What is NFPA 70?

Adopted in all 50 states, the NEC is the benchmark for safe electrical design, installation, and inspection to protect people and property from electrical hazards.

What does NFPA 70 address?

The NEC addresses the installation of electrical conductors, equipment, and raceways; signaling and communications conductors, equipment, and raceways; and optical fiber cables and raceways in commercial, residential, and industrial occupancies.

Description

Hundreds of changes in the 2017 edition NEC® bring you up-to-code and ready to address new sources of electrical power.

Throughout the United States and around the world, NFPA 70®: National Electrical Code® (NEC) sets the foundation for electrical safety in residential, commercial, and industrial occupancies. The 2017 edition of this trusted Code presents the latest comprehensive regulations for electrical wiring, overcurrent protection, grounding, and installation of equipment.

NFPA 70: NEC has been published since 1897, and a rigorous process of review keeps it up-to-date with new technologies. In fact, more than 4,000 public inputs and 1,500 comments went into the 2017 NEC alone. Hundreds of updates and five all-new articles pave the way to a safe and efficient electrical future.

Major additions reflect the continuing growth in renewable power technology.

The newest NEC addresses the advancement of privately owned wind and solar power generation and distribution equipment -- including coverage of higher voltage systems that were once only the utilities' domain. The new consumer role is a major factor in energy decentralization, and expanded NEC coverage is vital for designers, engineers, contractors, and AHJs.

• Large-Scale Photovoltaic (PV) Electric Power Production Facility (New Article 691) covers systems that produce at least 5 megawatts (MW) of power, or enough to power 800+ U.S. homes.
• Energy Storage Systems (New Article 706) governs ESS installation, disconnection, shutdown, and safety labeling.
• Stand-Alone Systems (New Article 710) covers power production sources that are not connected to the grid, including PV and wind-powered systems.
• Direct Current Microgrids (New Article 712) concerns independent energy distribution networks that allow the utilization of power from dc sources to direct-current loads. Microgrids are on the rise worldwide.

Other NEC revisions protect the public and workers from deadly hazards.

• New labeling, such as detailed arc flash hazard warning on equipment, helps workers and supervisors assess electrical risks.
• New minimum space clearances for equipment installation clarify the safeguards needed to protect installers and maintainers.
• Fixed Resistance and Electrode Industrial Process Heating Equipment (New Article 425) presents needed regulations for industry.
• Revised provisions for AFCI and GFCI protection improve electrical and fire safety in homes.

Be prepared to protect lives and property in the ever-changing electrical landscape. Order the 2017 National Electrical Code.

Work with the latest requirements governing public and private buildings, homes, and structures; outdoor yards and lots; utility equipment; installations that connect to the power grid; and consumer-owned power generation systems and equipment. The 2017 NEC is better aligned with the safe work practices in NFPA 70E®: Standard for Electrical Safety in the Workplace®. (Softbound, 888 pp., 2017)

Table of Contents

NFPA 70® National Electrical Code®, 2017 Edition

90 Introduction

Chapter 1 General 
100 Definitions 
110 Requirements for Electrical Installations

Chapter 2 Wiring and Protection 
200 Use and Identification of Grounded Conductors 
210 Branch Circuits 
215 Feeders 
220 Branch-Circuit, Feeder, and Service Load Calculations 
225 Outside Branch Circuits and Feeders 
230 Services 
240 Overcurrent Protection 
250 Grounding and Bonding 
280 Surge Arresters, Over 1000 Volts 
285 Surge-Protective Devices (SPDs), 1000 Volts or Less

