2017 NEC articles

Chapter 1 — General

• Article 100 Article 100 Definitions
• Article 110 Article 110 Requirements for Electrical Installations

• Article 90 - Introduction

• Chapter 2 — Wiring and Protection

• Article 200 Article 200 Use and Identification of Grounded Conductors
• Article 210 Article 210 Branch Circuits
• Article 215 Article 215 Feeders
• Article 220 Article 220 Branch-Circuit, Feeder, and Service Load Calculations
• Article 225 Article 225 Outside Branch Circuits and Feeders
• Article 230 Article 230 Services
• Article 240 Article 240 Overcurrent Protection
• Article 250 Article 250 Grounding and Bonding
• Article 280 Article 280 Surge Arresters, Over 1000 Volts
• Article 285 Article 285 Surge-Protective Devices (SPDs), 1000 Volts or Less

• Chapter 3 — Wiring Methods and Materials

• Article 300 Article 300 General Requirements for Wiring Methods and Materials
• Article 310 Article 310 Conductors for General Wiring
• Article 312 Article 312 Cabinets, Cutout Boxes, and Meter Socket Enclosures
• Article 314 Article 314 Outlet, Device, Pull, and Junction Boxes; Conduit Bodies; Fittings; and Handhole Enclosures
• Article 320 Article 320 Armored Cable: Type AC
• Article 322 Article 322 Flat Cable Assemblies: Type FC
• Article 324 Article 324 Flat Conductor Cable: Type FCC
• Article 326 Article 326 Integrated Gas Spacer Cable: Type IGS
• Article 328 Article 328 Medium Voltage Cable: Type MV
• Article 330 Article 330 Metal-Clad Cable: Type MC
• Article 332 Article 332 Mineral-Insulated, Metal-Sheathed Cable: Type MI
• Article 334 Article 334 Nonmetallic-Sheathed Cable: Types NM, NMC, and NMS
• Article 336 Article 336 Power and Control Tray Cable: Type TC
• Article 338 Article 338 Service-Entrance Cable: Types SE and USE
• Article 340 Article 340 Underground Feeder and Branch-Circuit Cable: Type UF
• Article 342 Article 342 Intermediate Metal Conduit: Type IMC
• Article 344 Article 344 Rigid Metal Conduit: Type RMC
• Article 348 Article 348 Flexible Metal Conduit: Type FMC
• Article 350 Article 350 Liquidtight Flexible Metal Conduit: Type LFMC
• Article 352 Article 352 Rigid Polyvinyl Chloride Conduit: Type PVC
• Article 353 Article 353 High Density Polyethylene Conduit: Type HDPE Conduit
• Article 354 Article 354 Nonmetallic Underground Conduit with Conductors: Type NUCC
• Article 355 Article 355 Reinforced Thermosetting Resin Conduit: Type RTRC
• Article 356 Article 356 Liquidtight Flexible Nonmetallic Conduit: Type LFNC
• Article 358 Article 358 Electrical Metallic Tubing: Type EMT
• Article 360 Article 360 Flexible Metallic Tubing: Type FMT
• Article 362 Article 362 Electrical Nonmetallic Tubing: Type ENT
• Article 366 Article 366 Auxiliary Gutters
• Article 368 Article 368 Busways
• Article 370 Article 370 Cablebus
• Article 372 Article 372 Cellular Concrete Floor Raceways
• Article 374 Article 374 Cellular Metal Floor Raceways
• Article 376 Article 376 Metal Wireways
• Article 378 Article 378 Nonmetallic Wireways
• Article 380 Article 380 Multioutlet Assembly
• Article 382 Article 382 Nonmetallic Extensions
• Article 384 Article 384 Strut-Type Channel Raceway
• Article 386 Article 386 Surface Metal Raceways
• Article 388 Article 388 Surface Nonmetallic Raceways
• Article 390 Article 390 Underfloor Raceways
• Article 392 Article 392 Cable Trays
• Article 393 Article 393 Low-Voltage Suspended Ceiling Power Distribution Systems
• Article 394 Article 394 Concealed Knob-and-Tube Wiring
• Article 396 Article 396 Messenger-Supported Wiring
• Article 398 Article 398 Open Wiring on Insulators
• Article 399 Article 399 Outdoor Overhead Conductors over 1000 Volts

• Chapter 4 - Equipment for General Use

• Article 400 Flexible Cords and Flexible Cables
• Article 402 Fixture Wires
• Article 404 Switches
• Article 406 Receptacles, Cord Connectors, and Attachment Plugs (Caps)
• Article 408 Switchboards, Switchgear, and Panelboards
• Article 409 Industrial Control Panels
• Article 410 Luminaires, Lampholders, and Lamps
• Article 411 Low-Voltage Lighting
• Article 422 Appliances
• Article 424 Fixed Electric Space-Heating Equipment
• Article 425 Fixed Resistance and Electrode Industrial Process Heating Equipment
• Article 426 Fixed Outdoor Electric Deicing and Snow-Melting Equipment
• Article 427 Fixed Electric Heating Equipment for Pipelines and Vessels
• Article 430 Motors, Motor Circuits, and Controllers
• Article 440 Air-Conditioning and Refrigerating Equipment
• Article 445 Generators
• Article 450 Transformers and Transformer Vaults (Including Secondary Ties)
• Article 455 Phase Converters
• Article 460 Capacitors
• Article 470 Resistors and Reactors
• Article 480 Storage Batteries
• Article 490 Equipment Over 1000 Volts, Nominal

• Chapter 5 - Special Occupancies
• Article 500 Hazardous (Classified) Locations, Classes I, II, and III, Divisions 1 and 2
• Article 501 Class I Locations
• Article 502 Class II Locations
• Article 503 Class III Locations
• Article 504 Intrinsically Safe Systems
• Article 505 Zone 0, 1, and 2 Locations
• Article 506 Zone 20, 21, and 22 Locations for Combustible Dusts or Ignitible Fibers/Flyings
• Article 510 Hazardous (Classified) Locations — Specific
• Article 511 Commercial Garages, Repair and Storage
• Article 513 Aircraft Hangars
• Article 514 Motor Fuel Dispensing Facilities
• Article 515 Bulk Storage Plants
• Article 516 Spray Application, Dipping, Coating, and Printing Processes Using Flammable or Combustible Materials
• Article 517 Health Care Facilities
• Article 518 Assembly Occupancies
• Article 520 Theaters, Audience Areas of Motion Picture and Television Studios, Performance Areas, and Similar Locations
• Article 522 Control Systems for Permanent Amusement Attractions
• Article 525 Carnivals, Circuses, Fairs, and Similar Events
• Article 530 Motion Picture and Television Studios and Similar Locations
• Article 540 Motion Picture Projection Rooms
• Article 545 Manufactured Buildings
• Article 547 Agricultural Buildings
• Article 550 Mobile Homes, Manufactured Homes, and Mobile Home Parks
• Article 551 Recreational Vehicles and Recreational Vehicle Parks
• Article 552 Park Trailers
• Article 553 Floating Buildings
• Article 555 Marinas, Boatyards, and Commercial and Noncommercial Docking Facilities
• Article 590 Temporary Installations

• Chapter 6 - Special Equipment
• Article 600 Electric Signs and Outline Lighting
• Article 604 Manufactured Wiring Systems
• Article 605 Office Furnishings
• Article 610 Cranes and Hoists
• Article 620 Elevators, Dumbwaiters, Escalators, Moving Walks, Platform Lifts, and Stairway Chairlifts
• Article 625 Electric Vehicle Charging System
• Article 626 Electrified Truck Parking Spaces
• Article 630 Electric Welders
• Article 640 Audio Signal Processing, Amplification, and Reproduction Equipment
• Article 645 Information Technology Equipment
• Article 646 Modular Data Centers
• Article 647 Sensitive Electronic Equipment
• Article 650 Pipe Organs
• Article 660 X-Ray Equipment
• Article 665 Induction and Dielectric Heating Equipment
• Article 668 Electrolytic Cells
• Article 669 Electroplating
• Article 670 Industrial Machinery
• Article 675 Electrically Driven or Controlled Irrigation Machines
• Article 680 Swimming Pools, Fountains, and Similar Installations
• Article 682 Natural and Artificially Made Bodies of Water
• Article 685 Integrated Electrical Systems
• Article 690 Solar Photovoltaic (PV) Systems
• Article 691 Large-Scale Photovoltaic (PV) Electric Power Production Facility
• Article 692 Fuel Cell Systems
• Article 694 Wind Electric Systems
• Article 695 Fire Pumps

• Chapter 7 - Special Conditions

• Article 700 Emergency Systems
• Article 701 Legally Required Standby Systems
• Article 702 Optional Standby Systems
• Article 705 Interconnected Electric Power Production Sources
• Article 706 Energy Storage Systems
• Article 708 Critical Operations Power Systems (COPS)
• Article 710 Stand-Alone Systems
• Article 712 Direct Current Microgrids
• Article 720 Circuits and Equipment Operating at Less Than 50 Volts
• Article 725 Class 1, Class 2, and Class 3 Remote-Control, Signaling, and Power-Limited Circuits
• Article 727 Instrumentation Tray Cable: Type ITC
• Article 728 Fire-Resistive Cable Systems
• Article 750 Energy Management Systems
• Article 760 Fire Alarm Systems
• Article 770 Optical Fiber Cables

• Chapter 8 - Communications Systems

• Article 800 Communications Circuits
• Article 810 Radio and Television Equipment
• Article 820 Community Antenna Television and Radio Distribution Systems
• Article 830 Network-Powered Broadband Communications Systems
• Article 840 Premises-Powered Broadband Communications Systems

Chapter 9 - Tables

• Article 362 — Electrical Nonmetallic Tubing (ENT)
• Article 348 — Flexible Metal Conduit (FMC)
• Article 342 — Intermediate Metal Conduit (IMC)
• Article 356 — Liquidtight Flexible Nonmetallic Conduit (LFNC-A*)
• Article 356 — Liquidtight Flexible Nonmetallic Conduit (LFNC-B*)
• Article 356 — Liquidtight Flexible Nonmetallic Conduit (LFNC-C*)
• Article 350 — Liquidtight Flexible Metal Conduit (LFMC)
• Article 344 — Rigid Metal Conduit (RMC)
• Article 352 — Rigid PVC Conduit (PVC), Schedule 80
• Articles 352 and 353 — Rigid PVC Conduit (PVC), Schedule 40, and HDPE Conduit (HDPE)
• Article 352 — Type A, Rigid PVC Conduit (PVC)
• Article 352 — Type EB, Rigid PVC Conduit (PVC)
• Dimensions of Insulated Conductors and Fixture Wires
• Compact Copper and Aluminum Building Wire Nominal Dimensions* and Areas
• Conductor Properties
• Alternating-Current Resistance and Reactance for 600-Volt Cables, 3-Phase, 60 Hz, 75°C (167°F) — Three Single Conductors in Conduit
• Conductor Stranding
• Class 2 and Class 3 Alternating-Current Power Source Limitations
• PLFA Alternating-Current Power Source Limitations

Article 100 Definitions

Part I. General

• Accessible (as applied to equipment).
• Accessible (as applied to wiring methods).
• Accessible, Readily (Readily Accessible).
• Adjustable Speed Drive.
• Adjustable Speed Drive System.
• Ampacity.
• Appliance.
• Approved.
• Arc-Fault Circuit Interrupter (AFCI).
• Askarel.
• Associated Apparatus [as applied to Hazardous (Classified) Locations].
• Associated Nonincendive Field Wiring Apparatus [as applied to Hazardous (Classified) Locations].
• Attachment Plug (Plug Cap) (Plug).
• Authority Having Jurisdiction (AHJ).
• Automatic.
• Bathroom.
• Battery System.
• Bonded (Bonding).
• Bonding Conductor or Jumper.
• Bonding Jumper, Equipment.
• Bonding Jumper, Main.
• Bonding Jumper, System.
• Branch Circuit.
• Branch Circuit, Appliance.
• Branch Circuit, General-Purpose.
• Branch Circuit, Individual.
• Branch Circuit, Multiwire.
• Building.
• Cabinet.
• Cable Routing Assembly.
• Charge Controller.
• Circuit Breaker.
• Clothes Closet.
• Coaxial Cable.
• Combustible Dust [as applied to Hazardous (Classified) Locations].
• Combustible Gas Detection System [as applied to Hazardous (Classified) Locations].
• Communications Equipment.
• Communications Raceway.
• Composite Optical Fiber Cable.
• Concealed.
• Conductive Optical Fiber Cable.
• Conductor, Bare.
• Conductor, Covered.
• Conductor, Insulated.
• Conduit Body.
• Connector, Pressure (Solderless).
• Continuous Load.
• Control Circuit.
• Control Drawing [as applied to Hazardous (Classified) Locations].
• Controller.
• Cooking Unit, Counter-Mounted.
• Coordination, Selective (Selective Coordination).
• Copper-Clad Aluminum Conductors.
• Cord Connector [as applied to Hazardous (Classified) Locations].
• Cutout Box.
• Dead Front.
• Demand Factor.
• Device.
• Disconnecting Means.
• Dust-Ignitionproof [as applied to Hazardous (Classified) Locations].
• Dusttight.
• Duty, Continuous.
• Duty, Intermittent.
• Duty, Periodic.
• Duty, Short-Time.
• Duty, Varying.
• Dwelling, One-Family.
• Dwelling, Two-Family.
• Dwelling, Multifamily.
• Dwelling Unit.
• Effective Ground-Fault Current Path.
• Electric Power Production and Distribution Network.
• Electric Sign.
• Electric-Discharge Lighting.
• Electrical Circuit Protective System
• Electronically Actuated Fuse.
• Enclosed.
• Enclosure.
• Energized.
• Equipment.
• Explosionproof Equipment.
• Exposed (as applied to live parts).
• Exposed (as applied to wiring methods).
• Externally Operable.
• Feeder.
• Festoon Lighting.
• Field Evaluation Body (FEB).
• Field Labeled (as applied to evaluated products).
• Fitting.
• Garage.
• Ground.
• Ground Fault.
• Grounded (Grounding).
• Grounded, Solidly.
• Grounded Conductor.
• Ground-Fault Circuit Interrupter (GFCI).
• Ground-Fault Current Path.
• Ground-Fault Protection of Equipment.
• Grounding Conductor, Equipment (EGC).
• Grounding Electrode.
• Grounding Electrode Conductor.
• Guarded.
• Guest Room.
• Guest Suite.
• Handhole Enclosure.
• Hermetic Refrigerant Motor-Compressor.
• Hermetically Sealed [as applied to Hazardous (Classified) Locations].
• Hoistway.
• Hybrid System.
• Identified (as applied to equipment).
• In Sight From (Within Sight From, Within Sight).
• Industrial Control Panel.
• Information Technology Equipment (ITE).
• Innerduct.
• Utility-Interactive Inverter.
• Interactive System.
• Interrupting Rating.
• Intersystem Bonding Termination.
• Intrinsically Safe Apparatus.
• Intrinsically Safe System [as applied to Hazardous (Classified) Locations].
• Isolated (as applied to location).
• Kitchen.
• Labeled.
• Lighting Outlet.
• Lighting Track (Track Lighting).
• Listed.
• Live Parts.
• Location, Damp.
• Location, Dry.
• Location, Wet.
• Luminaire.
• Mobile Equipment.
• Motor Control Center.
• Multioutlet Assembly.
• Neutral Conductor.
• Neutral Point.
• Nonautomatic.
• Nonconductive Optical Fiber Cable.
• Nonincendive Circuit [as applied to Hazardous (Classified) Locations].
• Nonincendive Component [as applied to Hazardous (Classified) Locations].
• Nonincendive Equipment [as applied to Hazardous (Classified) Locations].
• Nonincendive Field Wiring [as applied to Hazardous (Classified) Locations].
• Nonincendive Field Wiring Apparatus [as applied to Hazardous (Classified) Locations].
• Nonlinear Load.
• Oil Immersion [as applied to Hazardous (Classified) Locations].
• Optical Fiber Cable.
• Outlet.
• Outline Lighting.
• Overcurrent.
• Overcurrent Protective Device, Branch-Circuit.
• Overcurrent Protective Device, Supplementary.
• Overload.
• Panelboard.
• Photovoltaic (PV) System.
• Plenum.
• Portable Equipment.
• Power Outlet.
• Premises Wiring (System).
• Pressurized [as applied to Hazardous (Classified) Locations].
• Process Seal [as applied to Hazardous (Classified) Locations].
• Purged and Pressurized [as applied to Hazardous (Classified) Locations].
• Qualified Person.
• Raceway.
• Rainproof.
• Raintight.
• Receptacle.
• Receptacle Outlet.
• Remote-Control Circuit.
• Retrofit Kit.
• Sealable Equipment.
• Separately Derived System.
• Service.
• Service Cable.
• Service Conductors.
• Service Conductors, Overhead.
• Service Conductors, Underground.
• Service Drop.
• Service-Entrance Conductors, Overhead System.
• Service-Entrance Conductors, Underground System.
• Service Equipment.
• Service Lateral.
• Service Point.
• Short-Circuit Current Rating.
• Show Window.
• Signaling Circuit.
• Simple Apparatus [as applied to Hazardous (Classified) Locations].
• Special Permission.
• Stand-Alone System.
• Structure.
• Surge Arrester.
• Surge-Protective Device (SPD).
• Switch, Bypass Isolation.
• Switch, General-Use.
• Switch, General-Use Snap.
• Switch, Isolating.
• Switch, Motor-Circuit.
• Switch, Transfer.
• Switchboard.
• Switchgear.
• Thermal Protector (as applied to motors).
• Thermally Protected (as applied to motors).
• Unclassified Locations [as applied to Hazardous (Classified) Locations].
• Ungrounded.
• Uninterruptible Power Supply.
• Utilization Equipment.
• Ventilated.
• Volatile Flammable Liquid.
• Voltage (of a circuit).
• Voltage, Nominal.
• Voltage to Ground.
• Watertight.
• Weatherproof.
• Part II. Over 1000 Volts, Nominal

