wiring in Ducts for Dust, Loose Stock, or Vapor Removal.
(C) Equipment in Other Space Used for Environmental Air.
(D) Installation and Use.
(E) Installations of Conductive and Nonconductive Optical Fiber Cables.
(F) Communications Circuits.
(G) Network-Powered Broadband Communications Systems
(H) Premises-Powered Broadband Communications Systems
(I) Alternate Wiring Methods.
820.15 Power Limitations.
820.21 Access to Electrical Equipment Behind Panels Designed to Allow Access.
820.24 Mechanical Execution of Work.
820.25 Abandoned Cables.
820.26 Spread of Fire or Products of Combustion.
Part II. Coaxial Cables Outside and Entering Buildings
820.44 Overhead (Aerial) Coaxial Cables.
(A) On Poles and In-Span.
(B) Above Roofs.
(C) On Masts.
(D) Between Buildings.
(E) On Buildings.
820.47 Underground Coaxial Cables Entering Buildings.
(A) Underground Systems with Electric Light, Power, Class 1, or Non–Power-Limited Fire Alarm Circuit Conductors
(B) Direct-Buried Cables and Raceways.
820.48 Unlisted Cables Entering Buildings.
820.49 Metallic Entrance Conduit Grounding.
Part III. Protection
820.93 Grounding of the Outer Conductive Shield of Coaxial Cables.
(A) Entering Buildings.
(B) Terminating Outside of the Building.
(C) Location.
(D) Hazardous (Classified) Locations.
Part IV. Grounding Methods
820.100 Cable Bonding and Grounding.
(A) Bonding Conductor or Grounding Electrode Conductor.
(B) Electrode.
(C) Electrode Connection.
(D) Bonding of Electrodes.
(E) Shield Protection Devices.
820.103 Equipment Grounding.
820.106 Grounding and Bonding at Mobile Homes.
(A) Grounding.
(B) Bonding.
Part V. Installation Methods Within Buildings
820.110 Raceways and Cable Routing Assemblies for Coaxial Cables.
(A) Types of Raceways.
(B) Raceway Fill for Coaxial Cables.
(C) Cable Routing Assemblies.
820.113 Installation of Coaxial Cables.
(A) Listing.
(B) Ducts Specifically Fabricated for Environmental Air.
(C) Other Spaces Used For Environmental Air (Plenums).
(D) Risers — Cables in Vertical Runs.
(E) Risers — Cables and Innerducts in Metal Raceways.
(F) Risers — Cables in Fireproof Shafts.
(G) Risers — Oneand Two-Family Dwellings.
(H) Cable Trays.
(I) Distributing Frames and Cross-Connect Arrays.
(J) Other Building Locations.
(K) Oneand Two-Family and Multifamily Dwellings.
820.133 Installation of Coaxial Cables and Equipment.
(A) Separation from Other Conductors.
(B) Support of Coaxial Cables.
820.154 Applications of Listed CATV Cables.
Part VI. Listing Requirements
820.179 Coaxial Cables.
(A) Type CATVP.
(B) Type CATVR.
(C) Type CATV.
(D) Type CATVX.
820.180 Grounding Devices.
ARTICLE 830 Network-Powered Broadband Communications Systems
Part I. General
830.1 Scope.
830.2 Definitions.
830.3 Other Articles.
(A) Hazardous (Classified) Locations.
(B) Wiring in Ducts for Dust, Loose Stock, or Vapor Removal.
(C) Equipment in Other Space Used for Environmental Air.
(D) Installation and Use.
(E) Output Circuits.
(F) Protection Against Physical Damage.
830.15 Power Limitations.
830.21 Access to Electrical Equipment Behind Panels Designed to Allow Access.
830.24 Mechanical Execution of Work.
830.25 Abandoned Cables.
830.26 Spread of Fire or Products of Combustion.
Part II. Cables Outside and Entering Buildings
830.40 Entrance Cables.
(A) Medium-Power Circuits.
(B) Low-Power Circuits.
830.44 Overhead (Aerial) Cables.
(A) On Poles and In-Span.
(B) Above Roofs.
(C) Clearance from Ground.
(D) Over Pools.
(E) Final Spans.
(F) Between Buildings.
(G) On Buildings.
