NFPA_70,_National_Electrical_Code.pdf

NFPA 70

National Electrical Code International Electrical Code® Series

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NFPA 70®

National Electrical Code®

2017 Edition

This edition of NFPA 70, National Electrical Code, was prepared by the National Electrical Code Committee and acted on by NFPA at its June Association Technical Meeting held June 13–16, 2016, in Las Vegas, NV. It was issued by the Standards Council on August 4, 2016, with an effective date of August 24, 2016, and supersedes all previous editions.

This document has been amended by one or more Tentative Interim Amendments (TIAs) and/or Errata. See “Codes & Standards” at www.nfpa.org for more information.

This edition of NFPA 70 was approved as an American National Standard on August 24, 2016.

History and Development of the National Electrical Code ®

The National Fire Protection Association has acted as sponsor of the National Electrical Code since 1911. The original Code document was developed in 1897 as a result of the united efforts of various insurance, electrical, architectural, and allied interests.

In accordance with the Regulations Governing the Development of NFPA Standards, a National Electrical Code First Draft Report containing proposed amendments to the 2014 National Electrical Code was published by NFPA in July 2015. This report recorded the actions of the various Code- Making Panels and the Correlating Committee of the National Electrical Code Committee on each public input and first revision that had been made to revise the 2014 Code. The report was published at www.nfpa.org/70. Following the close of the public comment period, the Code-Making Panels met, acted on each comment, and created some second revisions, which were reported to the Correlating Committee. NFPA published the National Electrical Code Second Draft Report in April 2016, which recorded the actions of the Code-Making Panels and the Correlating Committee on each public comment on the National Electrical Code Committee First Draft Report. The National Electrical Code First Draft Report and the National Electrical Code Second Draft Report were presented to the 2016 June Association Technical Meeting for adoption.

NFPA has an Electrical Section that provides particular opportunity for NFPA members interested in electrical safety to become better informed and to contribute to the development of the National Electrical Code and other NFPA electrical standards. At the Electrical Section Codes and Standards Review Session held at the 2016 NFPA Conference and Expo, Section members had the opportunity to discuss and review the report of the National Electrical Code Committee prior to the adoption of this edition of the Code by the Association at its 2016 June Technical Session.

This 54th edition supersedes all other previous editions, supplements, and printings dated 1897, 1899, 1901, 1903, 1904, 1905, 1907, 1909, 1911, 1913, 1915, 1918, 1920, 1923, 1925, 1926, 1928, 1930, 1931, 1933, 1935, 1937, 1940, 1942, 1943, 1947, 1949, 1951, 1953, 1954, 1955, 1956, 1957, 1958, 1959, 1962, 1965, 1968, 1971, 1975, 1978, 1981, 1984, 1987, 1990, 1993, 1996, 1999, 2002, 2005, 2008, 2011, and 2014.

This Code is purely advisory as far as NFPA is concerned. It is made available for a wide variety of both public and private uses in the interest of life and property protection. These include both use in law and for regulatory purposes and use in private self-regulation and standardization activities such as insurance underwriting, building and facilities construction and management, and product testing and certification.

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NATIONAL ELECTRICAL CODE

70 –2 NATIONAL ELECTRICAL CODE 2017 Edition

Contents

90 Introduction ......................................................... 70– 30

Chapter 1 General 100 Definitions ............................................................ 70– 33 Part I. General ................................................................. 70– 33 Part II. Over 1000 Volts, Nominal .................................... 70– 42 110 Requirements for Electrical Installations ........... 70– 43 Part I. General ................................................................. 70– 43 Part II. 1000 Volts, Nominal, or Less ............................... 70– 47 Part III. Over 1000 Volts, Nominal .................................... 70– 49 Part IV. Tunnel Installations over 1000 Volts, Nominal .. 70– 52 Part V. Manholes and Other Electrical Enclosures

Intended for Personnel Entry ............................ 70– 53

Chapter 2 Wiring and Protection 200 Use and Identification of Grounded

Conductors ........................................................... 70– 55 210 Branch Circuits .................................................... 70– 57 Part I. General Provisions ............................................... 70– 57 Part II. Branch-Circuit Ratings ........................................ 70– 61 Part III. Required Outlets .................................................. 70– 63 215 Feeders .................................................................. 70– 67 220 Branch-Circuit, Feeder, and Service Load