• Electronically Actuated Fuse.
• Fuse.
• Multiple Fuse.
• Substation.
• Switching Device.

Chapter 1 — General

Article 110 - Requirements for Electrical Installations

• Part I. General
• 110.1 Scope.
• This article covers general requirements for the examination and approval, installation and use, access to and spaces about electrical conductors and equipment; enclosures intended for personnel entry; and tunnel installations.
• Informational Note: See Informative Annex J for information regarding ADA accessibility design.

• 110.2 Approval.
• 110.3 Examination, Identification, Installation, and Use, and Listing (Product Certification) of Equipment.
• 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.
• 110.13 Mounting and Cooling of Equipment.
• 110.14 Electrical Connections.
• 110.15 High-Leg Marking.
• 110.16 Arc-Flash Hazard Warning.
• 110.18 Arcing Parts.
• 110.19 Light and Power from Railway Conductors.
• 110.21 Marking.
• 110.22 Identification of Disconnecting Means.
• 110.23 Current Transformers.
• 110.24 Available Fault Current.
• 110.25 Lockable Disconnecting Means.
• Part II. 1000 Volts, Nominal, or Less

• 110.26 Spaces About Electrical Equipment.
• 110.27 Guarding of Live Parts.
• 110.28 Enclosure Types.

• Part III. Over 1000 Volts, Nominal
• 110.30 General.
• 110.31 Enclosure for Electrical Installations.
• 110.32 Work Space About Equipment.
• 110.33 Entrance to Enclosures and Access to Working Space.
• 110.34 Work Space and Guarding.
• 110.36 Circuit Conductors.
• 110.40 Temperature Limitations at Terminations.
• 110.41 Inspections and Tests.
• Part IV. Tunnel Installations over 1000 Volts, Nominal

• 110.51 General.
• 110.52 Overcurrent Protection.
• 110.53 Conductors.
• 110.54 Bonding and 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.
• 110.75 Access to Manholes.
• 110.76 Access to Vaults and Tunnels.
• 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.
• This article provides requirements for the following:(1)Identification of terminals(2)Grounded conductors in premises wiring systems(3)Identification of grounded conductors
• Informational Note: See Article 100 for definitions of Grounded Conductor, Equipment Grounding Conductor, and Grounding Electrode Conductor.
• 200.2 General.
• 200.3 Connection to Grounded System.
• 200.4 Neutral Conductors.
• 200.6 Means of Identifying Grounded Conductors.
• 200.7 Use of Insulation of a White or Gray Color or with Three Continuous White or Gray Stripes.
• 200.9 Means of Identification of Terminals.
• 200.10 Identification of Terminals.
• 200.11 Polarity of Connections.

Chapter 2 — Wiring and Protection

Article 210 - Branch Circuits

Article 210 Branch Circuits

• Part I. General Provisions
• 210.1 Scope.
• This article provides the general requirements for branch circuits.
• 210.3 Other Articles for Specific-Purpose Branch Circuits.
• 210.4 Multiwire Branch Circuits.
• 210.5 Identification for Branch Circuits.
• 210.6 Branch-Circuit Voltage Limitations.
• 210.7 Multiple Branch Circuits.
• 210.8 Ground-Fault Circuit-Interrupter Protection for Personnel.
• 210.9 Circuits Derived from Autotransformers.
• 210.10 Ungrounded Conductors Tapped from Grounded Systems.
• 210.11 Branch Circuits Required.
• 210.12 Arc-Fault Circuit-Interrupter Protection.
• 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.
• 210.20 Overcurrent Protection.
• 210.21 Outlet Devices.
• 210.22 Permissible Loads, Individual Branch Circuits.
• 210.23 Permissible Loads, Multiple-Outlet Branch Circuits.
• 210.24 Branch-Circuit Requirements — Summary.
• 210.25 Branch Circuits in Buildings with More Than One Occupancy.

• Part III. Required Outlets
• 210.50 General.
• 210.52 Dwelling Unit Receptacle Outlets.
• 210.60 Guest Rooms, Guest Suites, Dormitories, and Similar Occupancies.
• 210.62 Show Windows.
• 210.63 Heating, Air-Conditioning, and Refrigeration Equipment Outlet.
• 210.64 Electrical Service Areas.
• 210.70 Lighting Outlets Required.
• 210.71 Meeting Rooms.

• Articles 215 - Feeders

• 215.1 Scope.
• This article covers the installation requirements, overcurrent protection requirements, minimum size, and ampacity of conductors for feeders.Exception: Feeders for electrolytic cells as covered in 668.3(C)(1) and (C)(4).
• 215.2 Minmum Rating and Size
• 215.3 Overcurrent Protection
• 215.4 Feeders with Common Neutral Conductor
• 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

Chapter 2 — Wiring and Protection

Article 220 - Branch-Circuit, Feeder, and Service Load Calculations

Part I. General

• 220.1 Scope.
• This article provides requirements for calculating branch-circuit, feeder, and service loads. Part I provides general requirements for calculation methods. Part II provides calculation methods for branch-circuit loads. Parts III and IV provide calculation methods for feeder and service loads. Part V provides calculation methods for farm loads.
• Informational Note No. 1: See examples in Informative Annex D.Informational Note No. 2: See Figure 220.1 for information on the organization of Article 220.
• 220.3 Application of Other Articles for Specific-Purpose Calculations.
• 220.5 Calculations.

• Part II. Branch-Circuit Load Calculations
• 220.10 General.
• 220.12 Lighting Load for Specified Occupancies.
• 220.14 Other Loads — All Occupancies.
• 220.16 Loads for Additions to Existing Installations.
• 220.18 Maximum Loads.

• Part III. Feeder and Service Load Calculations
• 220.40 General.
• 220.42 General Lighting.
• 220.43 Show-Window and Track Lighting.
• 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.
• 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.

• Part IV. Optional Feeder and Service Load Calculations
• 220.80 General.
• 220.82 Dwelling Unit.
• 220.83 Existing Dwelling Unit.
• 220.84 Multifamily Dwelling.
• 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.
• 220.103 Farm Loads — Total.

Chapter 2 — Wiring and Protection

Article 225 - Outside Branch Circuits and Feeders

• 225.1 Scope.
• This article covers requirements for outside branch circuits and feeders run on or between buildings, structures, or poles on the premises; and electrical equipment and wiring for the supply of utilization equipment that is located on or attached to the outside of buildings, structures, or poles.

Informational Note: For additional information on wiring over 1000 volts, see ANSI/IEEE C2-2012, National Electrical Safety Code.

Article 225 provides requirements unique to the installation of feeders and branch circuits outside (overhead and underground) of buildings and structures. These circuits may be supplying specific items of electrical equipment, or they may be the power supply to another building or structure. Examples of outside feeders and branch circuits include the following:

• Conductors supplying the buildings of a multibuilding industrial complex or institutional campus
• Outdoor supply conductors from an emergency system, standby system, an alternative energy system, or on-site power generation
• Supply conductors between a dwelling unit and detached garage or other structure
• These requirements are in addition to the general requirements for branch circuits and feeders in Articles 210 and 215.

• 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.
• 225.7 Lighting Equipment Installed Outdoors.
• 225.8 Calculation of Loads 1000 Volts, Nominal, or Less.
• 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.
• 225.15 Supports over Buildings.
• 225.16 Attachment to Buildings.
• 225.17 Masts as Supports.
• 225.18 Clearance for Overhead Conductors and Cables.
• 225.19 Clearances from Buildings for Conductors of Not over 1000 Volts, Nominal.
• 225.20 Mechanical Protection of ConductorsProtection 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.
• 225.31 Disconnecting Means.
• 225.32 Location.
• 225.33 Maximum Number of Disconnects.
• 225.34 Grouping of Disconnects.
• 225.35 Access to Occupants.
• 225.36 Type of Disconnecting Means.
• 225.37 Identification.
• 225.38 Disconnect Construction.
• 225.39 Rating of Disconnect.
• 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.
• 225.56 Inspections and Tests.
• 225.60 Clearances over Roadways, Walkways, Rail, Water, and Open Land.
• 225.61 Clearances over Buildings and Other Structures.

• Article 230 - Services

230.1 Scope.

This article covers service conductors and equipment for control and protection of services and their installation requirements.

• Part I. General
• 230.2 Number of Services.
• 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.
• 230.10 Vegetation as Support.

• Part II. Overhead Service Conductors
• 230.22 Insulation or Covering.
• 230.23 Size and Rating.
• 230.24 Clearances.
• 230.26 Point of Attachment.
• 230.27 Means of Attachment.
• 230.28 Service Masts as Supports.
• 230.29 Supports over Buildings.

• Part III. Underground Service Conductors
• 230.30 Installation.
• 230.31 Size and Rating.
• 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.
• 230.43 Wiring Methods for 1000 Volts, Nominal, or Less.
• 230.44 Cable Trays.
• 230.46 Spliced Conductors.
• 230.50 Protection Against Physical Damage.
• 230.51 Mounting Supports.
• 230.52 Individual Conductors Entering Buildings or Other Structures.
• 230.53 Raceways to Drain.
• 230.54 Overhead Service Locations.
• 230.56 Service Conductor with the Higher Voltage to Ground.

• Part V. Service Equipment — General
• 230.62 Service Equipment — Enclosed or Guarded.
• 230.66 Marking.

• Part VI. Service Equipment — Disconnecting Means
• 230.70 General.
• 230.71 Maximum Number of Disconnects.
• 230.72 Grouping of Disconnects.
• 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.
• 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.
• 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.

• Part VIII. Services Exceeding 1000 Volts, Nominal
• 230.200 General.
• 230.202 Service-Entrance Conductors.
• 230.204 Isolating Switches.
• 230.205 Disconnecting Means.
• 230.206 Overcurrent Devices as Disconnecting Means.
• 230.208 Protection Requirements.
• 230.209 Surge Arresters (Lightning 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.
• Parts I through VII of this article provide the general requirements for overcurrent protection and overcurrent protective devices not more than 1000 volts, nominal. Part VIII covers overcurrent protection for those portions of supervised industrial installations operating at voltages of not more than 1000 volts, nominal. Part IX covers overcurrent protection over 1000 volts, nominal.

Informational Note: Overcurrent protection for conductors and equipment is provided to open the circuit if the current reaches a value that will cause an excessive or dangerous temperature in conductors or conductor insulation. See also 110.9 for requirements for interrupting ratings and 110.10 for requirements for protection against fault currents.

• 240.2 Definitions.
• 240.3 Other Articles.
• 240.4 Protection of Conductors.
• 240.5 Protection of Flexible Cords, Flexible Cables, and Fixture Wires.
• 240.6 Standard Ampere Ratings.
• 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.

• Part II. Location
• 240.21 Location in Circuit.
• 240.22 Grounded Conductor.
• 240.23 Change in Size of Grounded Conductor.
• 240.24 Location in or on Premises.

• Part III. Enclosures
• 240.30 General.
• 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.

• Part V. Plug Fuses, Fuseholders, and Adapters
• 240.50 General.
• 240.51 Edison-Base Fuses.
• 240.52 Edison-Base Fuseholders.
• 240.53 Type S Fuses.
• 240.54 Type S Fuses, Adapters, and Fuseholders.

• Part VI. Cartridge Fuses and Fuseholders
• 240.60 General.
• 240.61 Classification.
• 240.67 Arc Energy Reduction.

• Part VII. Circuit Breakers
• 240.80 Method of Operation.
• 240.81 Indicating.
• 240.82 Nontamperable.
• 240.83 Marking.
• 240.85 Applications.
• 240.86 Series Ratings.
• 240.87 Arc Energy Reduction.

• Part VIII. Supervised Industrial Installations
• 240.90 General.
• 240.91 Protection of Conductors.
• 240.92 Location in Circuit.

• Part IX. Overcurrent Protection over 1000 Volts, Nominal
• 240.100 Feeders and Branch Circuits.
• 240.101 Additional Requirements for Feeders.

