NFPA 70®: National Electrical Code® (NEC®) Softbound, 2008 Edition

NFPA 70 National Electrical Code 2008 Edition

ARTICLE 90 Introduction

Chapter 1 General

ARTICLE 100 Definitions

I. General
II. Over 600 Volts, Nominal

ARTICLE 110 Requirements for Electrical Installations

I. General
II. 600 Volts, Nominal, or Less
III. Over 600 Volts, Nominal
IV. Tunnel Installations over 600 Volts, Nominal
V. Manholes and Other Electrical Enclosures Intended for Personnel Entry, All Voltages

Chapter 2 Wiring and Protection

ARTICLE 200 Use and Identification of Grounded Conductors
ARTICLE 210 Branch Circuits

I. General Provisions
II. Branch-Circuit Ratings
III. Required Outlets

ARTICLE 215 Feeders
ARTICLE 220 Branch-Circuit, Feeder, and Service Calculations

I. General
II. Branch-Circuit Load Calculations
III. Feeder and Service Load Calculations
IV. Optional Feeder and Service Load Calculations
V. Farm Load Calculations

ARTICLE 225 Outside Branch Circuits and Feeders

I. General
II. More Than One Building or Other Structure
III. Over 600 Volts

ARTICLE 230 Services

I. General
II. Overhead Service-Drop Conductors
III. Underground Service-Lateral Conductors
IV. Service-Entrance Conductors
V. Service Equipment - General
VI. Service Equipment - Disconnecting Means
VII. Service Equipment - Overcurrent Protection
VIII. Services Exceeding 600 Volts, Nominal

ARTICLE 240 Overcurrent Protection

I. General
II. Location.
III. Enclosures
IV. Disconnecting and Guarding
V. Plug Fuses, Fuseholders, and Adapters
VI. Cartridge Fuses and Fuseholders
VII. Circuit Breakers
VIII. Supervised Industrial Installations
IX. Overcurrent Protection over 600 Volts, Nominal

ARTICLE 250 Grounding and Bonding

I. General
II. System Grounding
III. Grounding Electrode System and Grounding Electrode Conductor
IV. Enclosure, Raceway, and Service Cable Connections
V. Bonding
VI. Equipment Grounding and Equipment Grounding Conductors
VII. Methods of Equipment Grounding
VIII. Direct-Current Systems
IX. Instruments, Meters, and Relays
X. Grounding of Systems and Circuits of 1 kV and Over (High Voltage)

ARTICLE 280 Surge Arresters, Over 1 kV

I. General
II. Installation
III. Connecting Surge Arresters

ARTICLE 285 Surge-Protective Devices (SPDs), 1 kV or Less

I. General
II. Installation
III. Connecting SPDs.

Chapter 3 Wiring Methods and Materials

ARTICLE 300 Wiring Methods

I. General Requirements
II. Requirements for over 600 Volts, Nominal

ARTICLE 310 Conductors for General Wiring
ARTICLE 312 Cabinets, Cutout Boxes, and Meter Socket Enclosures

I. Installation
II. Construction Specifications

ARTICLE 314 Outlet, Device, Pull, and Junction Boxes; Conduit Bodies; Fittings; and Handhole Enclosures

I. Scope and General
II. Installation
III. Construction Specifications
IV. Pull and Junction Boxes for Use on Systems over 600 Volts, Nominal