Calculations .......................................................... 70– 70 Part I. General ................................................................. 70– 70 Part II. Branch-Circuit Load Calculations ....................... 70– 70 Part III. Feeder and Service Load Calculations ............... 70– 72 Part IV. Optional Feeder and Service Load

Calculations .......................................................... 70– 75 Part V. Farm Load Calculations ....................................... 70– 77 225 Outside Branch Circuits and Feeders ................. 70– 78 Part I. General ................................................................. 70– 78 Part II. Buildings or Other Structures Supplied by a

Feeder(s) or Branch Circuit(s) ........................... 70– 81 Part III. Over 1000 Volts. ................................................... 70– 82 230 Services ................................................................. 70– 84 Part I. General ................................................................. 70– 84 Part II. Overhead Service Conductors ............................. 70– 85 Part III. Underground Service Conductors ...................... 70– 86 Part IV. Service-Entrance Conductors .............................. 70– 86 Part V. Service Equipment — General ........................... 70– 89 Part VI. Service Equipment — Disconnecting Means ..... 70– 89 Part VII. Service Equipment — Overcurrent Protection .. 70– 90 Part VIII. Services Exceeding 1000 Volts, Nominal ............ 70– 92 240 Overcurrent Protection ....................................... 70– 93 Part I. General ................................................................. 70– 93 Part II. Location ................................................................ 70– 96 Part III. Enclosures ............................................................ 70– 99 Part IV. Disconnecting and Guarding .............................. 70– 99 Part V. Plug Fuses, Fuseholders, and Adapters .............. 70– 99 Part VI. Cartridge Fuses and Fuseholders ........................ 70– 100 Part VII. Circuit Breakers ................................................... 70– 100 Part VIII. Supervised Industrial Installations ...................... 70– 101 Part IX. Overcurrent Protection over 1000 Volts, Nominal ................................................................ 70– 103 250 Grounding and Bonding ..................................... 70– 103 Part I. General ................................................................. 70– 103 Part II. System Grounding ............................................... 70– 106 Part III. Grounding Electrode System and Grounding

Electrode Conductor ........................................... 70– 112 Part IV. Enclosure, Raceway, and Service Cable

Connections ......................................................... 70– 116 Part V. Bonding ................................................................ 70– 117

Part VI. Equipment Grounding and Equipment Grounding Conductors ....................................... 70– 121

Part VII. Methods of Equipment Grounding .................... 70– 125 Part VIII. Direct-Current Systems ........................................ 70– 127 Part IX. Instruments, Meters, and Relays ......................... 70– 128 Part X. Grounding of Systems and Circuits of over

1000 Volts ............................................................. 70– 129 280 Surge Arresters, Over 1000 Volts ......................... 70– 131 Part I. General ................................................................. 70– 131 Part II. Installation ............................................................ 70– 132 Part III. Connecting Surge Arresters ................................ 70– 132 285 Surge-Protective Devices (SPDs), 1000 Volts or

Less ....................................................................... 70– 132 Part I. General ................................................................. 70– 132 Part II. Installation ............................................................ 70– 133 Part III. Connecting SPDs ................................................. 70– 133

Chapter 3 Wiring Methods and Materials 300 General Requirements for Wiring Methods and

Materials ............................................................... 70– 134 Part I. General Requirements ......................................... 70– 134 Part II. Requirements for over 1000 Volts, Nominal ...... 70– 143 310 Conductors for General Wiring .......................... 70– 144 Part I. General ................................................................. 70– 144 Part II. Installation ............................................................ 70– 145 Part III. Construction Specifications ................................ 70– 154 312 Cabinets, Cutout Boxes, and Meter Socket

Enclosures ............................................................ 70– 171 Part I. Scope and Installation ......................................... 70– 171 Part II. Construction Specifications ................................ 70– 173 314 Outlet, Device, Pull, and Junction Boxes;