Chapter 2 — Wiring and Protection

Article 250 - Grounding and Bonding

• Part I. General
• 250.1 Scope.

• This article covers general requirements for grounding and bonding of electrical installations, and the specific requirements in (1) through (6).
• (1)
• Systems, circuits, and equipment required, permitted, or not permitted to be grounded

• (2)
• Circuit conductor to be grounded on grounded systems

• (3)
• Location of grounding connections

• (4)
• Types and sizes of grounding and bonding conductors and electrodes

• (5)
• Methods of grounding and bonding

• (6)
• Conditions under which guards, isolation, or insulation may be substituted for grounding

• Informational Note: See Figure 250.1 for information on the organization of Article 250 covering grounding and bonding requirements.
• 250.2 Definition.
• 250.3 Application of Other Articles.
• 250.4 General Requirements for Grounding and Bonding.
• 250.6 Objectionable Current.
• 250.8 Connection of Grounding and Bonding Equipment.
• 250.10 Protection of Ground Clamps and Fittings.
• 250.12 Clean Surfaces.

• Part II. System Grounding
• 250.20 Alternating-Current Systems to Be Grounded.
• 250.21 Alternating-Current Systems of 50 Volts to 1000 Volts Not Required to Be Grounded.
• 250.22 Circuits Not to Be Grounded.
• 250.24 Grounding Service-Supplied Alternating-Current Systems.
• 250.26 Conductor to Be Grounded — Alternating-Current Systems.
• 250.28 Main Bonding Jumper and System Bonding Jumper.
• 250.30 Grounding Separately Derived Alternating-Current Systems.
• 250.32 Buildings or Structures Supplied by a Feeder(s) or Branch Circuit(s).
• 250.34 Portable and Vehicle-Mounted Generators.
• 250.35 Permanently Installed Generators.
• 250.36 High-Impedance Grounded Neutral Systems.

• Part III. Grounding Electrode System and Grounding Electrode Conductor
• 250.50 Grounding Electrode System.
• 250.52 Grounding Electrodes.
• 250.53 Grounding Electrode System Installation.
• 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.
• 250.66 Size of Alternating-Current Grounding Electrode Conductor.
• 250.68 Grounding Electrode Conductor and Bonding Jumper Connection to Grounding Electrodes.
• 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.
• 250.86 Other Conductor Enclosures and Raceways.

• Part V. Bonding
• 250.90 General.
• 250.92 Services.
• 250.94 Bonding for OtherCommunication Systems.
• 250.96 Bonding Other Enclosures.
• 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.
• 250.104 Bonding of Piping Systems and Exposed Structural Metal.
• 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.
• 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.
• 250.120 Equipment Grounding Conductor Installation.
• 250.121 Use of Equipment Grounding Conductors.
• 250.122 Size of Equipment Grounding Conductors.
• 250.124 Equipment Grounding Conductor Continuity.
• 250.126 Identification of Wiring Device Terminals.

• Part VII. Methods of Equipment Grounding
• 250.130 Equipment Grounding Conductor Connections.
• 250.132 Short Sections of Raceway.
• 250.134 Equipment Fastened in Place or Connected by Permanent Wiring Methods (Fixed) — Grounding.
• 250.136 Equipment Considered Grounded.
• 250.138 Cord-and-Plug-Connected Equipment.
• 250.140 Frames of Ranges and Clothes Dryers.
• 250.142 Use of Grounded Circuit Conductor for Grounding Equipment.
• 250.144 Multiple Circuit Connections.
• 250.146 Connecting Receptacle Grounding Terminal to Box.
• 250.148 Continuity and Attachment of Equipment Grounding Conductors to Boxes.

• Part VIII. Direct-Current Systems
• 250.160 General.
• 250.162 Direct-Current Circuits and Systems to Be Grounded.
• 250.164 Point of Connection for Direct-Current Systems.
• 250.166 Size of the Direct-Current Grounding Electrode Conductor.
• 250.167 Direct-Current Ground-Fault Detection.
• 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.
• 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.
• 250.186 Ground-Fault Circuit Conductor Brought to Service EquipmentGrounding Service-Supplied Alternating-Current Systems.
• 250.187 Impedance Grounded Neutral Systems.
• 250.188 Grounding of Systems Supplying Portable or Mobile Equipment.
• 250.190 Grounding of Equipment.
• 250.191 Grounding System at Alternating-Current Substations.
• 250.194 Grounding and Bonding of Fences and Other Metal Structures.

• Article 280 - Surge Arresters, Over 1000 Volts

• Part I. General
• 280.1 Scope.
• This article covers general requirements, installation requirements, and connection requirements for surge arresters installed on premises wiring systems over 1000 volts.

• 280.3 Number Required.
• 280.4 Surge Arrester Selection.
• 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.
• 280.25 Grounding Electrode Conductor Connections and Enclosures.

• Article 285 - Surge-Protective Devices (SPDs), 1000 Volts or Less

• Part I. General
• 285.1 Scope.

This article covers general requirements, installation requirements, and connection requirements for surge-protective devices (SPDs) permanently installed on premises wiring systems of 1000 volts or less.

Informational Note: Surge arresters 1000 volts or less are also known as Type 1 SPDs.

The delineation between SPDs covered by Article 280 and those covered by Article 285 is the voltage rating of the supply system. The designations of SPDs are varied, depending on their location in the premises wiring system. For instance, a Type 1 SPD is permitted to be connected on the supply side of the service or building disconnecting means. Type 2 and Type 3 SPDs must be installed on the load side of overcurrent protective devices and are the devices formerly referred to by this article as TVSSs.

• 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.
• 285.24 Type 2 SPDs.
• 285.25 Type 3 SPDs.
• 285.26 Conductor Size.
• 285.27 Connection Between Conductors.
• 285.28 Grounding Electrode Conductor Connections and Enclosures.

• Article 300 - General Requirements for Wiring Methods and Materials

Part I. General Requirements

• 300.1 Scope.
• 300.2 Limitations.
• 300.3 Conductors.
• 300.4 Protection Against Physical Damage.
• 300.5 Underground Installations.
• 300.6 Protection Against Corrosion and Deterioration.
• 300.7 Raceways Exposed to Different Temperatures.
• 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.
• 300.12 Mechanical Continuity — Raceways and Cables.
• 300.13 Mechanical and Electrical Continuity — Conductors.
• 300.14 Length of Free Conductors at Outlets, Junctions, and Switch Points.
• 300.15 Boxes, Conduit Bodies, or Fittings — Where Required.
• 300.16 Raceway or Cable to Open or Concealed Wiring.
• 300.17 Number and Size of Conductors in Raceway.
• 300.18 Raceway Installations.
• 300.19 Supporting Conductors in Vertical Raceways.
• 300.20 Induced Currents in Ferrous Metal Enclosures or Ferrous Metal Raceways.
• 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 Environmental Air (Plenums).
• 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.

Chapter 3 — Wiring Methods and Materials

Article 310 - Conductors for General Wiring

• Part I. General
• 310.1 Scope.
• 310.2 Definitions.
• Part II. Installation

• 310.10 Uses Permitted.
• 310.15 Ampacities for Conductors Rated 0–2000 Volts.
• 310.60 Conductors Rated 2001 to 35,000 Volts.
• Part III. Construction Specifications

• 310.104 Conductor Constructions and Applications.
• 310.106 Conductors.
• 310.110 Conductor Identification.
• 310.120 Marking.

• 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.
• 312.6 Deflection of Conductors.
• 312.7 Space in Enclosures.
• 312.8 Switch and Overcurrent Device Enclosures with Splices, Taps, and Feed-Through Conductors.
• 312.9 Side or Back Wiring Spaces or Gutters.
• Part II. Construction Specifications

• 312.10 Material.
• 312.11 Spacing.

• 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.
• 314.17 Conductors Entering Boxes, Conduit Bodies, or Fittings.
• 314.19 Boxes Enclosing Flush Devices.
• 314.20 In Wall or CeilingFlush-Mounted Installations.
• 314.21 Repairing Noncombustible Surfaces.
• 314.22 Surface Extensions.
• 314.23 Supports.
• 314.24 Depth of Boxes.
• 314.25 Covers and Canopies.
• 314.27 Outlet Boxes.
• 314.28 Pull and Junction Boxes and Conduit Bodies.
• 314.29 Boxes, Conduit Bodies, and Handhole Enclosures to Be Accessible.
• 314.30 Handhole Enclosures.
• Part III. Construction Specifications

• 314.40 Metal Boxes, Conduit Bodies, and Fittings.
• 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.
• 314.71 Size of Pull and Junction Boxes, Conduit Bodies, and Handhole Enclosures.
• 314.72 Construction and Installation Requirements.

• 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.
• 320.24 Bending Radius.
• 320.30 Securing and Supporting.
• 320.40 Boxes and Fittings.
• 320.80 Ampacity.
• Part III. Construction Specifications

• 320.100 Construction.
• 320.104 Conductors.
• 320.108 Equipment Grounding Conductor.
• 320.120 Marking.

• Article 322 - 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.
• 322.56 Splices and Taps.
• Part III. Construction Specifications

• 322.100 Construction.
• 322.104 Conductors.
• 322.112 Insulation.
• 322.120 Marking.

• 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.
• 324.12 Uses Not Permitted.
• 324.18 Crossings.
• 324.30 Securing and Supporting.
• 324.40 Boxes and Fittings.
• 324.41 Floor Coverings.
• 324.42 Devices.
• 324.56 Splices and Taps.
• 324.60 Grounding.
• Part III. Construction Specifications

• 324.100 Construction.
• 324.101 Corrosion Resistance.
• 324.112 Insulation.
• 324.120 Markings.

• Article 326 - Integrated Gas Spacer Cable: Type IGS

Article 326, Integrated Gas Spacer Cable (IGS), is a specialty cable that has been in the Code since 1984. These cables are insulated with dry kraft paper and pressurized sulfur hexafluoride. They cannot be used as inside wiring or be exposed in contact with buildings. In the NEC , IGS is limited to 600V.

• 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.

Chapter 3 — Wiring Methods and Materials

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.

Chapter 3 — Wiring Methods and Materials

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.
• 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.
• 330.30 Securing and Supporting.
• 330.31 Single Conductors.
• 330.80 Ampacity.
• Part III. Construction Specifications

• 330.104 Conductors.
• 330.108 Equipment Grounding Conductor.
• 330.112 Insulation.
• 330.116 Sheath.

Chapter 3 — Wiring Methods and Materials

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.
• 332.30 Securing and Supporting.
• 332.31 Single Conductors.
• 332.40 Boxes and Fittings.
• 332.80 Ampacity.
• Part III. Construction Specifications

• 332.104 Conductors.
• 332.108 Equipment Grounding Conductor.
• 332.112 Insulation.
• 332.116 Sheath.

Chapter 3 — Wiring Methods and Materials

Article 334 - Nonmetallic-Sheathed Cable: Types NM, NMC, and NMS

• Part I. General
• 334.1 Scope.
• 334.2 Definitions.
• 334.6 ListedListing Requirements.
• Part II. Installation

• 334.10 Uses Permitted.
• 334.12 Uses Not Permitted.
• 334.15 Exposed Work.
• 334.17 Through or Parallel to Framing Members.
• 334.23 In Accessible Attics.
• 334.24 Bending Radius.
• 334.30 Securing and Supporting.
• 334.40 Boxes and Fittings.
• 334.80 Ampacity.
• Part III. Construction Specifications

• 334.100 Construction.
• 334.104 Conductors.
• 334.108 Equipment Grounding Conductor.
• 334.112 Insulation.
• 334.116 Sheath.

Chapter 3 — Wiring Methods and Materials

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.
• 336.116 Jacket.
• 336.120 Marking.

Chapter 3 — Wiring Methods and Materials

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.
• 338.12 Uses Not Permitted.
• 338.24 Bending Radius.
• Part III. Construction Specifications

• 338.100 Construction.
• 338.120 Marking.

Chapter 3 — Wiring Methods and Materials

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.

Chapter 3 — Wiring Methods and Materials

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.
• 342.14 Dissimilar Metals.
• 342.20 Size.
• 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.
• 342.42 Couplings and Connectors.
• 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.

Chapter 3 — Wiring Methods and Materials

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.
• 344.14 Dissimilar Metals.
• 344.20 Size.
• 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.
• 344.42 Couplings and Connectors.
• 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.

Chapter 3 — Wiring Methods and Materials

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.
• 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.
• 348.42 Couplings and Connectors.
• 348.56 Splices and Taps.
• 348.60 Grounding and Bonding.

Chapter 3 — Wiring Methods and Materials

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.
• 350.22 Number of Conductors or Cables.
• 350.24 Bends — How Made.
• 350.26 Bends — Number in One Run.
• 350.28 Trimming.
• 350.30 Securing and Supporting.
• 350.42 Couplings and Connectors.
• 350.56 Splices and Taps.
• 350.60 Grounding and Bonding.
• Part III. Construction Specifications

350.120 Marking.

Chapter 3 — Wiring Methods and Materials

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.
• 352.12 Uses Not Permitted.
• 352.20 Size.
• 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.
• 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.

Chapter 3 — Wiring Methods and Materials

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.
• 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.

Chapter 3 — Wiring Methods and Materials

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.
• 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.
• 354.120 Marking.

Chapter 3 — Wiring Methods and Materials

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.
• 355.12 Uses Not Permitted.
• 355.20 Size.
• 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.
• 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.

Chapter 3 — Wiring Methods and Materials

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.
• 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.

Chapter 3 — Wiring Methods and Materials

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.
• 358.12 Uses Not Permitted.
• 358.14 Dissimilar Metals.
• 358.20 Size.
• 358.22 Number of Conductors.
• 358.24 Bends — How Made.
• 358.26 Bends — Number in One Run.
• 358.28 Reaming and Threading.
• 358.30 Securing and Supporting.
• 358.42 Couplings and Connectors.
• 358.56 Splices and Taps.
• 358.60 Grounding.
• Part III. Construction Specifications

• 358.100 Construction.
• 358.120 Marking.

Chapter 3 — Wiring Methods and Materials

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.
• 360.22 Number of Conductors.
• 360.24 Bends.
• 360.56 Splices and Taps.
• 360.60 Grounding.
• Part III. Construction Specifications

360.120 Marking.

Chapter 3 — Wiring Methods and Materials

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.
• 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.
• 362.46 Bushings.
• 362.48 Joints.
• 362.56 Splices and Taps.
• 362.60 Grounding.
• Part III. Construction Specifications

• 362.100 Construction.
• 362.120 Marking.

Chapter 3 — Wiring Methods and Materials

Article 366 - Auxiliary Gutters

• Part I. General
• 366.1 Scope.
• 366.2 Definitions.
• 366.6 Listing Requirements.
• Part II. Installation

• 366.10 Uses Permitted.
• 366.12 Uses Not Permitted.
• 366.20 Conductors Connected in Parallel.
• 366.22 Number of Conductors.
• 366.23 Ampacity of Conductors.
• 366.30 Securing and Supporting.
• 366.44 Expansion Fittings.
• 366.56 Splices and Taps.
• 366.58 Insulated Conductors.
• 366.60 Grounding.
• Part III. Construction Specifications

• 366.100 Construction.
• 366.120 Marking.