830.47 Underground Network-Powered Broadband Communications Cables Entering Buildings.
(A) Underground Systems with Electric Light and Power, Class 1, or Non–Power-Limited Fire Alarm Circuit Conductors
(B) Direct-Buried Cables and Raceways.
(C) Mechanical Protection.
(D) Pools.
830.49 Metallic Entrance Conduit Grounding.
Part III. Protection
830.90 Primary Electrical Protection.
(A) Application.
(B) Location.
(C) Hazardous (Classified) Locations.
830.93 Grounding or Interruption of Metallic Members of Network-Powered Broadband Communications Cables.
(A) Entering Buildings.
(B) Terminating Outside of the Building.
Part IV. Grounding Methods
830.100 Cable, Network Interface Unit, and Primary Protector Bonding and Grounding.
(A) Bonding Conductor or Grounding Electrode Conductor.
(B) Electrode.
(C) Electrode Connection.
(D) Bonding of Electrodes.
830.106 Grounding and Bonding at Mobile Homes.
(A) Grounding.
(B) Bonding.
Part V. Installation Methods Within Buildings
830.110 Raceways and Cable Routing Assemblies for Network-Powered Broadband Communications Cables.
(A) Types of Raceways.
(B) Raceway Fill for Network-Powered Broadband Communications Cables.
(C) Cable Routing Assemblies.
830.113 Installation of Network-Powered Broadband Communications Cables.
(A) Listing.
(B) Ducts Specifically Fabricated for Environmental Air.
(C) Other Spaces Used For Environmental Air (Plenums).
(D) Risers — Cables in Vertical Runs.
(E) Risers — Cables and Innerducts in Metal Raceways.
(F) Risers — Cables in Fireproof Shafts.
(G) Risers — Oneand Two-Family Dwellings.
(H) Cable Trays.
(I) Other Building Locations.
830.133 Installation of Network-Powered Broadband Communications Cables and Equipment.
(A) Separation of Conductors.
(B) Support of Network-Powered Broadband Communications Cables.
830.154 Applications of Network-Powered Broadband Communications System Cables.
830.160 Bends.
Part VI. Listing Requirements
830.179 Network-Powered Broadband Communications Equipment and Cables.
(A) Network-Powered Broadband Communications Medium-Power Cables.
(B) Network-Powered Broadband Communication Low-Power Cables.
830.180 Grounding Devices.
ARTICLE 840 Premises-Powered Broadband Communications Systems
Part I. General
840.1 Scope.
840.2 Definitions.
840.3 Other Articles.
(A) Hazardous (Classified) Locations.
(B) Cables in Ducts for Dust, Loose Stock, or Vapor Removal.
(C) Equipment in Other Space Used for Environmental Air.
(D) Installation and Use.
(E) Output Circuits.
(F) Other Communications Systems.
(G) Electrical Classification of Data Circuits and Cables.
840.21 Access to Electrical Equipment Behind Panels Designed to Allow Access.
840.24 Mechanical Execution of Work.
840.25 Abandoned Cables.
840.26 Spread of Fire or Products of Combustion.
Part II. Cables Outside and Entering Buildings
840.44 Overhead (Aerial) Optical Fiber Cables.
(A) On Poles and In-Span.
(B) Above Roofs.
840.45 Overhead (Aerial) Communications Wires and Cables.
840.46 Overhead (Aerial) Coaxial Cables.
840.47 Underground Wires and Cables Entering Buildings
(A) Optical Fiber Cables.
(B) Communications Wires and Cables.
(C) Coaxial Cables.
840.48 Unlisted Wires and Cables Entering Buildings.
(A) Optical Fiber Cables.
(B) Communications Wires and Cables.
(C) Coaxial Cables.
840.49 Metallic Entrance Conduit Grounding.
Part III. Protection
840.90 Protective Devices.
840.93 Grounding or Interruption.
(A) Non–Current-Carrying Metallic Members of Optical Fiber Cables.
(B) Communications Cables.
(C) Coaxial Cables.
Part IV. Grounding Methods
840.100 Network Terminal and Cable Grounding.
840.101 Premises Circuits Not Leaving the Building.
(A) Coaxial Cable Shield Grounding.
(B) Communications Circuit Grounding.
(C) Network Terminal Grounding.