Conduit Bodies; Fittings; and Handhole Enclosures ............................................................ 70– 175

Part I. Scope and General ............................................... 70– 175 Part II. Installation ............................................................ 70– 175 Part III. Construction Specifications ................................ 70– 181 Part IV. Pull and Junction Boxes, Conduit Bodies, and

Handhole Enclosures for Use on Systems over 1000 Volts, Nominal ............................................. 70– 181

320 Armored Cable: Type AC ..................................... 70– 182 Part I. General ................................................................. 70– 182 Part II. Installation ............................................................ 70– 182 Part III. Construction Specifications ................................ 70– 183 322 Flat Cable Assemblies: Type FC ........................... 70– 183 Part I. General ................................................................. 70– 183 Part II. Installation ............................................................ 70– 184 Part III. Construction Specifications ............................... 70– 184 324 Flat Conductor Cable: Type FCC ........................ 70– 184 Part I. General ................................................................. 70– 184 Part II. Installation ............................................................ 70– 185 Part III. Construction Specifications ............................... 70– 186 326 Integrated Gas Spacer Cable: Type IGS .............. 70– 186 Part I. General ................................................................. 70– 186 Part II. Installation ............................................................ 70– 186 Part III. Construction Specifications ................................ 70– 186 328 Medium Voltage Cable: Type MV ....................... 70– 187 Part I. General ................................................................. 70– 187 Part II. Installation ............................................................ 70– 187 Part III. Construction Specifications ................................ 70– 188 330 Metal-Clad Cable: Type MC ................................. 70– 188 Part I. General ................................................................. 70– 188 Part II. Installation ............................................................ 70– 188 Part III. Construction Specifications ................................ 70– 189 332 Mineral-Insulated, Metal-Sheathed Cable: Type

MI .......................................................................... 70– 189

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CONTENTS

2017 Edition NATIONAL ELECTRICAL CODE 70 –3

Part I. General ................................................................. 70– 189 Part II. Installation ............................................................ 70– 190 Part III. Construction Specifications ................................ 70– 190 334 Nonmetallic-Sheathed Cable: Types NM, NMC, and NMS ............................................................... 70– 191 Part I. General ................................................................. 70– 191 Part II. Installation ............................................................ 70– 191 Part III. Construction Specifications ................................ 70– 192 336 Power and Control Tray Cable: Type TC ............ 70– 193 Part I. General ................................................................. 70– 193 Part II. Installation ............................................................ 70– 193 Part III. Construction Specifications ................................ 70– 194 338 Service-Entrance Cable: Types SE and USE ....... 70– 194 Part I. General ................................................................. 70– 194 Part II. Installation ............................................................ 70– 194 Part III. Construction Specifications ............................... 70– 195 340 Underground Feeder and Branch-Circuit

Cable: Type UF ..................................................... 70– 195 Part I. General ................................................................. 70– 195 Part II. Installation ............................................................ 70– 195 Part III. Construction Specifications ................................ 70– 196 342 Intermediate Metal Conduit: Type IMC ............. 70– 196 Part I. General ................................................................. 70– 196 Part II. Installation ............................................................ 70– 196 Part III. Construction Specifications ................................ 70– 197 344 Rigid Metal Conduit: Type RMC ......................... 70– 197 Part I. General ................................................................. 70– 197 Part II. Installation ............................................................ 70– 197 Part III. Construction Specifications ................................ 70– 199 348 Flexible Metal Conduit: Type FMC ..................... 70– 199 Part I. General ................................................................. 70– 199 Part II. Installation ............................................................ 70– 199 350 Liquidtight Flexible Metal Conduit: Type

LFMC .................................................................... 70– 200 Part I. General ................................................................. 70– 200 Part II. Installation ............................................................ 70– 201 Part III. Construction Specifications ................................ 70– 201 352 Rigid Polyvinyl Chloride Conduit: Type PVC ..... 70– 202 Part I. General ................................................................. 70– 202 Part II. Installation ............................................................ 70– 202 Part III. Construction Specifications ................................ 70– 203 353 High Density Polyethylene Conduit: Type