Chapter 3 — Wiring Methods and Materials

Article 368 - Busways

• Part I. General Requirements
• 368.1 Scope.
• 368.2 Definition.
• Part II. Installation

• 368.10 Uses Permitted.
• 368.12 Uses Not Permitted.
• 368.17 Overcurrent Protection.
• 368.30 Support.
• 368.56 Branches from 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.
• 368.236 Drain Facilities.
• 368.237 Ventilated Bus Enclosures.
• 368.238 Terminations and Connections.
• 368.239 Switches.
• 368.240 Wiring 6001000 Volts or Less, Nominal.
• 368.244 Expansion Fittings.
• 368.258 Neutral Conductor.
• 368.260 Grounding.
• 368.320 Marking.

Chapter 3 — Wiring Methods and Materials

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.
• 370.20 Conductor Size and Termination.
• 370.22 Number of Conductors.
• 370.23 Overcurrent Protection.
• 370.30 Securing and Supporting.
• 370.42 Fittings.
• 370.60 Grounding.
• 370.80 Ampacity of Conductors.
• Part III. Construction Specifications

370.120 Marking.

Chapter 3 — Wiring Methods and Materials

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.
• 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.

Chapter 3 — Wiring Methods and Materials

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.
• 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.

Chapter 3 — Wiring Methods and Materials

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.
• 376.23 Insulated Conductors.
• 376.30 Securing and Supporting.
• 376.56 Splices, Taps, and Power Distribution Blocks.
• 376.58 Dead Ends.
• 376.70 Extensions from Metal Wireways.
• Part III. Construction Specifications

• 376.100 Construction.
• 376.120 Marking.

Chapter 3 — Wiring Methods and Materials

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.
• 378.30 Securing and Supporting.
• 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.

Chapter 3 — Wiring Methods and Materials

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.
• 380.76 Metal Multioutlet Assembly Through Dry Partitions.

Chapter 3 — Wiring Methods and Materials

Article 382 - Nonmetallic Extensions

• Part I. General
• 382.1 Scope.
• 382.2 Definitions.
• 382.6 Listing Requirements.
• Part II. Installation

• 382.10 Uses Permitted.
• 382.12 Uses Not Permitted.
• 382.15 Exposed.
• 382.26 Bends.
• 382.30 Securing and Supporting.
• 382.40 Boxes and Fittings.
• 382.42 Devices.
• 382.56 Splices and Taps.
• Part III. Construction Specifications (Concealable Nonmetallic Extensions Only)

• 382.100 Construction.
• 382.104 Flat Conductors.
• 382.112 Insulation.
• 382.120 Marking.

Chapter 3 — Wiring Methods and Materials

Article 384 - Strut-Type Channel Raceway

Article 384, Strut-Type Channel Raceways, first appeared as part of the article on surface metal and nonmetallic raceways. At the time, it was Part C of Article 352. It first appeared as a separate article in the 2002 edition. Strut-type channel raceways are metal raceways that are intended to be mounted to the surface of or suspended from a structure, with associated accessories for electrical conductors and cable installation.

• 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.
• 384.56 Splices and Taps.
• 384.60 Grounding.
• Part III. Construction Specifications

• 384.100 Construction.
• 384.120 Marking.

Chapter 3 — Wiring Methods and Materials

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.

Chapter 3 — Wiring Methods and Materials

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.

Chapter 3 — Wiring Methods and Materials

Article 390 - Underfloor Raceways

• 390.1 Scope.
• 390.2 Definition.
• 390.3 Use.
• 390.4 Covering.
• 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.

Chapter 3 — Wiring Methods and Materials

Article 392 - Cable Trays

• Part I. General
• 392.1 Scope.
• 392.2 Definition.
• Part II. Installation

• 392.10 Uses Permitted.
• 392.12 Uses Not Permitted.
• 392.18 Cable Tray Installation.
• 392.20 Cable and Conductor Installation.
• 392.22 Number of Conductors or Cables.
• 392.30 Securing and Supporting.
• 392.46 Bushed Conduit and Tubing.
• 392.56 Cable Splices.
• 392.60 Grounding and Bonding.
• 392.80 Ampacity of Conductors.
• Part III. Construction Specifications

392.100 Construction.

Chapter 3 — Wiring Methods and Materials

Article 393  - Low-Voltage Suspended Ceiling Power Distribution Systems

• Part I. General
• 393.1 Scope.
• 393.2 Definitions.
• 393.6 Listing Requirements.
• Part II. Installation

• 393.10 Uses Permitted.
• 393.12 Uses Not Permitted.
• 393.14 Installation.
• 393.21 Disconnecting Means.
• 393.30 Securing and Supporting.
• 393.40 Connectors and Enclosures.
• 393.45 Overcurrent and Reverse Polarity (Backfeed) Protection.
• 393.56 Splices.
• 393.57 Connections.
• 393.60 Grounding.
• Part III. Construction Specifications

393.104 Sizes and Types of Conductors.

Chapter 3 — Wiring Methods and Materials

Article 394 - Concealed Knob-and-Tube Wiring

Article 394, Concealed Knob-and-Tube Wiring, is still in the Code because there are existing installations. Its only application today is for extensions to those existing installations. It is allowed elsewhere by special permission, but I don’t see that happening often. As this is an obsolete wiring system, there hasn’t been any Code activity in some time. A few cycles back there was a proposal for an article on historic wiring. The Code panel did not agree that it was a viable idea.

• 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.
• 394.23 In Accessible Attics.
• 394.30 Securing and Supporting.
• 394.42 Devices.
• 394.56 Splices and Taps.
• Part III. Construction Specifications

394.104 Conductors.

Chapter 3 — Wiring Methods and Materials

Article 396 - Messenger-Supported Wiring

• Part I. General
• 396.1 Scope.
• 396.2 DefinitionDefinitions.
• Part II. Installation

• 396.10 Uses Permitted.
• 396.12 Uses Not Permitted.
• 396.30 Messenger.
• 396.56 Conductor Splices and Taps.
• 396.60 Grounding.

Chapter 3 — Wiring Methods and Materials

Article 398 - Open Wiring on Insulators

Article 398, Open Wiring on Insulators, has been in the Code for many cycles. It is an inexpensive wiring method that was used in mill construction and farm buildings. It is an exposed wiring method that was permitted in wet and dry locations. It is not permitted to be concealed by the structure of a building. It is required to be protected from physical damage. If it is within 7 feet of the floor, it is considered to be exposed to physical damage. Its construction is similar to knob-and-tube wiring, except for the prohibition on concealment. It is rarely used today.

• 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.
• 398.17 Through or Parallel to Framing Members.
• 398.19 Clearances.
• 398.23 In Accessible Attics.
• 398.30 Securing and Supporting.
• 398.42 Devices.
• Part III. Construction Specifications

398.104 Conductors.

Chapter 3 — Wiring Methods and Materials

Article 399 - Outdoor Overhead Conductors over 1000 Volts

Article 399, Outdoor Overhead Conductors Over 1,000 Volts, first appeared in the 2011 Code . Most overhead transmission and distribution systems are operated by public utilities, which are governed by the National Electrical Safety Code (NESC). However, some college campuses, military bases and industrial parks have privately owned systems not maintained by utilities. The NESC has many pages addressing hazards to overhead conductors, including wind loading, ice loading and sag. Such hazards also exist on private distribution systems. Article 399 is written in performance-based language to permit industry standards to be used for these installations, which would allow installations to comply with the NESC.

• 399.1 Scope.
• 399.2 Definition.
• 399.10 Uses Permitted.
• 399.30 Support.

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.
• 400.6 Markings.
• 400.10 Uses Permitted.
• 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.
• 400.22 Grounded-Conductor Identification.
• 400.23 Equipment Grounding Conductor Identification.
• 400.24 Attachment Plugs.
• Part III. Portable Cables Over 600 Volts, Nominal

• 400.30 Scope.
• 400.31 Construction.
• 400.32 Shielding.
• 400.33 Equipment Grounding Conductors.
• 400.34 Minimum Bending Radii.
• 400.35 Fittings.
• 400.36 Splices and Terminations.

Chapter 4 — Equipment for General Use

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.
• 402.10 Uses Permitted.
• 402.12 Uses Not Permitted.
• 402.14 Overcurrent Protection.

Chapter 4 — Equipment for General Use

Article 404 - Switches

• Part I. Installation
• 404.1 Scope.
• 404.2 Switch Connections.
• 404.3 Enclosure.
• 404.4 Damp or Wet Locations.
• 404.5 Time Switches, Flashers, and Similar Devices.
• 404.6 Position and Connection of Switches.
• 404.7 Indicating.
• 404.8 Accessibility and Grouping.
• 404.9 Provisions for General-Use Snap Switches.
• 404.10 Mounting of Snap Switches.
• 404.11 Circuit Breakers as Switches.
• 404.12 Grounding of Enclosures.
• 404.13 Knife Switches.
• 404.14 Rating and Use of Snap Switches.
• Part II. Construction Specifications

• 404.20 Marking.
• 404.22 Electronic Lighting Control Switches.
• 404.26 Knife Switches Rated 600 to 1000 Volts.
• 404.27 Fused Switches.
• 404.28 Wire-Bending Space.

Chapter 4 — Equipment for General Use

Article 406 - Receptacles, Cord Connectors, and Attachment Plugs (Caps)

• 406.1 Scope.
• 406.2 DefinitionDefinitions.
• 406.3 Receptacle Rating and Type.
• 406.4 General Installation Requirements.
• 406.5 Receptacle Mounting.
• 406.6 Receptacle Faceplates (Cover Plates).
• 406.7 Attachment Plugs, Cord Connectors, and Flanged Surface Devices.
• 406.8 Noninterchangeability.
• 406.9 Receptacles in Damp or Wet Locations.
• 406.10 Grounding-Type Receptacles, Adapters, Cord Connectors, and Attachment Plugs.
• 406.11 Connecting Receptacle Grounding Terminal to Box.
• 406.12 Tamper-Resistant Receptacles.

Chapter 4 — Equipment for General Use

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.
• 408.4 Field Identification Required.
• 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.
• 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.
• 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.
• 408.56 Minimum Spacings.
• 408.58 Panelboard Marking.

Chapter 4 — Equipment for General Use

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.
• 409.22 Short-Circuit Current Rating.
• 409.30 Disconnecting Means.
• 409.60 Grounding.
• Part III. Construction Specifications

• 409.100 Enclosures.
• 409.102 Busbars and Conductors.
• 409.104 Wiring Space.
• 409.106 Spacings.
• 409.108 Service Equipment.
• 409.110 Marking.

Chapter 4 — Equipment for General Use

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.
• 410.11 Luminaires Near Combustible Material.
• 410.12 Luminaires over Combustible Material.
• 410.14 Luminaires in Show Windows.
• 410.16 Luminaires in Clothes Closets.
• 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.
• Part IV. Luminaire Supports

• 410.30 Supports.
• 410.36 Means of Support.
• 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.
• 410.56 Protection of Conductors and Insulation.
• 410.59 Cord-Connected Showcases.
• 410.62 Cord-Connected Lampholders and Luminaires.
• 410.64 Luminaires as Raceways.
• 410.68 Feeder and Branch-Circuit Conductors and Ballasts.
• Part VII. Construction of Luminaires

• 410.70 Combustible Shades and Enclosures.
• 410.74 Luminaire Rating.
• 410.82 Portable Luminaires.
• 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.
• Part X. Special Provisions for Flush and Recessed Luminaires

• 410.110 General.
• 410.115 Temperature.
• 410.116 Clearance and Installation.
• 410.117 Wiring.
• 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 Electric-Discharge Lighting Systems of 1000 Volts or Less

• 410.130 General.
• 410.134 Direct-Current Equipment.
• 410.135 Open-Circuit Voltage Exceeding 300 Volts.
• 410.136 Luminaire Mounting.
• 410.137 Equipment Not Integral with Luminaire.
• 410.138 Autotransformers.
• 410.139 Switches.
• Part XIII. Special Provisions for Electric-Discharge Lighting Systems of More Than 1000 Volts

• 410.140 General.
• 410.141 Control.
• 410.142 Lamp Terminals and Lampholders.
• 410.143 Transformers.
• 410.144 Transformer Locations.
• 410.145 Exposure to Damage.
• 410.146 Marking.
• Part XIV. Lighting Track

• 410.151 Installation.
• 410.153 Heavy-Duty Lighting Track.
• 410.154 Fastening.
• 410.155 Construction Requirements.
• Part XV. Decorative Lighting and Similar Accessories

410.160 Listing of Decorative Lighting.

Chapter 4 — Equipment for General Use

Article 411 Low-Voltage Lighting

Article 411, Low-Voltage Lighting, covers lighting systems that operate at no more that 30V AC or 60V DC. It first appeared in the 1996 Code . Some of the early systems used fixtures suspended from exposed bare conductors.

• 411.1 Scope.
• 411.3 Low-Voltage Lighting Systems.
• 411.4 Listing Required.
• 411.5 Specific Location Requirements.
• 411.6 Secondary Circuits.
• 411.7 Branch Circuit.
• 411.8 Hazardous (Classified) Locations.

Chapter 4 — Equipment for General Use

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.
• 422.6 Listing Required.
• Part II. Installation

• 422.10 Branch-Circuit Rating.
• 422.11 Overcurrent Protection.
• 422.12 Central Heating Equipment.
• 422.13 Storage-Type Water Heaters.
• 422.15 Central Vacuum Outlet Assemblies.
• 422.16 Flexible Cords.
• 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.
• 422.33 Disconnection of Cord-and-Plug-Connected or Attachment Fitting–Connected Appliances.
• 422.34 Unit Switch(es) as Disconnecting Means.
• 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.
• 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.
• 422.50 Cord-and-Plug-Connected Pipe Heating Assemblies.
• Part V. Marking

• 422.60 Nameplate.
• 422.61 Marking of Heating Elements.
• 422.62 Appliances Consisting of Motors and Other Loads.