Chapter 3 Wiring Methods and Materials 
300 General Requirements for Wiring Methods and Materials 
310 Conductors for General Wiring 
312 Cabinets, Cutout Boxes, and Meter Socket Enclosures 
314 Outlet, Device, Pull, and Junction Boxes; Conduit Bodies; Fittings; and Handhole Enclosures 
320 Armored Cable: Type AC 
322 Flat Cable Assemblies: Type FC 
324 Flat Conductor Cable: Type FCC 
326 Integrated Gas Spacer Cable: Type IGS 
328 Medium Voltage Cable: Type MV 
330 Metal-Clad Cable: Type MC 
332 Mineral-Insulated, Metal-Sheathed Cable: Type MI 
334 Nonmetallic-Sheathed Cable: Types NM, NMC, and NMS 
336 Power and Control Tray Cable: Type TC 
338 Service-Entrance Cable: Types SE and USE 
340 Underground Feeder and Branch-Circuit Cable: Type UF 
342 Intermediate Metal Conduit: Type IMC 
344 Rigid Metal Conduit: Type RMC 
348 Flexible Metal Conduit: Type FMC 
350 Liquidtight Flexible Metal Conduit: Type LFMC 
352 Rigid Polyvinyl Chloride Conduit: Type PVC 
353 High Density Polyethylene Conduit: Type HDPE Conduit 
354 Nonmetallic Underground Conduit with Conductors: Type NUCC 
355 Reinforced Thermosetting Resin Conduit: Type RTRC 
356 Liquidtight Flexible Nonmetallic Conduit: Type LFNC 
358 Electrical Metallic Tubing: Type EMT 
360 Flexible Metallic Tubing: Type FMT 
362 Electrical Nonmetallic Tubing: Type ENT 
366 Auxiliary Gutters 
368 Busways 
370 Cablebus 
372 Cellular Concrete Floor Raceways 
374 Cellular Metal Floor Raceways 
376 Metal Wireways 
378 Nonmetallic Wireways 
380 Multioutlet Assembly 
382 Nonmetallic Extensions 
384 Strut-Type Channel Raceway 
386 Surface Metal Raceways 
388 Surface Nonmetallic Raceways 
390 Underfloor Raceways 
392 Cable Trays 
393 Low-Voltage Suspended Ceiling Power Distribution Systems 
394 Concealed Knob-and-Tube Wiring 
396 Messenger-Supported Wiring 
398 Open Wiring on Insulators 
399 Outdoor Overhead Conductors over 1000 Volts

Chapter 4 Equipment for General Use 
400 Flexible Cords and Flexible Cables 
402 Fixture Wires 
404 Switches 
406 Receptacles, Cord Connectors, and Attachment Plugs (Caps) 
408 Switchboards, Switchgear, and Panelboards 
409 Industrial Control Panels 
410 Luminaires, Lampholders, and Lamps 
411 Low-Voltage Lighting 
422 Appliances 
424 Fixed Electric Space-Heating Equipment 
425 Fixed Resistance and Electrode Industrial Process Heating Equipment 
426 Fixed Outdoor Electric Deicing and Snow-Melting Equipment 
427 Fixed Electric Heating Equipment for Pipelines and Vessels 
430 Motors, Motor Circuits, and Controllers 
440 Air-Conditioning and Refrigerating Equipment 
445 Generators 
450 Transformers and Transformer Vaults (Including Secondary Ties) 
455 Phase Converters 
460 Capacitors 
470 Resistors and Reactors 
480 Storage Batteries 
490 Equipment Over 1000 Volts, Nominal

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

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

Chapter 7 Special Conditions 
700 Emergency Systems 
701 Legally Required Standby Systems 
702 Optional Standby Systems 
705 Interconnected Electric Power Production Sources 
706 Energy Storage Systems 
708 Critical Operations Power Systems (COPS) 
710 Stand-Alone Systems 
712 Direct Current Microgrids 
720 Circuits and Equipment Operating at Less Than 50 Volts 
725 Class 1, Class 2, and Class 3 Remote-Control, Signaling, and Power-Limited Circuits 
727 Instrumentation Tray Cable: Type ITC 
728 Fire-Resistive Cable Systems 
750 Energy Management Systems 
760 Fire Alarm Systems 
770 Optical Fiber Cables

Chapter 8 Communications Systems 
800 Communications Circuits 
810 Radio and Television Equipment 
820 Community Antenna Television and Radio Distribution Systems 
830 Network-Powered Broadband Communications Systems 
840 Premises-Powered Broadband Communications Systems

Chapter 9 Tables 
Informative Annex A Product Safety Standards 
Informative Annex B Application Information for Ampacity Calculation 
Informative Annex C Conduit and Tubing Fill Tables for Conductors and Fixture Wires of the Same Size 
Informative Annex D Examples 
Informative Annex E Types of Construction 
Informative Annex F Availability and Reliability for Critical Operations Power Systems; and Development and Implementation of Functional Performance Tests (FPTs) for Critical Operations Power Systems 
Informative Annex G Supervisory Control and Data Acquisition (SCADA) 
Informative Annex H Administration and Enforcement 
Informative Annex I Recommended Tightening Torque Tables from UL Standard 486A-B 
Informative Annex J ADA Standards for Accessible Design 
Index