840.106 Grounding and Bonding at Mobile Homes.
(A) Grounding.
(B) Bonding.
Part V. Installation Methods Within Buildings
840.110 Raceways and Cable Routing Assemblies.
(A) Optical Fiber Cables.
(B) Multipair Communications Cables.
(C) Coaxial Cables.
840.113 Installation on the Customer Premises Side of the Network Terminal.
(A) Premises Communications Circuits.
(B) Premises Community Antenna Television (CATV) Circuits
840.133 Installation of Optical Fibers and Electrical Conductors
840.154 Applications of Listed Optical Fiber Cables.
Part VI. Premises Powering of Communications Equipment over Communications Cables
840.160 Powering Circuits.
Part VII. Listing Requirements
840.170 Equipment and Cables.
(A) Network Terminal.
(B) Optical Fiber Cables.
(C) Communications Equipment.
(D) Cable Routing Assemblies and Communications Raceways
(E) Premises Communications Wires and Cables.
(F) Premises Community Antenna Television (CATV) Circuits
(G) Power Source.
(H) Accessory Equipment.
840.180 Grounding Devices.
Chapter 9 Tables
Table 1 Percent of Cross Section of Conduit and Tubing for Conductors and Cables
Table 2 Radius of Conduit and Tubing Bends
Table 4 Dimensions and Percent Area of Conduit and Tubing (Areas of Conduit or Tubing for the Combinations of Wires Permitted in Table 1, Chapter 9)
Table 5 Dimensions of Insulated Conductors and Fixture Wires
Table 5A Compact Copper and Aluminum Building Wire Nominal Dimensions and Areas
Table 8 Conductor Properties
Table 9 Alternating-Current Resistance and Reactance for 600-Volt Cables, 3-Phase, 60 Hz, 75°C (167°F) — Three Single Conductors in Conduit
Table 10 Conductor Stranding
Table 11(A) Class 2 and Class 3 Alternating-Current Power Source Limitations
Table 11(B) Class 2 and Class 3 Direct-Current Power Source Limitations
Table 12(A) PLFA Alternating-Current Power Source Limitations
Table 12(B) PLFA Direct-Current Power Source Limitations
Informative Annex A Product Safety Standards
Informative Annex B Application Information for Ampacity Calculation
B.1 Equation Application Information.
B.2 Typical Applications Covered by Tables.
B.3 Criteria Modifications.
B.4 Electrical Ducts.
B.5 Table B.310.15(B)(2)(6) and Table B.310.15(B)(2)(7).
B.6 Electrical Ducts Used in Figure B.310.15(B)(2)(2).
B.7 Examples Showing Use of Figure B.310.15(B)(2)(1) for Electrical Duct Bank Ampacity Modifications.
Informative Annex C Conduit and Tubing Fill Tables for Conductors and Fixture Wires of the Same Size
Table C.1 Maximum Number of Conductors or Fixture Wires in Electrical Metallic Tubing (EMT) (Based on Chapter 9: Table 1, Table 4, and Table 5)
Table C.1(A) Maximum Number of Conductors or Fixture Wires in Electrical Metallic Tubing (EMT) (Based on Chapter 9: Table 1, Table 4, and Table 5A)
Table C.2 Maximum Number of Conductors or Fixture Wires in Electrical Nonmetallic Tubing (ENT) (Based on Chapter 9: Table 1, Table 4, and Table 5)
Table C.2(A) Maximum Number of Conductors or Fixture Wires in Electrical Nonmetallic Tubing (ENT) (Based on Chapter 9: Table 1, Table 4, and Table 5A)
Table C.3 Maximum Number of Conductors or Fixture Wires in Flexible Metal Conduit (FMC) (Based on Chapter 9: Table 1, Table 4, and Table 5)
Table C.3(A) Maximum Number of Conductors or Fixture Wires in Flexible Metal Conduit (FMC) (Based on Chapter 9: Table 1, Table 4, and Table 5A)
Table C.4 Maximum Number of Conductors or Fixture Wires in Intermediate Metal Conduit (IMC) (Based on Chapter 9: Table 1, Table 4, and Table 5)