Chapter 4 — Equipment for General Use

Article 424 - Fixed Electric Space-Heating Equipment

• Part I. General
• 424.1 Scope.
• 424.2 Other Articles.
• 424.3 Branch Circuits.
• 424.6 Listed Equipment.
• Part II. Installation

• 424.9 General.
• 424.10 Special Permission.
• 424.11 Supply Conductors.
• 424.12 Locations.
• 424.13 Spacing from Combustible Materials.
• Part III. Control and Protection of Fixed Electric Space-Heating Equipment

• 424.19 Disconnecting Means.
• 424.20 Thermostatically Controlled Switching Devices.
• 424.21 Switch and Circuit Breaker to Be Indicating.
• 424.22 Overcurrent Protection.
• Part IV. Marking of Heating Equipment

• 424.28 Nameplate.
• 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.
• 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 Ceilings.
• 424.42 Finished Ceilings.
• 424.43 Installation of Nonheating Leads of Cables.
• 424.44 Installation of Cables in Concrete or Poured Masonry Floors.
• 424.45 Installation of Cables Under Floor Coverings.
• 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.
• 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.
• 424.93 Installation.
• 424.94 Clearances of Wiring in Ceilings.
• 424.95 Location of Branch-Circuit and Feeder Wiring in Walls.
• 424.96 Connection to Branch-Circuit Conductors.
• 424.97 Nonheating Leads.
• 424.98 Installation in Concrete or Poured Masonry.
• 424.99 Installation Under Floor Covering.
• Part X. Low-Voltage Fixed Electric Space-Heating Equipment

• 424.100 Scope.
• 424.101 Energy Source.
• 424.102 Listed Equipment.
• 424.103 Installation.
• 424.104 Branch Circuit.

Chapter 4 — Equipment for General Use

Article 425 - Fixed Resistance and Electrode Industrial Process Heating Equipment

• Part I. General
• 425.1 Scope.
• 425.2 Other Articles.
• 425.3 Branch Circuits.
• 425.6 Listed Equipment.
• Part II. Installation

• 425.8 General.
• 425.9 Approval.
• 425.10 Special Permission.
• 425.11 Supply Conductors.
• 425.12 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.
• 425.21 Switch and Circuit Breaker to Be Indicating.
• 425.22
• Part IV. Marking of Heating Equipment

• 425.28 Nameplate.
• 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.
• 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 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.
• 430.7 Marking on Motors and Multimotor Equipment.
• 430.8 Marking on Controllers.
• 430.9 Terminals.
• 430.10 Wiring Space in Enclosures.
• 430.11 Protection Against Liquids.
• 430.12 Motor Terminal Housings.
• 430.13 Bushing.
• 430.14 Location of 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.
• 430.23 Wound-Rotor Secondary.
• 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.
• 430.33 Intermittent and Similar Duty.
• 430.35 Shunting During Starting Period.
• 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.
• 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.
• 430.53 Several Motors or Loads on One Branch Circuit.
• 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.
• 430.63 Rating or Setting — Motor Load and Other Load(s).
• Part VI. Motor Control Circuits

• 430.71 General.
• 430.72 Overcurrent Protection.
• 430.73 Protection of Conductors from Physical Damage.
• 430.74 Electrical Arrangement of Control Circuits.
• 430.75 Disconnection.
• Part VII. Motor Controllers

• 430.81 General.
• 430.82 Controller Design.
• 430.83 Ratings.
• 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.
• 430.98 Marking.
• 430.99 Available Fault Current.
• Part IX. Disconnecting Means

• 430.101 General.
• 430.102 Location.
• 430.103 Operation.
• 430.104 To Be Indicating.
• 430.105 Grounded Conductors.
• 430.107 Readily Accessible.
• 430.108 Every Disconnecting Means.
• 430.109 Type.
• 430.110 Ampere Rating and Interrupting Capacity.
• 430.111 Switch or Circuit Breaker as Both Controller and Disconnecting Means.
• 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.
• 430.124 Overload Protection.
• 430.126 Motor Overtemperature Protection.
• 430.128 Disconnecting Means.
• 430.130 Branch-Circuit Short-Circuit and Ground-Fault Protection for Single Motor Circuits Containing Power Conversion Equipment.
• 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.
• 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.

Chapter 4 — Equipment for General Use

Article 440 - Air-Conditioning and Refrigerating Equipment

• Part I. General
• 440.1 Scope.
• 440.2 Definitions.
• 440.3 Other Articles.
• 440.4 Marking on Hermetic Refrigerant Motor-Compressors and Equipment.
• 440.5 Marking on Controllers.
• 440.6 Ampacity and Rating.
• 440.7 Highest Rated (Largest) Motor.
• 440.8 Single Machine.
• 440.9 Grounding and Bonding.
• 440.10 Short-Circuit Current Rating.
• Part II. Disconnecting Means

• 440.11 General.
• 440.12 Rating and Interrupting Capacity.
• 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.
• 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.
• Part VI. Motor-Compressor and Branch-Circuit Overload Protection

• 440.51 General.
• 440.52 Application and Selection.
• 440.53 Overload Relays.
• 440.54 Motor-Compressors and Equipment on 15- or 20--⁠Ampere Branch Circuits — Not Cord- and Attachment-Plug-Connected.
• 440.55 Cord- and Attachment-Plug-Connected Motor-Compressors and Equipment on 15- or 20-Ampere Branch Circuits.
• Part VII. Provisions for Room Air Conditioners

• 440.60 General.
• 440.61 Grounding.
• 440.62 Branch-Circuit Requirements.
• 440.63 Disconnecting Means.
• 440.64 Supply Cords.
• 440.65 Leakage-Current Detector-Interrupter (LCDI) and Arc-Fault Circuit Interrupter (AFCI)Protection Devices

Chapter 4 — Equipment for General Use

Article 445 - Generators

• 445.1 Scope.
• 445.10 Location.
• 445.11 Marking.
• 445.12 Overcurrent Protection.
• 445.13 Ampacity of Conductors.
• 445.14 Protection of Live Parts.
• 445.15 Guards for Attendants.
• 445.16 Bushings.
• 445.17 Generator Terminal Housings.
• 445.18 Disconnecting Means Required for Generatorsand Shutdown of Prime Mover.
• 445.20 Ground-Fault Circuit-Interrupter Protection for Receptacles on 15-kW or Smaller Portable Generators.

Chapter 4 — Equipment for General Use

Article 450 - Transformers and Transformer Vaults (Including Secondary Ties)

• Part I. General Provisions
• 450.1 Scope.
• 450.2 Definition.
• 450.3 Overcurrent Protection.
• 450.4 Autotransformers 1000 Volts, Nominal, or Less.
• 450.5 Grounding Autotransformers.
• 450.6 Secondary Ties.
• 450.7 Parallel Operation.
• 450.8 Guarding.
• 450.9 Ventilation.
• 450.10 Grounding.
• 450.11 Marking.
• 450.12 Terminal Wiring Space.
• 450.13 Accessibility.
• 450.14 Disconnecting Means.
• Part II. Specific Provisions Applicable to Different Types of Transformers

• 450.21 Dry-Type Transformers Installed Indoors.
• 450.22 Dry-Type Transformers Installed Outdoors.
• 450.23 Less-Flammable Liquid-Insulated Transformers.
• 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.
• 450.45 Ventilation Openings.
• 450.46 Drainage.
• 450.47 Water Pipes and Accessories.
• 450.48 Storage in Vaults.

Chapter 4 — Equipment for General Use

Article 455 - Phase Converters

Article 455, Phase Converters, was proposed as a new part to Article 430 in the 1990 Code , but did not become part of the NEC until the 1993 edition. Phase converters are used to convert single-phase power to three-phase power. Its primary application is areas where three-phase power is not commercially available, which tends to happen in rural areas. The most common method of obtaining three-phase power from a single-phase source is by using a rotary phase converter, which is a rotating machine-type generator. Some units also provide voltage regulation, which facilitates operation with voltage-sensitive electronic equipment. There are also some static power converters available, which use electronic means to convert a single-phase source to generate a three-phase output. These range from electronic circuits to simple arrangements that will switch capacitors during motor startups to provide an output that is out of phase with the existing line voltage.

• Part I. General
• 455.1 Scope.
• 455.2 Definitions.
• 455.3 Other Articles.
• 455.4 Marking.
• 455.5 Equipment Grounding Connection.
• 455.6 Conductors.
• 455.7 Overcurrent Protection.
• 455.8 Disconnecting Means.
• 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.

Chapter 4 — Equipment for General Use

Article 460 - Capacitors

• 460.1 Scope.
• 460.2 Enclosing and Guarding.
• Part I. 1000 Volts, Nominal, and Under

• 460.6 Discharge of Stored Energy.
• 460.8 Conductors.
• 460.9 Rating or Setting of Motor Overload Device.
• 460.10 Grounding.
• 460.12 Marking.
• Part II. Over 1000 Volts, Nominal

• 460.24 Switching.
• 460.25 Overcurrent Protection.
• 460.26 Identification.
• 460.27 Grounding.
• 460.28 Means for Discharge.

Chapter 4 — Equipment for General Use

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.
• 470.19 Grounding.
• 470.20 Oil-Filled Reactors.

Chapter 4 — Equipment for General Use

Article 480 - Storage Batteries

• 480.1 Scope.
• 480.2 Definitions.
• 480.3 Equipment.
• 480.4 Battery and Cell Terminations.
• 480.5 Wiring and Equipment Supplied from Batteries.
• 480.6 Overcurrent Protection for Prime Movers.
• 480.7 DC Disconnect Methods.
• 480.8 Insulation of Batteries Not Over 250 Volts.
• 480.9 Racks and TraysBattery Support Systems.
• 480.10 Battery Locations.
• 480.11 Vents.

Chapter 4 — Equipment for General Use

Article 490 - Equipment Over 1000 Volts, Nominal

• Part I. General
• 490.1 Scope.
• 490.2 Definition.
• 490.3 Oil-Filled EquipmentOther Articles.
• Part II. Equipment — Specific Provisions

• 490.21 Circuit-Interrupting Devices.
• 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.
• 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.
• 490.42 Interlocks — Interrupter Switches.
• 490.43 Stored Energy for Opening.
• 490.44 Fused Interrupter Switches.
• 490.45 Circuit Breakers — Interlocks.
• 490.46 Circuit Breaker Locking.
• 490.47 Switchgear Used as Service Equipment.
• 490.48 Substation Design, Documentation, and Required Diagram.
• Part IV. Mobile and Portable Equipment

• 490.51 General.
• 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.
• 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.
• 500.5 Classifications of Locations.
• 500.6 Material Groups.
• 500.7 Protection Techniques.
• 500.8 Equipment.
• 500.9 Specific Occupancies.

Chapter 5 — Special Occupancies

Article 501 - Class I Locations

• Part I. General
• 501.1 Scope.
• 501.5 Zone Equipment.
• Part II. Wiring

• 501.10 Wiring Methods.
• 501.15 Sealing and 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.
• 501.35 Surge Protection.
• Part III. Equipment

• 501.100 Transformers and Capacitors.
• 501.105 Meters, Instruments, and Relays.
• 501.115 Switches, Circuit Breakers, Motor Controllers, and Fuses.
• 501.120 Control Transformers and Resistors.
• 501.125 Motors and Generators.
• 501.130 Luminaires.
• 501.135 Utilization Equipment.
• 501.140 Flexible Cords, Class I, Divisions 1 and 2.
• 501.145 Receptacles and Attachment Plugs, Class I, Divisions 1 and 2.
• 501.150 Signaling, Alarm, Remote-Control, and Communications Systems.

Chapter 5 — Special Occupancies

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.
• 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.
• 502.35 Surge Protection — Class II, Divisions 1 and 2.
• Part III. Equipment

• 502.100 Transformers and Capacitors.
• 502.115 Switches, Circuit Breakers, Motor Controllers, and Fuses.
• 502.120 Control Transformers and Resistors.
• 502.125 Motors and Generators.
• 502.128 Ventilating Piping.
• 502.130 Luminaires.
• 502.135 Utilization Equipment.
• 502.140 Flexible Cords — Class II, Divisions 1 and 2.
• 502.145 Receptacles and Attachment Plugs.
• 502.150 Signaling, Alarm, Remote-Control, and Communications Systems; and Meters, Instruments, and Relays.

Chapter 5 — Special Occupancies

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.
• 503.25 Uninsulated Exposed Parts, Class III, Divisions 1 and 2.
• 503.30 Grounding and Bonding — Class III, Divisions 1 and 2.
• 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.
• 503.135 Utilization Equipment — Class III, Divisions 1 and 2.
• 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.
• 503.160 Storage Battery Charging Equipment — Class III, Divisions 1 and 2.

Chapter 5 — Special Occupancies

Article 504 - Intrinsically Safe Systems

• 504.1 Scope.
• 504.2 Definitions.
• 504.3 Application of Other Articles.
• 504.4 Equipment.
• 504.10 Equipment Installation.
• 504.20 Wiring Methods.
• 504.30 Separation of Intrinsically Safe Conductors.
• 504.50 Grounding.
• 504.60 Bonding.
• 504.70 Sealing.
• 504.80 Identification.

Chapter 5 — Special Occupancies

Article 505 - Zone 0, 1, and 2 Locations

• 505.1 Scope.
• 505.2 Definitions.
• 505.3 Other Articles.
• 505.4 General.
• 505.5 Classifications of Locations.
• 505.6 Material Groups.
• 505.7 Special Precaution.
• 505.8 Protection Techniques.
• 505.9 Equipment.
• 505.15 Wiring Methods.
• 505.16 Sealing and Drainage.
• 505.17 Flexible Cables, Cords and Connections.
• 505.18 Conductors and Conductor Insulation.
• 505.19 Uninsulated Exposed Parts.
• 505.20 Equipment Requirements.
• 505.22 Increased Safety “e” Motors and Generators.
• 505.25 Grounding and Bonding.
• 505.26 Process Sealing.

Chapter 5 — Special Occupancies

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.
• 506.5 Classification of Locations.
• 506.6 Material Groups.
• 506.7 Special Precaution.
• 506.8 Protection Techniques.
• 506.9 Equipment Requirements.
• 506.15 Wiring Methods.
• 506.16 Sealing.
• 506.17 Flexible Cords.
• 506.20 Equipment Installation.
• 506.25 Grounding and Bonding.

Article 510 - Hazardous (Classified) Locations — Specific

• 510.1 Scope.
• 510.2 General.

Chapter 5 — Special Occupancies

Article 511 - Commercial Garages, Repair and Storage

• 511.1 Scope.
• 511.2 Definitions.
• 511.3 Area Classification, General.
• 511.4 Wiring and Equipment in Class I Locations.
• 511.7 Wiring and Equipment Installed Above Class I Locations.
• 511.8 Underground Wiring.
• 511.9 Sealing.
• 511.10 Special Equipment.
• 511.12 Ground-Fault Circuit-Interrupter Protection for Personnel.
• 511.16 Grounding and Bonding Requirements.

Chapter 5 — Special Occupancies

Article 513 - Aircraft Hangars

• 513.1 Scope.
• 513.2 Definitions.
• 513.3 Classification of Locations.
• 513.4 Wiring and Equipment in Class I Locations.
• 513.7 Wiring and Equipment Not Installed in Class I Locations.
• 513.8 Underground Wiring.
• 513.9 Sealing.
• 513.10 Special Equipment.
• 513.12 Ground-Fault Circuit-Interrupter Protection for Personnel.
• 513.16 Grounding and Bonding Requirements.

Chapter 5 — Special Occupancies

Article 514 - Motor Fuel Dispensing Facilities

• 514.1 Scope.
• 514.2 Definition.
• 514.3 Classification of Locations.
• 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.
• 514.11 Circuit Disconnects.
• 514.13 Provisions for Maintenance and Service of Dispensing Equipment.
• 514.16 Grounding and Bonding.

