NFPA 70 2020-edited

Copyright© 2019 National Fi1·e Protection Association®. All Rig hts Reserved. NFPA 70® National Electrical Code® 2020 Edition T his edition of NFPA 70, NatjonalElecliical Cndf, was prepa1·ed by the National Elecu·ical Code Committee and acted on by NFPA at it~June Association Tech nica l Meeting held June l 7-20, 2019, in San Aiuonio, T X. It was issued by the Stanclarcl~ Council 0 11 August 5, 2019, with an effective dare ofAugu~t25, 2019, and supe1·se<les all previous editions. This Code was issued with Tentative Interim Ainendmen ts (T!As) that impacted provisions in 210.52(C)(2), 240.67'(C), 240.87 (C), 72Fi.l 21 (C), and Aimex D:t For more information on TIAs, see www.nfpa.org/ 70 and Section 5 of the Regulalions Goveming the Devewjmumt of NFPA Standards available al www.nfpa.org/ regs. This edition of NFPA 70was approved as an Am erican Natio na l Standard 0 11 Au g ust 25, 2019. History and Development of the National Electrirol Code® The National Fin.' Protection A~sociation has acted a~ spo nsor of the NationolE[r,rtr/1:"l Cod11 since l 9 I l. The m·igina l Code document was developed in I 897 as a result of the united effo rts of vari01.L5 insurance, e lec:u·ical, architectural , and a llied i.nteresL~. In accordance with the Regulations Governing the DevP!ofnnenl of NFPA Standards, a National Elertiicn.l Corle first draft 1·epo1·t con taining proposed amenrlme n t~ to the 20 17 Nationall.tPctrfol1l Code was published by NFPA inJ uly 20 J 8. This report recorded the actions of the va1fom code-making panels and tl1e correlating committee oftJ1e Na tio nal Electrical Code Committee on each public input and first revision th at had been made to revise the 2017 Code. The report wa.5 published at www.nfjJa.org/ 70. Following th e close oftJ1e pltblic commenl period, the code-making pane ls me t, acted on e ac h comment, and created s(1111e second revisions, which were reported to the correla ting committee. NFPA published d1e MilionalEleclrical Code second draft report in April 2019, which recorded the actions of the code-maki.ng panel.5 a nd th e correla ting committee on each public comme nt on the National Electrical Code Committee firs t. draflre port. The National Eln-triml Code firs t draft report and the Natinnal ElPctrical Code second draft report were presented to the 2019 June A5sociation Technical Meeting for adoptio n. NFPA has a n Electrical Section that provides particular opportunity fo ,- NFPA membe rs interested in electrical safety to become better informed a nd to conu·i bute to the development o f IJ1e Nntional Elflrtrital Code and other NFPA electrica.l standards. At IJ1e Elecu<ical Section codes and standards review session held at IJ1e 2019 NFPA Confe rence a nd Ex po, section memb e rs had the oppornmicy to discLL5S and review d1 e report of d1e Natio n al Elec1yical Code Committee prior to the adoption of this edition of IJ1e Code by the association at iL~ 20.1 9 June Technical Meeting. This 55d1 edition supersedes all othe1· previou.~ edition.~, supple men L~. a nd printings dated l897, 1899, L901, 1903, 1904, 1905, 1907, 1909, 1911 , 191 3, 19 15, 19 L8, 1920, 1923, 1925, 1926, 1928, 1930, 1931 , 1933, 1935, l937, 1940, 1942, 1943, 1947, 1949, 1951, 1953, 1954, 1955, 1956, 1957, 1958, 19.59, 1962, 1965, 1968, 1971, 1975, l 978, 1981. 1984, 1987, 1990, 1993, 1996, 1999, 2002, 2005, 2008, 2011 , 2014, and 2017. This Code is purely advi6or y as far as NFPA is con cerned. It is made availa ble for a wide variety of both public and private uses in the inte rest of life and properl.)' protection. These include both u se in law a nd for regu latory purpt)$es a nd u~e in private self-regula tion and standardizatio n activities such as insuran ce underwriting, building and faci lities construc tion and management, a nd product testing a nd certification. NFPA 70. Nation a l Electrical Code. NFPA a nd National Fire Pror.ect.ion A~sociatio11 a re regi,t~red trademarks of lhe NaLiona l Fire P ro1cction A_<;sociation . Quincy, Ma.~sachusetts 1l'.!16!l. NATIONAL ELECTRICAL CODE Contents 90 Introduction ............................. ............................ 70- 29 Chapter I General 100 Pan!. Pan II. Pan Ill. JIO Pan!. Pan II. Pan Ill. Pan IV. Pan V. D efinitions ........................................................... . General ..................... ................................... ........ . Over !000 VolL~, Nominal ................................... . H azardous (Classified) Locations (CMP-14) .... Requirements for Eleci:rical Installations .......... . General .............. ....... .................... ....................... . !000 Volts, Nominal, or Less .................... .......... . Over I 000 Volrs, Nominal ... .......... ..... ............... .. . Tunnel lnstallaLions over 1000 Volts, Nominal .. Manholes and Other Electrical Enclosu res Intended for Personnel Entry ............................ . 707070707070707070- 32 32 70- !'i6 41 42 46 46 50 52 55 Chapter 2 Wiring and Protection Pan ILL Grounding Elecrrocle System and Grounding Electrode Conductor ........................................... Pare IV. Enclosure, Raceway, and Service Cable Connections......................................................... Pan \I. Bonding ................................................................ Pan VI. Equipmem Grounding and Equipmem Grounding Conductors....................................... Pan Vil. Mei hods of Equipment Grounding Conductor Connections.......................................... ............... Pan VIII. Direct-Cur-re nt Systems ........................................ Pan IX. lnstrurnems, Meters, and Relays......................... PanX. Grounding of Systems and Circuits of ove.r 1000 VolL~ ............................................................ . 300 70-2 707070707070- 58 60 60 65 68 71 70- 73 70- 73 70- 74 70- 7fi 70707070- 79 81 82 82 7070707070707070707070707070707070707070- 85 86 88 88 89 90 91 93 9,1 95 96 97 97 101 104 104 104 104 10.5 107 70- 108 70- 109 70- 109 7070707070- 109 1 IO 111 111 113 70- 125 70- 125 70- 129 70- 133 70- 135 70- 136 70- 137 Chapter 3 Wiring Methods and Matedals 200 Use and IdenLilicat.ion of Grounded Conductors .................................... ............... ........ Branch Circuits ................................................... . 210 Part I. Genera I Provisions .............................................. . Pan 11. Branch-Circuit Ratings ...... ..... .......... .................. . Part UI. Required Outlets ......................................... ........ . 215 Feeders ...................................... .................... ....... . 220 Branch-Circuit, Feeder, and Service Load CalcuJations ........................................ ................. . Part I. Genera l ................ ................................................ . Pan 11. Branch-Circuit Load CalcuJations ............. .... ..... . Pan Ill. Feeder and Service Load Calcu lations .............. . Part rv: 0 pt.ion a I Feeder and Service Load CalctLlations ......................................................... . Farm Load Calculat.ions ...................................... . Pan V. Ourside Branch Circuits and Feeders ................. 225 Pan I. General ................................................... ............. . Pan II. Bu[ldlngs or Otl1er Su·ucrures Supplied by a Feeder(s) o r Brandi Circuit(s) ................... ....... . Pan Ill. Over 1000 Vol LS............ ....................................... . Services .............................. .................................. . 230 Part I. General ................ ................................................ . Pan II. Overhead Service Conducto rs ........... ..... ............ . Part IIL Underground Service Conductors .... ................. . Part rv: Service-En trance Conductors ............................. . PanV. Service Equipment - General ........................... Part VI. Service Equ ipment- Disconnecting Means .... . Pan Vil . Service Equipment- Overcurrent Protect.ion .. Pan V UI. Services Exceeding l 000 Volts, Nominal ............ 240 Overcurrent Protection ....... ............... ..... ........... . Part I. General .......................... ............... ....................... . Part II. Location ....................... .................... .................... . Pan IIL Enclosures ................................................. .......... . Pan rv: Disconnecting and Guarding ............................. . Plug Fuse$, Fuse ho ldus, a nd Adapters .............. PanV. Part VI. Cartridge Fuses and Fuse hold ers ..................... .. . Pan VU. Circu.it Breakers ........................................ .......... . Part VIU. Supervised lndusi:rial Installations ..................... . Part IX. Overcurrent Protection over 1000 Volts, Nominal ............................................................... . Overvohage P rotection ............. .......................... . 242 Part I. General ......................................... ....................... . Parr II. Surge-Protective Devices (SPDs), 1000 Volts or L ess ......................................................... ............. . Part IIL Surge Arresters, Over l000 Volrs ................. ....... . 250 Grounding and Bonding .................................... . General ................ ................................... ............. . Part I. Pan II. Sy~tem Ground.ing .............................................. . 70- 120 Part l. Part II . 310 Part J. Part ll . Part Ill. 311 Pa rt J. Pan 11 . Pan !IL Part IV. 312 Part I. P art II . 314 P art I. Pan 11 . Part II L. Pan lV. 320 Part I. Part II . Pan Ill. 322 Pa n I. Part II . P an Ill. 324 Pan I. Part LI . P a rt II L. 326 Part I. Pan II . Part 11 L. 330 P art 1. Part n. P art UL 332 Part l. Pan II. General Requirements for Wiring Me tl1ods an(l Materials............................................................... General Requirements .......................... ............... Requ irements for over IO00 Volts, Nominal ...... Conductors for General W iling .......................... General ......... ........................................ ................ Consr.ruction Speci fic;it.ions ............................... . Installation ............ ................................................ Medium Voh age Conductors and Cable............ General ............................. .................... .......... ...... Construction Spec.ilications .......................... ...... Installation .. .......................................................... Ampacities ............................................................ Cabinets. Cutout Boxes, ru1d Meter Socket Enclosures .. .................... .......... .......... ............... ... Scope and Installation ......................................... Construction Sped lica1.ions .......................... ...... Outlet. Device, Pull, and Junction Boxes ; Conduft Bodies: F,rt.ings; and Handhole Endosures .. ..... ..................................................... Scope and General ............................................... Installation ............................................................ Construction Spec.i lications ................................ Prill ancl.JuncL.ion Boxes, Conduit Bodies, ru1d Hanclho le Enclosures for Use on Systems over 1000 Voll~, Nominal ......................................... .... Armored Cable: Type AC ..................................... General .................................. .............. ,................ Installation .. .......... .............................. .......... ........ Construction Sped lications ................................ Flat Cable AssembJies: Type FC ........................... General ................................................ ,................ Installation ............................................................ Construct.ion Spedlka1.ions .......................... ...... Flat Conducrnr Cahle: Type FCC ........., .............. General ................................................................. Installation ............................................................ Construction Sped lica1.ions ................................ lnregraLed G,,;; Spacer Cable: Type l GS .............. General ................................................................. Installation ............................................................ Construct.ion Specifications................................ Metal-Clad Cable: Type MC ................................. Genera l ................................................................. fnstallat.ion ...................... ...................................... Construction Specifications............................... . Mine ral-Insulated. Meta.I-Sheathed Cable: Type Ml ......... ..... ....................................................... .... General ............................................ ..................... Installation ..................................... ..... ..... ............. NATIONAL ELECTRICAL CODE 707070707070707070707070- 140 140 149 15.1 151 151 156 165 16!\ 165 l(j'7 168 70- 170 70- 179 70- 182 70707070- 182 182 183 18!) 707070707070707070707070707070707070707070- 189 190 190 190 191 191 191 192 192 192 192 I93 194 194 194 104 195 195 195 195 197 70- 197 70- 197 70- 197 2020Edition CONTENTS Part ill. 334 Part I. Part IJ . Part llJ. 336 Pan I. Pan 11. Pan llJ. 337 Pan I. Part II. Part IIJ. 338 Pare I. Pare II. Pare Ill. 340 Pan I. Part IL Pan Ill. 342 Part I. Pan IJ . Part Ill. 34.4 Pan J. Pan IJ . Pm·1.JJI. 348 Pm·tJ. P,u·1. Il . 350 P,u·i.J. PmT JJ. Pm·1. JJJ.. 352 Pm·tl. Pm·1. IJ. Pm·1. HI. 353 Pan. I. PmT JJ. Pm·1. Ill. 354 Pm·1. J. P,u·1. .U . PmT JJJ.. 355 Pm·tl. Part JJ. P,u·1. JJJ.. 356 P,u·1. J. Pan JJ. Pm·1. lJJ. 358 Parl I. Pan ll . Pan ill. 2020 ll\lirjon Construction Specifications ................................ Nonme calJic.Sheathed Cable : Types NM and NMC ...................................................................... Ge neral ..................... .......... .................................. Installation ............................................................ Construnion Specifications................................ Power a nd Contro l Tray Cable: Type TC ...... ...... Ge neral ..................... .......... .................................. Installation ............................................................ Construction Specifications ................................ Type P Cable ............................ ............................. General ................................................................. lnstallai,ion ............................. ............................... Constructio n Speci ficatio ns ............................ .... Service•Entrance Cable: Types SE and USE ....... Gene ral ............................... ..... ............................. I.n stallation ............................................................ Construction Specifications............................ .... Underg rounp Feeder a nd Branch-Circuit Cable: Typ e U F ..................................................... Ge neral ............................... .................................. lnstalla1.ion ............................. ............................... Construction Specificatio ns ............................ .... Inte rmediate Me tal Conduit: Typ e IMC ............. Gene ral ................................................................. Installatio n ............................................................ Construction Specifications ................................ Rigid Mew.I Cond uit; Type RMC ......................... General..................... ............................................ Installation .................................. .......................... Construe Lio n Speci ficatjo ns .................. .............. Flexib le Meta.I Conduji: Type FMC ..................... General .......................... ..... .................................. Installatio n ............................................................ Li9ufrltigh1. Flexible Meta.I Conduit: Type LFMC ......... .................... ..... .................................. General . ......................... ..... .................................. Insta llatio n ............................. ............................... Conslructio n Specifications .................. .............. Rigid Polyvinyl Chloride Conduit: Type PVC ..... General.......................... ....................................... InsLallation ............................. ............................... Construction Speci ficatjo ns .................. .............. High De nsity Polyethyle ne Conduit: Type HOPE Conduit ..................................................... General................................................................. lnsta ll<1tion ....................................... ..................... Construction Specificatio ns................................ Nonmeta!Ec Unde rground CondniL with Conductors: Type NUCC .............................. ....... General................................................................. Installation ............................................................ Constructio n Sped ficatio ns .................. .............. Reinforced The rmosetting Resin Conduit: Type RTRC .......................... ..... .......... ............................ General ...... .................... ..... .................................. In stallation ............................................................ Construnion Specificatjons ................................ Liqu.idtigh1. Flexible Nonmeta.llic Condu.it: Type LFNC ..................................................................... Gene ral..................... ............................................ Installation ............................................................ Construct.ion Specifications................................ Elec1.rica.l Memllic Tabing: Type El\1T ................ Gene ra l ..................... ..... ....................................... Lnsi.allation ................... ......................................... ConsLrucLio n Specifi.caLio ns ............................ .... NATIONAL £ LllCTRIC"AL CODE 70- 198 70707070707070707070707070707070- 198 200 200 200 200 201 202 202 202 202 202 202 203 203 707070707070707070707070707070- 204 204 204 204 204 204 204 206 20fi 206 206 207 207 207 208 7070707070707070- 209 209 209 2l0 210 210 210 212 70707070- 212 212 213 213 70707070- 213 213 214 214 70707070- 215 2 15 215 216 7070707070707070- 217 217 217 218 218 218 218 219 198 198 360 Part l. PartJI. Part III. 362 Part 1. Part II. Pan II I. 366 Part I. Pa rt II. Pa rtJII. 368 Pa rt I. Part JI. Part II I. Part IV. 370 Part I. Part II. PartJIJ. 372 Pa rt I. PartJl. 374 Pan I. Pan II. Pan III. 376 Pan I. Pan II. Part Ill. 378 Pan I. Panll. Part III. 380 Part I. Part II. 382 Pan I. Partll. Part fl l. 384 Pan I. Pa rt II. Pan III. 386 P<1rt I. Pan II. Pan Ill. 388 Pan L Pan II. Part III. 390 P an l. Part II. 392 P<1nl. Pan IL Pan Ilf. 393 P artl. P an IL Flexible Metallic U tbing: Typ e FMT ........ ........... General ...................................................... ..... ...... Installation ............................................... ..... ........ Construction Specifications ...... .......................... Electrical Nonmetallic Tubing: Type ENT ......... General ......... ............................................. ..... ...... Installation ..................... ............................... ........ Consu·uction Specifications ................................ Auxiliary Gmters ............................................ ...... Ge neral ......... ..... ........................................ ........... Installation ....... ............................................. ........ Construction Specifications ................................ Busways ..................... ..... .............................. ........ General Requirem en L, ..................... .................... Installatjon ....... ........................................ ............. Consu·uction ............................................... .......... Require ments for O ver 1000 Vo lts, Nominal ..... Cablebus ......... ...................................................... General .............. ................................................... Installation ....... .............. .......................... ..... ........ Construction Specifications ...... ..... ..................... Cellular Co.ncrete Floor Raceways ...................... General ................................................. ..... ..... ...... Installations.......................................................... Cellular Metal Floor R<1ceways ............................ General .... .................................................. ,.......... Inst.a.llat:io ,1 ............................................................ Construction SpecHic<1Lions ................................ Meta.I W.i reways ......... ..................,......................... Ge neral .... ............... ......................... .......... ........... Insta.llation ............................................................ Constrnction Specitications ...... .......................... Nonrneta.11.ic Wireways ........................... ..... .......... General ...................................................... ........... Insta.llat:ion ............................................... ............. Consu·uction Specifications................................ Mult.ioutlet A,sembly ........ ..... .............................. General .... ............... ................................... ..... ...... Inst.a.llat:ion ....... ..................................................... Nonme ta.llic Extensio ns ....................................... General .... ............... ................................... ........... Inst.a.ll<1tion ....... ..................................................... Const.ruction Spedtic<1tio ns ( Concealable Nonmeta.llit Extensio ns Only) ............................ Strm-Typ e C han nel Ritceway .................. ............. Ge neral ................................................................. Insta.llat:ion ....... ........................................ ............. Constrnction Spec:ificatio.ns ..................... ........... Surface Metal Raceways ................ .......... ............. Gene ral ...................................................... ........... lnst.a.11<\t:ion ....... ..................................................... Consm,ction Specifications........... ..................... Surface Nonmetallic Raceways ............................ General ......... ........................................................ Insmllation ............................................................ Construction Specifications................................ Unde rfloor Raceways....................... .................... Gene ra l ......... ............................................. ........... Installation ............................................................ C,ble Trays........................................................... Ge ne ra l ................................................................. Installation ............................................................ Consu·u ction Specifications........... ..................... Low-Vo ltage Suspended Ceil.ing P ower Disuibution Systems............................................ Genera l ................................................. ..... ........... Insmllation ....... ..................................................... 7070707070707070707070707070707070707070707070707070707070707070707070707070707070707070707070707070707070707070707070707070- 21H 21 ~) 220 220 220 220 221 222 222 222 222 223 224 224 224 225 225 226 226 226 227 '1.27 227 227 228 228 228 229 229 229 229 230 230 230 230 231 231 231 231 232 232 232 233 233 233 233 234 234. 234 234 23.5 23.5 23.5 23.5 236 236 236 236 237 237 237 24'1. 70- 244 70- 244 70- 244 70-3 NATIONAL ELEl.'TRICAL CODE Part 111. 394 Part I. Part II. Parr Ill. 396 Part I. Part II. 398 Part I. Part II. Part Ill. 399 Co nstrucr.ion Speci~icar.ions ....................... ......... Concealed Kno b-and-Tube Wiring..................... General ........... .......... ............................................ lnstallaLinn .................................. ......................... . Constructio n Specilicatio ns ................................ Messenger-S1.1pported Witing .............................. General ........... .......... .......... .......... ............... ......... lnstallaifo n ......... .............................. ..................... Open Wiring on Insulators ................... ..... ......... General ........... ... ....... ................................... ......... Installation ......... ............... ............... ..................... Constn.telitrn Specilicar.io ns ....................... ......... Outdoo r Overhead Conductors over I 000 Volts ............ ............... ..... ............... ..... ......... 707070707070707070707070- 245 246 246 246 246 247 247 247 247 247 248 24!J 408 Pan I. Pan II. Pan Ill. Pan lV. 409 Pan I. Pan ll. Pan Ill. 410 Pan I. Pan II. Pan Ill. Pan Iv. PanV. PanVL Pan Vil. Part VW . Parr IX. PanX. Part XI. Pan X II. P artXIU. Pan XIV. P an XV: Pru·t XVI. 411 422 Part I. P an II. Pru·r m. Part IV. Part V. 424. Part I. 70-4 F1ex.ible Cords a nd Flexible Cables ..................... Gene ral ................ ................................................. Construction Specificatio ns ................................ Po rtable Cables Over 600 Volts, Nominal .......... Fixrnre Wires .......................................... .............. Switc hes....................... ............... .......... ................ lnswllation ............................................................ Construct.ion SpecificaLio ns ............................... . ReceJJtacles. Cord Connectors, a nd Attachmem Plugs (Caps) .................... .................... ...... .......... . S"ilch boards. Switch gear, and Pane.lboards ...... General . ............... ................................................. Switchboards and Switchgear .............................. Panelboards ......................................................... . Construct.ion Specitications ................................ Ind ustrial Comro l Pane ls ................................... . Gene ra l ........... ..... ............... ................................. . lnswllation ........................ .................... ............... . Construct.ion Specifications ............................... . Lurninaires, L·unpho lders. and Lamps .............. . General ............ ... ................................................ . L urninaire Locations ..................... ...................... . Provisions at L urninaire OLuJet Boxes. Canopies, a nd Pans ............................................. . Lurninaire Supports ............................................ . Grnuncling ............... ........................................... .. Wiring of Lu m inaires ....... ................................... . Construct.ion of Lumina.ires ............................... . lns ta.llalion of Lampho lde rs ............................... . Lamps and Aux.iliary Equipmem ..... .................. . Special Provisions for Flush and Recessed L wninaires ..... ...................................................... Construction of Flush a nd Recessed L wninaires .......................................................... . Special Provisions for Elecu·ic-Discharge Lighting Systems of 1000 Vo ll~ o r Less .............. . Special Provisions for Elecu·ic-Discharge Lighting System s of More Tha n JOO() Volts ....... . Lighting Track ............. ........................................ . Decor ative Lighting and Similar Accessories .... . Special ProvLqions for H n rriculrural Lighting Equ.ipment ........................................................... . L ow-Vo ltage Lig h ting .......................................... . Appliru1ees .................. ......................... ................ . General .......................... .................... .................. . los wJlation ........................................................... . DisconnecLi.ng Mean s .............................. ............. Construction ........................................................ . Marking ............................................................... . Fixed Elecuic Space-Heating Eqttip me nt ......... . General .............................................. .................. . Pan IV. Part V. Part VJ. Pa rt Vil. Parl VIII . Part IX. Pa rt X. 425 70- 24\l Chapter 4 Equipment for General Use 400 Pan I. Pan ll. Pan Ill. 402 404 Pant. Pan II. 406 Pan H . Pa rt Ill. 7070707070707070- 250 70707070707070707070707070- 266 70707070707070- 279 279 Part I. Pa rt II. Part Ill. 250 259 260 260 Pa n IV. Part V. Pa rt VJ. 263 263 266 27l 271 273 273 274 275 275 275 276 277 277 278 280 280 282 282 Pa rt Vll. 426 Part I. Part J I. Part 111. Part IV: Pa rt V. Pa rt VI. 427 Pa rt I. Pa rt II. Part Ill. Pan IV. Part V. Pa rt VJ. Pa rt VU. 430 Pa n I. Pan II. Pa n Ill. PanlV. 282 Pa nV. 70- 282 70- 283 70- 283 70- 284 70- 285 70- 285 70707070707070707070- 285 286 286 286 287 289 WO 291 PanVl. Pa n V II. PanV III. Part I X. PartX. Pan XL. Part XU. Pa rt XUL Pan XIV. 440 Pa rt I. Pa n II. Pan Ill. Pan rv. Pa rt V. PartVI. 291 291 Pan V II. I nstaJlation .. ..... ..... .......... ..... .......... ..... .......... ........ Co ntrol and Pro tection of Fixed Elecuic SpaceHea tingEquiprnem ........... .................................. Ma rking of H eating Equipment .......................... Electric Space-Healing Cables ............................. Duct Heaters ....................................................... . Resistance-Type Bo ilers ....... .......... ..... .................. Elecu-ode-Type Boile rs ......................................... Electric Radiant Healing Panels and H earing Pa nel Sets .... .......... .......... ............... ..... .................. Low-Voltage Fixed Elecu·ic Space-H eating Equipmem ........................................................... . Fixed Resistance and Electrode Industrial Process H eating Equipment ................................ General ......... .......... .............................. .......... ...... Installation ............................................... ............. Conu·ol and Protection of Fix ed [ndusuial Process H eatin g Equipmen t ....................... ......... Ma rking of H eating Equipment ............. ............. Fixed Industrial Process Duct H eaters.............. . Fixed Industrial Process Resistance-Type Boile rs ....................... .............. .......... ............... ..... Fixed Indusu-ial Process Electrode-Type Boile rs Fixed Outdoor Electric De.icing and SnowMelting Equipment .............................. .......... ...... Gene ral ......... .......... ............... ............................... Installatio n ........................... ................................. Resistance H eating Eleme n ts ......... ..... ................ Impedance.Heating ............................................. Skin-Effect Heating................ .................... .......... Conu·ol and Protection............. .................... ..... . Fixed E lectric Healing Equipmen t for Pipelines and Vessels ....................... ................................... .. Gene ral ......... .......... ..... .................... ..... ..... ........... Installatio n ...................... ..... .................... ............. Resistance H eating Elem e n ts .............................. Impedance H eating ............................. ..... ........... Induction Heating ........................... ............... ..... Skin-Effect Heating................ .............................. Co n tro l and Protection............. ......................... . Mowrs, Moto r Circui tS, anrl Contro llers .. .......... General ................... ..... ............... .......... .......... ...... Mawr CircuitCondncLOrs ................................... MoLOr and Branch-Circuit O verload P rotection Mowr Branch -Circuil Sho n -Circuit and Ground-Fault Prntectlon ..................................... MoLOr Feed er Sh on-Ci rcu it and Ground-Fault Protect.io n ............................................................. Mawr Comro l CircL1its ........................................ Moto r Concrollers .. .............................................. Motor Concrol Cem e.rs ........................................ Disconnecting Means ........................................... AqjusL-ible-Speed D rive Systems .......................... O ver 1000 Volt5, Nomina l .................................... Protect.ion of Live Paris - All Voltage.-'> .............. Ground.ing· - All Voltages ............. ..................... Tables .............. ..... ..... ..... ..... ..... ............... .............. _Ajr,Co nd.itjoning and Refrigerating Equipment General ................... .................... .......................... Disconnecting Means ........................................... Branch-C ircuit ShortcCircuit and Ground-Fault. Protection ...... .................................................. ..... Brru1ch -Circuit Conducto rs ................................. Conlrollers for Mornr,Compressors .................... Moto r-Compressor and B ranch.{;ircu.it Overload Protection . ..... .................... ............... .. Provisions for Room Air Cond itione rs .. .......... ... NATIONAL ELECTRICAL CODE 70- 29 1 707070707070- 292 2!J!l 293 295 295 296 70- 297 70- 2!J8 70- 2!)9 70- 2!J9 70- 2\l!J 70- 299 70- 30 I 70- 301 70- 30 I 70- 302 7070707070707070707070707070707070- 303 303 ?,()3 303 ?,04 ?.04 305 '.305 305 306 306 ?,06 307 307 307 308 308 70-- 31'.3 70- 315 70- 318 70707070707070707070707070-- 321 321 32'.1 324 325 327 329 3'.10 330 330 335 335 336 70- 337 70-- 338 70-- 339 70- 339 70-- 340 2020falition CONTENTS 445 450 Part I. Pan II. Pan Ill. 455 Pan I. Part U. 460 Part I. Pan II. 470 Part I. Part II. 480 490 Part I. Part IL Part IU. Parr IV. Parr V. Generators ............................................................ Transfom1ers an(! Transformer Vaults (Indu!iing Secondary Ties) .. .............................. General Provisions .......... ............... ...................... Specifi c Provisions Applicable to Differem Types ofTransfonners ..................... .................... Transfom1er Vaults ............... ..... ............... , ........... Pha~e Converters ......... ......................................... Gen eral ............................... ..... ............................. Specitic Provisions Applicable to Differe nt Types of Phase Conveners ................................... Capacitors ............................................................ . 1000 Volts, Nominal, and Under ........................ Over 1000 Volts, Nominal ................................. ... Resistors a nd Reactors ........................ ................ . 1000 Volts, Nominal, and Under ........................ Over l000 Volts, Nominal .................................... Storage Batteries .................................................. Equipmem Over 1000 Volts, Nominal ................ General ................................................................ . Equi pment- Specific Provisions ..................... .. Equipmem - Switchgear a nd Industrial Con trol Assemblies .............................................. Mobile and Porrable Equipmen t ....................... . Electrode-Type Bo ile rs ..................... ................... . 70- 340 70- 34'.:' 70- 34'.:' 70- 346 70- 348 70- 349 70- 349 7070707070707070707070- 350 350 3.50 351 352 352 352 352 3.55 355 355 70- 357 70- 359 70- 360 Chapter 5 Special Occupancies 500 50 1 Pan L Pan II. Pan Ill. 502 Pan I. Pan II. Pan Ill. 503 Pan L Pan IL Pan Ill. 504 505 506 510 511 513 5 14 515 516 Pan I. Part II. Pan JU. Part IV. Pan V. 517 Pan I. Pan ll. Part ill. Part IV. Part V. 2020 ll\lirjon Hazardous (Classitied) Locations, ChL~ses I, LI. a.nd Ill, Divisio ns l and 2 ... ............... ..... .............. Class I L ocations ................................................... Gene ml ............................... .................................. Wiring................................................................... Eqoipment ............................................................ Class II Locations ..........,...... .......... ...................... Gene ra l ................................................................. Wiring ................................................................... Eqoipment .................................... ........................ Class Ill Locations .......................... ...................... Gene ml ............................... .................................. Wirin g................................. .................................. Eqoipmen t ............................................................ Intrinsically Safe Systems ..................................... Zone 0, l , ,md 2 Locations .................................. Zone 201 21, a nd 22 L ocations for Combus1jb(e Dusts o r lgnitible Fibe rs/ flyings ......................... H azardous (Classified ) Locations - Specific .... Commercia.l Garages, Repair and Smrage ......... Aircraft Hangars ................................................... MOLor Fuel D ispensing Facilities ......................... Bulk Storage Plants ........................................ ...... Spray Application , Dippin g, Coating, an d Printing Processes Using Fla mmab le or Combustible Macerials ......................................... Gene ra l ............................... .................... .......... .... Open Containers .. ................................................ Spray Application Processes ................................ Spray Application Operations in Membrane Enclosures .............. ..... ......................................... Printing, Di pping, and Coating Processes .......... H ealth Care Facilities ........................................... General ..................... ............................................ Wiring and Protection ......................................... Essential Elecuica.1 System (EES) ........................ Inhalation Anesth elizing Locations .................... X-Ray Installations............................................... NATLONAL ELECTRIC-AL CODE 70707070707070707070- 7070707070- 361 368 368 368 373 377 377 378 380 383 383 383 384 386 388 Part VL Pa rt VU. 5 18 520 Part!. Part U. Part ll l. Pa rt IV. Part \I. Pa rt VI. Part VU. 522 Pa rLl. Part II. Pa rt .III. 525 Pan I. Part II. Part JII. Part IV. 530 Pa rt I. Pa rt II. Part JI I. Part IV. Part V. Pan \IL 540 Parr 1. Parrll. Part 11 1. Part IV. 545 70- 402 70- 408 70- 409 70- 411 70- 414 70- 420 70707070- 423 423 424 424 7070707070707070- 431 432 434 434 437 440 447 449 Pa rt I. Part II. 547 550 Pan I. Part II. Part Ill. 551 Pa rt I. Pa rt II. Pan III. PartlV. Pan \!. Pan VI. 552 Pan I. Pan II. Part Ill. Pan lV. PanV. Communications, Signaling Systems, Daca Systems, Fire Alarm Systems, and Systems Less Than .120 Volts, Nominal ..................................... Isolated Power Systems ....................................... Assembly Occupancies ......................................... Theaters, Audience Areas of Motion Picture and Tele,isio n Studios, Perfornrnnce Areas, and Similar Locations ................................................. General ......... ..... ................................................... Fixed Stage Switc hboards .................................... Fixed Stage Equipment Othe r Than Swiech boards............................ ............................ Portable Switchboards on Stage .................. ,....... Portable Scage Equipment Other Tirnn Switch boards............................ ............................ Dressing Rooms, Dressing Areas, and Makeup Areas. .................................................................... Equipmen t Groundjng Conductor ..................... Comrol Systems fo r Pe rma ne n1 Amusement Am-actions.................. .......................................... General ................................................................. Comrol Circujts .................................................... Com rol Circuit Wiring Meth ods ......................... Carniva.ls, Circuses, Fairs, and Similar Events .... General Require m ents ......................................... Pm~er Sources ...................................................... Wiring Meth ods .............................. .......... ........... Equipment Groundjng and Bonding ...... ....... .... Motion Picture and Television. Studios a nd Similar Locations ......... ........................................ General .............. ........................................... ,....... Stage or Set .................. .. ....................................... Dressing Rooms .................................................... Viewing, Cutting, and Patching Tables ............... Cellulose N itrate Film Storage Vaults ................. Substatfons ............................................................ Motion Pic1ure Projection Roo m s ...................... General ........... ...................................... ..... ........... Equipmen Land Prqjectors ofL11e Professio nal Type ............................................................. .......... Nonprofessional Projectors ................................. Audio Signal Processing, Amplification , a nd Reproduction Equipment.......... ......................... Mamtfacturecl Bu il(lings a nd Relocmahle Sa·unures .................................................. ........... General .............. ................................................... Relocatable Strucnires ................ .. ....................... AgricuJLura l Builrlings ................................ .......... Mobile H omes. Manufacwr ed H omes, and Mobile H ome P ark!,............................................. Genera.I ................................................................. Mobile an.d Manufacu.1recl Homes ...................... Services a nd Feeders............................................ Recreational Vehicle.san d Recreational Vehicle Parks ...................................................................... General ...................................................... ........... Com bination Electrical Sysrem s .. ........................ OL11er Power Sou rces........................... ................ Nominal 120-Voltor 120/ 240-VoltSystems ........ Factory Tests............. ............................................ Recreational Vehicle Parks ........... .......... ............. Park. Traile rs............................ ............................. General .............. ................................................... Low-Voltage Systems ............................................ Combination Electrical Systems.......................... Nominal 120-Vohor I 20/ 240-VoltSysten1s ........ Factory Tests ........ ................................................. 70- 450 70- 451 70- 452 70- 453 70- 453 70- 454 70- 455 70- 457 70- 459 70- 460 70- 460 707070707070707070- 461 461 461 461 462 462 463 463 464 707070707070707070- 464 464 465 467 467 467 467 467 467 70- 467 70- 468 70- 468 70707070- 4(j8 468 469 470 70707070- 4i2 472 473 479 70707070707070707070707070- 480 480 481 482 483 489 489 491 491 492 493 493 MO 70-5 NATIONAL ELECTRJCAL CODE 555 J>an I. Part II. Pan Ill. 590 Marinas, Boacyards, Float.ing Bi,ildi ngs, and Comm e rcia l and Noncommercial Docking· Facilit.ies ................................................................ General ............ .. ....... .......... .......... ............... ......... Marinas, Boatyards, a nd Docking Faci lities ........ Floating Buildings ......................... ............... ........ Temporary Installations .............. ......................... 660 7070707070- 500 500 502 504 504 Chapter 6 Special Equipment 600 Part I. Pan II. Electric Signs and Outline Lighting ................... General . .................... .......... .......... ............... ..... .... Fie ld-Installed Skeleton Tubing, Outline Lighting, a nd Seconc1al)' Wiring ......................... 604 Manufactured Wiring Systems............................ 605 OHice Furnish ings............................................... 610 Cranes and Hoist~ ......................................... ....... Pan I. General ................................................................. PanU. Wiring ................................................................... Part Ill. Con met Co ndLLcrors ....................... ..... , ................ Pan Iv: Disconnecting Means .............................. ............. Pan V. Overcurrent P rotect.io n ....................................... Parr VI. Contro l................................................................. Pan VII. Grounding and Bo nding.............. ....................... 620 Elevators, D umbwaiters, Escalators, Moving Walks, Platform Lifts. and Stairway Chairliti.s ..... Pan I. General ........... ................................... ................... Pan 11. Concluctors ........................................................... Pan Ill. Wiring ............. .................................. ,................... Pan Iv: Installation of Conductors ................................... PanV. Traveling Cables ....................................... ............ D isconnecting Means and Control ..................... PanVL. Pan VII. Qvercurre nt Protect.in n ....................................... Pan VIII. Machi ne Rooms. Control Rooms, Machiner y Spaces, and Control Spaces . .......... ...................... Pan IX. Grounding and Bo nd ing.............. ..... .......... ........ PanX. Eme rgency a nd Standby P ower Systems ............. Electric Vehicle Power Transfer System.............. 625 Pan I. General ................................................................. Pan 11. Equipme ruConstruction ............................ ......... Part Ill. Installation ............................................................ Pan Iv: Wireless Power Transfer Equipment................... 626 Electrified T ruck P arking Spaces ............. ........... Genera l .............. ................. .................................. P arr I. P art II. Electrified Truck Parking Space EleCLrical Wiring Systems..................................................... P art Ill. Elecrrified Truck Parking Space Suppl)• Equipment ..................... ..... .................... .............. Pan Iv: T ransporr Refrigerated U n its (TRUs) ................ 630 Electric Welders ...................... .................... ......... Pan I. Gene ra l ................................................................. Pan II. A.re Welders ........................... ..... .......... .......... ..... . Parr IIL Resisrance Welders ............................................... Parr JY. Welding-Cable ................................... ..... .............. 640 Audio Signal Processing, Amplification. and Reproduction Equipment ................................... Parr I. General ...... ..... ..... ..... ..... ............... .......... ..... ......... P arr II. Pe rma nent Audio System Installations ............... Parr III. Portable and Temporary Audio System installations........................................... ............... 645 ln fonnation Technology Equipme nt .................. Modular Data Cenrers ......................................... 646 P arr I. General ................................................................. Parr II. EqLLipment ................................................... ......... P arr III. Liglning ............ .......... ......................... ..... ............ Pan rv. Workspace ...... .......... ..... .......... ............... .............. 647 Sensitive Electronic EqLLipmem ............. ............. 650 Pipe Organs ............. ............................................. 70--6 70- 508 70- 508 70- .~12 70- 5 14 70- 515 70- .~16 70- 516 70- 517 70- 519 70- 520 70- 520 70- 521 70- 521 7070707070707070- 521 521 523 525 527 528 70707070707070707070- 530 530 531 531 528 530 531 532 532 535 535 535 70- 536 70707070707070- 537 53~ 540 540 54() 541 541 70- 542 70- 542 70- 544 707070707070707070- .545 .546 .549 549 552 552 553 553 554 X-Ray Equipment.............. ..... .................... ..... ..... General ......... ........................................ ................ Control .............. ..... .................... ......................... . Transformers and Ca pacitors .............................. Guarding and Grounding...................... ............. 665 Induction and Dielectric H eating Equi pmen t ... Pa rt J. General................... .............................................. Part II . Guarding, Grounding, a nd L abeling ..... ............. 668 Elecu·olytic Cells ............. ............... ..... ..... ..... ........ 669 Elecu·oplali ng .... .......... .......... ............... .......... ...... 670 Industrial Machinery .......... ................................. 675 Electrically Driven or Controlled hTig-at.ion Machines ............................................................... Pan l. General ......... ..... ............... .................... ................ Part JI . Center Pivo t lrrigat.ion Machines ........................ 680 Swimming Pools, Fountains, a nd Similar Installations .......................................................... Part J. General ......... .......... ............... .......... ..... ................ Pa rt II . Pe rmane ntly Installed P ools ........ ............... ......... Part Ill. Storable Pools, Storable Spas, Storable Hot TLLbs, a nrl Storable Imme rsion P ools ................. Part JV. Spa5, H ot Tubs, and Permanently JJ1sralled Imme rsio n Pools ..................... ............................. Part V. FoL1ntains .. ....................................................... ..... Pa rt VJ. Pools and TLLbs for Therapeutic Use .................. Part VII. Hydromassage Batl1tuhs .................. .................... PartVlll. Electrically P owered Pool Lifis .... ..... ................... Natural and A rtificially Made Bodies or Water .. 682 Part L General ......... .......... ......................... ..... ............... . Part II . Installation ...................... .................... .................. Pan JI I. Grow1ding and Bonding................................ ..... Integrated E lecu;cal Systems.............................. 685 Part I. General ....................................... ......... , ................ Pan II . Orderly Shutdown ................................................ 690 Solar Photovollaic (PV) Sysrems . ........................ Part I. Ge ne ral ................................................ ,................ Part II. Circuit Req11Jreme111s .......................................... Part II L. Disconnect.ing Means ............................ ............... P an IV. Wiring Me d1ods and MaLerials ............................ Pa rLV. Grounding· ancl Bonding .......................... , ..... ..... Marki ng ....................................................,........... PanVI. Pan VII. Connection to Other Sources .................... ......... ParLVIII . Energy Storage Syste ms ....................................... 691 ~r~e-Scale P hotovoltaic (PY) Electric Supply Stallons ................................................................. 692 Fue l Cell Systems ..........., ...................................... P a rt I. C,eneral ................... .......... ..... ..... .......... ................ Part II. Circuit Requlremenr.s .......................................... .Part II L Disconnect.ing Means ........................................... Pa n IV. Wiring Me d1ods ..... .............................................. Pa n V. Grounding ............................................................ Pan VI. Marki ng................................................................ P an VII. Connection to Other Circuits ............ ................. 694 Wind Elenric Sys rems ..... .................... ................. Pa rt I. Gene ral ................................................. ................ P art II. Circuit Require m e n r.s .......................................... .Pan Ill. Disconnect.ing Means ........................................... Pan fV. v\1iring Meth od~ ................................................... Pan\!. Grounding· and Bonding .......................... , .......... P a rt VI. Marking...... .......................................................... P a rt V i l. Connection co OLher Sources ............... .............. 695 Fir·e Pumps ................................... ......................... Part l. Part JI. Part Ill. Part IV. 7070707070707070707070- 5.~5 555 556 556 557 557 557 558 558 560 .~6 1 70- 562 70- 562 70- 564 70- 564 70- 564 70- 567 70- 573 70- 574 70- 576 70- ·578 578 707070707070707070707070707070707070- 580 580 581 581 582 582 582 58:3 587 588 590 .592 .592 .592 707070707070707070707070707070707070- .593 594 .594 .594 595 595 595 595 595 596 .596 597 597 599 599 -599 -599 600 579 (>79 579 Chapter 7 Special Conditions 700 Pa rt L Pan rr. Emergency Systems . .......... ..... ............... ............... 70- 605 General .... ........................................ ..................... 70- 605 Circuit Wiring ....................................................... 70- 607 NATIONAL ELECTRICAL CODE 2020Edition CONTENTS Part ill. Part IV. Part V. Pan VI. 701 Part I. Part II. Part 111. Part IV. 702 Part I. Part II. 705 Pan I. Part II. 706 Pan I. Pan II. Part ill. Pan IV. Pare V. Parr VI. 708 Pan I. Part 11. Part IU. Pan IV. Pan V. 710 712 Pan !. Pfu·1. U. Pan Ul. Pm·t IV. Pm·1.V. Pm"L VI. Pm·t VII. 720 725 Pm·t J. Pm·t IJ . Pan IJI. Pm·t JV. 727 728 750 760 Pfu·1. I. Pm·t U. Pfu·1. UI. PmT JV. 770 Pm·1. J. Pm·t Jl. Pan ill. Pan IV. ParL V. ParL VJ. Sources or Powe,· .... ............................................. . Emergen cy Syst.em Circuits for Lighting and Power ................................................................... . ConLrol - Emergency Lighting Circuits ............ Overcu rrent Protection ...................................... . Legally Required Standby Systems ..................... . General ..................... ........................................... . CircuiLWiring .................................................... ... Sources of Power .................................................. Overcurrent Protection ..........,...... ...•.................. Optional Standby Systems ................................... General ................................................................ . Wiring ................................. ................................. . lnterconnec1ed Electric Power Production Sources .................................................................. General ................................•....,.......................... . Microgrict Systems .. ...................................... ........ Energy Storage Systems ......... .............................. General .....................................,.......................... . Disconnectin.g Means ........................................ ... Installation Requirements .................................. . Circuit RequiremenLS ..............................., ......... . Flow Batt.ery Ene rgy Storage Systems .................. Other Energy Storage Technologies .................. . CriLical Operatio ns Power Systems (CO PS) ....... General ................................................................ . CircuiL Wiring and Equipment ......... .......... ....... . Power Sources and Connenio n ......................... . Overcurrent Protection ...................................... . System Pe rforma nce a nd Analysis ....................... Stand-Atone Systems ........................................... . Direct Current Microgrids ................................... General ................................................................ . Cirn ,i t Requirements .......................................... Disconnecting Means ............... ............................ Wiring Methods ................................................... Marking ....................... ......................... ..... ..... ..... . Protection .................. .............................. ............. Sys rems over 1000 Volts ....................................... Cirn ,i ls and Equipment Operating :u Less Than 50\/olts ................................................... .... Class J , Class 2, m1d Class 3 Remote-Control. Signal ing, and Power-Limited Circuits .............. . General .......................... ....................................... Class l Circui ls ..................................................... Class 2 a nd Class 3 CircuiLS .................. ............... . Listing .Reqniremenls ........................................... lnstrwnentation T ray Ca hie: Type ITC ............... Fire-Resistive Cable Syslems .............................. .. Energy Managemem Syscems .............................. Fire Alarm Systems .............................................. . Gene ral ................................................................ . Non- Power-Limited Fire Alarm (NPLFA) Cirn1i ts ......................... ........................................ . Power-Limited Fire Alarm (PLFA) Circu.irs ....... . Listing Reqni rements ........................................... Optical Fiber Cables ...................................... ..... . General ................................................................ . Cables Outside and Enrering Buildings ............. Protection ... ..... ..................................................... Grou nding Methods ........................................... . LnstallaLion Methods Within Buildin b'S ............... Listing Req.uiremenL~ ........................................... 7070707070707070707070- 6 10 6 1() 6 1l 612 fil2 613 613 614 6 15 6 1.5 616 70707070707070707070707070707070707070707070707070- 616 (H6 620 621 621 621 622 623 624 624 624 624 625 627 628 629 629 630 630 6'.30 631 631 631 (j31 631 2020 ll\lirjon Part Ill. PartLV. Part V. Part I. Pa rt II. Part Ill. Part IV. 820 Pa rt I. Pa rt II. Part IIJ. Pa rt LV. Part V. Part VI. 830 Part I. Part LI. Part Ill. Part LV. Pan V. Pan VT. 840 J'an L Pan II. Pan In. Pan[\( Pan V. Parl VI. 70- 631 70707070707070707070- 632 632 633 635 642 644 64.5 6{.5 646 646 70707070707070707070- 647 649 652 6.56 656 656 657 (-i57 65!J 661 General Requireme n ts for Co ,.r nnunicalions Systems ....... ..... ......................... .......... ..... .............. 70- 664 NATLONAL ELllCTRW.AL CODE Part Ill. Part LV. Part V. 805 Pa rt I. Pa rtll. 8 1() Chapter 8 Communications Systems 800 Pa rt I. Pan IL 70- 608 Part VIJ.. General ......... ......... .................................... ........... W ires and Cables O utside and Entering Buildings ............................................................... Grounding Methods....... ..................................... lnstalla1ion Meth ods Within Building-s ............... Lisr.ing Require ments ........................................... Communications Circuits .... ..... ........................... General ...................................................... ........... Wires and Cables Outside a 11dEntering Buildings ...................... ........................................ . Protect ion ............................................................. Installation Meth ods Within Buildings ............... Listi ng Require ments ........................................... Radio a nd Televisio n Equipment ........................ General ................................................................. Receiving Equipmem - Antenna Systems ........ Amateur and Citizen Band Trnnsmitting and Receiving Srntions - Antenna Systems .............. In terior Installation - Tra nsmitting Sra1jons .... Community Antenna Television and Radio Distribution Systems ................ ............................ Ge neral .............. ................................... ..... ........... Coaxia l Cables Outside and Entering Buildings P rotect.ion ............................................................. Grounding Methods.. ........................................ .. lnsLalla1ion Methods W ithin Bnildings ............... Listing Requirements ........................................... Network-Powered Broadband Com municarlons Systems ..... .................... ......................................... General .... ............................................. ................ Cables O,nside and Entering Buildings............. Protection ............................................................. Grounding Met.hods............................................ Installa1jon Meth ods Within Buildings .............. . Listing R equi remen lS ... ................................ ........ Prem i.ses-Powe reci Broadband Communicalions Sysr:ems ..... ...... ... . ... ....... ...... .............. ..... . ... .... .. ..... . General ...................................................... ........... Cables Outsicie a ndEnte1i ng Builrlings ............. Protection ............................... ..... ......................... Grouncting Melhods ............................................ lnstallatio11 Methncls With.in Buildings ............... .Premi.ses Poweling of Communicatio ns Equipment over Corn municatinns Cables .......... Listing Requi remems ............................ ..... .......... 70- 664 707070707070- 665 (-i66 668 675 675 675 70707070707070- 676 676 678 679 680 680 681 70- 683 70- 683 70707070707070- 684 684 684 684 685 685 686 70707070707070- 686 686 687 688 690 690 691 7 07070707070- fi(J I 6!ll 6()2 692 693 693 70- 693 70- 693 Chapter 9 Tab]es 1 2 4 5 5A 8 9 10 II (A) Pe rcem of Cross Section of Conduit and Tubing fr,r Conduc.t ors and Cables ................... .. Radius ofCond,tit and Tubing Bends................ Dimensions and P ercem Area of Conduit and Tubing (.Area.., of Conduit or T ubing for the Combinations of Wires Perm.irled in Table I , Chapter 9) ........................... ................................. Dimensions ofl nsulated Co nductors a nd Fixture Wires ............................................. ........... Compact. Copper and.Aluminum B uilding Wire Nominal Dimensions** and Areas ......... ..... ........ Conducwr Properties .......................................... Alternating-Current Resistance and React.ance for 600-Volt Cables, 3-Phase., 60 Hz, 7!'i°C (167°F) -Three Single Coorluctors in Conduit .... ............................................................. Cond ucror Stranding .............. ............................. CJa5s 2 and Class. 3 Alcernating-Currem Power Source Limitations ............................................... 70- 6% 70- 695 70- 6\16 70- 700 70- i04 70- 705 70- i06 70- 707 70- 707 70-7 NATIONAL ELEC..'TRJCAL CODE 12(A) PL!i'A Alternating-Curren L Power Source Limitations ........................................................... 70- 709 In-formative Annex G: Supervisory Control and Data Acquisition (SCADA) ................................................. .... 70- 83!l J nfom1ativeAnnex;\; Product Safety Stanrla.rd.s .......... 70- 710 lnformacive Annex H: Administration a nd Enforcement ......................... ......................... ................. 70- 834 J n fom,ativeAnnex.B: Application Informal.ion for Ampaci cy Calculation ..................................................... 70- 716 Informative Annex C: Conduit, Tubing, and Cable Tray Fill Tables for Conductors anrl Fixture Wires of t.he Same Size ............................. ............... .......... ............ 70- 729 lnformaLive Airnex D: Examples ................................... 