HDPE Conduit ..................................................... 70– 204 Part I. General ................................................................. 70– 204 Part II. Installation ............................................................ 70– 204 Part III. Construction Specifications ................................ 70– 205 354 Nonmetallic Underground Conduit with

Conductors: Type NUCC ..................................... 70– 205 Part I. General ................................................................. 70– 205 Part II. Installation ............................................................ 70– 205 Part III. Construction Specifications ................................ 70– 206 355 Reinforced Thermosetting Resin Conduit: Type

RTRC ..................................................................... 70– 206 Part I. General ................................................................. 70– 206 Part II. Installation ............................................................ 70– 206 Part III. Construction Specifications ................................ 70– 207 356 Liquidtight Flexible Nonmetallic Conduit: Type

LFNC ..................................................................... 70– 208 Part I. General ................................................................. 70– 208 Part II. Installation ............................................................ 70– 208 Part III. Construction Specifications ................................ 70– 209 358 Electrical Metallic Tubing: Type EMT ................ 70– 210 Part I. General ................................................................. 70– 210 Part II. Installation ............................................................ 70– 210 Part III. Construction Specifications ................................ 70– 211 360 Flexible Metallic Tubing: Type FMT ................... 70– 211 Part I. General ................................................................. 70– 211

Part II. Installation ............................................................ 70– 211 Part III. Construction Specifications ................................ 70– 212 362 Electrical Nonmetallic Tubing: Type ENT ......... 70– 212 Part I. General ................................................................. 70– 212 Part II. Installation ............................................................ 70– 212 Part III. Construction Specifications ................................ 70– 213 366 Auxiliary Gutters .................................................. 70– 213 Part I. General ................................................................. 70– 213 Part II. Installation ............................................................ 70– 214 Part III. Construction Specifications ................................ 70– 215 368 Busways ................................................................. 70– 215 Part I. General Requirements ......................................... 70– 215 Part II. Installation ............................................................ 70– 215 Part III. Construction ......................................................... 70– 217 Part IV. Requirements for Over 1000 Volts, Nominal ..... 70– 217 370 Cablebus ............................................................... 70– 217 Part I. General ................................................................. 70– 217 Part II. Installation ............................................................ 70– 217 Part III. Construction Specifications ................................ 70– 218 372 Cellular Concrete Floor Raceways ...................... 70– 218 Part I. General ................................................................ 70– 218 Part II. Installations ......................................................... 70– 219 374 Cellular Metal Floor Raceways ............................ 70– 219 Part I. General ................................................................ 70– 219 Part II. Installation ........................................................... 70– 219 Part III. Construction Specifications ............................... 70– 220 376 Metal Wireways ..................................................... 70– 220 Part I. General ................................................................. 70– 220 Part II. Installation ............................................................ 70– 220 Part III. Construction Specifications ................................ 70– 221 378 Nonmetallic Wireways .......................................... 70– 221 Part I. General ................................................................. 70– 221 Part II. Installation ............................................................ 70– 221 Part III. Construction Specifications ................................ 70– 222 380 Multioutlet Assembly ........................................... 70– 222 Part I. General ................................................................. 70– 222 Part II. Installation ............................................................ 70– 222 382 Nonmetallic Extensions ....................................... 70– 223 Part I. General ................................................................. 70– 223 Part II. Installation ............................................................ 70– 223 Part III. Construction Specifications (Concealable

Nonmetallic Extensions Only) ............................ 70– 224 384 Strut-Type Channel Raceway ............................... 70– 224 Part I. General ................................................................. 70– 224 Part II. Installation ............................................................ 70– 224 Part III. Construction Specifications ................................ 70– 225 386 Surface Metal Raceways ....................................... 70– 225 Part I. General ................................................................. 70– 225 Part II. Installation ............................................................ 70– 226 Part III. Construction Specifications ................................ 70– 226 388 Surface Nonmetallic Raceways ............................ 70– 226 Part I. General ................................................................. 70– 226 Part II. Installation ............................................................ 70– 226 Part III. Construction Specifications ................................ 70– 227 390 Underfloor Raceways ........................................... 70– 227 392 Cable Trays ........................................................... 70– 228 Part I. General ................................................................. 70– 228 Part II. Installation ............................................................ 70– 228 Part III. Construction Specifications ................................ 70– 234 393 Low-Voltage Suspended Ceiling Power