ARTICLE 320 Armored Cable: Type AC

I. General
II. Installation
III. Construction Specifications

ARTICLE 322 Flat Cable Assemblies: Type FC

I. General
II. Installation
III. Construction

ARTICLE 324 Flat Conductor Cable: Type FCC

I. General
II. Installation
III. Construction

ARTICLE 326 Integrated Gas Spacer Cable: Type IGS

I. General
II. Installation
III. Construction Specifications

ARTICLE 328 Medium Voltage Cable: Type MV

I. General
II. Installation
III. Construction Specifications

ARTICLE 330 Metal-Clad Cable: Type MC

I. General
II. Installation
III. Construction Specifications

ARTICLE 332 Mineral-Insulated, Metal-Sheathed Cable: Type MI

I. General
II. Installation
III. Construction Specifications

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

I. General
II. Installation
III. Construction Specifications

ARTICLE 336 Power and Control Tray Cable: Type TC

I. General
II. Installation
III. Construction Specifications

ARTICLE 338 Service-Entrance Cable: Types SE and USE

I. General
II. Installation
III. Construction

ARTICLE 340 Underground Feeder and Branch-Circuit Cable: Type UF

I. General
II. Installation
III. Construction Specifications

ARTICLE 342 Intermediate Metal Conduit: Type IMC

I. General
II. Installation
III. Construction Specifications

ARTICLE 344 Rigid Metal Conduit: Type RMC

I. General
II. Installation
III. Construction Specifications

ARTICLE 348 Flexible Metal Conduit: Type FMC

I. General
II. Installation

ARTICLE 350 Liquidtight Flexible Metal Conduit: Type LFMC

I. General
II. Installation
III. Construction Specifications

ARTICLE 352 Rigid Polyvinyl Chloride Conduit: Type PVC

I. General
II. Installation
III. Construction Specifications

ARTICLE 353 High Density Polyethylene Conduit: Type HDPE Conduit

I. General
II. Installation
III. Construction Specifications

ARTICLE 354 Nonmetallic Underground Conduit with Conductors: Type NUCC

I. General
II. Installation
III. Construction Specifications

ARTICLE 355 Reinforced Thermosetting Resin Conduit: Type RTRC

I. General
II. Installation
III. Construction Specifications

ARTICLE 356 Liquidtight Flexible Nonmetallic Conduit: Type LFNC

I. General
II. Installation
III. Construction Specifications

ARTICLE 358 Electrical Metallic Tubing: Type EMT

I. General
II. Installation
III. Construction Specifications

ARTICLE 360 Flexible Metallic Tubing: Type FMT

I. General
II. Installation
III. Construction Specifications

ARTICLE 362 Electrical Nonmetallic Tubing: Type ENT

I. General
II. Installation
III. Construction Specifications

ARTICLE 366 Auxiliary Gutters

I. General
II. Installation
III. Construction Specifications

ARTICLE 368 Busways

I. General Requirements
II. Installation
III. Construction
IV. Requirements for Over 600 Volts, Nominal

ARTICLE 370 Cablebus
ARTICLE 372 Cellular Concrete Floor Raceways
ARTICLE 374 Cellular Metal Floor Raceways

I. Installation
II. Construction Specifications

ARTICLE 376 Metal Wireways

I. General
II. Installation
III. Construction Specifications

ARTICLE 378 Nonmetallic Wireways

I. General
II. Installation
III. Construction Specifications

ARTICLE 380 Multioutlet Assembly
ARTICLE 382 Nonmetallic Extensions

I. General
II. Installation
III. Construction Specifications (Concealable Nonmetallic Extensions only)

ARTICLE 384 Strut-Type Channel Raceway

I. General
II. Installation
III. Construction Specifications

ARTICLE 386 Surface Metal Raceways

I. General
II. Installation
III. Construction Specifications

ARTICLE 388 Surface Nonmetallic Raceways

I. General
II. Installation
III. Construction Specifications

ARTICLE 390 Underfloor Raceways
ARTICLE 392 Cable Trays
ARTICLE 394 Concealed Knob-and-Tube Wiring

I. General
II. Installation
III. Construction Specifications

ARTICLE 396 Messenger-Supported Wiring

I. General
II. Installation

ARTICLE 398 Open Wiring on Insulators

I. General
II. Installation
III. Construction Specifications

Chapter 4 Equipment for General Use

ARTICLE 400 Flexible Cords and Cables

I. General
II. Construction Specifications
III. Portable Cables Over 600 Volts, Nominal

ARTICLE 402 Fixture Wires
ARTICLE 404 Switches

I. Installation
II. Construction Specifications

ARTICLE 406 Receptacles, Cord Connectors, and Attachment Plugs (Caps)
ARTICLE 408 Switchboards and Panelboards

I. General
II. Switchboards
III. Panelboards
IV. Construction Specifications

ARTICLE 409 Industrial Control Panels

I. General
II. Installation
III. Construction Specifications

ARTICLE 410 Luminaires, Lampholders, and Lamps

I. General
II. Luminaire Locations
III. Provisions at Luminaire Outlet Boxes, Canopies, and Pans
IV. Luminaire Supports
V. Grounding
VI. Wiring of Luminaires
VII. Construction of Luminaires
VIII. Installation of Lampholders
IX. Construction of Lampholders
X. Lamps and Auxiliary Equipment
XI. Special Provisions for Flush and Recessed Luminaires
XII. Construction of Flush and Recessed Luminaires
XIII. Special Provisions for Electric-Discharge Lighting Systems of 1000 Volts or Less
XIV. Special Provisions for Electric-Discharge Lighting Systems of More Than 1000 Volts
XV. Lighting Track
XVI. Decorative Lighting and Similar Accessories