70- 8 15 lnfom1ative Annex I: Recommended Tigluenjng Torque Tables from UL Standard 48f:iA•486B .............. 70- 840 Informative AnnexJ : ADA Stanrlard5 for Accessible Design ......... ......................... .......... ..... .......... .................. 70- 842 Index ... ..... .......... ..... ..... ..... .......... ..... .......... ..... ..... ..... ...... 70- 845 JnformaLiveAnnexE:Types ofConstruction ............... 70- 829 Ln fom1ative Annex F: Availability and Reliability for Critical Operations Power Systems; and Development and Implementation of Functional Performance Tests (FPTs) fo r Crilical Operal.ions Power System$ .............. 70- 831 70-8 NATIONAL ELECTRICAL CODE 2020falition COMMITTEE PERSONNEL NATIONAL ELECTRICAL CODE COMMIITEE These lists represent the membership at the time the Committee was balloted on the final text of this edition. Since that time, changes in the membership may have occurred. A key to classifications is found at the back of this docume nt. Correlating Committee on National Electrical Code® Michael}- Johnston, Chair Natio na l Elecirical Con u·actors Associa tio n, MD [IM] Mark W. Earley, &cretrwy (Nonvoting) Natio nal Fire Protec1jo n Associatio n , MA Sanh D. Caldwell, Ted1,,i1:al Comntilu:e 1ldmi11ist.r(l.lor (Nonvoting) Natio nal Fire P rotec tio n A.~sociation, MA James E. Brunssen, Te lco rdia Technologies (Ericsso n ), NJ [UT] Re p. Allia nce for Telecommun ications Industry Solutio ns Kevin L. Dressman, U.S. Departme111 of Energy, l'vlD [ U ] Palmer L. Hickman, Electrical Training AUiance, MD [L] Rep. ln te rna1io nal Brotl)e rhood of Electrical Workers David L. Hittinger, Indep en de nt £lec1rical Com racwrs of Greater C incinnati. O H [IM] Rep. Ind e pe nde n t Electrical Contractors, lnc. Richard A Holub , The DuPonl Com pany, Inc., DE [U] Rep. Am e rican Che01istry Council John R. Kovacik, UL LLC, IL [RT] Alan Manche, SchneiderElectric. KY [M] Roger D. McDaniel, Georgia Power Compa ny, GA [UT] Rep. £lec1ric Lig h1 & Power Grou p/ EEi David A. Williams, De lta Ch arter Towns hip, Ml [E ] Rep. In ternational Association of Elecu·ical lnspen.ors Alternates Lawrence S. Ayer, Biz Com Elenric, Inc., OH [lM ] (AIL. to David L. Hitti nger) Roland E. Deike, Jr., Ce nte rPoint Energy, Inc., TX [ UT] (AIL. LO Ro ge r D. McDaniel) James T. Dollard,Jr., IBEW L ocal Unio n 98, PA [ L) (Al l. lo Palmer L. H ickman ) ErnestJ. Gallo, Telcordia Technologies (Ericsson ), NJ [UT] (Al L to J ames E. Brunssen) Robert A. McCuUo ugh, Tucker mn, ~ [ El (AI L to David A. Williams) RobertD. Osborne, U L LLC, NC [RT] (Alt. r.o j o h n R. Kovacik) Christine T. Porter, lmertek Testing Sewices, WA [RT] (Voting Alt.) George A. Straniero, AFC Cable Systems, Inc., NJ [M] (Voting Ali.) Nonvoting Timothy J. Pope, Can adia n Standa rds A~ociatjon. Canad a [SE] Rep. CSA/Canadia n Elecrrical (',ode Co mmittee William R. Drake, Fair field, CA [ M] (Me mbe r Emerillls) D. H arold Ware, Lib ra Electric Com pany. OK [[M] (Member Emeritus) Mark W. Earley, N FPA Staff Lia ison 2U20 Edition NATLONAL £U.CTRICAL COD!l 70-9 NATIONAL ELEl.'TRICAL CODE Code-Making Panel No. 1 Articles 90,100, 110, Chapter 9, Table 10, Annex A, Annex H , Annex I, and Annex} Kenneth P. Boyce, Chair UL LLC, IL [RT] Louis A. Barrios, Sh e ll Global Solutio ns, TX [U] Rep. American Chemistry Council Roland E. Deike, Jr., CenLerPoint Energy, Inc., TX [UT] R ep. Electric Ligh1 & Power Group/ EEi Ernest]. GaUo, Telcordia Technologies (Ericsson ), NJ [VJ Rep. Alliance for Te lecc;imm unicaLions Industry SoluLions Palmer L. Hickman, Electrical Training A lliance, MD [L ] Re p. tmernational B rotherh ood nfE.lectrirnl Wc;irkers David L. Hlttinger, I ndependem Electrical Contrac 1nrs of G re;uer Cincinnati, 0 1-l [IM] Rep. lnclepenclent Elecuical Contractors, lnc. Donald R. [verson , National Elec1rical Manufac1urers Association, Ml [ Ml Rep. National Elecu·ical Manufacturers A~sociarion James F. Pierce, l merrek Testing Services, O R [RT] Harry J. Sassaman, fo resr.Eleccric Co,porarion, NJ [IMJ R ep. National Elecrrical Contractnrs AssociaLion Kent A. Sayler, P2$ Inc., CA [U) Rep. 1.nsLitnte of Electrical & Electronks Engineers, Inc. Mohinder P. Sood, Cicy of A lexandria, VA [El Rep. lmernational Association of Elecuical Jnspecrors Alternates James E. Brunssen , Telcordia Technologies (E,icsson) , NJ LUJ (Al t. to Ernestj. Gallo) Mark Christian, Electrical Training Alliance, T N [L] (Alt. to Palmer L. H ickmat1) Jon Coulimore,JC Elewic, Inc., WA [IM] (Alt. to David LJ-littinger) TimotJty Garland, Keene State College, N I-I [U] (Voti ngAlc.) Larry Geyer, QLtali ty Electric Inc.. ID [IM] (Ale. to H an-yj. Sassaman) Joseph Marquardt, ExxonMobil Productio n Compa n}, TX [U] (AJ1. co Louis A. Barrios) Roger D. M cDaniel, Georgia Power Company, GA [UT] (AJt. to Ro land E. Deike.J r.) Kenneth L. McKinney, Jr., UL LLC, NC [RT] (Alt. lO Kenne th P. Boyce) Donald R . Offerdahl, lntenek Testing Sen~ces, N D [RT] (AJt. to J ames F. Pierce) Michael C. Stone, National Electrical Manufacturers A%ociation, CA [M] (AJt. 10 Donald R. Iverson) Frank E. Tyler, The Du Po n t Co!llpany, Inc.. DE [U) (AIL to KemA. Say.le r) Charles VaJaer, City Of G lendale Californ ia, CA LE] (Alt. t0 Mohincler P. Sood ) Nonvoting Ark Tsisserev, AES Engineering, Canada [SE] Rep. CSA/ Canadia n Electrica l Code CommitLee 70-10 NAT IONAL ELECTRICAL CODE 2020fali,ion COMMITTEE PERSONNEL Code-Making Panel No. 2 Articles 210,220, Annex D, Exam.pies Dl through D6 Mark R. Hilbert, Chr,ir MR Hilbert Elenrical lnspectfon ~ & Training, N I-I [E) Rep. In ternational Association of Electrical inspectors Mathher Abbassi, N ew York City Depa run em O f B uildings, NY [El Charles L. Boynton, The DuPont Company, Inc., TX LU] Rep. Am e rican Chemistry Council Daniel Buuck, National Association o f Ho m e Blti.lders ( NAH B) . DC [U] Re p. National Association of HQme .Builders Steve Campolo, Levito n ManLtfacturin g Company, Inc., NY [M] Thomas A. Domitrovich, Eaton Corporation, MO [Ml Rep. National Electrical Ma nufacwr ers Association Nehad El.Sherif, Saskatoon, SKCanacla [U] Rep. lnstian e of Electrical & Electronics Engineers, Inc. TI1omas L. Harman, U ni versity of Housto n.Clear Lake, TX [SE] DavidW. Johuson, CenTexJEC, TX [ IM ] Rep. Independent E lectrical Con tracto rs, Inc. Alan Manche, Schneide r Electric, KY [Ml John McCan,ish, NECA IBEW Elecrrical Training Ce111.e r, OR [L ] Rep. l m e rna tio nal Brothe rhood ofElecuical Workers Christopher J. Pavese, Duke Ene rgy, KY [ UT] Rep. Electric Light & P ower Group/ EEi Frederick P. Reyes, U L LLC, NY [ RT] Michael Weaver, M&W Electric, OR [ IM] Rep. National Electrical Contractors A~sociation Alternates William B. Crist.Jr., lES Residential Lnc., TX [JM] (Al t. to David W. J ohnson) Andrew Kriegman, Le,~ton Manufacturing Company, J nc., NY [M] (Ah. 10 Steve Campolo) Brett Larson, Schneider Electric, lA [M] (.A.It. LO Alan Manch e) Cesar Lujan, National Association ofl-fome Builders (NAHB), DC [UJ (AIL LO D aniel Buuck) Roger D. McDaniel, Georg ia P ower Compan y, GA [UT ] (Al t. LO ChristopherJ. Pavese) Daniel J. Naughton, .JATC of Greater Boston. MA [L) (Alt. lo.J ohn McCamish) Fred Neubauer, Neubauer Electric Inc.. CA [lM] (Alt. 1.0 Mkhael Weaver) Robert D. Osborne, UL LLC,NC [ RT ] (Alt. to Fred e rick P. Reyes) Femando E. Pacheco, Methanex Chile SA. TX LU] (Ah. to Charles .L. Bni~1ton) BrianE. Rock, H ubbell Incorpo rated, CT [M] (A.11. to Thomas A. D o rnitrovich ) JosephJ. Wages, Jr., lmernaLio naJ A~oclation ofElectricaJ Inspeck,rs, TX [El (Alt. to Mark R. Hilben) Nonvoting Douglas A. Lee, U.S. Consume r Product Safety Com.mission, MD [Cl R ep. U.S. ConsLU11er Product Safecy Commissio n 2020 lldirjon NATLONAL £ L£CTRLCAL CODE Andrew M. Trotta, U .S. Con sumer Product Safety Commissio n, l\lID [Cl Rep. U.S. Consumer Product Safety Colllrnissio n 70-11 NATIONAL ELEl.'TRICAL CODE Code-Making Panel No. 3 Articles 300, 590, 720, 725, 727, 728, 760, and Chapter 9, Tables 11 (A) and (B), and Tables 12(A) and (B) Robert A.Jones, Chair l ndependem Electrical ContracLOrs, Inc., TX [IM] R ep. Independent Electrical Co nu-actors, Inc. Randolph J. Ivans, UL LLC, NY [RT] Chad M.Jones, Cisco Systems, O H [ M] T. David M.ills, T. David l\llills Associates. LLC, GA [U] Rep. lnstitme ofEiecu·ical & ElecLronks Engineers, Inc. Steven j. Owen, Steven j. Owen, Inc., AL [IM] Rep. Associated Builders & Conu.ictors David A. P ace, Olin Corporation. AL [VJ Rep. American Ch emistry Council Charles j. Palmieri, Tow11 n!'Norwell, MA LE] Re p. lmernational Association Elecu'ical Jnspectors John E. Sleis hts, Travelers Insurance Company, CT [I ) George Allan Zimmerman, CM_E Consu lting, Inc., CA [SE] Rep. Ethernet Allia nce Richard S.Anderson, RTKLAssociates lnc.,VA [M) Rep. Bujlding. Industry Consulting Services lnternauonaJ Douglas P. Bassett, XFinicy H ome, FL [ IM] Rep. Elenronic Sec uricy Association Larry G. Brewer, lmertek Testing Services, NC [RT] Steven D. Burlison, Duke Energy, FL [UT) R ep. Elenric Light & Power Group/ EE! Paul J. Casparro, Scram o n Electricians JATC, PA [L] Rep. lmernatio nal Brmhe rhood of Electrical Workers or Shane M. Clary, Bay Alarm Compa ny, CA [M) R ep. A utomatic Fire Afarn1 Association, Inc. Raymond W. Horner, Allied Tube & Conduit, IL [M) R ep. National Elenrical Manufacturers A~sociation Alternates Adani D . Corbin, Corbin Elecrrical Services, lnc., NJ [IM) (AIL to Rohen A.J o nes) Mich aelJ. Farrell ill, Luca~ County Building Regulation, Ml [L] (Alt. r.o Paul.J. Casparro) J oel Goergen, Cisco Syste ms, Inc., CA [Ml (AIL LO Chad M.Jones) Ward Judson, Pencair/ ERICO Lnrernationa l Corporation. O H [M] (AIL r.o Richard S. Anderson) Kyle Krueger, National Electrical Contractors- Milwaukee Ch apter, Wl [1.M] (Voti ng AIL) J ohn Lupacchino, Ga)ilorEleCLric lnco ,vomted, IN [ LM] (AIL to Steve n .J. Owen) Jack M cNamara, Bosch Security Systems, NY [M] (Alt. to Shane M. C lary) Timothy J . Mikloiche, Town of Wesr. H artford, CT [E] (Alt. to Charles.). Palmieii) MarkC. Ode, ULLLC,AZ [RT] (Alt. LO Randolph J. Ivans) Christopher J . Pavese, Duke Energy, KY l UT] (AJL to Steven D. Burlison) Dmitriy V. Plotnikov, l ntertek Testing Services, NJ [RT] (AIL LO L 1tT)' G. B rewer) Rick D. Sheets, AT&T Digira.l Life. TX [IM] (AIL to Douglas P. Basseu) George A. Straniero, AFC Cable Systems, Jo e., NJ [Ml (Ah. m Raymo nd W. H orner) William C. Sze to, McKinney, TX [U J (AIL Lo T. David Mi lls) Rebecca S. Templet, Shell Chemical, 1A [UJ (AIL 10 David A. Pace) Nonvoting Edward C. Lawry, Oregon, WL [E] (Member Emeriws) 70-1 2 NATIONAL ELECTRICAL CODE 2020falition COMMITTEE PERSONNEL Code-Making Panel No. 4 Articles 690, 692, 694, 705 JamesJ. Rogers, Chair To-.11S of Oak Bluffs, T isbury, West Tisbury, MA [El Rep. International Association ofElecLrirnl lnspecwrs William F. Brooks, Brooks Engi neering, GA [U) Rep. Photovoltaic lnrlusr.ry Code Council Bill Brown, Schneider Eleccric, T N [M) Rep. National Electrical Manufacturers Association Thomas E. Buchal, hnenek Testing Services, NY [RT] James G. Cialdea, CE Power Engineered Services, LLC, MA [IM] Rep. l.n terNational Electrical Testing A~sociat.ion Timothy M. Croushore, Fi rsl.Energy Technologies, PA [UT) Rep. Electric Ligh t & Power Croup/ EEi Jason M. Fisher, Tesla Inc., VA [U J Rep. Solar Energy Industries Association Todd Fries, J-lellem1annTyLOn, Wl [M] Mark D. Gibbs, URSICH2M Oak Ridge LLC (UCOR), TN [U] Rep. lnstitme of Electrical & Elenrnnics Engineers, lnc. Rebekah Wharton Hren, IPP NC LLC, NC [U] Rep. Solar Energy Internationa l Lee M. Kraemer, Fi,~~t Sola,; OH [Ml Rep. Large-Scale Solar Association Matthew Paiss, San.Jose Fire Department, CA [L] Rep. International Association of Fire Fighters Irozenell Pruitt, TI1e DuPont Company, Inc., TX [Ul Rep. American Chemistry Council DukeW. Schamel, Electrical Service Solutions, In.c., CA [£Ml Rep. Independent Electrical ConcraClo rs, Inc. RonaldJ. Toomer, Toomer Eleetrical Company Inc., LA [IM] Rep. National Electrical Contracrors Association Wendell R. Whistler, I BEW 1547, O R [L] Robert H. Wills, Tmergrid, LLC. NH [ U) Rep. American Wind Energy A.ssociation Tunothy P. Zgonena, UL LLC, lL [RT) Alternates J ohn S. Berdner, Sola rcowboyz, CA [Ul (Ah. co William F. Brooks) Ron Borowski, Ealon Corporation, WI [MJ (Ah. to 13ill Brown) Ward I. Bower, Solar Energy I nrlustries Association, NM [U J (AJ L LO .Jason M. Fisher) Mark Gillespie, TMlElec1ric, OH [lM] (Alt. to Duke W. Sch amel) Anthony Granato, Manchester Fire Rescue EMS, CT [ LJ (All. lO Matthew Paiss) Howard Liu, lntenek Testing Services, NY [RT] (AIL t0 TI10rnas E. Buchal) Brian Mehalic, Winston-Salem. NC [UJ (AIL to Rebekah Wharton Hren) Harold C. Ohde, IBEW 134/ Electrical j oimApprenticeship Trai ni ng & Tn.Lst, IL [ L] (AJL LO Wen dell R. Whistler) Isaac Opalinsl<y, Sunpower Corporation, MD [MJ (Alt. to Lee M. Krae mer) Rhonda Parkhurst, Ory of Palo Alto, CA [El (Alt. 1.o J amesJ. Rogers) Robert W. Preus, National Re newable Energy Lab. CO [U) (AIL to Robert H. Wills) Kent Whitfield, Underwriters L'lboraLOries, CA [RT) (Alt. to Timo1J1y P. Zgone na) Leo Zieman, Florida Power & Light (Nexcera Energy), FL [UT ) (Alt. to Tirnorh y M. CroLIShore) Nonvoting Stephen W. Douglas, QPS Evalnation Services Inc., Ca11ada [SE) Rep. CSA/ Canadian Elecu·ical Code Commictee 2020 ll(l.irjon NATLONAL £L£CTRLCAL CODE 70-13 NATIONAL ELEl.'TRICAL CODE Code-Making Panel No. 5 Articles 200, 250 Nathan Philips, Chai,· lntegr;uerl Elenronic Systems, OR [ IM] Rep. National Elecu·ical Contractors Association Paul W. Abernathy, Encore Wire Corporat io n , TX [Ml R e p . The AlLLmimunA~sociation. lnc. Joseph F. Andre, Slee! Tube Institute, WA [M] Rep. Steel Titbe Institute of North America Gary A. .Beckstrand, Utah Elec.trical .JAT C, UT [L] Rep. International Brotherhood of Elecu-ical Workers Trevor N. Bowmer, Telcorclia (Ericsson ), NJ [UJ Re p. Alliance for Telecommunications Industry Solutions David .B.-ender, Copper D evelopmemA~sociation, Inc., NY [Ml Re p . Copper Developmem A<;sociarion Inc. Paul Dobrowsky, Innovative Tech no logy Services, NY [UJ Re p. American Ch emistry Council David A. Gerstetter, UL LLG, IL [RT) G. Scott Harding, F. B. Harding, Inc., MD [IMl Rep. LnrlependentElectrical Contractors, lnc. Joseph Harding, Power Tool Institute, OH [M] DaJeep C. Mohla, DCM Eleccrical Consulting Services, Inc., TX [U] Rep. lnstimce of"Elecu-ical & Electronics Engineers, Inc. Mike O'Meara, Arizona Public Service Company, AZ [UT] Rep. Electric Lig ht& Power Group/ EEi William A. Pancake, Ill, CAP Governmenc, FL [E] Rep. lmernational Association of Elecu;cal Jnspecrors Christine T. Porter, lntertek Testing Services, WA [RT) Nick Sasso, Srnte of Wyoming, W'Y [El Gregory J. Steinman, Thoma~ & Betts Corporation, T N [M] Rep. National Elecffical Manufacturers Association Alternates Larry Albert, Stan ley Black A nd Decker, MD [M] (AIL to.Joseph I-larding) Derrick L Atkins, Minneapolis Elecu-icalJ ATC, MN [L] (A1L r.o Gary A. Beckstrand) Kenneth S. Crawford, Ch emou rs Company, WV [U] (Alt. to Paul Dobrowsky) Joseph P. DeGregoria, UL LLC, NY [RT] (AIL to David A. Gemener) Raymond Dunnigan, lntertek, NY [RT] (AIL to C hristine T. Porter) Ernestj. Gallo, Telcordia 'Technologies (Ericsson ), NJ [U) (Voti ng Al t.) Bobby J. Gray, H oydar/ Buck, Inc., WA [(Ml (Alt. to Nathan Phili ps) Buster Grissett, Mississippi P mver Company, MS [UT] (Alt. w Mike O 'Meara) Raymond W. Horne r, Allied Tube & Conduit, IL [Ml (Alt. m .Joseph F.Anrlre) Ronald Lai, Burndy LLC, NI-I [M] (Alt. lo Gregory.I- Steinman) Karin Manfredi, AFG Cable Systems/Atkore, MA [M] (AIL LO Paul W. Abernathy) Richard M. O'Brien, IAEI, NV [ E] (Alt. to William A. Pancake , Ill) Davidj. Picatti, Picaui Bros. Inc. , OBA lndusu-ial Service & Elecu·ic, WA l1Ml (AIL to G. Scott Harding) Phil Simmons, Simmons Elecuirnl Services, WA [l\•l l (Al t. l0 David Brende r) Nonvoting Robert A. N elson, Canadian Sl.-.nd.,rds .Associatio n , Canad a [RT ] 70-1 4 NATIONAL ELECTRICAL CODE 2020fali,ion COMMITTEE PERSONNEL Code-Making Panel No. 6 Artlcles310, 311,320, 322,324,326,328,330,332,334,336 1 337, 338,340,382,394,396,398, 399,400, 402, Chapter 9, Tables 5 through 9, Annex B and Example D7 Susan Newman Sce arce, Chair City of Humboldt, T N, T N lE) Rep. l nLernational As.sociatio n of Elecu-ical Inspectors Todd Crisman, !BEW Local 22.JAT C, NE [ L) Rep. lnternaLio nal Brothe rhood of Elenrical Workers Joseph W. Cross, Eastma n Chemical Company. TN LU] Rep. American Chemistry Council Timothy Earl, G BH lmernational. MI [M) Rep. The Vinyl lns1:iru1e Christel K. Hunter, Cerro Wire, NV [M) Rep. The A lurni11Lun Associarjo n , Inc. G erald W. Kent, KenL Elecu-ic & Plumbing System s, TX [IM] Rep . l ndepe ndenL Elecu-ical ConLractors, Inc. Charles David Mercier, Soutl1\,'ire Company, GA [M] Rep. National Electrical Manufacturen Association Dennis A. Nielsen, Lawren ce Berkeley Natio nal Laboratory, CA [Ll] Rep. Ins1jwre of Elec1rical & Electronics E ngineers, Inc. Michael Thomas Porcaro, National Grid, MA [UT) Rep. Electric Lig h r & P ower Gro up/ EEl Kenneth Riedl, l menek Testin g Services, NY [RTJ Rep. l m enek Testing Services Susan L. Stene, UL LLC, CA. [RT ) George A. Stranjero, A FC Cable System s, l11c., NJ [M] Rep. C',apper D evelopme n t Association Inc. Wesley L. Wheele.r, National Electrical Contractors Association , MD [IM] Re p. National Electrical Con tractors Associac:inn Alternates David Carroll, Florida Power And Ligh t, FL [UT ] (AIL Lo Mic hael Thomas Po rcaro) Chris]. Fahrenthold, Facili1y Solutions Group, TX [IM ) (Alt. Lo Gerald W. Kem) Samue l. B. Fdedman, Gene ral Cable Co,poration, RJ [Ml (Ah. to C harles David Me rcier) Herman]. Hall, ALL~Lin , TX [M] (Alt. t0 T imothy Earl) Samuel R. La Dart, City of Me mphis, TN [LJ (Al t. LO Todd Crisman) 2U20 Edition NATLONAL £ U.CTRICAL CODE Kelly Lamp, Idaho Chapter NECA, LO [IM] (AIL to Wesley L. \¥heeler) Borgia Noel, State ofWyo ming Fire Marsha l's Office, WY [El (Alt. to Susan Newm an Scearce) Kevin T. Porter, Encore Wire Co1poration, TX lM) (A lt to Christel K. Hunte r) Mario Xerd, UL LLC, NY [RT ] (AIL r.o Susan L. St.ene) Joseph S. Zimnoch, TI,e Okonile Company, NJ [Ml (AIL to George A. Srraniero) 70-15 NATIONAL ELEl.'TRICAL CODE Code-Making Panel No. 7 Articles 545, 547, 550, 551, 552, 553, 555, 604, 675, and Annex D , Examples D11 and Dl2 L. Keith Lofland, Chair lme rnatio naJ A5soclation ofEJec.rrkal Inspectors (IAEI) , T X [E] Rep. Internat ional Association of Elecrrical l nspeetors Jorge L. Arocha, Flo rida Power & Liglu , FL lUT) Rep. Edison Electric lnslicme Joseph R. Chandler, lndependemE!ecrrical Conrractors-Dallas, TX [ IM] Rep. lndependem Elecui cal Comractors. I nc. Wade Elliott, Utili ty Services Group, Inc., WA [U ] Re p. National Associa tio n of RV Parks & Campgrounds Robertj. Fick, AHiant Energy, Wl [U] Rep. American Sociery of Agricultural & Bio logical Engi neers Robert A. Garcia, Cavco f ndusu-ies/ Fleetwood Hornes , Inc.. AZ [Ml Bruce A. Hopkins, R ecreatio n Vehicle Industry Associatio n , VA [M] Ryan H yer, Testing Engineers lmernationa l, UT [RT] Thomas R.Lichtenstein, UL LLC, IL [RT] Doug Mulvaney, Karnpgrounds of.America, Inc., MT l U] Clifford Norton, Belling ham Ma rine ULiJiries, FL [ IM] Richard A. Paredes, IBEW Local J 64 .JATC. NJ lL] Rep. lncernational B rotherhood ofElecu·ical Wo rke rs Stephen G. Rood, Legrand North America, NY [M] R ep. National Electrical Ma nufacwre rs Associatio n Dave Watson, Southwire, (;A [M] Rep. The Aluminum Associatio n, Inc. Wesley L Wheeler, Nalional Electrical Contractors.Associa\io n, MD [IM] Rep. National Eleccricai Contract.ors. Associatio n Michael L. Zieman, RADCO, CA [M] Rep. Manufactured H ousing Jnsliuu e Alternates Barry S. Bauman, Allian t Energy, WI [U] (AIL to RobenJ. Fick) William Bruce Bowman, Fox System s, Inc., GA [IM] (Alt. r.o.Joseph R. Chandle r) Byron Carroll, Carro l Woods Inc., NC [UJ (AIL LO Wade Elliott) Gerald D. Dix, H ampto n Roads J o imApprenticeship Training Committee, VA [ L] (AIL LO Richa rd A. P aredes) Dean C. Hunter, Minnesota Depa nm enc of L abo r &. Jndusuy. MN [El (Alt. to L. Keith Lofland) 70-lfi J e ffrey Kreidler, Kampgrnunds of' America J nc., MT [ UJ (Ale. ro Do ug Mulvan ey) Mark C. Ode, U L LLC, AZ lRT] (AIL. LO TI10mas R. Lichte nstei n) Kent Perkins, Recreali0n Vehicle Industry A5Socialion, VA LM ] (AJL LO Bruce A. H opkins) Paulj. Reis, A FC Cable Systems, Inc., MA [M] (AIL LO Dave WaLSon) Matthew J. Samojeden, Hubbell inco rporated, CT [M] (Ah. co Stephe n. G. Rood ) NATIONAL ELECTRICAL CODE 2020falition COMMITTEE PERSONNEL Code-Making Panel No. 8 Articles 342, 344, 348, 350, 352, 353, 354, 355, 356, 358, 360, 362, 366, 368, 370, 372, 374, 376, 378, 380, 384, 386, 388, 390, 392, Chapter 9, Tables I through 4, Example DI3, and Annex C Larry D. Cogburn, Chair Cogburn Bros., Inc .. FL [ IM] Rep. National Electdcal ConrraCLors Association Doug Adams, MP L-I usky LLC, SC [M] Rep. Cable Bus ManufacLUrers Association Rkha.i-d.J. Berman, ULLLC, IL [RT] David M . Campbell, AFC Cable Systems, Inc., MA [M] Rep. The A luminum Association , Inc. Kenneth W. Hengst, 4C2 E lectrical Specialists, TX [ IM] Rep. Indepenclent Electrical Conrrnctors, Inc. Pete Jackson, City of Bakersfield. California, CA [El Rep. l nternatinnal Association of Electrical Inspectors David H . Kendall, Thomas & Beus Corporation, TN [MJ Rep. TI1e Vinyl Institute Richard E. Loyd, R & N Associates, AZ [M) Rep. Steel Tube Jnstitute ofNon:h America Michael C. Martin, ExxonMobil Research & Engineering, TX [U] Rep. American Chemistry Corn1c.il PauIW. Myers, Nutrien, OH [U] R ep. l ns ti ru te of Electrical & Electronics Engl nee rs, Inc. Donald R. Offerdahl, Intenek Testing Services, ND [Rn Rhett A. Roe, IBEW Local Unio n 26 JATC, MD [L) Rep. International Brnr..herhood of Electrical Wnrkers Rodney J . West, Schneider Electric, OH [M] Rep. National Electrical Man1.1fac1.urers Association Alternates Jay Burris, WheaLlancl Tuhe ( Div. ofZekelman lndusLries), OH [M) (Alt. to Richard E. Loyd) Stephen P. Poholski, Newkirk Elecuic Associates, Inc., Ml [ IM) (Alt LO L-,rry D. Cogb urn) Joel (Joey) Crider, AEP, O H [UT ] (Voting AIL) Brian D eacy, Allied Tube Condu..i1 Corp0raLio n, J.L [M] (AIL LO D avid H . Kendall) Dan Rodriguez, IBEW Lncal Unfon 332, CA [L] (AIL io Rheu A. Roe) FredericF. Small, Hubbell IncorporaLed, CT [Ml (AIL m Rodney .J. West) 03.11 Suriyamongkol, Adviu1ced Cable Bus, SC [M] (AIL m Doug Adams) Raul L. Vasquez, Independent Elecuical Contractors, TX [IM] (AJL m Kennelh W. Hengst) Dave Watson, SouLl11vjre, GA [M] (AIL Lo David M. Campbell) David A. Gerstetter, UL LLC, IL [RT] (AIL. LO Richa rd.). Bemmn) J. Grant Hanunett, Colorarlo Stme Electrical Board, CO [E) (Alt. to Pete.Jack.son) Gary K. Johnson, D ow Corning Corporation, L\ [U] (Ah. IO Michael C. Martin) Nonvoting Stephen W. Dougfas, Q PS Evaluation Services Inc., Canada [SE] Rep. CSA/ Canadian Electrical Code Committee 2U20 Edition NATLONAL £U.CTRICAL CODE 70-17 NATIONAL ELEl.'TRICAL CODE Code-Making Panel No. 9 Articles312, 314, 404,408, 450,490 David G. Humphrey, Chair Coumy of 1-Je nrico, Virginia, VA [EJ Rep. International Association ofElecrtical Inspectors Richard Anderson, Fluo r Corporation , TX [U] R ep. A~sociated BujJde rs & Concracrors Timothy Schultheis, T.S.B Inc .. Schultheis Electric, PA [ IM] Rep. Natio nal Electrical Contractors Association Rodney D. Belisle, N ECA-LBEW Electrical Training Trust, O R [L] Rep. Internatio nal Brmherhood ofElecrrical Workers Carmon A. Colvin", Brigh t Future E lecffic, LLC, AL [ IM] Rep. lndependem Electrical Contractors, Inc. Frederic P. Hartwell, 1-lartwell Electrical Services. tnc., l\llA [SE] Kevin R. Miller, I m e rLek Testing Services. WA [RT] Robert D. O sborne, UL LLC, NC [RT ] Bradford D. Rupp, Allied Moulded Pmducts, I nc., OH [M] Re p . National Electrical Ma nufactu re rs A.