Distribution Systems ............................................ 70– 234 Part I. General ................................................................. 70– 234 Part II. Installation ............................................................ 70– 235 Part III. Construction Specifications ................................ 70– 236 394 Concealed Knob-and-Tube Wiring ..................... 70– 236 Part I. General ................................................................. 70– 236 Part II. Installation ............................................................ 70– 236

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70 –4 NATIONAL ELECTRICAL CODE 2017 Edition

Part III. Construction Specifications ................................ 70– 237 396 Messenger-Supported Wiring .............................. 70– 237 Part I. General ................................................................. 70– 237 Part II. Installation ............................................................ 70– 238 398 Open Wiring on Insulators ................................. 70– 238 Part I. General ................................................................. 70– 238 Part II. Installation ............................................................ 70– 238 Part III. Construction Specifications ................................ 70– 239 399 Outdoor Overhead Conductors over

1000 Volts ............................................................. 70– 239

Chapter 4 Equipment for General Use 400 Flexible Cords and Flexible Cables ..................... 70– 241 Part I. General ................................................................. 70– 241 Part II. Construction Specifications ................................ 70– 250 Part III. Portable Cables Over 600 Volts, Nominal .......... 70– 251 402 Fixture Wires ........................................................ 70– 251 404 Switches ................................................................ 70– 254 Part I. Installation ............................................................ 70– 254 Part II. Construction Specifications ................................ 70– 257 406 Receptacles, Cord Connectors, and Attachment

Plugs (Caps) ......................................................... 70– 258 408 Switchboards, Switchgear, and Panelboards ...... 70– 262 Part I. General ................................................................. 70– 262 Part II. Switchboards and Switchgear .............................. 70– 263 Part III. Panelboards .......................................................... 70– 264 Part IV. Construction Specifications ................................ 70– 264 409 Industrial Control Panels .................................... 70– 265 Part I. General ................................................................. 70– 265 Part II. Installation ............................................................ 70– 265 Part III. Construction Specifications ................................ 70– 266 410 Luminaires, Lampholders, and Lamps ............... 70– 267 Part I. General ................................................................. 70– 267 Part II. Luminaire Locations ............................................ 70– 268 Part III. Provisions at Luminaire Outlet Boxes, Canopies, and Pans .............................................. 70– 269 Part IV. Luminaire Supports ............................................. 70– 269 Part V. Grounding ............................................................ 70– 270 Part VI. Wiring of Luminaires ........................................... 70– 270 Part VII. Construction of Luminaires ................................ 70– 271 Part VIII. Installation of Lampholders ................................ 70– 272 Part IX. Lamps and Auxiliary Equipment ........................ 70– 272 Part X. Special Provisions for Flush and Recessed

Luminaires ........................................................... 70– 272 Part XI. Construction of Flush and Recessed

Luminaires ........................................................... 70– 273 Part XII. Special Provisions for Electric-Discharge

Lighting Systems of 1000 Volts or Less ............... 70– 273 Part XIII. Special Provisions for Electric-Discharge

Lighting Systems of More Than 1000 Volts ........ 70– 274 Part XIV. Lighting Track ...................................................... 70– 275 Part XV. Decorative Lighting and Similar Accessories ..... 70– 275 411 Low-Voltage Lighting .......................................... 70– 275 422 Appliances ............................................................ 70– 276 Part I. General ................................................................. 70– 276 Part II. Installation ............................................................ 70– 276 Part III. Disconnecting Means ........................................... 70– 278 Part IV. Construction ......................................................... 70– 279 Part V. Marking ................................................................ 70– 280 424 Fixed Electric Space-Heating Equipment .......... 70– 280 Part I. General ................................................................. 70– 280 Part II. Installation ............................................................ 70– 281 Part III. Control and Protection of Fixed Electric Space-