ARTICLE 411 Lighting Systems Operating at 30 Volts or Less
ARTICLE 422 Appliances

I. General
II. Installation
III. Disconnecting Means
IV. Construction
V. Marking

ARTICLE 424 Fixed Electric Space-Heating Equipment

I. General
II. Installation
III. Control and Protection of Fixed Electric Space-Heating Equipment
IV. Marking of Heating Equipment
V. Electric Space-Heating Cables
VI. Duct Heaters
VII. Resistance-Type Boilers
VIII. Electrode-Type Boilers
IX. Electric Radiant Heating Panels and Heating Panel Sets

ARTICLE 426 Fixed Outdoor Electric Deicing and Snow-Melting Equipment

I. General
II. Installation
III. Resistance Heating Elements
IV. Impedance Heating
V. Skin-Effect Heating
VI. Control and Protection

ARTICLE 427 Fixed Electric Heating Equipment for Pipelines and Vessels

I. General
II. Installation
III. Resistance Heating Elements
IV. Impedance Heating
V. Induction Heating
VI. Skin-Effect Heating
VII. Control and Protection

ARTICLE 430 Motors, Motor Circuits, and Controllers

I. General
II. Motor Circuit Conductors
III. Motor and Branch-Circuit Overload Protection
IV. Motor Branch-Circuit Short-Circuit and Ground-Fault Protection
V. Motor Feeder Short-Circuit and Ground-Fault Protection
VI. Motor Control Circuits
VII. Motor Controllers
VIII. Motor Control Centers
IX. Disconnecting Means
X. Adjustable-Speed Drive Systems
XI. Over 600 Volts, Nominal
XII. Protection of Live Parts - All Voltages
XIII. Grounding - All Voltages
XIV. Tables

ARTICLE 440 Air-Conditioning and Refrigerating Equipment

I. General
II. Disconnecting Means
III. Branch-Circuit Short-Circuit and Ground-Fault Protection
IV. Branch-Circuit Conductors
V. Controllers for Motor-Compressors
VI. Motor-Compressor and Branch-Circuit Overload Protection
VII. Provisions for Room Air Conditioners

ARTICLE 445 Generators
ARTICLE 450 Transformers and Transformer Vaults (Including Secondary Ties)

I. General Provisions
II. Specific Provisions Applicable to Different Types of Transformers
III. Transformer Vaults

ARTICLE 455 Phase Converters

I. General
II. Specific Provisions Applicable to Different Types of Phase Converters

ARTICLE 460 Capacitors

I. 600 Volts, Nominal, and Under
II. Over 600 Volts, Nominal

ARTICLE 470 Resistors and Reactors

I. 600 Volts, Nominal, and Under
II. Over 600 Volts, Nominal

ARTICLE 480 Storage Batteries
ARTICLE 490 Equipment, Over 600 Volts, Nominal

I. General
II. Equipment - Specific Provisions
III. Equipment - Metal-Enclosed Power Switchgear and Industrial Control Assemblies
IV. Mobile and Portable Equipment
V. Electrode-Type Boilers

Chapter 5 Special Occupancies

ARTICLE 500 Hazardous (Classified) Locations, Classes I, II, and III, Divisions 1 and 2
ARTICLE 501 Class I Locations

I. General
II. Wiring
III. Equipment

ARTICLE 502 Class II Locations

I. General
II. Wiring
III. Equipment

ARTICLE 503 Class III Locations

I. General
II. Wiring
III. Equipment

ARTICLE 504 Intrinsically Safe Systems
ARTICLE 505 Class I, 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, and Coating Processes
ARTICLE 517 Health Care Facilities

I. General
II. Wiring and Protection
III. Essential Electrical System
IV. Inhalation Anesthetizing Locations
V. X-Ray Installations
VI. Communications, Signaling Systems, Data Systems, Fire Alarm Systems, and Systems Less Than 120 Volts, Nominal
VII. Isolated Power Systems