~ociatio n Paul B . Sullivan, DuPo nc, SC [ U ] Rep. lnstituLe of Electrical & Electronics Engineers, Inc. Darrell M. Sumbera, Centerpoi nr Energy, TX [ UT] Rep. Edison Elecu·ic Institute Ralph fl. Young, Easunan Ch emical Company. TN [U] Rep. American l.11ernistry Council Alternates Jeffrey A. Fecteau, Underwriters Laboratories LLC, AZ [RT] (Alt. r.o Robert D . Osborne) Ken Filips, Bergelectric, OR [ JM] (AIL to Carmon A. Colvin) Barry N. Hornberger, PECO Energy Com pany. PA [UT ] (Alt. to Darre ll M. Sumbera) Ronnie H. Ridgeway, Siem ens lnd ttsU')', Inc.. TX [M] (AIL LO Bradford D . Rupp) Pat Griffith Rose, City of Greensboro, NC [E] (Alt. t(l David C. H umphrey) Michael Simister, Intenek Testi ng Sen1ces, T X [RT) (AIL to Kevi n R . l\lljlJer) Michael O'Connell, J ointApprentice & Training Corrnnittee of Gremer BosLOn, MA [ L] (Alt. to Rodney D. Be lisle) 70-1 8 NATIONAL ELECTRICAL CODE 2020fali,ion COMMITTEE PERSONNEL Code-Making Panel No. I 0 Articles 215, 225, 230, 240, 242 Julian R. Burns, Chair Qualicy Power Solutions, Inc., NC [IM] Rep. Independent Electrical Contractors, Inc. Paul D. Barnhart, UL LLC, NC [RT ) Scott A. Blizard, American Electrical Testing Company. Inc., tvlA (IM] Rep. lnterNational Electrical Testing As.~ocintion James T. Dollard, Jr. , IBEW Local Union 98, PA [ Ll Rep. lnternalional BroLherhood of Elecu·ical Wo rkers Ed Koepke, Nirtec Mornr Corporal.ion, MO [Ml Kenne th]. Rempe, Siemens lndtL~try lr1c., GA [M) Rep. National Elenrical Manufacrurers A.~ociation Vincent]. Saporita, Eaton's Bussmann Business, MO [M.] Roy K. Sparks, ill, E li Lilly and Company, IN [U] Rep. American Chemis1sy Council StevenE. Townsend, General Motors 0)mfX111Y, Ml [U) Rep. Institute ofElecuical & E lenronicsEn gineers, Inc. Christopher R. Vance, National Grid, NY [ UT] Rep. Elecu·ic Ligh t & Power Group/ EE! David A. Williams, De ir.a Ch anerTownship, Ml [El Rep. ln LernationalAssociarion of E lectrical Inspectors Alternates Anthony Dawes, DTE Energy, MJ [UT] (AlL LO C hri~toph er R. Vance) James Dorsey, Do ug las C,)unry Eleccrical lnspecrnr, CO [EJ (Alt. to D m1d A. Williams) Kevin]. Lippert, Eacon Corporation, PA [M] (Ah. Lo Vincentj. Saporita) Richard E. Lofton, II, IBEW Local Union 280, O R [ L] (AIL lOJ amesT. Dollard, J r.) Alan Manche, Sch neider Electric, KY [Ml (All. LO Kenneth.]. Rempe) David Morrissey,American E lectrical Testing Company. I nc., MA [ IM) (All. to ScouA. Blizard) 2020 ll(l.irjon NATLONAL ELECTRICAL CODE Nathan Philips, Integrated Electronic Systems. O R [IM] (Voting· Alt.) Steve A. Struble, Freeman's Electric Service. Inc., SD [I.M] (AIL r.o J u lian R. Burns) Peter R. Walsh, Tea ticket Technical A.~oci,nes, LLC, MA [U] (AIL r.o Steven E. Townsend) D anish Zia, UL LLC, NY [ RT) (AIL to Paul D. B arnhan) 70-19 NATIONAL ELEC..'TRICAL CODE Code-Making Panel No. 11 Articles 409,430, 440, 460,470, and Annex D, Example D8 Dirk R. F. Mueller, Chair UL LLC, Germany [ RT] Rep. ULLLC Luis M. Bas, In tenek TesUng Services, FL [ RT] John E. Cabaniss, Easm1an Ch e mical Company. TN [U ] R ep. American Chemisrry Councfl Terry D. Cole, Hamer Electric, Inc ., WA [I Ml Re p. lnrl.ependem Electrical Co111racmrs, Inc. Zivorad Cosic, ABB Inc., WI [M ] Robert G. Fahey, City ofJ a t1esville, WI lE] R ep. l mernaUonal Association ofE1ecuical lnspec10rs Paul E. Guidry, Fluor Enterprises, Inc., TX [U] R ep.Associated Builde rs & Conrractors Stephen M.Jackson, Smu.hern Company, GA [UT] Rep. Elec1ric Light & Powe r Group/ EEi Arthur S. Neubauer, Arseal Technologies, GA [ U] Rep. American Petrolernn lns tirute JebecUahJ. Novak, Cedar Rapids Elecrrirnl.JATC. IA [L] Rep. lmernationa.1 Brm herhoocl orElecrrical Workers Joe Schomaker, Eaton, MQ [M] Arthur J. Smith, III, Waldemar S. Nelson & Company, Inc., LA [U] Rep. lnsti[ule of Electrical & Electronics Engineers, Inc. Keilh Waters, Schneider Elecrric, KY [M) Rep. National Eleccrica.l Manufacrnrers AssociaUon Ron Widup, Shennco Jndustries, TX [IM] Rep. l merNational Electrical Testi ng Association Alternates Se th J. Carlton, UL LLC, IL [RT] (Alt. LO Dirk R. F. Muelle r) Donald P. Deachin, DTE, Ml [ UT] (Alt. LO Steph e n 1\11. J ackson) Eric Gesualdi, Sh ell Oil Company, T X [ U ) (Alt. wArt hm S. Neubauer) Chester K-elly; DuponLCh esuwL Run Plaza, DE [U] (A.It. 10 J o hn E. C'.abaniss) Trm LaLonde, H askin Electric, Jnc., WA [IM] (Alt. 10 Ten-y D . Cole) Charles Littlefield, Goochla nd Coumy, VA [EJ (Alt. tO Robert G. Fahey) . Charles A. Goetz, Siemens lndtLStry, I nc., IL [Ml (Alt. r.o Ke.i th Waters) Darryl Hill, Wichita ElecrricalJ ATC/ IBEW 271, KS [L j (Alt. 10J e bedia h.J. Novak) Tim Hinson, Miller Electric Co m pany, FL [I M] (Vo ting Alt.) VmcentJ. Saporita, Eaton's Bussman n Business, MO [Ml (Alt. m J oe Schomak er) Steven E. Townsend, General Motors Company. Ml [U] (Alt. 10 Arthur.J, SniiLh , Ill) Bobby A. Walton, lmenek, TX [RT] (A IL 10 Lujs M. Bas) 70-20 NAT IONAL ELECTRICAL CODE 2020falition COMMITTEE PERSONNEL Code-Making Panel No. 12 Articles 610, 620, 625,626, 630,640, 645, 646, 647, 650, 660, 665,668, 669,670, 685 and Annex D , Examples D9 and D10 Scott Cline, Chair Mcl\forirey Electric, Inc .. CA [IM) Rep. Natio nal Electrical Con tractors Associa tio n J oseph M. Bablo, UL LLC, IL [RT ] Frank Anthony Bello, Internation a l Un io n of Elevator Constructors, CA [ L ) J effrey W. Blain, Schi mlle r Elevator Corporalion , NJ [M) Rep. National Elevator I ndustry Inc. Philip Clark, Cicy o f Southfield, Ml LE) Rep. Internatio nal Associatio n of Electrical Jnspectors Karl M . Cunningham, Alcoa, Corporation. PA [Ml Rep. The AluminLLrn Associatio n , In c. Joel Goergen, Cisco Systems, In c., CA [M] Jody B . Greenwood, Navy Crane Cemer, VA [ UJ Jeffrey L. Holmes, I.BEW Local Unio n l .JATC, MO [ L] Rep. In ternational Broth erhood of Elecu-ical Workers Robert E . Johnson, ITE Safety. MA [U) Rep. In formation Tech nology l ndusuy Council MarkS. Jo iner, Office State Fire Ma rsha l, LA [EJ Stanley Kaufman, CableSafe, lnc./O FS, GA [M] Rep. Plastics lndusu·y Association (Plastics) To dd R. Konieczny, lntenek Testing Services, MA [RT ] Rep. l n terrek Testi ng Services To dd F. Lotbnann, Eato n 's Bussmann Business, PA [M) Rep. Natio n~! Electrical Ma nufacturers Association Karl Re ighard, Delmarva P ower and Liglu, MD [UT] Rep. Ediso n Elecrric Institute Edward E. Rodriguez, Walker Engineering, Inc., TX [IM) Rep. Independem Electrical Comracto rs, Inc. James E. Tarchins k.i, Gen eral MoLot-s Com pany, l\lU [ UJ Rep. SAE H ybrid/ EV Tedrnical Standards. Committee Robert C. Tunter, lnductOLherm Corporarion , .PA [M ] Alternates Rocco DeLuca, Jr., City An d Coun ty Of Broomfie ld, CO [El (Alt. Lo Philip Clark) Jacob Haney, General Cable Corporatfon, JN [ M ) (Ah . LO Karl M. Cunningha m) JohnD. (Doug) Henderson, ThyssenKrupp Elevator MMufacturing Inc .. T N [M J (AIL to.J effreyW. Blain) John R. Kovacik, UL LLC, IL [RT] (AJL to .Josep h M . Bablo) Richard (Tony) O 'Brien, Cisco Sys1ems. In c., CA [M) (Al t. toJoel Goergen ) Mike 0 1Meara, Arizona Public Service Company, A2 [ UT ] (Ah. ro Karl Reighard) Joseph F. P r'isco, IBM Corporation , M N [U) (Alt. to Rohen E. J o h nson) P e ter Sedor, l merrek, NIA [RT] (AJL to Todd R. Ko nieczny) Richard R. Shawbell, Jr., Flo rida East Coast ElectricalJ ATC, FL [L] (Alt. r.oJ effrey L. Ho lmes) David B. Stump, lndependem Electrical Comractors, TX [I.M] (Alt. to Edw;i rd E. RodrigL1e2) Emad Tabata.baei, l nductotherm Corporation, l\[J [M] (Alt. 1.0 Roben C. Turner) Frank Tse, Leviton Man ufacturi ng Company, Inc., NY [MJ (AJL Lo Todd fl. Lotunann) N onvoting Andre R. Carta!, Yard ley, PA [E] (Member Emeritus) 2U20 Edition NATLONAL £U.CTRICAL COD!l 70-2] NATIONAL ELEC..'TRJCAL CODE Code-Making Panel No. 13 Articles 445, 455, 480, 695, 700, 701 , 702, 708, 750, Annex F and Annex G Linda J. Little, Chair IBEW L ocal l Elewicia ns.JATC, MO [L] Martin D. Adams, Adams Electric, Inc., CO [ IM] Rep. National Electrica l Comracwrs Association Steve Baldwin, In tertek, CA [RT] R ep. lmenek Testing Services GregJ. Ball, Tesla, CA [M] Krista McDonald Biason, HGA Architects a nd Engjneers, MN LU) Rep. Americ;an Society for Heah.hcare Engineering Daniel]. Caron, Bard, Rao+ Athanas Consulting Engineers, LLC, MA [SE) Richard D. Currin,Jr., NorU1 Carolina State U niversity, NC [ll] Rep . American Society of'Agriculrura l & Biological Engineers Neil A. Czarnecki, Relia nce Co nu·ols Corpo ra1jo 11. W I [M] Re p. N aliom1I Electrical Ma nufac1urersAssociation Ste ven F. Froemming, City of Fran klin, Wl [E) Rep. lmernaLio nal Associatio n of Electrical Inspectors Robert 'E. Jordan , A laba ma Power Company, AL [UT] R ep. Elecu·ic Liglu & Power Croup/EEi John R. Kovacik, ULLLC., IL [RT] Greg Marchand, Briggs & Straito n, WI [M] Rep. Portable Generawr ManttfacLL1rers' Association Daniel R. Neeser, Eaton's Bussmann Division. MO [Ml Shawn Paulsen , CSA Group, Canada [RT] ArnoldoL. Rodriguez,LyonclelJBasell Industries. TX [U] Rep. Ame rican C11emistry Council Mjchael L Savage, Sr., Mario n County Building Safety, FL [E] Mario C. Spina, Verizon Wire less, OH [UJ R ep, InslitUle ofEleccrical & E lectronks Engineers, Inc. Kendall M. Waterman, Draka Cable ce<J. MA [MJ Rep. Copper DevelopmemA~sociatio n Inc. James R. White, Sh ermco Indnstries, Inc., TX [IM) R ep. ln cerNalional Electrical Testing Association Timothy P. Windey, Cummins P ower Gene ration , MN [ M] Alternates Lawrence S. Ayer, Biz Com Electric, lnc., OH [ IM] (Vo ling AIL) Barry S. Bauman, Allialll Energy, WI [U] (Ale. r.n Rjchard D. Currin.Jr.) Glenn Brown, CJL Engineering, PA [U) (Alt. LO Krista McDo na ld Biaso n) William P. Cantor, TPI Corpora1jo n. PA (U] (Ale. LO Mario C. Spina) James S. Conrad, RSCC Wire & Cable, CT [M] (Alt. LO Kendall M. Waternrnn) Timothy Cmko, Eato n "s .Bussmann Business. MO [M] (Ale. to Danje l R Neeser) James T. DoUard, Jr., I.BEW Local Union 98, PA [L] (Alt. lo Lind a j. Lillie) Laurie B. Florence, UL LLC, LL [RT) (Alt. to J ohn R. Kovacik) Travis Foster, Sh ell Oil Company, TX [U] (Alt. ro Arnoldo L. Rodriguez) Richard Garbark, BC E, MD [UT] (Alt. lll Robert E ..Jordan) 70-22 Jan Gromadzki, Tesla, CA [M] (Ah . 10 Greg.). Ball) Jeff Jonas, Generac Power Systems, Inc., Wl [M] (Voling Alt.) Chad Kennedy, Schne ider Electric, SC [M) (Alt. t(1 Neil A. Czarnecki) Raymond Richard Prucha, Bard. Rao ;.. Amhanas Consulting Engineers, LLC. NY [SE] (Alt. lo Da nielJ. Caron ) Daniel Schlepp, Wacke r Neuson , WI [MJ (Ah. to Greg Marcha nd) Rich Scroggins, Cr,mmjns Power Generatioo. MN [M] (Alt. 10 Timo 1.h y I'. Windey) Rkhard Tice, VEC, Inc., 01-1 [IM] (AI L LO Martin D. Adams) Anton Tomasin, City Of Rochesier Hills, MI [E] (Alt. lo Steven F. Froemming) Mkhael Wilson, CSA Group, Canada [RT] (Alt. to Sha wn Paulsen ) NATIONAL ELECTRICAL CODE 2020fali,ion COMMITTEE PERSO NNEL Code-Making Panel No. 14 Articles 500, 501, 502, 503, 504, 505, 506, 510, 511 , 513, 514, 515, 516 Michael W. Smith, Chair Sch aefler E leclric Co mpany, MO [IM] Rep . N ation al Elecu·ical Comracm rs Associa tio n Donald W. Ankele, UL LLC, JL [ RT] Steven]. Blais, Applecon G roup, IL [ MJ Rep. National Elenrica l Man ufacture rs Association Corey Cahill, U.S. CoascGuard, D C [El Mark A. Chrysler, Cii:y of San Diego, CA [El Rep. lm e rnario nal A'iSociation ofElenrical l nspeccors William T. Fiske, Tnrenek Testing Services, NY LRT) Mark Coodtnan, Mark Goodman t lecll'ical Consu lting, CA LU] Rep. Am e rica n Petro le um lnslirnte William C. Lawrence,Jr., FM Glohal, NL'\ [ I) L. E vans Massey, Baldor Electric Company, SC [MJ Rep. Instrumenr,ation, System s, & Autom a tio n Society William E. M cBride, CO NA M Co nstruction Company, AK [VJ Rep. Ins titme o f Electrical & Electronics Eng ineers, Inc. Jeremy Neagle, U .S. Burea u ofAlcoho l, Tobacco, Firearms & Explosive!', MD [U] Thomas L. Pottschmidt, Indlanapolis P ower & Ligh t, IN [ UT] Rep. Edison Electric l nstinne Lowell Reith, l nterstates Constructio n Services, Inc., KS [IM] Rep. Indep ende n tElectrical Concrncro rs, l nc. John L. Simmons, Flo rida East CoastJ AT C, FL [L] Re p. Inte rnatio nal Broth e rho od of E lectrical Wo rke rs Ft-ed K. Walker, U .S. De partme nt Of The Air Fo rce, FL [El DavidB. Wechsler, Go nsu lta nt, T X [ U] Rep. Ame rican Che mistry Counc.il M ark C. Wirfs, R & W Engineering, Inc., OR [U] Rep. Grain Elevator a nd P rocessing tiocie cy Alter n ates Miliail Bantic, l n tertek, TX [RT] {Alt. LO William T. Fiske) Dave Burns, Shell P&T, Tn novatio n/ R&D. TX fU l (All. Lo Mark Goodma n ) Cory Cole, Ha me r Electric, Inc., WA [IM] {AlL LO Lowell Reith) Thomas E. Dwme, Lo ng lslanrl j oint Ap pren ticesh ip & Train ing Committee, NY [L] (AIL to.Jo hn L. Simmo ns) Andrew Hernandez, Asu·aZen eca Pharmace micals, DE [U] (AJL co WiJliam E . McBride) Richard A. Holub, The Du Pon t Company, Inc., D E [ U] (AIL. Lo D avid B. Wec hsle r) Paul T. Kelly, UL LLC, JL [RT] (A lt. r.o Do nald W. Ankele) Haywo od Kines, P rince William Co u n ty Building Develo pment, VA [El (Alt. Lo Ma rk A. Ch rysle r) Edmund R. Leubner, Eato n's Crouse-Hinds Business. NY [M] (AIL LO Steven .J. B lais) Ed die Ramirez, FM Glo bal, l\llA [I] (AIL LO William G. Lawre nce. Jr.) Ted H . Schnaare, Rosem o unLIncorpo rated, MN [M l (A lt.. Lo L. Evans Massey) Nonvoting Mich aelE. Aaron, Wiss.Ja nney Elstner Associales, Inc., lL [SE] R e p. T C o n Airpo n Facilities 2020 ll(l.irjon NATLONAL £ L£CTRLCAL CODE Timo thy J. P op e, Canadian S4"1nda rds A,sociaLion, Canada [RT ) 70-23 NATIONAL ELEC..'TRJCAL CODE Code-Making Panel No. 15 Articles517,518, 520,522,525,530,540 Lawrence E. Todd, Chair lme n ek Testing Services, KY [RT] Chad E.- Beebe, AsHE • AH A, WA [U] David A. Dagenais, Panners/ Wentwonh-Douglass Hospi tal, NH [ U ] Rep. NFPA H eald1 Care Sectio n Matthew B . Dozier, !Design Services, TN [U] Rep. Lnstimre of Electrical & Electronics Engineers, lnc. Joe L. DuPriest, City of SL Cloud, FL [E] Rep. Inte rnatio nal Associatio n of Electrical Inspecto rs Kenneth J. Gilbert, Florida Power & Lig ht Company, FL [UT ] R ep. Electric Light & Power Gro,1p/ EEI Pamela Gwynll, UL LLC, NC [RT] R e p. ULLLC Mitchell K. Hefter, Signify, TX [ IM] Re p. 111um.inati ng Engineering Society of North AmeriGI Kim Jones, Fun ta~tic Sh ows, OR [U] Rep. Ourdoo r Amusement B usiness Association , J nc. Edwin S. Kramer, Radio City Music Hall, NY [ L] Rep. 1111.e rnat.io nal Alliance ofTheairical Stage Employees Gary J. Krupa, U.S. Depanm enc ofVet.erans Affairs, NE [U] Kevin T. Porter, Encore Wi1·e Corporation, TX [M] Rep. TI1e Aluminum A5sociation, Inc. Brian E . Rock, Hubbell Incorporated, CT [M] Rep. National Electrical Ma mtfacru re rsAssociatio n James C. Seabury Ill, Ence rprise Elect.ric, LLC, T N [IM] Rep. lnrlependem Electrical Comracwrs, Inc. Bruce D. Shelly, Sh elly Electric Company. Inc., PA [IM] Re p. National Electrical Co ntractors Associa tio n Michael D. Skinner, CBS Studio Center, CA LU] Rep. Alliance of Motion Picture and Televis io n Produ cers Steven R. Terrr., Electronic Theatre Controls Inc., NY [M ] R e p. U.S. lns tit.me for Theatre Technology, Inc. Alternates Michael A. Anthony, Standards Michigan , Ml [U] (AIL LO MauJ1ew 8 . D ozier) Gary A. Beckstrand, Ucah ElecuicalJAT C, UT [ L] (Voting Alt.) David M. Campbell, AFC Cable S)'s tems, In c., MA LMJ (Alt. to Kevin T. Poner) Carmon A. Colvin, Briglu Future Electric. LLC . AL [ IM] (Al L LO.James C . Seabury Ill) Connor Wright Frazier, HGA A rchitecLs And Engineers. MN [CJ] (AIL ro Chad E. Beebe) Samuel B. Friedman, General Cable Corporation . R1 [M] (AIL to Brian E. Rock) Edward Joseph, Underwrite rs Laboratories Inc., NY [RT] (Alt. tO Pamela Owynn) Jay Y. Kogoma, lntertek Testing Services, CA [RT] (Alt. to Lawre nce E. Todd) 70-24 FrankNovitzki, U.S. DeparunemofVeteransAffairs, VA [ U] (AlL LO Gary J. Krupa) Don Rabel, Micl-Wesc Electric Company, T X [I M] (Alt. 10 Bruce D. Sh e lly) Douglas Rbeinbeimer, Paramount Pictures, CA [ U ] (AIL. to Michael D . Skinner) Alan M. Rowe, lnternational Alliance of Theatrical St_age Employees, CA [L) (Alt. LO Edwin S. Kram et) Clinton Bret Stoddard, Cit.y of Rexburg, ID [E] (Alt. Lo Jo e L. DuPriest ) Walter N. Vernon, IV, Mazzet.t.i, CA [SE] (Voong AIL) R. Duane Wilson, Geo rge C. lze no ur Assocfaces, Inc., NM [IM] (Alt. to Mitch e ll K. 1:i.erter) NATIONAL ELECTRICAL CODE 2020falition COMMITTEE PERSONNEL Code-Making Panel No. 16 Articles770, 800, 805, 810,820, 830, 840 Thomas E. Moore, Chair City of Beachwood, O l-1 [El Rep. International Association or Elecuical l nspectors G eorge Bish, Amazon/ Ri ng Protect Inc .. NC [ IM ] Rep. Satellire Broarlcasting & Communications Association James E. Brunssen, Telcordia Technologies (Ericsson), NJ [U) Rep. Al liance for Telecommun ications lndusu-y Solutions Terry C. Coleman, Electrical Traini ng,A lliance, TN [LJ Rep. Interualional Brotherhood of Elecu·ital Workers Robert Davies, Davies E lectric Company. CA [LM) Rep. Naliona l Elecirical Contractors Associatio n Fred C. Dawson, Chemours, Canada [U] Re p.Am erican Chemisu-y Council Gerald Lee Dorna, Belrlen Wire & Cable Co., IN [M) Rep. Insulated Cable Engineers Associalion, Inc. Robert W.Jensen, dbi-TelecommunicaLion l nfrastrncm re D esign, T X [Ml Rep. Buildi ng Industry Consulting Services International Steven C. Johnson,J ohnson Telecom, LLC, T X [UT ] Rep. Society of Cable Telecommunicatio ns Engineers (SGfE) William]. Mc Coy, Telco Sales, Inc., TX [U] Rep. lnstirme of Electrical & E lecrronics Enginee rs. Inc. Michael F. Murphy, l ntertek Testing Ser vices, MA [ R1] Thomas ]. Parrish , Telgian Corporation , Ml [M) Rep. Aurnmatic Fire Alarm Association, Inc. Roy Pollack, Comcast Xfiniry Home, FL [UT ) Rep. Electronic Security Association Luigi G. Pre zioso, M, C. Dean. Inc .. VA [ IM] Rep. Independent E lectrical Cnn tracrors, 1.nc. Rodger Rei!mrig, J oh nso n Controls, FL [M] Rep. National Electrical ManufanurersAssociation Masood Shariff, Commscope, NJ [M] Rep. Telecornmun.ications Industry Association Anthony Tassone, UL L LC, NY [ RT J Rep. UL LLC Leo Zieman, Florida Power & Ligh t ( Nexcera Energy), FL [UT ) Rep. Electric Ligh c & Power Group/ EEi Alternates Rendell K. Bourg, Natio nal Fire Protection Company Inc., 1--ll [MJ (All. to ThornasJ. P arrish ) Trevor N. Bowmer, Telcordfa (Ericsson ), NJ [U] (Ah . Lo.James E. Brunssen) Larry Chan, City of New O rleans, LA LEJ (AIL. Lo TI10mas E. Moore) Timothy D. Cooke, Times Fiber Commun ications, Lnc., VA [UT] {Alt. to SLeven C.Jo hnson ) Rando lph]. Ivans, UL LLC, NY [ RT ] (Alt. Lo Anthony Tasso ne) John A. Kacperski, P2S Engi neering, Inc.. CA [MJ (Alt. to Robert W. J ensen) Stanle y Kaufman , CahleSafe, Inc./OFS, GA [M] (AIL. to Gerald Lee Dorna) 2020 ll(l.irjon NATLONAL E LECTRICAL CODE Eric Lawrence, Berk-Te k, A Nexans Company, PA [M] (Alt. to Masood Sh ariff) Diana M. Lettkeman, Dish Network Service, LLC, CO [ IM] (Alt. to George Bish) Christopher Rawson , Jnte rnalio na l Bro th e rhood of Elend caJ Worke rs-- Tech nical I.nstirur.e (IBEW), LL [L] (A lt. to Terry C. Colem an) David B. Schrembeck, DBS Communicarions, Inc., O H [ IM] {Ale. r.n Luigi G. Prezioso) Carl R Wetterhan, General Cable Industries, Inc.. KY [M) {AIL to