Table C.4(A) Maximum Number of Conductors or Fixture Wires in Intermediate Metal Conduit (IMC) (Based on Chapter 9: Table 1, Table 4, and Table 5A)
Table C.5 Maximum Number of Conductors or Fixture Wires in Liquidtight Flexible Nonmetallic Conduit (Type LFNC-A) (Based on Chapter 9: Table 1, Table 4, and Table 5)
Table C.5(A) Maximum Number of Conductors or Fixture Wires in Liquidtight Flexible Nonmetallic Conduit (Type LFNC-A) (Based on Chapter 9: Table 1, Table 4, and Table 5A)
Table C.6 Maximum Number of Conductors or Fixture Wires in Liquidtight Flexible Nonmetallic Conduit (Type LFNC-B) (Based on Chapter 9: Table 1, Table 4, and Table 5)
Table C.6(A) Maximum Number of Conductors or Fixture Wires in Liquidtight Flexible Nonmetallic Conduit (Type LFNC-B) (Based on Chapter 9: Table 1, Table 4, and Table 5A)
Table C.7 Maximum Number of Conductors of Fixture Wires in Liquidtight Flexible Nonmetallic Conduit (Type LFNC-C) (Based on Chapter 9: Table 1, Table 4, and Table 5)
Table C.7(A) Maximum Number of Conductors of Fixture Wires in Liquidtight Flexible Nonmetallic Conduit (Type LFNC-C) (Based on Chapter 9: Table 1, Table 4, and Table 5A)
Table C.8 Maximum Number of Conductors or Fixture Wires in Liquidtight Flexible Metal Conduit (LFMC) (Based on Chapter 9: Table 1, Table 4, and Table 5)
Table C.8(A) Maximum Number of Conductors or Fixture Wires in Liquidtight Flexible Metal Conduit (LFMC) (Based on Chapter 9: Table 1, Table 4, and Table 5A)
Table C.9 Maximum Number of Conductors or Fixture Wires in Rigid Metal Conduit (RMC) (Based on Chapter 9: Table 1, Table 4, and Table 5)
Table C.9(A) Maximum Number of Conductors or Fixture Wires in Rigid Metal Conduit (RMC) (Based on Chapter 9: Table 1, Table 4, and Table 5A)
Table C.10 Maximum Number of Conductors or Fixture Wires in Rigid PVC Conduit, Schedule 80 (Based on Chapter 9: Table 1, Table 4, and Table 5)
Table C.10(A) Maximum Number of Conductors or Fixture Wires in Rigid PVC Conduit, Schedule 80 (Based on Chapter 9: Table 1, Table 4, and Table 5A)
Table C.11 Maximum Number of Conductors or Fixture Wires in Rigid PVC Conduit, Schedule 40 and HDPE Conduit (Based on Chapter 9: Table 1, Table 4, and Table 5)
Table C.11(A) Maximum Number of Conductors or Fixture Wires in Rigid PVC Conduit, Schedule 40 and HDPE Conduit (Based on Chapter 9: Table 1, Table 4, and Table 5A)
Table C.12 Maximum Number of Conductors or Fixture Wires in Type A, Rigid PVC Conduit (Based on Chapter 9: Table 1, Table 4, and Table 5)
Table C.12(A) Maximum Number of Conductors or Fixture Wires in Type A, Rigid PVC Conduit (Based on Chapter 9: Table 1, Table 4, and Table 5A)
Table C.13 Maximum Number of Conductors or Fixture Wires in Type EB, PVC Conduit (Based on Chapter 9: Table 1, Table 4, and Table 5)
Table C.13(A) Maximum Number of Conductors or Fixture Wires in Type EB, PVC Conduit (Based on Chapter 9: Table 1, Table 4, and Table 5A)
Informative Annex D Examples
Example D1(a) One-Family Dwelling
Example D1(b) One-Family Dwelling
Example D2(a) Optional Calculation for One-Family Dwelling, Heating Larger Than Air Conditioning
Example D2(b) Optional Calculation for One-Family Dwelling, Air Conditioning Larger Than Heating
Example D2(c) Optional Calculation for One-Family Dwelling with Heat Pump (Single-Phase, 240/120-Volt Service)
Example D3 Store Building
Example D3(a) Industrial Feeders in a Common Raceway
Example D4(a) Multifamily Dwelling
Example D4(b) Optional Calculation for Multifamily Dwelling
Example D5(a) Multifamily Dwelling Served at 208Y/120 Volts, Three Phase
Example D5(b) Optional Calculation for Multifamily Dwelling Served at 208Y/120 Volts, Three Phase
