C_FM.qxd 3/9/04 10:56 Page i Audel ™ Guide to the 2005 National Electrical Code® C_FM.qxd 3/9/04 10:56 Page i C_FM.qxd 3/9/04 10:56 Page i Audel ™ Guide to the 2005 National Electrical Code® All New Edition Paul Rosenberg C_FM.qxd 3/9/04 10:56 Page ii Vice President and Executive Group Publisher: Richard Swadley Vice President and Publisher: Joseph B Wikert Executive Editor: Carol A Long Editorial Manager: Kathryn A Malm Development Editor: Emilie Herman Production Editor: Vincent Kunkemueller Text Design & Composition: Wiley Composition Services Copyright © 2004 by Wiley Publishing, Inc All rights reserved Copyright © 1999 by Macmillan USA Published simultaneously in Canada No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written 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professional services If professional assistance is required, the services of a competent professional person should be sought Neither the publisher nor the author shall be liable for damages arising herefrom The fact that an organization or Website is referred to in this work as a citation and/or a potential source of further information does not mean that the author or the publisher endorses the information the organization or Website may provide or recommendations it may make Further, readers should be aware that Internet Websites listed in this work may have changed or disappeared between when this work was written and when it is read For general information on our other products and services please contact our Customer Care Department within the United States at (800) 762-2974, outside the United States at (317) 572-3993 or fax (317) 572-4002 Trademarks: Wiley, the Wiley Publishing logo, Audel, and The Books That Work are trademarks or registered trademarks of John Wiley & Sons, Inc and/or its affiliates National Electrical Code and NEC are registered trademarks of the National Fire Protection Association, Inc., Quincy, MA All other trademarks are the property of their respective owners Wiley Publishing, Inc., is not associated with any product or vendor mentioned in this book Wiley also publishes its books in a variety of electronic formats Some content that appears in print may not be available in electronic books Library of Congress Control Number: eISBN: 0-7645-7903-7 Printed in the United States of America 10 C_FM.qxd 3/9/04 10:56 Page iii Contents Foreword Introduction Article Chapter General 100 Definitions 110 Requirements for Electrical Installations General 600 Volts, Nominal or Less Over 600 Volts, Nominal Tunnel Installations Over 600 Volts, Nominal 200 210 230 1 12 16 21 30 43 48 Feeders 55 Branch-Circuit, Feeder, and Service Calculations 60 General Feeders Optional Calculations for Computing Feeder and Service Loads Method for Computing Farm Loads 225 xvii Chapter Wiring and Protection 25 Use and Identification of Grounded Conductors 25 Branch Circuits 30 General Provisions Branch-Circuit Ratings Required Outlets 215 220 xv 60 63 71 75 Outside Branch Circuits and Feeders 75 More Than One Building or Structure Over 600 Volts 84 88 Services General Overhead Services Underground Service—Lateral Conductors 88 88 92 97 iii C_FM.qxd 3/9/04 10:56 Page iv iv Contents Service-Entrance Conductors Service Equipment—General Service Equipment—Disconnecting Means Service Equipment—Overcurrent Protection Service Exceeding 600 Volts, Nominal 240 Overcurrent Protection General Location Enclosures Disconnecting and Guarding Plug Fuses, Fuseholders, and Adapters Cartridge Fuses and Fuseholders Circuit Breakers Supervised Industrial Installations Overcurrent Protection Over 600 Volts, Nominal 250 Grounding General Circuit and System Grounding Grounding Electrode System and Grounding Electrode Conductor Grounding Conductors Enclosure and Raceway Grounding Bonding Equipment Grounding and Equipment-Grounding Conductors Methods of Equipment Grounding Direct Current Systems Instruments, Meters, and Relays Grounding of Systems and Circuits of kV and Over (High Voltage) 280 Surge Arresters General Installation Connecting Surge Arresters 98 107 107 115 120 123 123 127 134 135 136 138 139 140 142 143 143 147 162 166 174 175 183 190 197 198 200 202 202 203 204 C_FM.qxd 3/9/04 10:56 Page v Contents v 300 310 312 Chapter Wiring Methods and Materials Wiring Methods 207 207 General Requirements Requirements for Over 600 Volts, Nominal 207 225 Conductors for General Wiring Cabinets and Cutout Boxes