Rodger Reiswig) 70-25 NATIONAL ELEC..'TRJCAL CODE Code-Making Panel No. 17 Articles 422, 4241 426, 427, 680, 682 Donald R. Cook, Chair Sh e lby Coumy Deparm1em of Developme nt Services. AL [ E] Rep. lncernational Association of Elecrrical Inspectors Thomas V. Blewitt, UL LLC, NY [RT] Jerry Lee Daniel, Texas Department of Licensing Regulation, TX lEJ E. P. Hamilton, lli, E. P. Hamilto n & A~sociaces, Inc., TX [M] Rep. Associatio n of Poo I & Spa Professionals Emmanuel (Lee) De Wayne Jones, Georgia P ower Company, GA [UT] Rep. E leCLi-ic Ligh t & Power Group/ EEi Brian Myers, lBEW Local Unio n 98, PA [L ] Rep. International .Brotherliood of Electrical Workers Timothy R. O'Brien, C hula Vista Electr.ic, CA LIM) Re p. National Electdml Contractors Association D ennis Michael Querry, Trini cy River A,,thority, TX [ll\ll] Rep . Indepe ndent Electrical Contractors, fn c. Chester L. Sandberg, C L Sandberg & Associates, LLC, CA [U] R ep. Lnstitute of Electrical & Electronics Engineers, Inc. Kenneth M . Shell, nVem T h ermal ManagemenL. CA [Ml Rep. Copper Developmem Associ;ujon Inc. Kam Fai Siu, lmerrek Testing Services, Hong Ko ng [ RT] Rep. lntercek Testing Services P eter C. Swim, 'Whirlpool Corporation, Ml [M) Re p. Air-Conditioning, H eating, & Refrigeration lnsti n11.e Marce lo E. Valdes, GE Energy Industrial Solutio ns, NC [M] Rep. National Electrica l Manufacturers Association Matt B. Williams, Associatjo n of H ome Appliance Manufacturers (AHAM ), DC [M] Rep. Association of Home Applia nce ManufaCLure rs Alternates PauJ W. Abernathy, Encore Wire Corpo ratio n , T X [Ml (AJt. LO Ke nneth M. She ll) Ryan Andrew, Ala~kaJ o inr Electrical Apprenticeship and Training Trust, AK [L] (Alt. tn Brian Mye rs) Bernie Donnie Bell, Gulf Power Company, FL [UT] (AJt. LO Emma nuel (Lee) DeWayneJ o nes) Masud Chowdhury, AssociaLion of Home Appliance Man ufucwrers (AH.AM), VA [M] (Alt. tO Mat! .B. Williams) Chris Faucette, State of Nonh Carolina, NC [E] (AJL ro DonaJd R Cook) StepbenR. Kuscsik, Underwri ters L,boratories Inc., LL [RTJ (AIL w "n 10 mas V. Blewin) Armando M . Lozano, MSF"Electric , lnc. , TX [IM] (AIL to Dennis Michael Querry) Stephen Macey, Watkins Manufacturing Corporation, CA [M) (Al L LO E. P. H amil ton, 111) Bernard Poton, lnLenek, TX [RT] (AIL. to Kam Fai Siu) Larry Reichle, Texas Depanme nt Of Licensing Regulation, TX [EJ (Alt. m J erry Lee Daniel) Svetlana Ulemek, H ubbel/ BLtrndy LLC. NH [ M ] (Ah. co Marcelo E. Valdes) Thomas H. Wood, Cecil B. Wood, Inc., IL [ lM] (Alt. to Tiiuoihy R. O'Brien) Nonvoliug Andrew M. Trotta, U .S. Consume r Product SaJety Com.mj ssio n. MD Douglas A. Lee, U.S. Con sumer P roduc t Safety Com miss.io n, MD [CJ [CJ Re p. U.S. Consurne·r Product Safety Commissio n 70-26 Rep. U.S. Consumer Product Safety Co mmission NATIONAL ELECTRICAL CODE 2020falition COMMITTEE PERSONNEL Code-Making Panel No. 18 Articles 393, 406, 410, 411, 600, 605 Bobby J. Gray, Chair H oydar/ Buck, Inc., WA [IM] Rep. National Electrical Contractors Association Ron D.Alley, Northern New Mexico lEC, NM. [IM] Rep. lndepe ndenl Electrical Concracmrs, Inc. Frederick L. Carpenter,Act.ticy Brands Lighling. GA [M] Rep. National Electrical Manufacwrers Association Kw·tJ. Clemente, Clark Nexsen, Inc., VA [U] Rep. lnscirute of Elecu;cal & Elecu·nnics Engineers, Inc. Paul Costello, NECA and IBEW Local 90 JATC, CT [L] Rep. lnte rnalional Brotherhood ol'Electrical Workers Hakim Hasan, lnterLek, GA [RT] Charles S. Kurte n , UL LLC, NY [RT] William Ross McCotcle, American Electric Power, O K [UT] Rep. Electric L ight & Power Group/ EEI Michael S. O'Boyle, Philips Lightolie r, MA [MJ Rep. American Lighting A~socialion Wesley j . Wilkens, Persona., Inc., SD [M] Rep. International Sign Association Randall K Wright, RKW Consulting, PA [SEJ Jack E.Jamison,Jr., Miller Engineeling, I nc., \l\'V [E) Rep. International Association ofElectlical Inspectors Alte rnates D onald Berlin, lmermatic Inc.. IL [M] (Alt. 10 Michael S. O'Boyle) Juan M. Caamano, ULLLC, NY [RT] (AJL to Ch arles S. Kurten) Mark CoshaJ, !ES Commercial of San Amonio, TX [IM) (All. LO Ron D. Alley) Gabriel A. Griffin, Clear Sign and Design Inc., CA [M] (Alt to Wesleyj. Wilkens) Richard Hollander, City ofn1cson, AZ [E) (AIL. to.J ack E ..Jarnison,J r.) Robert Setaro, l ntertek. GA [Rl] (Alt. 10 Hakim H asan) Frank Tse, L eviton Manufacturing Company, Inc., NY [tvl] (Alt. 1.0 Frederick L. Carpenter) Daruel Van Sickle, ill, Elecu·ical Tra,njng Alliance of.Jacksonville. F'L [L] (Alt. t.n Paul Costello) Paul Yesbeck, ACU Sign Corporation . FL [IM] (AlL to Bobby J. Gray) Committee Scope: Thi~ Committee shall haveplimary responsibility for documents 011 minimizing the risk of electricity as a source of electric shock and as a po ten Lia I igni1jon source of Ii res and explosions. It shall also be responsible for teX:t to minimize t.he propagation or lire and explosions due 10 electrical installatio ns. 2020 lldirjon NATLONAL £L£CTRLCAL CODE 70-27 NATIONAL ELEl.'TRlCAL CODE NFPA Electrical Engineering Division Technical Staff Gordon S. Frost, Division Manager Mai·k w. Earley, Chief Electrical Engineer Mark Cloutier, Senior Electrical En~ineer Christopher Coache, Senior Elecuical Engineer Sarah D. Caldwell, Technical Committee Aclrn:inisu-amr Kimberly H . Cervantes, Senio r Technical Con tem Ed itor Erik Hoheogasser, TechnicaJ Lead. Electrical RichardJ. Roux, Senior Electi-ical Specialist Jeffrey S . Sargent, Principal Elecu·ical Specialist Barry Chase, Senior Enf(ineer 70-28 NATIONAL ELECTRJ CAL CODE 2020Etli,ion 90.2 ARTICLE 90- INTRODUCTION NFPA70 National Electrical Code 2020 Erulion IMPORTANT NOTE: Th is NFPA ilocument is made available for use su~ject to important notices a nd legal disclaimers. These notices and discfoimers appear in all publications con/a.ining this document and may be found under the heading ''1mportant Notices and Disclaimers Concerning NFPA Standards. " They can also be viewed at www.,,jpa.org/disclaimers or obtained on request from NFPA. UPDATES, ALERTS, AND FUTURE EDITIONS: New ed·itio11s of NFPA codes, standards, recommended practices, and guides (i.e., NFPA Standards) are released on scheduled revision iycles. This edition may be superseded by a later one, or it may be ame,uled outside of its scheduled revision c:yde through the issuance of Tentative Interim Amendments (TIAs). An official NFPA Standard at any point in time consists of the current edition of the document, together with all TlAs and Errata in effect. To verify that this document· is the current edition or to determine if it has been amended by TlAs or Errata, please consult the National Fire Codes® Subscription Service or the "List of NFPA Codes & Standards" at www.nfpa.org/doci:nfo. In, addition lo TIA:; and En-ata, the document informr:ttion ,pages alro include the aption to sign up for aleits for individual documents mid In be involved in the development ofthe next edition. (C) Relation to Othe1· International Standards. The requirem e n t~ in tl1is Code address the fundamental principles of protection for safety contained in Section 131 of Inter:natior1a l Electrotechnical Commiss ion Standard 60364-1, 1:.t edrical installation~ of Buildings. lnformational Note: IEC 60364-l , Section 131, conu'lins fundamental principles of protection for safety tlrnt e ncompas.5 prOLec1.ion against elecuic s hock, protection aiainst themrnl effects, prntecl.inn against overcurrem, prmecl.ion against fault c1.U-ren1s , and protection agains1 overvoltage. All of these potential hazards are addressed by the requirements in ,his Codi/. 90.2 Scope . (A) Covered. This Code covers the installation and removal of electrical conducto rs, equipment, and raceways; sig naling and communicatio ns conductors, equ ipment, and raceways; and optic.al fiber cables for the fo llowin g: (1) (2) (3) ( 4) (5) ARTICLE90 Introduction (6) Public and pl'ivate premises, including buildings, stn.1ctures, mobile hom es, 1·ecreational vehic.les, and floating buildings Yards, lo ts, parking lots, carnivals, and industrial substations Installations of conductors and equipm ent th at connect to the supply of elecrrici t)' ul.!;talla tions used by the electric u tility, such as office buildings, warehouses, garages, m achine shops, and re creational buildin gs, tliat are not an integral part of a generating planl, substation, or conu·ol center Insta llations supplyin g shore power to sh ips a nd watercraft in marinas and boatyards, includi ng monitoring of leakage currenl Installations used to export elecu·ic powe r from vehicle~ to premises wirin g or for bidirectional current fl ow (B) Not Covered. This Corle does not cover the following: 90.1 Purpose. ( J) (A) Practical Safeguarding. The pmpose of this Corle is th e practical safeguarding of persons and property from hazards arising from the use of elec tricity . This Corle is not intended a~ a design specification or an instruction manual for untrained persons . (B) Adequacy. This Cod1: co ntains proV1s1o ns Lha t are conside1·ed n ecessary for safety. Compliance th erewith and prope1· maintenance result in an installation that is essentia lly free from hazard but not n ecessarily efficient, convenient, or adequate fo r good sen1ice or furure expansio n of electrical use. Informational Nore: H azards often occur because of overloading of wiring systems by method~ o r usage nor in conformit)' with this Code. This occLtts because iniLia.1 ,,,iring did noL provide for increases in the lLSe of electrici1y. An iniL.ial adequa,e insrallaLio n and reasonable provisio ns for system changes provide for fu ture increa.~es in the use ofelectriciLy. 2020 ll\lirjon NATLONAL ELECTRLC-.AL CODE Installation.~ in ships, watercraft ot11er than fl oating buildings, railway rolling stock, a.iro·aft, or automo1:ive vehicl es o tl1e r t11an mobile homes and reo·eational ve hicles I n formation a l Nme: Altho ugh the scope of this Code indicates thaL th e Goilt does nm cover ins1a llar.ions jn ships. portions of this Code are inco rpo rated b y reference into Title 46, Code of Fede ral Regula Lions. Parts 110- 113. (2) (3) (4) Insta llations undergrnund in mines and self-prope ll ed m obil e surface min in g mac hine ry a nd il.5 atten dant electrical u·ai ling cable Installations of railways for generation, transformation, transtuissio n, e ne rgy storage, or d istribution of p ower used exclusively for operation of rolliJ1g stock Qr i.nstallations used exclusively fo1· signaling an d communications purposes Installations of communications equipm ent unde r th e exclLt~ive conu·ol of communications utilities located outdoors or in building spates used exclusively for su ch installations 70-29 90.2 (.5 ) ARTICLE 90- INTRODUCTION Installations under Lhe exclu.~ive co11n-ol of an e lecn-ic ut.ility whe1·e such installations a . Consist of service d rops or service laterals, and associated metering, or b. Are o n property owned or leased by tl1e e lectric ut.ility for the purpose of communications, metering, gene1·• ation, co11trol, u-ansformation, u-ansmission, energy storage, o r distribution of e lectric energy, or c. Are located in legally established easem ents or rig h t~of~way, or d . Are located by other written agreements either designated by or recognized by public service commissions, utility comm issions, or other 1·egulato1-y agencies having j1Lrisdiction fo r such installat.ions. These written agreements shall be limited to installations for the prn:pose of cornmunications, meteri ng, generation, control. transforn1ation, tran~mission. energy storage, or distributio n of elecu·ic energy where legally established easemenL~ or righ ts-of-way cannot be obtained. These installations shall be Limited to federal land~. Native A meric,µ1 reservations through the U .S. Department of d1e In terior Bureau of Indian Affairs, military ba~es, lands controlled by port aum.orities and state agenc ies and deparUlJents, and lands owned by railroads. Informational Nme LO (4) and (5): Examples of utilities may include those enriLie.s Lhat are typically designated or recognized hy governmen tal law or regulation by p1tblic service/ m.ility commissions and that install, operate, and maintain elecr.ric supply (such as g·enera1ion, r.ransmission, or disLribuLion systems) or communications sys1ems (such as telephone, CATV, Internet, satellite, or dat,-i servi ces). ULiliLies may be su~ject 10 compliance with codes -and sr.andards covering their regulated acrivities as adopted under governmental law or regulation. Additional inJorn1ation ca n he found through consultation with the appropriate governm ental bodies. such a~ ~tale regulatory com missions, Lhe Federal ~~nergy Regulatory Commi5sio n, and the Feder.ii Comm unicalion~ Commission. (C) Special Permission. The autl1ority having jurisdiction for enforc;ing thi~ CQ(le may gr-ant exceptio n fqr tl1e installatio n of conductors and equipment that ar e not unde1· th e exclusive control of the e lecu·ic utilities and are LL5ed LO con nect the electric utility supply system to the service conductors of the premises served, provided such installa tions are outside a building or structure, or terminate inside at a 1·eadily accessible location nearest the point of enu·ance of d1e service conductors. 90. 3 Code Arrangement. This Code is d ivided in to the inu·o· duction a.nd nine c hapters, as shown in Fig ure 90.3. Chapters 1. 2, 3, and 4 apply generally. Chapters 5, 6, and 7 apply to special occupancies, special equipment, or odie1· special conditions and may s u pplem ent or modify tlle requirements in Chapters I through 7. Cl1apter 8 covers commw1ications syste ms and is not subject to th e reguiremerns of Chapters l tl1rough 7 except where the requirements are speci fically referenced in Chapter 8. Ch apter 9 consists of tables mat are applicable as referenced. Jnfomrntive annexes are not part of m e requirements of d1is CorlP but are included for informatio na l purposes only. 70-30 Chapter 1 - General Chapter 2 - Wiring and Protection Chapter 3 - Wiring Methods and Materials Chapter 4 - Equipment for General Use Supplements or modifies Chapters 1 through 7 I. Chapter 8 - Applies generally to all electrical installations I Chapter 5 I Chapter 6 - { IChapter 7 - Communications Systems I Chapter 9 - Tables Informative Annex A through Informative Annex J FIGURE 90.3 I} . I} Special Equipment I I Special Conditions I Special Occupancies Chapter 8 is not subject to the requirements of Chapters 1 th r~ugh 7 except where the reqt11rements are specifically referenced In Chapter 8. Applicable as referenced } Informational on ly; not mandatory Code Arrangement. 90.4 Enforcement. This Code is intended Lo be suitable for mandatory applicatio n by governmental bodies ciiat exercise legal jurisdic tio n over elecu·ical installations, including signaling and communications systems, and for use by insura nce iMpectors. The autl1ority having jmisdiction fo1· enforce ment of d1e Code has the responsibility for making interpretations of the rules, for decicUng on d1e approval of equipme nt and materials, a nd for granti ng tl1e special pen nission contemplated in a number of die rules. By special permissio n, d1e auU1ority having ju rl~dic tio n may waive specific requirements in th is Cod11 o r pe rmit a lternative med1ocl5 where it is a~sured that equivalent o bj ectives can be achieved b y establishing ,mcl maintaining effective safely. Th is Corl(! may require new products, consn·uctions, or materials that m<1y not yet he available at tl1e time U1e Code is adopted. In such event, d1e aud10rity having jurisdiction may permi t the use of the products, constructions, o r materials m at comply with die most recent previous edition of d1is Code adopted by the jur isdiction. 90.5 Mandatory Rules, Permissive Rules, and Explanatory Material. (A) Mandatory Rules. Ma ndatory rules of th is Cod11 a re those that ide n tify actions tllat are specifically required or prohibited and are characterized by 1.h e use of the terms shall or shn11 not. (B) Permissive Rules. Permissive rules of this Cor/p, are those that ide nti fy actions tl1at are a llowed b u t not req11i 1·ed, a1·e normally used to describe optio ns or alternative methods, and are characteri zed by the ll5e of the terms shall bti permilled or shall. not bP rrqui-red. NATIONAL ELECTRICAL CODE 2020Edition ARTICLE 90- INTRODUCTION (C) Explanatory Material. Explanatory material, such as references to other standards, references to related secLions of this CIJllti, or information re lated to a Corle rule, is included in this Code in the form of informational notes. Such notes are inforrnational only and are not enforceable a~ req uirements of this Code. Brackets con taining section references to anoci1er NFPA document are for infonll;itional purposes only a nd are provided as a guide to indicate the source of the exo-acted text. These bracketed references immediately fo llow the exu·acted text. 90.9 additional spaces a llow for future increases in electric power a nd communications cit-cuit~. D istrilmLion centers located in readily accessible locations provide conven ience and safety of o peration. (B) Number of Circuits in Enclosures. It is elsewhe1-e provided in this Codi! d1at the number of circ uit~ confined in a single enclosure be vaqing ly reso·icted. Limiting the number of circuit;.~ in a single enclosw-e minimizes the effect~ from a short circuit or ground fault. 90.9 Units of Measurement. (A) Measurement System of Preference. For the pw-pose of Infom1ational Note: The fonnat an<! language used in this Code follows guidelines es1ablished hy NFPA and publishe<1 in d1e NEC Sty/p Manual Copies of this manual can be obtained from NFPA. this Code, meuic unit~ of measurement are in accordance wid1 ci1e modernized meu-ic system known as ci1e Internationa l System of Un.its (S I) . (D) Informative Annexes. Nonmandatory information relative to the nse of the NEC is provided in informative annexes. Informative annexes are not part of the enforceable requiremenL~ of ci1e NEC, but are included for irrformation purposes only. (B) Dual System of Units. SI units sha ll appear first, a nd inchpound units shall immediately follow in parend1eses. Con version from inch-pound units to SI uniLi shall be based on ha1-d conversion except a5 provided in 90.9(C). 90.6 Formal Interpretations. To promote uniformity of interpretation and applicaLion of this Cod11, formal interpretation procedures have been established and are found in the NFPA RegulaLions Governing Committee Proje cL5. (C) Permitted Uses of Soft Conversion. The cases g iven in 90.9(C)( l ) L11rough (C) (4) shall not be required tO use ha rd conversion and shall he permitted to use soft conversion . 90. 7 Examination of Equipment for Safety. For specific items of equipment and materials referred to in this Code, exami nations for safety made w1cler standard conditions provide a basis for approval where ci1e record is made generally available through pro mulgation by organ izations properly equipped a11d qualified for experi.mental testing, inspe ctions of the run of goods at factories, and service-value determination through field inspections. This avoids the necessity for repetition of examinations by different exantiners, frequenlly with inadequate facil ities fo r such work, and the confusion ciiat would result from conflicti11g repo rts on the sui.rabilit:y of devices and materials examined for a given purpose. It is the intent of this Code that factory-installed internal wiring or the construction of equipment need not be inspected at the time of installation of the equipment, except to detect alterations or damage, if the equi pment has been listed by a qualified electrical testing lab oratory that is recognized as having the facilities described in the preceding paragraph and that requires suitability for installaLion in accordance with this Corle. Suita bili ty shall be determined by application of requirements ci1at are compatible wici1 this Code. Informational Note No. 1: See recp.uremenis in 1 10.3. Informational Note No. 2: Listed is defined in Article 100. Informational Note No. 3: Informative Annex A con rains a lis1 o f product safety standards 1.hat are compatible with 1his God,:. 90.8 Wiring Planning. (A) Future Expansion and Convenience. Plans and specifications ci1at provide amp le space in racewa)'S, spare raceways, and 2020 ll\lirjon NATIONAL E LECTRICAL CODE (1) Trade Sizes. Where me actual measured size of a product is not the sam e a5 the nomina l size, u-ade size designarors shall be used rather cha:n d imensio ns. Trade practices shall be followed in all cases. (2) Extracted Material. Where material is extracted From a nother standard, ci1e context of the original mate rial shall not be compromised or violated. Any edi ting of the exu-acted text shall be confined to making the style consistent wiLh that of the NEC. (3) Industry Practice. Where indLL5try p r;i_cLice is to expres.s units in inch-potmcl units, the inclusion of SI tmit5 shall nor. be 1·equired. (4) Safety. Wh ere a negative impact on safety would result, soft conversion shal l be u sed. (D) Compliance. Conversio n from inch-pound unit~ to SJ LltliLs sha ll be permitted to be an a pproximate conversion. Compliance with the numbers shown in e ithe r me SI system or the inch-pound system shal.l constitute compliauce ¼ith this Code. Informational Nole No. I; Hard conversion is considered a change in dimensions or prope rties of an ii.em into new sizes tha1 mighL or rnighr not be interchangeable with the sizes used in rJ1e original m easu remenL Sot\. conversion is conside red a direcc maLhematical conversion and involves a change in r.he description of an existing measurement but not in the actual d ime nsion. lnformational Note No. 2: Sl conversions are based o n LEEE/ ASTM SJ 10-1\197, Stcwdiml.for th,i ll.w• uf the l nlematioual Syi ll.