Chapter 5 — Special Occupancies

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.
• 515.8 Underground Wiring.
• 515.9 Sealing.
• 515.10 Special Equipment — Gasoline Dispensers.
• 515.16 Grounding and Bonding.

Chapter 5 — Special Occupancies

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.
• 516.6 Wiring and Equipment in Class I Locations.
• 516.7 Wiring and Equipment Not Within Classified Locations.
• 516.10 Special Equipment.
• 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.
• 516.40 Static Electric Discharges.

Chapter 5 — Special Occupancies

Article 517 - Health Care Facilities

• Part I. General
• 517.1 Scope.
• 517.2 Definitions.
• Part II. Wiring and Protection

• 517.10 Applicability.
• 517.11 General Installation — Construction Criteria.
• 517.12 Wiring Methods.
• 517.13 Grounding of Receptacles and Fixed Electrical Equipment in Patient Care AreasSpaces.
• 517.14 Panelboard Bonding.
• 517.16 Use of Isolated Ground Receptacles.
• 517.17 Ground-Fault Protection.
• 517.18 General Care Areas(Category 2) Spaces.
• 517.19 Critical Care Areas(Category 1) Spaces.
• 517.20 Wet Procedure Locations.
• 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.
• 517.30 Sources of Power.
• 517.31 Requirements for the Essential Electrical System.
• 517.32 Branches Requiring Automatic Connection.
• 517.33 Life Safety Branch.
• 517.34 Critical Branch.
• 517.35 Equipment Branch Connection to Alternate Power Source.
• 517.40 Type 2 Essential Electrical Systems for Nursing Homes and Limited Care Facilities.
• 517.41 Sources of PowerRequired Power Sources.
• 517.42 Essential Electrical Systems.
• 517.43 Automatic Connection to Life Safety Branch.
• 517.44 Connection to CriticalEquipment Branch.
• 517.45 Essential Electrical Systems for Other Health Care Facilities.
• Part IV. Inhalation Anesthetizing Locations

• 517.60 Anesthetizing Location Classification.
• 517.61 Wiring and Equipment.
• 517.62 Grounding.
• 517.63 Grounded Power Systems in Anesthetizing Locations.
• 517.64 Low-Voltage Equipment and Instruments.
• Part V. X-Ray Installations

• 517.70 Applicability.
• 517.71 Connection to Supply Circuit.
• 517.72 Disconnecting Means.
• 517.73 Rating of Supply Conductors and Overcurrent Protection.
• 517.74 Control Circuit Conductors.
• 517.75 Equipment Installations.
• 517.76 Transformers and Capacitors.
• 517.77 Installation of High-Tension X-Ray Cables.
• 517.78 Guarding and Grounding.
• Part VI. Communications, Signaling Systems, Data Systems, Fire Alarm Systems, and Systems Less Than 120 Volts, Nominal

• 517.80 Patient Care AreasSpaces.
• 517.81 Other-Than-Patient-Care Areas.
• 517.82 Signal Transmission Between Appliances.
• Part VII. Isolated Power Systems

517.160 Isolated Power Systems.

Article 518 - Assembly Occupancies

• 518.1 Scope.
• 518.2 General Classification.
• 518.3 Other Articles.
• 518.4 Wiring Methods.
• 518.5 Supply.

Chapter 5 — Special Occupancies

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.
• 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.
• 520.26 Type of Switchboard.
• 520.27 Stage Switchboard Feeders.
• Part III. Fixed Stage Equipment Other Than Switchboards

• 520.40 Stage Lighting Hoists.
• 520.41 Circuit Loads.
• 520.42 Conductor Insulation.
• 520.43 Footlights.
• 520.44 Borders, Proscenium Sidelights, 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).
• 520.51 Supply.
• 520.52 Overcurrent Protection for Branch Circuits.
• 520.53 Construction and Feeders.
• 520.54 Supply Conductors.
• Part V. Portable Stage Equipment Other Than Switchboards

• 520.61 Arc Lamps.
• 520.62 Portable Power Distribution Units.
• 520.63 Bracket Fixture Wiring.
• 520.64 Portable Strips.
• 520.65 Festoons.
• 520.66 Special Effects.
• 520.67 Multipole Branch-Circuit Cable Connectors.
• 520.68 Conductors for Portables.
• 520.69 Adapters.
• 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.

Chapter 5 — Special Occupancies

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.
• Part III. Control Circuit Wiring Methods

• 522.20 Conductors, Busbars, and Slip Rings.
• 522.21 Conductor Sizing.
• 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.
• 522.25 Ungrounded Control Circuits.
• 522.28 Control Circuits in Wet Locations.

Chapter 5 — Special Occupancies

Article 525 - Carnivals, Circuses, Fairs, and Similar Events

• Part I. General Requirements
• 525.1 Scope.
• 525.2 Definitions.
• 525.3 Other Articles.
• 525.5 Overhead Conductor Clearances.
• 525.6 Protection of Electrical Equipment.
• Part II. Power Sources

• 525.10 Services.
• 525.11 Multiple Sources of Supply.
• Part III. Wiring Methods

• 525.20 Wiring Methods.
• 525.21 Rides, Tents, and Concessions.
• 525.22 Portable Distribution or Termination Boxes.
• 525.23 Ground-Fault Circuit-Interrupter (GFCI) Protection.
• Part IV. Grounding and Bonding

• 525.30 Equipment Bonding.
• 525.31 Equipment Grounding.
• 525.32 Equipment Grounding Conductor Continuity Assurance.

Chapter 5 — Special Occupancies

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.
• 530.13 Stage Lighting and Effects Control.
• 530.14 Plugging Boxes.
• 530.15 Enclosing and Guarding Live Parts.
• 530.16 Portable Luminaires.
• 530.17 Portable Arc Lamps.
• 530.18 Overcurrent Protection — General.
• 530.19 Sizing of Feeder Conductors for Television Studio Sets.
• 530.20 Grounding.
• 530.21 Plugs and Receptacles.
• 530.22 Single-Pole Separable Connectors.
• 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.

Chapter 5 — Special Occupancies

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.
• 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.

Chapter 5 — Special Occupancies

Article 545 - Manufactured Buildings

• 545.1 Scope.
• 545.2 Definitions.
• 545.4 Wiring Methods.
• 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.
• 545.10 Receptacle or Switch with Integral Enclosure.
• 545.11 Bonding and Grounding.
• 545.12 Grounding Electrode Conductor.
• 545.13 Component Interconnections.

Chapter 5 — Special Occupancies

Article 547 - Agricultural Buildings

• 547.1 Scope.
• 547.2 Definitions.
• 547.3 Other Articles.
• 547.4 Surface Temperatures.
• 547.5 Wiring Methods.
• 547.6 Switches, Receptacles, Circuit Breakers, Controllers, and Fuses.
• 547.7 Motors.
• 547.8 Luminaires.
• 547.9 Electrical Supply to Building(s) or Structure(s) from a Distribution Point.
• 547.10 Equipotential Planes and Bonding of Equipotential Planes.

Chapter 5 — Special Occupancies

Article 550 - Mobile Homes, Manufactured Homes, and Mobile Home Parks

Part I. General

• 550.1 Scope.
• 550.2 Definitions.
• 550.4 General Requirements.
• Part II. Mobile and Manufactured Homes

• 550.10 Power Supply.
• 550.11 Disconnecting Means and Branch-Circuit Protective Equipment.
• 550.12 Branch Circuits.
• 550.13 Receptacle Outlets.
• 550.14 Luminaires and Appliances.
• 550.15 Wiring Methods and Materials.
• 550.16 Grounding.
• 550.17 Testing.
• 550.18 Calculations.
• 550.19 Interconnection of Multiple-Section Mobile or Manufactured Home Units.
• 550.20 Outdoor Outlets, Luminaires, Air-Cooling Equipment, and So Forth.
• 550.25 Arc-Fault Circuit-Interrupter Protection.
• Part III. Services and Feeders

• 550.30 Distribution System.
• 550.31 Allowable Demand Factors.
• 550.32 Service Equipment.
• 550.33 Feeder.

Chapter 5 — Special Occupancies

Article 551 - Recreational Vehicles and Recreational Vehicle Parks

• Part I. General
• 551.1 Scope.
• 551.2 Definitions.
• 551.4 General Requirements.
• Part II. Combination Electrical Systems

• 551.20 Combination Electrical Systems.
• Part III. Other Power Sources

• 551.30 Generator Installations.
• 551.31 Multiple Supply Source.
• 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.
• 551.41 Receptacle Outlets Required.
• 551.42 Branch Circuits Required.
• 551.43 Branch-Circuit Protection.
• 551.44 Power-Supply Assembly.
• 551.45 Panelboard.
• 551.46 Means for Connecting to Power Supply.
• 551.47 Wiring Methods.
• 551.48 Conductors and Boxes.
• 551.49 Grounded Conductors.
• 551.50 Connection of Terminals and Splices.
• 551.51 Switches.
• 551.52 Receptacles.
• 551.53 Luminaires and Other Equipment.
• 551.54 Grounding.
• 551.55 Interior Equipment Grounding.
• 551.56 Bonding of Non–Current-Carrying Metal Parts.
• 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.
• 551.72 Distribution System.
• 551.73 Calculated Load.
• 551.74 Overcurrent Protection.
• 551.75 Grounding.
• 551.76 Grounding — Recreational Vehicle Site Supply Equipment.
• 551.77 Recreational Vehicle Site Supply Equipment.
• 551.78 Protection of Outdoor Equipment.
• 551.79 Clearance for Overhead Conductors.
• 551.80 Underground Service, Feeder, Branch-Circuit, and Recreational Vehicle Site Feeder-Circuit Conductors.
• 551.81 Receptacles.

Chapter 5 — Special Occupancies

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.
• Part III. Combination Electrical Systems

• 552.20 Combination Electrical Systems.
• Part IV. Nominal 120-Volt or 120/240-Volt Systems

• 552.40 120-Volt or 120/240-Volt, Nominal, Systems.
• 552.41 Receptacle Outlets Required.
• 552.42 Branch-Circuit Protection.
• 552.43 Power Supply.
• 552.44 Cord.
• 552.45 Panelboard.
• 552.46 Branch Circuits.
• 552.47 Calculations.
• 552.48 Wiring Methods.
• 552.49 Maximum Number of Conductors in Boxes.
• 552.50 Grounded Conductors.
• 552.51 Connection of Terminals and Splices.
• 552.52 Switches.
• 552.53 Receptacles.
• 552.54 Luminaires.
• 552.55 Grounding.
• 552.56 Interior Equipment Grounding.
• 552.57 Bonding of Non–Current-Carrying Metal Parts.
• 552.58 Appliance Accessibility and Fastening.
• 552.59 Outdoor Outlets, Fixtures, Including Luminaires, Air-Cooling Equipment, and So On.
• Part V. Factory Tests

552.60 Factory Tests (Electrical).

Chapter 5 — Special Occupancies

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.
• Part III. Grounding

• 553.8 General Requirements.
• 553.9 Insulated Neutral.
• 553.10 Equipment Grounding.
• 553.11 Bonding of Non–Current-Carrying Metal Parts.

Chapter 5 — Special Occupancies

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.
• 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.
• 555.15 Grounding.
• 555.17 Disconnecting Means for Shore Power Connection(s).
• 555.19 Receptacles.
• 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.

Chapter 5 — Special Occupancies

Article 590 - Temporary Installations

• 590.1 Scope.
• 590.2 All Wiring Installations.
• 590.3 Time Constraints.
• 590.4 General.
• 590.5 Listing of Decorative Lighting.
• 590.6 Ground-Fault Protection for Personnel.
• 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.
• 600.4 Markings.
• 600.5 Branch Circuits.
• 600.6 Disconnects.
• 600.7 Grounding and Bonding.
• 600.8 Enclosures.
• 600.9 Location.
• 600.10 Portable or Mobile Signs.
• 600.12 Field-Installed Secondary Wiring.
• 600.21 Ballasts, Transformers, Electronic Power Supplies, and Class 2 Power Sources.
• 600.22 Ballasts.
• 600.23 Transformers and Electronic Power Supplies.
• 600.24 Class 2 Power Sources.
• 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.
• 600.32 Neon Secondary-Circuit Wiring, over 1000 Volts, Nominal.
• 600.33 LEDClass 2 Sign Illumination Systems, Secondary Wiring.
• 600.34 Photovoltaic (PV) Powered Sign.
• 600.41 Neon Tubing.
• 600.42 Electrode Connections.

Chapter 6 — Special Equipment

Article 604 - Manufactured Wiring Systems

Article 604, Manufactured Wiring Systems, discusses systems that use manufactured subassemblies that are assembled on-site. They are used for branch circuits, remote-control circuits, signaling and communications circuits. Manufactured wiring systems and all of their associated components are required to be listed.

• 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.

Chapter 6 — Special Equipment

Article 605 - Office Furnishings

• 605.1 Scope.
• 605.2 Definition.
• 605.3 General.
• 605.4 Wireways.
• 605.5 Office Furnishing Interconnections.
• 605.6 Lighting Accessories.
• 605.7 Fixed-Type Office Furnishings.
• 605.8 Freestanding-Type Office Furnishings.
• 605.9 Freestanding-Type Office Furnishings, Cord- and Plug-Connected.

Chapter 6 — Special Equipment

Article 610 - Cranes and Hoists

• Part I. General
• 610.1 Scope.
• 610.2 Definition.
• 610.3 Special Requirements for Particular Locations.
• Part II. Wiring

• 610.11 Wiring Method.
• 610.12 Raceway or Cable Terminal Fittings.
• 610.13 Types of Conductors.
• 610.14 Rating and Size of Conductors.
• 610.15 Common Return.
• Part III. Contact Conductors

• 610.21 Installation of Contact Conductors.
• 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.
• 610.42 Branch-Circuit Short-Circuit and Ground-Fault Protection.
• 610.43 Overload Protection.
• Part VI. Control

• 610.51 Separate Controllers.
• 610.53 Overcurrent Protection.
• 610.57 Clearance.
• Part VII. Grounding

610.61 Grounding.

Chapter 6 — Special Equipment

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.
• 620.4 Live Parts Enclosed.
• 620.5 Working Clearances.
• Part II. Conductors

• 620.11 Insulation of Conductors.
• 620.12 Minimum Size of Conductors.
• 620.13 Feeder and Branch-Circuit Conductors.
• 620.14 Feeder Demand Factor.
• 620.15 Motor Controller Rating.
• 620.16 Short-Circuit Current Rating.
• Part III. Wiring

• 620.21 Wiring Methods.
• 620.22 Branch Circuits for Car Lighting, Receptacle(s), Ventilation, Heating, and Air-Conditioning.
• 620.23 Branch Circuits for Machine Room or Control Room/Machinery Space or Control Space Lighting and Receptacle(s).
• 620.24 Branch Circuit for Hoistway Pit Lighting and Receptacle(s)Receptacles.
• 620.25 Branch Circuits for Other Utilization Equipment.
• 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.
• 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.
• 620.52 Power from More Than One Source.
• 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.
• 620.62 Selective Coordination.
• Part VIII. Machine Rooms, Control Rooms, Machinery Spaces, and Control Spaces

• 620.71 Guarding Equipment.
• 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.