ARTICLE 518 Assembly Occupancies
ARTICLE 520 Theaters, Audience Areas of Motion Picture and Television Studios, Performance Areas, and Similar Locations

I. General
II. Fixed Stage Switchboards
III. Fixed Stage Equipment Other Than Switchboards
IV. Portable Switchboards on Stage
V. Portable Stage Equipment Other Than Switchboards
VI. Dressing Rooms
VII. Grounding

ARTICLE 522 Control Systems for Permanent Amusement Attractions

I. General.
II. Control Circuits.
III. Control Circuit Wiring Methods.

ARTICLE 525 Carnivals, Circuses, Fairs, and Similar Events

I. General Requirements
II. Power Sources
III. Wiring Methods
IV. Grounding and Bonding

ARTICLE 530 Motion Picture and Television Studios and Similar Locations

I. General
II. Stage or Set
III. Dressing Rooms
IV. Viewing, Cutting, and Patching Tables
V. Cellulose Nitrate Film Storage Vaults
VI. Substations

ARTICLE 540 Motion Picture Projection Rooms

I. General
II. Equipment and Projectors of the Professional Type
III. Nonprofessional Projectors
IV. Audio Signal Processing, Amplification, and Reproduction Equipment

ARTICLE 545 Manufactured Buildings
ARTICLE 547 Agricultural Buildings
ARTICLE 550 Mobile Homes, Manufactured Homes, and Mobile Home Parks

I. General
II. Mobile and Manufactured Homes
III. Services and Feeders

ARTICLE 551 Recreational Vehicles and Recreational Vehicle Parks

I. General
II. Combination Electrical Systems
III. Other Power Sources
IV. Nominal 120-Volt or 120/240-Volt Systems
V. Factory Tests
VI. Recreational Vehicle Parks

ARTICLE 552 Park Trailers

I. General
II. Low-Voltage Systems
III. Combination Electrical Systems
IV. Nominal 120-Volt or 120/240-Volt Systems
V. Factory Tests

ARTICLE 553 Floating Buildings

I. General
II. Services and Feeders
III. Grounding

ARTICLE 555 Marinas and Boatyards
ARTICLE 590 Temporary Installations

Chapter 6 Special Equipment

ARTICLE 600 Electric Signs and Outline Lighting

I. General
II. Field-Installed Skeleton Tubing and Wiring

ARTICLE 604 Manufactured Wiring Systems
ARTICLE 605 Office Furnishings (Consisting of Lighting Accessories and Wired Partitions)
ARTICLE 610 Cranes and Hoists

I. General
II. Wiring
III. Contact Conductors
IV. Disconnecting Means
V. Overcurrent Protection
VI. Control
VII. Grounding

ARTICLE 620 Elevators, Dumbwaiters, Escalators, Moving Walks, Platform Lifts, and Stairway Chairlifts

I. General
II. Conductors
III. Wiring
IV. Installation of Conductors
V. Traveling Cables
VI. Disconnecting Means and Control
VII. Overcurrent Protection
VIII. Machine Rooms, Control Rooms, Machinery Spaces, and Control Spaces
IX. Grounding
X. Emergency and Standby Power Systems

ARTICLE 625 Electric Vehicle Charging System

I. General
II. Wiring Methods
III. Equipment Construction
IV. Control and Protection
V. Electric Vehicle Supply Equipment Locations

ARTICLE 626 Electrified Truck Parking Spaces

I. General
II. Electrified Truck Parking Space Electrical Wiring Systems
III. Electrified Truck Parking Space Supply Equipment
IV. Transport Refrigerated Units (TRUs)

ARTICLE 630 Electric Welders

I. General
II. Arc Welders
III. Resistance Welders
IV. Welding Cable

ARTICLE 640 Audio Signal Processing, Amplification, and Reproduction Equipment

I. General
II. Permanent Audio System Installations
III. Portable and Temporary Audio System Installations

ARTICLE 645 Information Technology Equipment

TIA

ARTICLE 647 Sensitive Electronic Equipment
ARTICLE 650 Pipe Organs
ARTICLE 660 X-Ray Equipment

I. General
II. Control
III. Transformers and Capacitors
IV. Guarding and Grounding

ARTICLE 665 Induction and Dielectric Heating Equipment

I. General
II. Guarding, Grounding, and Labeling

ARTICLE 668 Electrolytic Cells
ARTICLE 669 Electroplating
ARTICLE 670 Industrial Machinery
ARTICLE 675 Electrically Driven or Controlled Irrigation Machines