Installation Construction Specifications 314 Outlet, Device, Pull, and Junction Boxes, Conduit Bodies, Fittings, and Handhole Enclosures General Installation Construction Specifications Manholes and Other Electric Enclosures Intended for Personnel Entry Pull and Junction Boxes for Use on Systems Over 600 Volts, Nominal 320 Armored Cable: Type AC General Installation Construction 322 Flat Cable Assemblies: Type FC Installation Construction 324 Flat Conductor Cable: Type FCC General Installation Construction 326 328 330 Integrated Gas Spacer Cable: Type IGS Medium Voltage Cable: Type MV Metal-Clad Cable: Type MC General Installation Construction Specifications 227 237 237 243 244 244 245 261 262 263 265 265 265 267 268 269 270 270 270 272 274 274 274 275 275 275 278 C_FM.qxd 3/9/04 10:56 Page vi vi Contents 332 Mineral-Insulated, Metal-Sheathed Cable: Type MI General Installation Construction Specifications 334 Nonmetallic-Sheathed Cable: Types NM and NMC General Installation Construction Specifications 336 Power and Control Tray Cable: Type TC Installation Construction Specifications 338 340 Service-Entrance Cable: Types SE and USE Underground Feeder and Branch-Circuit Cable: Type UF Installation 342 344 287 287 288 289 292 293 294 294 297 Rigid Metal Conduit Flexible Metal Conduit Rigid Nonmetallic Conduit Nonmetallic Underground Conduit with Conductors General Installation Construction 356 283 284 287 294 Installation 354 283 General Installation Construction Specifications Installation Installation 352 278 280 282 Intermediate Metal Conduit Installation Construction Specifications 348 278 Liquid-Tight Flexible Nonmetallic Conduit General Installation 297 298 302 303 303 305 308 308 311 311 311 313 313 313 313 C_FM.qxd 3/9/04 10:56 Page vii Contents vii 358 Electrical Metallic Tubing Installation 360 Flexible Metallic Tubing Installation 362 Electrical Nonmetallic Tubing General Installation 366 368 Auxiliary Gutters Busways General Requirements Requirements for over 600 Volts, Nominal 315 315 317 317 319 319 319 322 326 326 330 370 372 374 Cablebus Cellular Concrete Floor Raceways Cellular Metal Floor Raceways 376 378 380 Metal Wireways Nonmetallic Wireways Multioutlet Assembly 382 Nonmetallic Extensions 386 Surface Metal Raceways 388 Surface Nonmetallic Raceways 350 Installation Construction Specifications 350 351 Installation Installation Installation Installation 331 333 334 335 336 339 341 341 343 343 348 348 390 392 394 396 398 Underfloor Raceways Cable Trays Concealed Knob-and-Tube Wiring Messenger-Supported Wiring Open Wiring on Insulators 351 357 372 375 377 400 Chapter Equipment for General Use Flexible Cords and Cables 381 381 General Construction Specifications Portable Cables Over 600 Volts, Nominal 381 385 386 C_FM.qxd 3/9/04 10:56 Page viii viii Contents 402 404 408 409 410 Fixture Wires Switches Installation Construction Specifications 388 396 Switchboards and Panelboards 397 Switchboards Panelboards Construction Specifications 399 400 404 Industrial Control Panels Lighting Fixtures, Lampholders, Lamps, Receptacles, and Rosettes General Fixture Locations Provisions at Fixture Outlet Boxes, Canopies, and Pans Fixture Supports Grounding Wiring of Fixtures Construction of Fixtures Installation of Lampholders Construction of Lampholders Lamps and Auxiliary Equipment Receptacles, Cord Connectors, and Attachment Plugs (Caps) Special Provisions for Flush and Recessed Fixtures Construction of Flush and Recessed Fixtures Special Provisions for Electric-Discharge Lighting Systems of 1000 Volts or Less Special Provisions for Electric-Discharge Lighting Systems of More Than 1000 Volts Lighting Track 411 422 387 388 Lighting Systems Operating at 30 Volts or Less Appliances General Branch-Circuit Requirements 405 406 406 407 411 412 414 415 420 420 420 420 421 424 426 426 429 432 433 434 434 435 ... sections of the Code that were assigned to their committee Then, they circulate the changes among the various committees, coordinate the changes, and rewrite again So, obviously, the updating of the. ..C_FM.qxd 3/9/04 10:56 Page i C_FM.qxd 3/9/04 10:56 Page i Audel ™ Guide to the 2005 National Electrical Code? ? All New Edition Paul Rosenberg C_FM.qxd 3/9/04 10:56 Page ii Vice President and... is to arrange all of the pertinent requirements of the National Electrical Code in a manner that is userfriendly, allowing the reader to find the needed information painlessly and quickly The