Chapter 6 — Special Equipment

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.
• 625.15 Markings.
• 625.16 Means of Coupling.
• 625.17 Cords and Cables.
• 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 Electric Vehicle Supply Equipment Connection.
• 625.46 Loss of Primary Source.
• 625.47 Multiple Feeder or Branch Circuits.
• 625.48 Interactive Systems.
• 625.50 Location.
• 625.52 Ventilation.
• 625.54 Ground-Fault Circuit-Interrupter Protection for Personnel.
• 625.56 Receptacle Enclosures.
• Part IV. Wireless Power Transfer Equipment

• 625.101 Grounding.
• 625.102 Construction.

Chapter 6 — Special Equipment

Article 630 - Electric Welders

• Part I. General
• 630.1 Scope.
• 630.6 Listing.
• Part II. Arc Welders

• 630.11 Ampacity of Supply Conductors.
• 630.12 Overcurrent Protection.
• 630.13 Disconnecting Means.
• 630.14 Marking.
• 630.15 Grounding of Welder Secondary Circuit.
• Part III. Resistance Welders

• 630.31 Ampacity of Supply Conductors.
• 630.32 Overcurrent Protection.
• 630.33 Disconnecting Means.
• 630.34 Marking.
• Part IV. Welding Cable

• 630.41 Conductors.
• 630.42 Installation.

Chapter 6 — Special Equipment

Article 640 - Audio Signal Processing, Amplification, and Reproduction Equipment

Part I. General

• 640.1 Scope.
• 640.2 Definitions.
• 640.3 Locations and Other Articles.
• 640.4 Protection of Electrical Equipment.
• 640.5 Access to Electrical Equipment Behind Panels Designed to Allow Access.
• 640.6 Mechanical Execution of Work.
• 640.7 Grounding.
• 640.8 Grouping of Conductors.
• 640.9 Wiring Methods.
• 640.10 Audio Systems Near Bodies of Water.
• Part II. Permanent Audio System Installations

• 640.21 Use of Flexible Cords and Cables.
• 640.22 Wiring of Equipment Racks and Enclosures.
• 640.23 Conduit or Tubing.
• 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.
• 640.43 Wiring of Equipment Racks.
• 640.44 Environmental Protection of Equipment.
• 640.45 Protection of Wiring.
• 640.46 Equipment Access.

Chapter 6 — Special Equipment

Article 645 - Information Technology Equipment

• 645.1 Scope.
• 645.2 Definitions.
• 645.3 Other Articles.
• 645.4 Special Requirements for Information Technology Equipment Room.
• 645.5 Supply Circuits and Interconnecting Cables.
• 645.10 Disconnecting Means.
• 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.

Chapter 6 — Special Equipment

Article 646 - Modular Data Centers

• Part I. General
• 646.1 Scope.
• 646.2 Definitions.
• 646.3 Other Articles.
• 646.4 Applicable Requirements.
• 646.5 Nameplate Data.
• 646.6 Supply Conductors and Overcurrent Protection.
• 646.7 Short-Circuit Current Rating.
• 646.8 Field-Wiring Compartments.
• 646.9 Flexible Power Cords and Cables for Connecting Equipment Enclosures of an MDC System.
• Part II. Equipment

• 646.10 Electrical Supply and Distribution.
• 646.11 Distribution 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.
• 646.20 Working Space for ITE.
• 646.21 Work Areas and Working Space AroundAbout Batteries.
• 646.22 Workspace for Routine Service and Maintenance.

Chapter 6 — Special Equipment

Article 647 - Sensitive Electronic Equipment

Article 647, Sensitive Electronic Equipment, originated as Part G of Article 530, Motion Picture and Television Studios. It applies to separately derived 120V, three-wire, single-phase systems operating at 60V to ground. These circuits are primarily used where there is objectionable noise in sensitive electronic equipment. The primary application has been audio and video systems where there is a need to eliminate noise. These systems are permitted to be used in commercial and industrial establishments, but not residential. The location must be “under close supervision by qualified personnel.” This is one of very few places in the NEC where there is a limit on voltage drop. The limit on branch circuits is 1.5%. The combined voltage drop for feeders and branch circuits is 2.5%. The reason provided was to prevent impedances that might limit the ability of overcurrent devices to operate.

• 647.1 Scope.
• 647.3 General.
• 647.4 Wiring Methods.
• 647.5 Three-Phase Systems.
• 647.6 Grounding.
• 647.7 Receptacles.
• 647.8 Lighting Equipment.

Chapter 6 — Special Equipment

Article 650 - Pipe Organs

Article 650, Pipe Organs, covers large organs used in houses of worship. Modern pipe organs may produce sound electronically or through pressurized air. They are often very large and custom-built systems that are assembled in the field.

• 650.1 Scope.
• 650.2 Definitions.
• 650.3 Other Articles.
• 650.4 Source of Energy.
• 650.5 Grounding or Double Insulation of the DC Power Supply.
• 650.6 Conductors.
• 650.7 Installation of Conductors.
• 650.8 Overcurrent Protection.
• 650.9 Protection from Accidental Contact.

Chapter 6 — Special Equipment

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.
• 660.5 Disconnecting Means.
• 660.6 Rating of Supply Conductors and Overcurrent Protection.
• 660.7 Wiring Terminals.
• 660.9 Minimum Size of Conductors.
• 660.10 Equipment Installations.
• Part II. Control

• 660.20 Fixed and Stationary Equipment.
• 660.21 Portable and Mobile Equipment.
• 660.23 Industrial and Commercial Laboratory Equipment.
• 660.24 Independent Control.
• Part III. Transformers and Capacitors

• 660.35 General.
• 660.36 Capacitors.
• Part IV. Guarding and Grounding

• 660.47 General.
• 660.48 Grounding.

Chapter 6 — Special Equipment

Article 665 - Induction and Dielectric Heating Equipment

Article 665, Induction and Dielectric Heating Equipment, discusses industrial plants with processes that used induction and dielectric heating systems to provide process heating. Induction heating is used to heat metal parts, and dielectric heating is used to heat nonmetallic parts. Induction heating uses alternating current operating in a range of 50 hertz to 500 kilohertz and 5 kilowatts to 42 megawatts.

Dielectric heating operates on assigned frequencies of 13.56 megahertz (MHz), 27.12 MHz and 40.68 MHz. Some operate on microwave frequencies.

• Part I. General
• 665.1 Scope.
• 665.2 Definitions.
• 665.4 Hazardous (Classified) Locations.
• 665.5 Output Circuit.
• 665.7 Remote Control.
• 665.10 Ampacity of Supply Conductors.
• 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.

Chapter 6 — Special Equipment

Article 668 - Electrolytic Cells

• 668.1 Scope.
• 668.2 Definitions.
• 668.3 Other Articles.
• 668.10 Cell Line Working Zone.
• 668.11 Direct-Current Cell Line Process Power Supply.
• 668.12 Cell Line Conductors.
• 668.13 Disconnecting Means.
• 668.14 Shunting Means.
• 668.15 Grounding.
• 668.20 Portable Electrical Equipment.
• 668.21 Power-Supply Circuits and Receptacles for Portable Electrical Equipment.
• 668.30 Fixed and Portable Electrical Equipment.
• 668.31 Auxiliary Nonelectrical Connections.
• 668.32 Cranes and Hoists.
• 668.40 Enclosures.

Chapter 6 — Special Equipment

Article 669 - Electroplating

• 669.1 Scope.
• 669.3 General.
• 669.5 Branch-Circuit Conductors.
• 669.6 Wiring Methods.
• 669.7 Warning Signs.
• 669.8 Disconnecting Means.
• 669.9 Overcurrent Protection.

Chapter 6 — Special Equipment

Article 670 - Industrial Machinery

Article 670 covers industrial machinery. The NEC does not cover the internal wiring of equipment, so other requirements were needed. In 1961, NFPA 79, Industrial Machinery, was adopted as a tentative standard, subject to comments, under “Standard for Machine Tools.” It was created to address requirements for industrial machinery, which can consist of a number of different motors and controllers that work together in a manufacturing process. The standard has evolved over time so that it now recognizes equipment built to IEC standards with U.S. deviations. This allows some equipment to be imported if it complies with the U.S. deviations contained in NFPA 79.

• 670.1 Scope.
• 670.2 Definition.
• 670.3 Machine Nameplate Data.
• 670.4 Supply Conductors and Overcurrent Protection.
• 670.5 Short-Circuit Current Rating.
• 670.6 Surge Protection.

Chapter 6 — Special Equipment

Article 675 - Electrically Driven or Controlled Irrigation Machines

Article 675 covers electrically driven irrigation machines, and these are occasionally found in rural areas where three-phase power is not available. They may be supplied by a phase converter, which is governed by the requirements of Article 455.

• Part I. General
• 675.1 Scope.
• 675.2 Definitions.
• 675.4 Irrigation Cable.
• 675.5 More Than Three Conductors in a Raceway or Cable.
• 675.6 Marking on Main Control Panel.
• 675.7 Equivalent Current Ratings.
• 675.8 Disconnecting Means.
• 675.9 Branch-Circuit Conductors.
• 675.10 Several Motors on One Branch Circuit.
• 675.11 Collector Rings.
• 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.

Chapter 6 — Special Equipment

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.
• 680.9 Overhead Conductor Clearances.
• 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.
• Part II. Permanently Installed Pools

• 680.20 General.
• 680.21 Motors.
• 680.22 Lighting, Receptacles, and Equipment.
• 680.23 Underwater Luminaires.
• 680.24 Junction Boxes and Electrical Enclosures for Transformers or Ground-Fault Circuit Interrupters.
• 680.25 Feeders.
• 680.26 Equipotential Bonding.
• 680.27 Specialized Pool Equipment.
• 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.
• 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.
• 680.43 Indoor Installations.
• 680.44 Protection.
• Part V. Fountains

• 680.50 General.
• 680.51 Luminaires, Submersible Pumps, and Other Submersible Equipment.
• 680.52 Junction Boxes and Other Enclosures.
• 680.53 Bonding.
• 680.54 Grounding.
• 680.55 Methods of Grounding.
• 680.56 Cord-and-Plug-Connected Equipment.
• 680.57 Signs.
• 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).
• Part VII. Hydromassage Bathtubs

• 680.70 General.
• 680.71 Protection.
• 680.72 Other Electrical Equipment.
• 680.73 Accessibility.
• 680.74 Bonding.
• 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.

Chapter 6 — Special Equipment

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).
• 682.15 Ground-Fault Circuit-Interrupter (GFCI) Protection.
• Part III. Grounding and Bonding

• 682.30 Grounding.
• 682.31 Equipment Grounding Conductors.
• 682.32 Bonding of Non–Current-Carrying Metal Parts.
• 682.33 Equipotential Planes and Bonding of Equipotential Planes.

Chapter 6 — Special Equipment

Article 685 - Integrated Electrical Systems

Article 685, Integrated Electrical Systems, discusses some facilities with processes that could become a serious hazard if the process lost power. The hazard could endanger personnel or damage equipment. Examples include chemical processes, steel production and large electromagnets used for lifting scrap iron. In the case of the scrap iron, dropping it could seriously injure workers. Removal of power for chemical processes can create a hazard for personnel, including the potential for an explosion. Removal of power for melting steel can result in damage to processes and equipment.

The purpose of the NEC is the protection of personnel and property from hazards arising from the use of electricity. The use of Article 685 is very limited. As noted in the scope, it can be used where “an orderly shutdown is required to minimize personnel hazard and equipment damage.”

There is a requirement for qualified personnel to supervise and maintain the installation. The responsible person must have documented safety training on the hazards involved, which must be maintained in the office responsible for the installation. Finally, the safeguards used for the installation must be approved by the authority having jurisdiction. A circuit fault will usually be indicated by an alarm. This gives the trained personnel the opportunity to initiate an orderly shutdown. There is a table in 685.3 that refers to a number of sections in other parts of the Code that correlate the requirements for shutdown. The overcurrent protection rules in 240.12 and 240.13(1) govern installation where an orderly shutdown is essential.

• 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.

Chapter 6 — Special Equipment

Article 690 - Solar Photovoltaic (PV) Systems

• Part I. General
• 690.1 Scope.
• 690.2 Definitions.
• 690.4 General Requirements.
• 690.6 Alternating-Current (ac) Modules.
• Part II. Circuit Requirements

• 690.7 Maximum Voltage.
• 690.8 Circuit Sizing and Current.
• 690.9 Overcurrent Protection.
• 690.10 Stand-Alone Systems.
• 690.11 Arc-Fault Circuit Protection (Direct Current).
• 690.12 Rapid Shutdown of PV Systems on Buildings.
• Part III. Disconnecting Means

• 690.13 Building or Other Structure Supplied by a Photovoltaic SystemPhotovoltaic System Disconnecting Means.
• 690.15 Disconnection of Photovoltaic Equipment.
• Part IV. Wiring Methods

• 690.31 Methods Permitted.
• 690.32 Component Interconnections.
• 690.33 Connectors.
• 690.34 Access to Boxes.
• Part V. Grounding and Bonding

• 690.41 System Grounding.
• 690.42 Point of System Grounding Connection.
• 690.43 Equipment Grounding and Bonding.
• 690.45 Size of Equipment Grounding Conductors.
• 690.46 Array Equipment Grounding Conductors.
• 690.47 Grounding Electrode System.
• 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 Power Systems EmployingSystems Connected to Energy Storage Systems.
• 690.56 Identification of Power Sources.
• Part VII. Connection to Other Sources

• 690.59 Connection to Other Sources.
• Part VIII. Energy Storage Systems

• 690.71 InstallationGeneral.
• 690.72 Self-Regulated PV Charge Control.

Chapter 6 — Special Equipment

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.

Chapter 6 — Special Equipment

Article 692 - Fuel Cell Systems

Part I. General

• 692.1 Scope.
• 692.2 Definitions.
• 692.4 Installation.
• 692.6 Listing Requirement.
• Part II. Circuit Requirements

• 692.8 Circuit Sizing and Current.
• 692.9 Overcurrent Protection.
• 692.10 Stand-Alone Systems.
• 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.
• 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.

Chapter 6 — Special Equipment

Article 694 - Wind Electric Systems

• Part I. General
• 694.1 Scope.
• 694.2 Definitions.
• 694.7 Installation.
• Part II. Circuit Requirements

• 694.10 Maximum Voltage.
• 694.12 Circuit Sizing and Current.
• 694.15 Overcurrent Protection.
• Part III. Disconnecting Means

• 694.20 All Conductors.
• 694.22 Additional Provisions.
• 694.23 Turbine Shutdown.
• 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.
• Part V. Grounding and Bonding

• 694.40 Equipment 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.
• 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.