Heating Equipment ............................................. 70– 281 Part IV. Marking of Heating Equipment .......................... 70– 282 Part V. Electric Space-Heating Cables ............................. 70– 282 Part VI. Duct Heaters ........................................................ 70– 284

Part VII. Resistance-Type Boilers ........................................ 70– 285 Part VIII. Electrode-Type Boilers ......................................... 70– 285 Part IX. Electric Radiant Heating Panels and Heating

Panel Sets .............................................................. 70– 286 Part X. Low-Voltage Fixed Electric Space-Heating

Equipment ............................................................ 70– 287 425 Fixed Resistance and Electrode Industrial

Process Heating Equipment ................................ 70– 288 Part I. General ................................................................. 70– 288 Part II. Installation ............................................................ 70– 288 Part III. Control and Protection of Fixed Industrial

Process Heating Equipment ................................ 70– 289 Part IV. Marking of Heating Equipment .......................... 70– 290 Part V. Fixed Industrial Process Duct Heaters ............... 70– 290 Part VI. Fixed Industrial Process Resistance-Type

Boilers ................................................................... 70– 290 Part VII. Fixed Industrial Process Electrode-Type Boilers 70– 291 426 Fixed Outdoor Electric Deicing and Snow-

Melting Equipment .............................................. 70– 292 Part I. General ................................................................. 70– 292 Part II. Installation ............................................................ 70– 292 Part III. Resistance Heating Elements .............................. 70– 292 Part IV. Impedance Heating ............................................. 70– 293 Part V. Skin-Effect Heating .............................................. 70– 293 Part VI. Control and Protection ....................................... 70– 294 427 Fixed Electric Heating Equipment for Pipelines and Vessels ............................................................ 70– 294 Part I. General ................................................................. 70– 294 Part II. Installation ............................................................ 70– 295 Part III. Resistance Heating Elements .............................. 70– 295 Part IV. Impedance Heating ............................................. 70– 295 Part V. Induction Heating ............................................... 70– 296 Part VI. Skin-Effect Heating .............................................. 70– 296 Part VII. Control and Protection ....................................... 70– 296 430 Motors, Motor Circuits, and Controllers ............ 70– 297 Part I. General ................................................................. 70– 297 Part II. Motor Circuit Conductors ................................... 70– 302 Part III. Motor and Branch-Circuit Overload Protection 70– 304 Part IV. Motor Branch-Circuit Short-Circuit and

Ground-Fault Protection ..................................... 70– 307 Part V. Motor Feeder Short-Circuit and Ground-Fault

Protection ............................................................. 70– 310 Part VI. Motor Control Circuits ........................................ 70– 310 Part VII. Motor Controllers ................................................ 70– 312 Part VIII. Motor Control Centers ........................................ 70– 313 Part IX. Disconnecting Means ........................................... 70– 314 Part X. Adjustable-Speed Drive Systems .......................... 70– 316 Part XI. Over 1000 Volts, Nominal .................................... 70– 318 Part XII. Protection of Live Parts — All Voltages .............. 70– 318 Part XIII. Grounding — All Voltages .................................. 70– 319 Part XIV. Tables .................................................................... 70– 319 440 Air-Conditioning and Refrigerating Equipment 70– 324 Part I. General ................................................................. 70– 324 Part II. Disconnecting Means ........................................... 70– 325 Part III. Branch-Circuit Short-Circuit and Ground-Fault

Protection ............................................................. 70– 326 Part IV. Branch-Circuit Conductors ................................. 70– 327 Part V. Controllers for Motor-Compressors .................... 70– 328 Part VI. Motor-Compressor and Branch-Circuit

Overload Protection ............................................ 70– 328 Part VII. Provisions for Room Air Conditioners ............... 70– 329 445 Generators ............................................................ 70– 329 450 Transformers and Transformer Vaults

(Including Secondary Ties) ................................ 70– 331 Part I. General Provisions ............................................... 70– 331 Part II. Specific Provisions Applicable to Different

Types of Transformers ......................................... 70– 335

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2017 Edition NATIONAL ELECTRICAL CODE 70 –5