Example D6 Maximum Demand for Range Loads
Example D7 Sizing of Service Conductors for Dwelling(s)
Example D8 Motor Circuit Conductors, Overload Protection, and Short-Circuit and Ground-Fault Protection
Example D9 Feeder Ampacity Determination for Generator Field Control
Example D10 Feeder Ampacity Determination for Adjustable Speed Drive Control
Example D11 Mobile Home
Example D12 Park Trailer
Example D13 Cable Tray Calculations
Example D13(a) Multiconductor Cables 4/0 AWG and Larger
Example D13(b) Multiconductor Cables Smaller Than 4/0 AWG
Example D13(c) Single Conductor Cables 1/0 AWG through 4/0 AWG
Example D13(d) Single Conductor Cables 250 kcmil through 900 kcmil
Informative Annex E Types of Construction
Table E.1 Fire Resistance Ratings for Type I Through Type V Construction (hr)
Table E.2 Maximum Number of Stories for Types V, IV, and III Construction
Table E.3 Cross-Reference of Building Construction Types
Informative Annex F Availability and Reliability for Critical Operations Power Systems; and Development and Implementation of Functional Performance Tests (FPTs) for Critical Operations Power Systems
Availability and Reliability for Critical Operations Power Systems
Development and Implementation of Functional Performance Tests (FPTs) for Critical Operations Power Systems Development of FPT
Informative Annex G Supervisory Control and Data Acquisition (SCADA)
(A) General.
(B) Power Supply.
(C) Security Against Hazards.
(D) Maintenance and Testing.
Informative Annex H Administration and Enforcement
80.1 Scope.
80.2 Definitions.
80.3 Purpose.
80.5 Adoption.
80.7 Title.
80.9 Application.
(A) New Installations.
(B) Existing Installations.
(C) Additions, Alterations, or Repairs.
80.11 Occupancy of Building or Structure.
(A) New Construction.
(B) Existing Buildings.
80.13 Authority.
80.15 Electrical Board.
(A) Creation of the Electrical Board.
(B) Appointments.
(C) Terms.
(D) Compensation.
(E) Quorum.
(F) Duties.
(G) Appeals.
(H) Meetings and Records.
80.17 Records and Reports.
(A) Retention.
(B) Availability.
80.19 Permits and Approvals.
(A) Application.
(B) Content.
(C) Issuance of Permits.
(D) Annual Permits.
(E) Fees.
(F) Inspection and Approvals.
(G) Revocation of Permits.
(H) Applications and Extensions.
80.21 Plans Review.
(A) Authority.
(B) Responsibility of the Applicant.
(C) Responsibility of the Authority Having Jurisdiction.
80.23 Notice of Violations, Penalties.
(A) Violations.
(B) Penalties.
80.25 Connection to Electricity Supply.
(A) Authorization.
(B) Special Consideration.
(C) Notification.
(D) Other Territories.
(E) Disconnection.
80.27 Inspector’s Qualifications.
(A) Certificate.
(B) Experience.
(C) Recertification.
(D) Revocation and Suspension of Authority.
80.29 Liability for Damages.
80.31 Validity.
80.33 Repeal of Conflicting Acts.
80.35 Effective Date.
Informative Annex I Recommended Tightening Torque Tables from UL Standard 486A-B
Table I.1 Tightening Torque for Screws
Table I.2 Tightening Torque for Slotted Head Screws Smaller Than No. 10 Intended for Use with 8 AWG (8.4 mm2) or Smaller Conductors
Table I.3 Tightening Torque for Screws with Recessed Allen or Square Drives
Informative Annex J ADA Standards for Accessible Design
J.1 Protruding Objects.
J.2 Protrusion Limits.
J.3 Post-Mounted Objects.
J.4 Vertical Clearance.
J.5 Required Clear Width.
J.6 Forward Reach.
J.6.1 Unobstructed.
J.6.2 Obstructed High Reach.
J.7 Side Reach.
J.7.1 Unobstructed.
J.7.2 Obstructed High Reach.
Index
Important.pdf
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