Chapter 6 — Special Equipment

Article 695 - Fire Pumps

• 695.1 Scope.
• 695.2 Definitions.
• 695.3 Power Source(s) for Electric Motor-Driven Fire Pumps.
• 695.4 Continuity of Power.
• 695.5 Transformers.
• 695.6 Power Wiring.
• 695.7 Voltage Drop.
• 695.10 Listed Equipment.
• 695.12 Equipment Location.
• 695.14 Control Wiring.
• 695.15 Surge Protection.

Chapter 7 — Special Conditions

Article 701 - Legally Required Standby Systems

Part I. General

• 701.1 Scope.
• 701.2 Definition.
• 701.3 Tests and Maintenance.
• 701.4 Capacity and Rating.
• 701.5 Transfer Equipment.
• 701.6 Signals.
• 701.7 Signs.
• Part II. Circuit Wiring

• 701.10 Wiring Legally Required Standby Systems.
• Part III. Sources of Power

• 701.12 General Requirements.
• Part IV. Overcurrent Protection

• 701.25 Accessibility.
• 701.26 Ground-Fault Protection of Equipment.
• 701.27 Selective Coordination.

Chapter 7 — Special Conditions

Article 701 - Legally Required Standby Systems

• Part I. General
• 701.1 Scope.
• 701.2 Definition.
• 701.3 Tests and Maintenance.
• 701.4 Capacity and Rating.
• 701.5 Transfer Equipment.
• 701.6 Signals.
• 701.7 Signs.
• Part II. Circuit Wiring

• 701.10 Wiring Legally Required Standby Systems.
• Part III. Sources of Power

• 701.12 General Requirements.
• Part IV. Overcurrent Protection

• 701.25 Accessibility.
• 701.26 Ground-Fault Protection of Equipment.
• 701.27 Selective Coordination.

Chapter 7 — Special Conditions

Article 702 - Optional Standby Systems

• Part I. General
• 702.1 Scope.
• 702.2 Definition.
• 702.4 Capacity and Rating.
• 702.5 Transfer Equipment.
• 702.6 Signals.
• 702.7 Signs.
• Part II. Wiring

• 702.10 Wiring Optional Standby Systems.
• 702.11 Portable Generator Grounding.
• 702.12 Outdoor Generator Sets.

Chapter 7 — Special Conditions

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.
• 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.
• 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.
• 705.65 Overcurrent Protection.
• 705.70 Utility-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.
• 705.100 Unbalanced Interconnections.
• 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).

Chapter 7 — Special Conditions

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.
• 706.8 Connection to Other Energy Sources.
• 706.10 Energy Storage System Locations.
• 706.11 Directory.
• Part II. Circuit Requirements

• 706.20 Circuit Sizing and Current.
• 706.21 Overcurrent Protection.
• 706.23 Charge Control.
• Part III. Electrochemical Energy Storage Systems

• 706.30 Installation of Batteries.
• 706.31 Battery and Cell Terminations.
• 706.32 Battery Interconnections.
• 706.33 Accessibility.
• 706.34 Battery Locations.
• 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.

Chapter 7 — Special Conditions

Article 708 - Critical Operations Power Systems (COPS)

• Part I. General
• 708.1 Scope.
• 708.2 Definitions.
• 708.4 Risk Assessment.
• 708.5 Physical Security.
• 708.6 Testing and Maintenance.
• 708.8 Commissioning.
• Part II. Circuit Wiring and Equipment

• 708.10 Feeder and Branch Circuit Wiring.
• 708.11 Branch Circuit and 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.
• 708.21 Ventilation.
• 708.22 Capacity of Power Sources.
• 708.24 Transfer Equipment.
• 708.30 Branch Circuits Supplied by COPS.
• Part IV. Overcurrent Protection

• 708.50 Accessibility.
• 708.52 Ground-Fault Protection of Equipment.
• 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.

Chapter 7 — Special Conditions

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.
• 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.
• Part VI. Protection

• 712.70 Overcurrent Protection.
• 712.72 Interrupting and Short-Circuit Current Ratings.
• Part VII. Systems over 1000 Volts

712.80 General.

Chapter 7 — Special Conditions

Article 720 - Circuits and Equipment Operating at Less Than 50 Volts

There isn’t a lot in Article 720, Circuits and Equipment Operating at Less Than 50 Volts. Several articles have their own requirements for installations operating at less than 50V.

• 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.

Chapter 7 — Special Conditions

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.
• 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.
• 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.
• 725.43 Class 1 Circuit Overcurrent Protection.
• 725.45 Class 1 Circuit Overcurrent Device Location.
• 725.46 Class 1 Circuit Wiring Methods.
• 725.48 Conductors of Different Circuits in the Same Cable, Cable Tray, Enclosure, or Raceway.
• 725.49 Class 1 Circuit Conductors.
• 725.51 Number of Conductors in Cable Trays and Raceway, and Ampacity Adjustment.
• 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.
• 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.
• 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.
• 725.136 Separation from Electric Light, Power, Class 1, Non–Power-Limited Fire Alarm Circuit Conductors, and Medium-Power Network-Powered Broadband Communications Cables.
• 725.139 Installation of Conductors of Different Circuits in the Same Cable, Enclosure, Cable Tray, Raceway, or Cable Routing Assembly.
• 725.141 Installation of Circuit Conductors Extending Beyond One Building.
• 725.143 Support of Conductors.
• 725.144 Transmission of Power and Data.
• 725.154 Applications of Listed Class 2, Class 3, and PLTC Cables.

• 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; Communications Raceways; and Cable Routing Assemblies.

Chapter 7 — Special Conditions

Article 727 - Instrumentation Tray Cable: Type ITC

Article 727, Instrument Tray Cable, is located in an odd place. These cables operate at 150V or less and 5A or less. For the 2023 Code , relocation to Chapter 3 has been proposed so that it appears with other wiring articles.

• 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.

Chapter 7 — Special Conditions

Article 728 - Fire-Resistive Cable Systems

• 728.1 Scope.
• 728.2 Definition.
• 728.3 Other Articles.
• 728.4 General.
• 728.5 Installations.
• 728.60 Grounding.
• 728.120 Marking.

Chapter 7 — Special Conditions

Article 750 - Energy Management Systems

• 750.1 Scope.
• 750.2 Definitions.
• 750.20 Alternate Power Sources.
• 750.30 Load Management.
• 750.50 Field Markings.

Chapter 7 — Special Conditions

Article 760 - Fire Alarm Systems

• Part I. General
• 760.1 Scope.
• 760.2 Definitions.
• 760.3 Other Articles.
• 760.21 Access to Electrical Equipment Behind Panels Designed to Allow Access.
• 760.24 Mechanical Execution of Work.
• 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.
• Part II. Non–Power-Limited Fire Alarm (NPLFA) Circuits

• 760.41 NPLFA Circuit Power Source Requirements.
• 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.
• 760.49 NPLFA Circuit Conductors.
• 760.51 Number of Conductors in Cable Trays and Raceways, and Ampacity Adjustment Factors.
• 760.53 Multiconductor NPLFA Cables.
• Part III. Power-Limited Fire Alarm (PLFA) Circuits

• 760.121 Power Sources for PLFA Circuits.
• 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.
• 760.133 Installation of Conductors and Equipment in Cables, Compartments, Cable Trays, Enclosures, Manholes, Outlet Boxes, Device Boxes, and RacewaysRaceways, and Cable Routing Assemblies for Power-Limited Fire Alarm Circuits.
• 760.135 Installation of PLFA Cables in Buildings.
• 760.136 Separation from Electric Light, Power, Class 1, NPLFA, and Medium-Power Network-Powered Broadband Communications Circuit Conductors.
• 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.
• 760.142 Conductor Size.
• 760.143 Support of Conductors.
• 760.145 Current-Carrying Continuous Line-Type Fire Detectors.
• 760.154 Applications of Listed PLFA Cables.
• Part IV. Listing Requirements

• 760.176 Listing and Marking of NPLFA Cables.
• 760.179 Listing and Marking of PLFA Cables and Insulated Continuous Line-Type Fire Detectors.

Chapter 7 — Special Conditions

Article 770 - Optical Fiber Cables

• Part I. General
• 770.1 Scope.
• 770.2 Definitions.
• 770.3 Other Articles.
• 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.
• 770.47 Underground Optical Fiber Cables Entering Buildings.
• 770.48 Unlisted Cables and Raceways Entering Buildings.
• 770.49 Metallic Entrance Conduit Grounding.
• Part III. Protection

• 770.93 Grounding or Interruption of Non–Current-Carrying Metallic Members of Optical Fiber Cables.
• Part IV. Grounding Methods

• 770.100 Entrance Cable Bonding and Grounding.
• 770.106 Grounding and Bonding of Entrance Cables at Mobile Homes.
• Part V. Installation Methods Within Buildings

• 770.110 Raceways and Cable Routing Assemblies for Optical Fiber Cables.
• 770.113 Installation of Optical Fiber Cables.
• 770.114 Grounding.
• 770.133 Installation of Optical Fibers and Electrical Conductors.
• 770.154 Applications of Listed Optical Fiber Cables.
• Part VI. Listing Requirements

• 770.179 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.
• 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.
• 800.47 Underground Communications Wires and Cables Entering Buildings.
• 800.48 Unlisted Cables Entering Buildings.
• 800.49 Metallic Entrance Conduit Grounding.
• 800.50 Circuits Requiring Primary Protectors.
• 800.53 Lightning Conductors.
• Part III. Protection

• 800.90 Protective Devices.
• 800.93 Grounding or Interruption of Non–Current-Carrying Metallic Sheath Members of Communications Cables.
• Part IV. Grounding Methods

• 800.100 Cable and Primary Protector Bonding and Grounding.
• 800.106 Primary Protector Grounding and Bonding at Mobile Homes.
• Part V. Installation Methods Within Buildings

• 800.110 Raceways and Cable Routing Assemblies for Communications Wires and Cables.
• 800.113 Installation of Communications Wires, Cables and Raceways, and Cable Routing Assemblies.
• 800.133 Installation of Communications Wires, Cables, and Equipment.
• 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.
• 800.173 Drop Wire and Cable.
• 800.179 Communications Wires and Cables.
• 800.180 Grounding Devices.
• 800.182 Communications Raceways and Cable Routing Assemblies and Communications Raceways.

Chapter 8 — Communications Systems

Article 810 - Radio and Television Equipment

Article 810, Radio and Television Equipment, covers radio and television receiving equipment installations, amateur radio transmission and receiving equipment and citizens band (CB) radio equipment. Amateur radio is licensed by the Federal Communications Commission (FCC). CB radio no longer requires a license. Most people using either of these services are unaware that they are also covered by the NEC because such installations are never inspected by an AHJ. The FCC reserves the right to inspect an installation; however, it is not inspecting for Code compliance, but is primarily concerned with transmissions that interfere with other radio services.

• 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.
• 810.17 Size of Lead-in — Receiving Station.
• 810.18 Clearances — Receiving Stations.
• 810.19 Electrical Supply Circuits Used in Lieu of Antenna — Receiving Stations.
• 810.20 Antenna Discharge Units — Receiving Stations.
• 810.21 Bonding Conductors and Grounding Electrode Conductors — Receiving Stations.
• 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.
• Part IV. Interior Installation — Transmitting Stations

• 810.70 Clearance from Other Conductors.
• 810.71 General.

Chapter 8 — Communications Systems

Article 820 - Community Antenna Television and Radio Distribution Systems

• Part I. General
• 820.1 Scope.
• 820.2 Definitions.
• 820.3 Other Articles.
• 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.
• 820.47 Underground Coaxial Cables Entering Buildings.
• 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.
• Part IV. Grounding Methods

• 820.100 Cable Bonding and Grounding.
• 820.103 Equipment Grounding.
• 820.106 Grounding and Bonding at Mobile Homes.
• Part V. Installation Methods Within Buildings

• 820.110 Raceways and Cable Routing Assemblies for Coaxial Cables.
• 820.113 Installation of Coaxial Cables.
• 820.133 Installation of Coaxial Cables and Equipment.
• 820.154 Applications of Listed CATV Cables.
• Part VI. Listing Requirements

• 820.179 Coaxial Cables.
• 820.180 Grounding Devices.

Chapter 8 — Communications Systems

Article 830 - Network-Powered Broadband Communications Systems

• Part I. General
• 830.1 Scope.
• 830.2 Definitions.
• 830.3 Other Articles.
• 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.
• 830.44 Overhead (Aerial) Cables.
• 830.47 Underground Network-Powered Broadband Communications Cables Entering Buildings.
• 830.49 Metallic Entrance Conduit Grounding.
• Part III. Protection

• 830.90 Primary Electrical Protection.
• 830.93 Grounding or Interruption of Metallic Members of Network-Powered Broadband Communications Cables.
• Part IV. Grounding Methods

• 830.100 Cable, Network Interface Unit, and Primary Protector Bonding and Grounding.
• 830.106 Grounding and Bonding at Mobile Homes.
• Part V. Installation Methods Within Buildings

• 830.110 Raceways and Cable Routing Assemblies for Network-Powered Broadband Communications Cables.
• 830.113 Installation of Network-Powered Broadband Communications Cables.
• 830.133 Installation of Network-Powered Broadband Communications Cables and Equipment.
• 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.
• 830.180 Grounding Devices.

Chapter 8 — Communications Systems

Article 840 - Premises-Powered Broadband Communications Systems

• Part I. General
• 840.1 Scope.
• 840.2 Definitions.
• 840.3 Other Articles.
• 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.
• 840.45 Overhead (Aerial) Communications Wires and Cables.
• 840.46 Overhead (Aerial) Coaxial Cables.
• 840.47 Underground Optical FiberWires and Cables Entering Buildings.
• 840.48 Unlisted Cables and RacewaysWires and Cables Entering Buildings.
• 840.49 Metallic Entrance Conduit Grounding.
• Part III. Protection

• 840.90 Protective Devices.
• 840.93 Grounding or Interruption.
• Part IV. Grounding Methods

• 840.100 ONT and Optical FiberNetwork Terminal and Cable Grounding.
• 840.101 Premises Circuits Not Leaving the Building.
• 840.106 Grounding and Bonding at Mobile Homes.
• Part V. Installation Methods Within Buildings

• 840.110 Raceways for Premises-Powered Broadband Communications Optical Fiber Cablesand Cable Routing Assemblies.
• 840.113 Installation Past the ONTon the Customer Premises Side of the Network Terminal.
• 840.133 Installation of Optical Fibers and Electrical Conductors Associated with Premises-Powered Broadband Communications Systems.
• 840.154 Applications of Listed Optical Fiber Cables and Raceways.
• Part VI. Premises Powering of Communications Equipment over Communications Cables

• 840.160 Powering Circuits.
• Part VII. Listing Requirements

• 840.170 Equipment and Cables.
• 840.180 Grounding Devices.