I. General
II. Center Pivot Irrigation Machines

ARTICLE 680 Swimming Pools, Fountains, and Similar Installations

I. General
II. Permanently Installed Pools
III. Storable Pools
IV. Spas and Hot Tubs
V. Fountains
VI. Pools and Tubs for Therapeutic Use
VII. Hydromassage Bathtubs

ARTICLE 682 Natural and Artificially Made Bodies of Water

I. General
II. Installation
III. Grounding and Bonding

ARTICLE 685 Integrated Electrical Systems

I. General
II. Orderly Shutdown

ARTICLE 690 Solar Photovoltaic Systems

I. General
II. Circuit Requirements
III. Disconnecting Means
IV. Wiring Methods
V. Grounding
VI. Marking
VII. Connection to Other Sources
VIII. Storage Batteries
IX. Systems over 600 Volts

ARTICLE 692 Fuel Cell Systems

I. General
II. Circuit Requirements
III. Disconnecting Means
IV. Wiring Methods
V. Grounding
VI. Marking
VII. Connection to Other Circuits
VIII. Outputs Over 600 Volts

ARTICLE 695 Fire Pumps

Chapter 7 Special Conditions

ARTICLE 700 Emergency Systems

I. General
II. Circuit Wiring
III. Sources of Power
IV. Emergency System Circuits for Lighting and Power
V. Control - Emergency Lighting Circuits
VI. Overcurrent Protection

ARTICLE 701 Legally Required Standby Systems

I. General
II. Circuit Wiring
III. Sources of Power
IV. Overcurrent Protection

ARTICLE 702 Optional Standby Systems

I. General
II. Circuit Wiring
III. Grounding
IV. Sources of Power

ARTICLE 705 Interconnected Electric Power Production Sources

I. General
II. Utility-Interactive Inverters
III. Generators

ARTICLE 708 Critical Operations Power Systems (COPS)

I. General
II. Circuit Wiring and Equipment
III. Power Sources and Connection
IV. Overcurrent Protection
V. System Performance and Analysis

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

I. General
II. Class 1 Circuits
III. Class 2 and Class 3 Circuits
IV. Listing Requirements

ARTICLE 727 Instrumentation Tray Cable: Type ITC
ARTICLE 760 Fire Alarm Systems

I. General
II. NonPower-Limited Fire Alarm (NPLFA) Circuits
III. Power-Limited Fire Alarm (PLFA) Circuits
IV. Listing Requirements

ARTICLE 770 Optical Fiber Cables and Raceways

I. General
II. Cables Outside and Entering Buildings.
III. Protection
IV. Grounding Methods
V. Installation Methods Within Buildings
VI. Listing Requirements

Chapter 8 Communications Systems

ARTICLE 800 Communications Circuits

I. General
II. Wires and Cables Outside and Entering Buildings
III. Protection
IV. Grounding Methods
V. Installation Methods Within Buildings
VI. Listing Requirements

ARTICLE 810 Radio and Television Equipment

I. General
II. Receiving Equipment - Antenna Systems
III. Amateur Transmitting and Receiving Stations - Antenna Systems
IV. Interior Installation - Transmitting Stations

ARTICLE 820 Community Antenna Television and Radio Distribution Systems

I. General
II. Coaxial Cables Outside and Entering Buildings
III. Protection
IV. Grounding Methods
V. Installation Methods Within Buildings
VI. Listing Requirements

ARTICLE 830 Network-Powered Broadband Communications Systems

I. General
II. Cables Outside and Entering Buildings
III. Protection
IV. Grounding Methods
V. Installation Methods Within Buildings
VI. Listing Requirements

Chapter 9 Tables

Annex A Product Safety Standards

Annex B Application Information for Ampacity Calculation

Annex C Conduit and Tubing Fill Tables for Conductors and Fixture Wires of the Same Size

Annex D Examples

Annex E Types of Construction

Annex F Availability and Reliability for Critical Operations Power Systems; and Development and Implementation of Functional Performance Tests (FPTs) for Critical Operations Power Systems

Annex G Supervisory Control and Data Acquisition (SCADA).

Annex H Administration and Enforcement

Formal Interpretations

Tentative Interim Amendment

Index

A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Z