•m o/ Units (SI): Thr. Mo,lem Metrir S)\511,m. 70-31 CHAPTERl ARTICLE 100-DEFINlTIONS Chapter l ARTICLE 100 Definitions Scope. This article contains only those definitions essentia l to the application of chis Code. It is noL intended to include comm on ly defined general terms o r commo nly defined technical terms fro m related codes and standards. In general, on ly those terms tl1at are used in t:"1110 or mo re articles a re defined in Article lOO. DefiniLions are aL~o found in XXX.2 sectio ns of other articles. Part I of th is article contains defmitions intended Lo apply whereve1- the terms are used throughout Lhis Code. Part IT contain..~ definitions applicable to installa l.ions and eg uipment operating at over 1000 volts, nominal . Part m contain.~ definitio ns appl icable to Hazardou~ (Classified) Locations. Part I. General Accessjble (as applied to equipment). Capable of bein g reached for operation, renewal, and U'L~pection. (CMP-1) Accessible (as applied to wiring methods) . Capable of be u1g removed or exposed witlm ut damaging the building structure or fi nish or not p ermanently closed in by tl1e su-ucttu-e or finish of the building. (CMP-1) Accessjble, Readily (Readily Accessible) . Capable of being reached quickly for operation, renewal, o r inspections without requiring those tO whom ready access is requisite to rake actions suc h as to use tools (other than keys), to cl imb over or under, to remove obstacles, or to resort to portable Ladders, and so forth. (CMP-1) Informational Note: Use of keys is a common practke unde1· conU"o lled or supervised conditions and a common alLernaLive to 1.he ready access requiremem5 under such supervised condi.Lions as provided elsewhe re in th e NEC. Adjustable Speed Drjve. Power con version eqt1.ipmem tha t provides a means of adjusting the speed of an e lectric moLOr. (CMP-1 l ) Informational Note: A variable frequency drive is one type or elecrronic a(\jL1stahle speed drive Lha1. comrols 1he rota.tio nal speed of an ac eleci.ric mmor by controlling 1.he frequen cy a nd voltage of 1.he elecu'ical power supplied LO rhe mOLor. Adjustable Speed Drive System. A combination of an acljustable speed drive, its associated motor(s), a nd auxiliary e<]uipment. (CM P-11 ) Ampacity. 111e m aximum current, in amperes, that a conductor can cany continuoll5ly under tl1e conrliLion.s of use witl1om exceeding it5 temperature rating. (CMP-6) Appliance. Uti lizalion e<]Uipment, generally other than industrial, that is normally built u1 standardized sizes 01· types and L5 installe d or connected as a unit to perform one or more fw1ctions suc h a~ clothes washing, air-condiLioning, food mixing, deep f1y ing, and sofonh. (CMP-17) 70-32 General Approved. (CMl'-1) Acceptable to the autl1ority havi ng juriscliction. Arc-Fault Circuit Interrupte r (AFCn. A device inte nded to p1-ovide protection from tl1e effect5 of a.re fau lt5 by recognizing cl1aract;eristics uniq ue to a rcing and by functionin g to deenergize m e circuit when an arc fau lt is detected. (CMP-2) Askarel. A gene ric tenn for a group of nonAammable synthe tic chlorinated hydrocarbons used as elecu·ical insulating media. (CMP-9) fn formationa l Note: Askarels or various cornposiLional types are used. Under arcing cond.iLions, rhe gases produced, 1,hile consisting predominanrly of noncombusLible hrdrogen chloride, can include varying amounts of combus1.ible gases, depending 011. the askarel type. Attachment Fitting. A device tllal, by insertion mto a locking s upport and mounting receptacle, establis hes a connection betwee n th e cond1-1ctors of the attached 1.1tilization equipment and the b ranch-ci1-cuit conductors connected to the locking support and mounting receptacle. (CMP- 18) Informational Note; An auachme111 liuing is different from an :rnach1uent p lug because llO cord is associated with 1.he fi tting. An attachmenc titting in combination wirl1 a locking support and mo1.1111jng receptacle sec1.1r1~s the associated uLilizaLion equipment in p lace and supports irs weighL A ttachment. Plug (Plug Cap) (Plug). A device tl1at, by inse rtion in a receptacle, establishes a connection between th e conductors of the a ttached flexihle cord and tJ1e conductors connected pennanently to tl1e receptacle . (CMP-18) Authority Having Jurisdiction (AHJ). An o rganization, office, or iJ1tlividual r esponsible for e nforcin g the requi remen t~ of a code or standard, or f'or a pprovmg equipment, mate rials, an instal laLion, or a procedtu-e . (CMP-1) Tnfo nnalional Note: The phrase "aurl10ri1:y having jurisdiction." or its acronym AHJ, is 1.1sed in Nl"PA documents in a broad manner, since jurisdictions and approval agencies l"ary, a;; do their responsfoilities. 'v\fhere public safety is primary, rhe authority having jurisdinion may be a federal, srai.e, local, or 111.her regional departmem o r individual such as a lire chief; fire marsh al: chief of a fire prevention bureau, labor department, o r health deparnnem; build ing official; electrical inspector; or orherll having statutory authority. F'o-r insurance purposes, an insurance inspenio n deparu11enL, raring bureau, or ot her insurance compa ny represe ntative may he the amhorii:y having jurisrliclion. Jn many circwnstances, rhe properly owner or his or her designa1ed age111. a.~sumes the ro le o f 1.he aurl1oricy having jurisdiction; a1 governmem insr.allat.io ns, the commanding officer or deparunen~,I official may be the a urhori1.y havingjllrisdic6011. Automatic. Performing a function with out the necessity of h Ltman intervention. (CMP-1) B athroom. An area. including a sink (basin) with o ne or more of tl1e fo llowing: a toilet, a urinal , a tub, a shower, a bid e L, o r similar p lumbing fixtures. (C..MP-2) Battery System . interconnected batter y subsystems consisting of one rn- 111.ore strn·age ba tteri es a nd battery chargers, a nd. can NATIONAL ELECTRICAL CODE 2020Edition ARTICLE 100 - DEFINITIONS inclurle inverters, converters, and associated electrical equipment. (CMP-13) Bonded (Bonding). Connected to establish eleco·ical continuity and conductivity. (CMP-5) Bonding Conductor or Jumper. A reliable conductor to e nsure th e required e lectrical conductivity between metal parts required to be electrically con nected. (CMP-5) Bonding Jumper, Equjpment. The connection between Lwo or more portions of the equiprnent grounding condu ctor. (CMP-.5) Bonding Jumper, Main. The connecticm l;>elween the grow1ded ci rcuit conductor a nd the equipment grounding conductor, or the supply-side bonding jumper, or both, al the se1vice. (CM.P-5) Bonding Jumper, Supply-Side . A conductor installed on the supply side of a service or within a service equipment enclosure(s), or for a separately derived system, that enst\l'es th e required electrical conductivity between metal parts required Lo be electrically co1mected. (CMP-5) Bonding Jumper, System. The connect.ion between the grounded circuit conductor and the supply-si<;le bondingjumpei~. 01· d1e e<]uipment grounding condu ctor, or born, at a separately derived system. (CMP-5) Branch Circuit. The circuit conductors between me final overcurrent device protecting me circui t and the o udet(s) . (CMP-2) Branch Circuit, Appliance. A branch circuit that supp lies energy to one or more outlets to which appliances are to be connected and that ha~ no permanently connected luminaires d1at are not a part of an appliance. (CMP-2) Branch Circuit, General-Purpose. A branch circuit d1al supplies two 01· more receptacles or outlet.~ for lighting a nd appliances. (CMP-2) Branch Circuit, Individual. A branch circuit drnt supplies on ly one utilization equ.ipm ent. (CMP-2) _Branch Circuit, Multiwire. A bra n ch circuit that consisrs of two or more ungrotmded conductors tlrnt have a voltage between them, and a grounded conductor that h a-, eC]Ual voltage between it and each ungrounde d conductor of the circuit and d1aL L~ connected to the neutral or grounded conductor of the system. (CMP-2) Building. A stn.1cture that stands a lone or that is separated from acljo ining scructures by fire walls. (CMP-1) Cabinet. An enclosw·e that is designed for e ither surface mounting or flush mounting and is provided with a fram e, mat, or u·im in which a swinging door or doors are or can be hung. (CMP-9) CabJe, Coaxial. A cylindi-ical assembly composed of a conductor centered inside a metallic tube or sh ie ld, separated b y a dielectric material, and usually covered b)' an insulatingjacket. (CMP- l fi) Cable, Optical Fibe1·. A factory assembly or field assembly of one or more optical fibers having an overaU covering. (CMP- l fi) 2020 ll\lirjon NATIONAL ELECTRICAL CODE CHAPTER I lnfr>rmarlonal Nme: A lie lcl-a~sembled opl.ical fiber cable is an assembly of one or more op Li cal fibers wirhin a jacker. TI1e jacket, without optical liber.s, i.s installed in a manner similar to conduit or raceway. Once the jacker i~ installed. the opl.ical fibers are insened inm the jacket, completing the cable assembly. Cable, Optical Fiber, Composite. A cable containing optical fibers and current-canying e lectrical condu ctors. (CMP-16) Cable, Optical Fiber, Conductive. A factory assembly of one or more optical fibers having an overaU covering and containing non-current-carrying conductive member(s) suc h a5 metallic su·ength member(s), metallic vapor h arrier(s) . metall ic armor, or m etallic sheath. (CMP-16) Cable, Optical Fiber, Nonconductive. A factory assembly of one or more o p tical fibers havi.ng an overall covering and containing no electricaUy conducti11 e materials. (CMP-16) Cable Routing Assembly. A single c ha,mel o r c01mected multiple c ha nnels, as well a5 a5sociated fittings, forming a SU'Uctural system d1at is used to support and route communications wires and cables, optical fiber cables, data cables associated with information technology and commun ications e<]uipment, Class 2, Cla.5s 3, and Type PLTC cables, and power-limited fire a larm cables in plenum, rise1~ and general-purpose a pplications. (CMP-16) Charge Controller. Eqttipme nt Lhat con trol~ de voltage o r de current, or botJ1, and dial is used to charge a battery or otJ1er e nergy storage device . (CMP-13) Cfrcuit Breaker. A device designed to open and close a c ir cuit by nonautomatic means and to open the c ircuit automatically on a predetermined overcurren t wimo ut damage to j tqelf when prope d y applied within it5 rating. (CMP-10) Informationa l No1e: The automatic opening rne<1ns can be integral, direct acting with the circuit breaker, or remote l'rom 1he circuhbreaker. Adjustable (as appluid lo rimdt brPaliers). A qualifying term indicating diat the circuit breaker can be set to u·ip at variom values of ctu-renl, time, or both, within a predetermined range. lnsta.nl11nmw; 'trip (as 11J1plinl to circuit brealun:1). A q ua lifying term indicating diat no delay is purposely inu·oduced in tJ1e tripping action of die c ircuit breaker. lnversf Time (as applier/ /.o circuit 1:n-ealle,:O. A qualifying term i nclicating tl1at the1·e is purposely introduced a delay in the tripping action of tJ1e circuit hreake,~ which delay decreases as the magnitude of th e current inCl"ea~es. Nmwdjustablf (as a/1plied to drcuit bmalle1:r). A qualifying term indicating tl1aL the circuit breaker does nm have any adju~tmenl to a lter m e value of die current at which it will n-.ip or die time required for it~ operation. Setting (of cirr1.ti/. bmakers). The va lue of current, Lime, or both, al which a n adjustable c ircui t breaker is set to trip. Circuit Integrity (CI) Cable. Cable(s) LL\ecl for remote-control, signal.ing, or power-limited system s that supply c1i tical c ircuits to e nsure survivability for continued cir·cuit o peration fot' a specified time LU1der fire conditio t1s. (CMP-3) 70-33 CHAPTER! ARTICLE 100-DEFINITIONS CJass I Circuit. The porlion of the wi ring system between the load side of me overcurrent device or power-limited supply and the connecLed eguipment. (CMP-3) lnformational Note: See 725.41 for voltage and power limimuons of Cla.$S l circ1-1irs. Class 2 Circuit. The portion of the wiring system bet-ween the load side of a Class 2 power source and the connected equipment. Due to iL~ power limitatio1L~. a Class 2 circuit considers safety from a fire initiation standpoint and provides acceptable protection from electric shock. (CMP-3) Class 3 Circuit. The portion of the wiring syste m between the load side of a Class 3 power source and the connected equipment. Due to its power li1nitations, a Class 3 circuit considers safel)' from a fire initiation standpoint. Since higher level~ of voltage and current than for Class 2 are pern1ittecl, adrlitio nal safeguards are specified to provide protection from an e lecU"ic shock hazard that could be encountered. (CMP-3) Clothes Closet. A nonJ1abitable room or space inte 11ded primarily for storage of garmenl~ and apparel. (CMP-1) Communications Equipment. The elecb·onic equipment that performs the telecommrn1ications operations for the tran.~mission of audio, video, and data, and in cludes power equipment (e.g., de converters, inverters, and batteries), technical support equipment (e .g., computers), and conductors dedicated solely co the operalion of the erruipment. (CMP- 16) Lnforrnational Note: A.s the telecommunications network minsii:ions IO a more data-cen1.ric network, computers, routers, servers. and !heir powerin,g equipmen1. a 1·e becoming essential to the transmission of a1-1dio. video. and data and are finding increasing application in communkauons equipmenr insmllacions. Control Circuit. The cirCLtit of a conu·ol appararus or system that carries the electric sign,1ls directing the performance of the conu·oller but does not carry the main powe1· curre nt. (CMP-11) Controller. A device 01· group of devices that se1·ves to govern, in some predetermined manner, the e lectric powei· delivered to the apparatus to which it is connected. (CMP-1) Cooking Unit, Counter-Mounted. A cooking appliance designed for mounting in or on a counter and consisting of one or more heating elements, internal ·wiring, and built-in or mountable controls. (CMP-2) Coordination, Selective (Selective Coordination). Localization of an overcurrent condition to restrict outages to the circuit or equipment affected, accornpli.5hed by the selection a nd inst:albtion of overcurrent protective devices and tJ1eir ratings or settings for me full rnnge of available overcurrents, from overload to the available fault cw-rent, and for th e foll range o r overcurrent protective device opening times associated with those overcurrents. (CMl'-10) Copper-Clad Aluminum Conductors. Conductors drawn from a copper-clad aluminum rod, with the copper metallurgically bonded to an alum.inu1u core, where the copper forms a minimum of l O percent of the cross-sectional ,u·ea of a .~olid conductor or each strand of a sU"anderl condu ctor. (CMP-fi) Cutout Box. An enclosure desig ned for surface mounting that has swinging doors or covers secured d irectly to and telescoping wici1 the walls of the enclosure. (CMP-9) DC-to-DC Convertet A device ci1at can provide ,u1 output de voltage and cm-rent at a higher or lower Vo=1lue than the input de voltage and current. (CMP-4) Concealed. Rendered inaccessible by the su·ucture or finish of the building. (CMP- 1) Dead Front. v\Tithour live parts exposed to a person on die operating side of the egwpment. (CMP-9) lnformacional Note: Wires in concealed raceways are considered con cealed. even though 1:hey may become accessible by wir.hdrawing them. Demand Factor. The ratio of tJ1e m a-ximum demand of a system , or part of a system , to tl1e total connected load of a system or the pa.rt of the system under consideration. (CMP-2) Conductor, Bare. A conductor having no covering or elect1·ical insulation whaLsoever. (CMP-6) Device. A Lmit of a n electrical s-ystem, other than a conducto1·, that carries or controls e lecu·ic energy a~ its principal function. (CMP-1) Conductor, Covered. A conducror enca5ed wi thin material of composition or thickness that is n ot recognized b y ci1is CodP as e lecu·ical insulation. (CMP-6) Conductor, Insulated. A conduc tor encased within material of composition and ci1ickness that is recognized by this CodP as electrical insulation. (CMP-6) Conduit Body. A separate portion of a condttil or tubing system that provides access tJ1rough a removable cover(s) to the inte rior bf the system at a junction of two or more sections of the system or at a terminal point of the system. Boxes such as FS and FD or larger ca5t or sheet meta l boxes are not classified as conduit bodies. (CMP-9) Connector, Pressure (Solderless). A device that establish es a connection between two or more conductors or between one or more conductors and a terminal by means of mechanicaJ pressure and without ci1e use o f solder. (CMP-1 ) Continuous Load. A load where the rua-ximum current i~ expected to conti nue fo r 3 lwurs or more. (CMP-2) 70-34 Disconnecting Means. A device, or group of d evices, o r other means by wh ich the conductors of a circuit can be clisconnect.ed from their som ce of s11pply. (CMP-1) Dormitory Unit. A building o r a space in a building in which group sleep ing accommodations ar e provided for more d1an 16 perso1L5 who are not membe rs of the same family in one room, or a se1·ies of closely associated rooms, under j oint occupancy and single m anagement, witJ1 or w ici1out meals, bu t witJ1oUL individual cooking facilities. (CMP 2) Duly, Continuous. Operation at a substan tially constant load for a n indefinite ly long time. (CMP-1) Duty, Intermittent. Operation for a lternate intervals of( ! ) load and no load; or (2) load and rest; or (3) load, no load, and rest. (CMP- l ) Duty, Periodic. l ntennittent operation in which the load conditions are regularly recurrent. (CMP-1) Duty, Short-Time. Operation at a substan tially constant load for a short and definite, specified time. (CMP-1) NATIONAL ELECTRICAL CODE 2020Edition CHAPTER I AIITIC.LE 100- DEFlNITlONS Duty, Varying. Operation at loads. and for i.ntervals of time, both of which may be subject to wide variation. (CMP-1) Dwelling, One-Family. A bui.kling that consist5 solely of one dweUing unil. (CMP-1) Dwelling, Two-Family. A building that consists sole ly of two dwelling units. (CMP-1) Dwelling, Multifamily. A building that contains three or more dwelling units. (CMP-1) Dwelling Unit. A single unit, providi.ng complete and independent Living facilities for one or mo1·e persons, iucluding permanent provisions for living, sleepi ng, cooking, and sanitation. (CMP-2) Effective Ground-Fault Current Path. An intentionally cor1.rnT1cted, low-impedance elecu·ically conductive path designed and intended to carry current m1der ground-fault conditions from the point ofa ground fault on a wiring system to the electrical supply smu-ce and that facilitates the operation of the ove1·current protective device or ground-fault detectors. (CMP-5) Electric Power Production and Distribution Network. Power production, distribution, and utilization equipment and facilities, such as e lecu·ic utility systems that ar e con nected to premL~es wiring and are external to and not conu·olled by an interactive system. (CMP-13) Electric Sign. A fixed, stationary, or portable self-contained, electrically operated and/ or electrically illuminated milization equipment with words or symbols designed to convey info1rnation or attract attention. (CMP-18) Electric Vehicle (EV). An automotive-type vehicle for on-road Llse, such as passenger automobil es, buses, truck.