Part III. Transformer Vaults ............................................... 70– 337 455 Phase Converters .................................................. 70– 338 Part I. General ................................................................. 70– 338 Part II. Specific Provisions Applicable to Different

Types of Phase Converters ................................... 70– 339 460 Capacitors ............................................................. 70– 339 Part I. 1000 Volts, Nominal, and Under ........................ 70– 339 Part II. Over 1000 Volts, Nominal .................................... 70– 340 470 Resistors and Reactors ......................................... 70– 340 Part I. 1000 Volts, Nominal, and Under ........................ 70– 340 Part II. Over 1000 Volts, Nominal .................................... 70– 341 480 Storage Batteries .................................................. 70– 341 490 Equipment Over 1000 Volts, Nominal ................ 70– 343 Part I. General ................................................................. 70– 343 Part II. Equipment — Specific Provisions ....................... 70– 343 Part III. Equipment — Switchgear and Industrial

Control Assemblies .............................................. 70– 345 Part IV. Mobile and Portable Equipment ........................ 70– 347 Part V. Electrode-Type Boilers ......................................... 70– 348

Chapter 5 Special Occupancies 500 Hazardous (Classified) Locations, Classes I, II, and III, Divisions 1 and 2 ..................................... 70– 349 501 Class I Locations ................................................... 70– 355 Part I. General ................................................................. 70– 355 Part II. Wiring ................................................................... 70– 355 Part III. Equipment ............................................................ 70– 360 502 Class II Locations ................................................. 70– 364 Part I. General ................................................................. 70– 364 Part II. Wiring ................................................................... 70– 364 Part III. Equipment ............................................................ 70– 366 503 Class III Locations ................................................ 70– 369 Part I. General ................................................................. 70– 369 Part II. Wiring ................................................................... 70– 369 Part III. Equipment ............................................................ 70– 370 504 Intrinsically Safe Systems ..................................... 70– 371 505 Zone 0, 1, and 2 Locations .................................. 70– 374 506 Zone 20, 21, and 22 Locations for Combustible

Dusts or Ignitible Fibers/Flyings ......................... 70– 387 510 Hazardous (Classified) Locations — Specific .... 70– 392 511 Commercial Garages, Repair and Storage ......... 70– 393 513 Aircraft Hangars ................................................... 70– 396 514 Motor Fuel Dispensing Facilities ......................... 70– 398 515 Bulk Storage Plants .............................................. 70– 403 516 Spray Application, Dipping, Coating, and

Printing Processes Using Flammable or Combustible Materials ......................................... 70– 407

Part I. General ................................................................ 70– 407 Part II. Open Containers .................................................. 70– 408 Part III. Spray Application Processes ................................ 70– 408 Part IV. Spray Application Operations in Membrane

Enclosures ............................................................ 70– 414 Part V. Printing, Dipping, and Coating Processes .......... 70– 415 517 Health Care Facilities ........................................... 70– 418 Part I. General ................................................................. 70– 418 Part II. Wiring and Protection ......................................... 70– 420 Part III. Essential Electrical System ................................... 70– 423 Part IV. Inhalation Anesthetizing Locations .................... 70– 430 Part V. X-Ray Installations ............................................... 70– 432 Part VI. Communications, Signaling Systems, Data

Systems, Fire Alarm Systems, and Systems Less Than 120 Volts, Nominal ..................................... 70– 433

Part VII. Isolated Power Systems ........................................ 70– 434 518 Assembly Occupancies ......................................... 70– 435 520 Theaters, Audience Areas of Motion Picture and Television Studios, Performance Areas, and Similar Locations ................................................. 70– 436

Part I. General ................................................................. 70– 436 Part II. Fixed Stage Switchboards .................................... 70– 437 Part III. Fixed Stage Equipment Other Than

Switchboards ........................................................ 70– 438 Part IV. Portable Switchboards on Stage .......................... 70– 440 Part V. Portable Stage Equipment Other Than

Switchboards ........................................................ 70– 442 Part VI. Dressing Rooms, Dressing Areas, and Makeup

Areas. ................................................................... 70– 443 Part VII. Grounding ............................................................ 70– 443 522 Control Systems for Permanent Amusement