~, vans, neighborhood e lecu-ic vehicles, electric motorcycles, anc;l the like, primarily powered by an electric m otor that draws current from a rechargeable stornge batte1·y, fuel cell, photovoltaic army, or other source of electric cu1TenL Plug-in h ybrid e lectric vehicles (PHEV) are electric vehicles li.aving a second source of motive power. Oll~road, selC-prope lled electric mobile equipme nt, su ch as industrial trucks, ho ist~, Li.fts, transports, golf carts, ajrline ground support equjpment, tractors, boats, and the Jjke, are not considered elecu-ic vehicles. (CMP- 12) Electrical Circuit Protective System A $}'Stem consisting of components and materials intended for installation as protection for specific elech·ical wi ring systems with respect ro the disruption of electrical c i1-cui t integrity upon exterior fire exposure . (CMP-16) Electrical Datum Plane. A specified distance above a water level above which e lectrical equipment can be installed and elecu·ical connections can be made. (CMP-7) Enclosed. Surrounded by a case, housing, fen ce, or wal.l(s) that prevent5 persons from accidentaUy contacting energized parts. (CMP-1) Enclosure. The case or housing of apparatus, or the fence or walls surrounding an installation to prevent personnel from accidentally contacting energized parts or to protect the equipm ent from physical damage. (CMP-1) Informational Not.e: See Table 110.28 for examples of enclosure types. Energized. Elecu·ically connected to, (CMP -1) 01- is, a source of voltage. Equipment. A general tern1, including fittin gs, devices, appliances, luminaires, apparan1s, machinery, and the like med as a part ol·; or in connectio n with , an e lectrical installation. (CMP-1) Equipotential PJane. Accessible conductive parts bonded togeth er to 1~ed11ce voltage gradients in a designated area. (CMP-17) Exposed (as applied to live parts). Capable of being inadvertently wuched o r approached neai·er than a safe distance by a pe1-son. (CMP-1 ) lnfrirmariona l Note: This Lenn applies to partt that are not suitably guarded, isolated, o r insulated. Exposed (as applied to wiring methods). O n or attached to the smface or behind panels designed to a llow access. (CM P-1) E.xtemally Operable. Capable of being operated without exposing the operator to contact with live parts. (CMP-1 ) Fault Current. D1e nu-rent delivered at a point on the system du1i.ng a sh o rt-circuit condition. (CMP-10) Fault Current, Available (Available Fault Current). The largest amount of current capable of being delivered at a poin t on the system during a short-circuit condition. (CMP-10 ) Informational Note; A short-circuit can occur during abnormal conditions s1.1cl1 as a fault between circuit conductors or a ground fau lt. See lnfonuational Nore Figure 100.1. Feeder. All circuit conductors between tl1e service equipment, the soLu·ce of a separately derived system , or other power supply source and the final branch-circuit overcurrent device. (CTvIP-10) Festoon Lighting. A string of outdoor Lights that is stt5pended between two point~. (CMP-18) Field Evaluation Body (FEB). An organization or p,u·t of an organization ihat performs field evaluations of electrical or other eq uipment. (790, 2018] (CMP-1) Electric-Discharge Lighting. Systems of illumination utilizin g fluorescent lamps, high-inte nsity discharge (HID) lamps, or neon tubing. (CMP-18) Informational Noce: NFPA 790-2018, Star,tlmd Jc,,: G'o·mptJ(tnl)' of 17iitd-Pctr~ Field b1a.ltwtian BoditS, provides guidelines lo r esral>lishing rhe qualification and competency of a body performing fi eld evaluat.ions of elecu:ical products and assembles with elec1rica.l components. Electronically Actuated Fuse. An overcmrem protec tive device that generally consists of a control module that provides cun:ent-sensing, eleetronicaUy de1·ive d time-etuTent ch aracteristics, energy to init.iate tripping, and an interrupting module that interrupts current when an overcurrem occurs. Such fuses may or may not operate in a current-limiting fash ion, depending on the type of conu-ol selected. (CMP-JO) Field Labeled (as applied to evaluated products). Equipment or mate1·ials to wh ich has been attach e d a label, symbol, or other identrfying mark ofan FEB indicating the equipment or material~ were evaluated and found to comply with requirements a~ described in at1 accompanying fie ld evaluation 1·eport. [790,20 181 (CMP-1) 2020 ll\lirjon NATIONAL ELECTRICAL CODE 70-35 CHAPTER l ARTICLE 100-DEFINITIONS Grounded (Grounding). Connected (connectin g) to ground or to a conductive b ody that extends the groLmd connectio n. (CMP-5) Supply source: ac or de Grounded, Solidly. Connected to groLmd wid1our inserting any resistor or impeda n ce device. (CMP-5) Grounded Conductor. A system or circuit conductor that is intentionally grounded. (CMP-5) Available fault current Equipment Informational Nme: AlLhough an eqnipmenL grounding conducrnr i.s grounded. it is not considered a grow1clecl conclLtcto1: Equipment with a short-circuit current rating I I I I : OCPD: Overcurrent protective device--'---' with an interrupting rating [__ : __ _J lnformatinna.l Nore: Class A ground-fault c ircuit imerrnpleri; u'ip when the ground-fault currem is 6 mA or higher and do not trip when the grnund-faulr. current is less than 4 mA. For forther information, see U L 943, Strmdard for Grot(.'lld-Frwll Gi1n1il lnl.L1·rnp1ers. Available fault current Load Informational Note Figure 100.1 Ground-Fault Circuit Interrupter (GFCI). A device intended for the protection of personnel th a t functions to de-energize a circuit o r portion thereof within an established period of time when a ground-fault current exceeds the values established for a Class A device. (CMP-2) Available Fault Current. Fitting. An accessory such as a locknut, bushing, or other part of a wiring system tha t is intended primati_ly to perform a mechanical rather than an electricaJ function. (CMP-1) Free Au· (as applied to conductors) . Open or ventilated environment that allows fo1· heal dissipation and air flow around an installed conducwr. (GMP-6) Fuel Cell. An electroch em ical system that consumes fue l to produce an electric current. In such cells, the m a in chemical reaction used for producing electric power is not combu~tion. However, th ere may be sources of combustion used within the overall cell system, su ch as reformers/ fuel processors. (CMP-4) Ground-Fault Current Path. An elecu·ically conductive pal11 from the po int of a ground fault on a wiring system th rough n ormally non-current-carrying conductors, grounded conductors, equipment, 01· die earth to the e lectrical supply source. (CMP-5) lnfomrnUonaJ Nore: E.xamples of ground·faulr curre m paths are -any comhinaUon of equipmem grounding conductors, metallic raceways. metallic cable shearhs. e lecu·kal e<]uipmenr. and any mher electricall)' conducLive material such as metal, warer, and ga~ piping; steel framing members: srucco mesh: metal ~lucling; reinforcing sceel; shields of communicat.ions cables; grounded conductors; and the earth itself'. Ground-Fault Protection of EquipmenL A system intended tO provide protection of equipment from damaging Ii ne-toground fault currents by operating Lo cause a disconnecting means to open all ungrounded conductors of the faulted circuit. l11is protection is p rovided at c urrent levels less than those required to protect conductors from damage through d1e operation of a supply circuit overcunent device. (CMP-5) Fuel Cell System. l11e complete aggregate of equipment used to convert chemica l fuel into usable electricity and typically consi~ting of a refo1·mer, stack, power inverte1·, and auxiliary equipment. (CM P-4) Grounding Conductor, Equipment (EGC). A conductive path (s) d1at is part of an effective ground-fault current path and co11.11ects normally non-current-can-ying me ta l parL~ of equipment toged1er and to the system grounded conductor o r to L11e grounding electrode conductor, or both. (CMP-5) Garage. A building or porti on of a building i.n which one or more self-propelled vehicles can be kept for use, sale, storage, rental, repair, exhibition, or demonstration purposes. (CMP-1) In formaUona l Note No. 1: Ir is recognized chat the equipment grounding condLtctor a lso performs bonding. lnformaUonal Note: For comme1·dal garages. re pair and storage, see Article 51 I. Generating Capacity, Inverter. The sum of parallel-connected inverter maximum continuou5 output power at 40°C in watts or kilowatt~. (CMP-4) Ground. The earth. (CMP-5) Ground Fault. An unintentiona.l, electrically conductive conn ection between an w1grounded conducto1· of an e lectrical circuit a.nd the normally non-current-carrying conductors, metallic enclosures, m etallic raceways, metallic equipment, or earth . ( CMP-5) 70-36 In formationa l Note No. 2: See 250.118 for a list of acce ptable equipmenL grounding conductors. Grounding Electrode. A conducting ol:!ject through which a direct connection to earth is established. (CMP-5) Grounding Electrode Conductor. A conductor used to connec t the system grounded conductor or the equipment to a grounding e lecn·od e or to a point on the grow1ding e lecu·ode syste m. (CMP-5) Guarded. Covered, shielded, fenced, e nclosed, or otherwise protected by means af suitable covers, casings, barriers, rails, screens, mats, or platforms to remove the like lihood of NATIONAL ELECTRICAL CODE 2020Edition AITTTCLE 100 - DEFlNrTJONS approach or contact by persons or objects w a point of danger. (CMP-1) Guest Room. An acco11unodation combining living, sleeping, sanitary, and storage fac ilities within a compartment. (CMP-2) Guest Suite. An accommodation \vith two rn· more contigumL5 rooms comprising a compartment, with or without doors between such rooms, that provides living, sleeping, sanitary, and storage faciJities. (CMP-2) Habitable Room. A room in a building for living, sleeping, eating, or cooking, but excluding bathroom.~, toilet rooms, closet,;, hallways, stonJge or uti lity spaces. and similar area5. (CMP-2) Handhole Enclosure. An enclosure for use in u.ndergrow1d systems, provided with an open or closed bottom, and sized to allow personnel to reach into, but not ente1·, for the ptu·pose of installing, operating, or maintaining equipment or wiring or both. (CMP-9) Hermetic Refrigerant Motor-Compressor. A combination consisting of a compressor a nd mot01; both of which are enclosed in the same housing, with no external shaft or shaft. seals, wid1. the motor opei-ating in the refrigerant. (CtvrP-11) H oistway. An y shaftway, hatchway, well hole, or other vertical opening 01· space in which an e levator or d umbwaiter is designed to operate. (CMP-12) CHAPTER I The indusuial control panel does not include the conn·oUed equipment (CMP-11) Information Technology Equipment (ITE). E9ttipment and system.5 raced 1000 vol ts or less, n ormally found in offices or o d1er business establishments and similar environments classified as ordinary locations, tJ1at are u sed for creation and manipulation of data, voice, video, and similar sig nal5 that are not communications equipmenL as defined in Pan I of Articl e LOO and do not process com munications circuits as defined in 805.2. (CMP-12) l nform::nlonal Note: Fo r informarjo n on listing re.qufrernenLS for both information technology eq,tipmem and communications equipment, see UL 60950-1-2014, fojimnation Terlmology Eq11i/>·mmL - Safety - Pat/ I: Gmernl Requimme11Lr or UL 62368-1-20 14. A11dio/Vid,'o Infi1rmatio11 anri Com.1111.miralion Technology l!:qui/muml Pr,rt 1: Sctfaly R.equir11111.11nls:. Information Technology Equipment Room. A room within tJ1e information technoloi,,iy equipment a rea th at contains d1e information technology equipment. f75:3.3.14l (CMP-12) Innerduct. A no nmetallic raceway placed ,vit11in a larger raceway. (CMP-16) Interactive Inverter. An inverter i_ntended for use in parallel 1\litl1 power soLU·ce(s) such as an elecu·ic utility ro supply commo n loads and capable of deli\1ering power to the utility. (CMP-13) Interactive System. An elecu·ic power production system tJ1at is operating in parailel with and capable of delivering ene1-gy to an electric primary som ce supply system. (CMP-4) Hybrid System. A system comprised of multiple power sources. These power sou rces could includ e photovoltaic, wind, microhydro generators, engine-driven generators, and others, but do not include electric power production and disu·ibution network systems. Energy storage systems sucl1 a5 batteries, nywheels, or superconducting magnetic storage equipment do not constitute a powe1· source for d1e purpose of this definition. The energy regenerated by an overhauling (descending) e levator does not constitute a power source for the purpose of this de finition. (CMP-4) Interrupting Rating. The highest currem at ra ted voltage tJ1at a device is identified co interrupt under standard test concliLiom. (CMP-10) Identified (as applied to equipment). Recognizable a~ suitable for the specific purpose, function, use, environment, application. and so ford1, where described in a pa.rticula1· Code req u.i1-ement. (CMP-l ) Intersystem Bonding Termination. A device that provides a means for connecting intersystem bond ing conductors for communication.5 systems to the grounding electrode system. (CMP-16) Informational Note: Some examples of ways to determine suitabi lity of equipmem for a specific purpose, e nviro nme nt., or app]jcation include investigations by a qualified rest.ing laboralO',i (listing and labeling), an inspec tion agency, or other organizations concerned with product evaluation. In Sight From (Within Sight From, Wilhm Sight) . Where this Codi' specifie:s that one e9uipme nt $hall be "in ~ight from ," "wi thin sig ht from,"' o r "within sight oe'" and so forth, another e9uipmem, the specified equipment is r.o be vi~ible and not more tl1.111. L5 m (50 ft) d istant from the other. (CMP-1) Industrial Control Panel. An a5sembl)' of two or more components consisting of one of the following: (l ) power circuit compone nts only, such a5 motor controll ers, overload re lays, fu~ed disconnect switches, and c ircuit breakers; (2) control circuit component5 only, such as push buttons, pilot light5, selector switches, timers, switches, and conu·ol .relays; (3) a combinatio n of powe r and control circuit components. These components, with a5sociated wiring and terminals, are mounted on, or con tained -w ithin, an endostu-e or mounted on a subpanel. 2020 ll\lirjon NATIONAL ELECTRICAL CODE Informational Note: Equipmem intended LO interrupt current at j L~ interrupting 111r.ing implied in pther ratings, such as horsepower or locked rotor current. 01.her than fault le\lels may have Inverter. Equipment that changes de to ac. (CMP-4) Inverter Input Circuit. Conductors connected to tl1e de i11put ofan inverter. (CMP-13) Inverter Output Circuit. Conductors connected to d1e ac outpu t ofan inverter. (CM P- 13) Inverter, Multimode. Equipment having tJ1e capabilities of bodl tl1e interactive inverter a nd the stand-alone inverter. (CMJl-4) Island Mode. The operational mode for stand-alone power productio n equipme nt o r an isolated microgrid, o r for a multimode inverter or an in terconnected microg1-id tha t i.5 disconnected from an e lectr ic power production and distribution network or other primary power sotu-ce. (CMP-4) lnformat.ional Nore: Isolated microgrids are distingujshed from interconnected microgri<ls, which are addressed in Article 705. Isolated (as applied to location). Not readi ly accessible to persons unless special means for access are ·used. (Cl\1P- l ) 70-37 CHAPTER I ARTICLE 100 -DEFINITIONS Kitchen. An area with a sink and permanent provision.~ for food preparation and cooking. (GMP-2) Labeled. Equipment or materials to which has· been attached a label, symbol, or other iden ti.fyin g mark of an organizatio n Lhar is acceptable to the authority having jurisdiction and concerned with product evaluation, that maintains periodic inspection of production of labeled equipment or materials, and by whose labe ling tJ1e manufacn,rer indicates compliance with appropriate standards or perfrn-ma nce in a specified manner. (CMP-1) lnformal.ional Note: Lf a l.i sted product is of such a size, shape, material. or s urface texture thar iris not possible LO apply legjhly rhe complete label m the proclLJct, rhe complete label may appear on the smallest 1.111il contmnet in which the product is packaged. Laundry Area. An area containing or designed to contain a laundry tray, clod1es washer, or clothes rlryer. (CMP-2) Lighting Outlet. An outlet intended for the direct connec tion ofa lampho lder or luminaire. (GMP-18) Lighting Track (Track Lighting). A manufactured assembl)' designed to support and en ergize lumina.ires that are capable of being readil y repositioned on the track. Its length om be altered by tJ1e addition or subtraction of sections of track. (CMP-18) Listed. Equ·ipment, material~, or services included in a list puhli~herl by an organization that is acceptable to the authority having jurisd.iction a nd concerned with evaluation of products or services, that ma intains periodic inspection ofp1-oduction of listed equipment or materials or periodic evaluation of services, and whose listing states that e ithe ,- Lhe equipment, material, or se1-vice meets appropriate d esign ated standards or has been tested and found suitable for a specified purpose. (GMP-1) Informational NOLe: The means for ide ntifying lis1ed equipmem may vary for each organization con cerned with product evaluaLion , some ofwh·ich rlo nOL recognize equipment as lisLed unless iL is also labeled. Use of Lhe sysLem employed by Lhe Jjsting organizal.ion a llows Lhe aL1Lhoriiy hal'ingjurisdictio n to idenLify a lis1ed product. Live Parts. Energized conductive components. (CMP-J) Location, Damp. Locations protected from weather and not: subject to satLu·ation with water or othe1· liquids but subject to moderate degrees of moisture. (CMP-1) Informational No Le: Examples or such locaLions inc lude partially protecLecl locations under canopies. marCJuees. roofed o pen porches, and like locations, and imerior focal.ions subjen LO moder,1te degrees or moisture, SLJch as some basements, some barns, and some colcl-s1orage 1varehouses. Location, Dry. A location not normally subject to dampness o r wetness. A location classified as dry may be temporarily subject to darnpnes$ or werness, as in the case of a building 1111der constrnction. (CMP-1 ) Location, Wet. Installations underground or in concrete slabs or masonry in di.re ct con tact with tJ1e earth; in locations subject to saturation with water or other liquids, such as vehicle wa~hing :u-eas; and in w1protected loc.a.tions exposed to weather. (CMP-1) Lum.ina.ire. A comp lete lighting unit consisting of a light sow-ce such as a lamp or lamps, together with the parLs 70-38 designed to position tJ1e light source and connect it to the power supply. It may also include parts to protect the light source 01- t;he balla~t or to disu-ilmte the light. A lampholder itself is notaluminaire. (GMP-18) Messenger or Messenger Wire . A wire that is run along with o r integral with a cable or conductor to provide mechanical support for d1e cable or conductor. (GMP-6) Motor Control Center. An assembly of o n e or more enclosed sections having a common power btt~ and principally containing motor conu-ol units. (CMP-11) MultioutJeLAssembly. A type of surface, flush, or freestanding raceway designed to hold c.on_ductors and receptacles, a~sembled in the field or at the factory. (GMP-18) Neutral Conductor. The conductor connected to the n eLLD·al point of a system that is intended to carry cu rrent w1der normal conditions. (CMP-5) Neutral Point. The common point on a wye-connection in a polypha~e system or midpoint on a single-phase, 3-wire system, or midpoint of a single-phase port.ion of a 3-phase delt.;, system, or a midpoint of a 3-wire, direct-current system. (CMP-5) lnfomrnLional Nore: At the ne uLral poinL of the sysLem, Lhe vectorial sum of the no,ninal volta.ges from all other phases within Lhe system Lhat ul.ilize the neurral. with respecL Lo the neut.ml point, is zero poLenLial. Nonautomatic. Requiring human intervention to perform a function. (CMP-l ) Nonlinear Load. A load where tJ1e wave shape of the steadystate current does not follow the wave shape of the a pplied voltage. (CMP-1) lnformationaJ Note: 'Electronic equipment, eleCLronic/ e lectricclischarge liglning, :cidjustat,le-speed drive systems, and similar equipmenLmay be nonlinear loarls. Outlet. A point on the wiring system at which current is taken to supply utilization equipment. (CMP-1) Outline Lighting. An arrangement of incandescent la mps, electric-discharge lighting, o r other elecu-ically powered light sources to o utline or call attention co certain featw·es s uch as the shape of a building or the dee.oration of a window. (CMP-18) Overcurrent. Any current in excess of the rated current of equipment or the ampac.ity of a conductor. l t m ay result from overload , sh ort circuit, or ground fault. (CMP-LO) lnJornrnLiona l NOLe: A currenL in excess of rating may be accommodated by certa.in equipme nt and conductors for a given set of conditions. The refore, the rules lor overct.1rre 11t protecrjon are specific for particular situations. Overcurrent Protective Device, Branch-Circuit, A device capable of providing protect.ion for service, feeder, a nd branch circuit5 and equipment over the full range of overcurrent5 between its rated nu-rent and iL~ interrupting ratin g. Su ch cle,.,ices are provided with interrupting ratings appropriate for the intended u se hut n o less tJ,an 5000 amperes. (CMP-10) Overcurrent Protective Device, Supplementary. A device intended to provide limited overc1u-rent protection for specific applications and utilization equipment such as lum.ina.ires and app.liances. This limited protection is in addition to the protec- NATIONAL ELECTRICAL CODE 2020EdiLion AITTICU: 100 tion provided in the required branch circuit by the branchcircuit overcurrent protective device. (C'v!P-10) Overload. Operation of equipment in excess of normal , fullload rati.ng, or of a conductor in excess of it~ a mpacity that, when it persists for a sufficient length of time, would cause damage or dangerous overheating. A fau lt, such as a short circuit or ground fau lt, is not an overload. (CMP-10) Panelboard. A single panel or group of panel un.its designed for assembly in the form ofa single panel, includ.ing buses and automatic overcurrent devices, and equipped wit.h or wid1out switches for the conU'ol of light, heat, or power circuits; designed to be placed in a cabinet or c utout box placed in or against a wall, partition, or o ther support; and accessible only from d1e front. (CMP-9) Photovoltaic (PV) System. The total components, cir·cuits, and equipment up to and including tJ1e PV system clisconnecting means tlial, in combination, convert so lar energy into e lectric energy. (CMP-4) Pier. A su-ucture extending over d1e water a nd supported on a fixed foundation (fixed pier), or on flotation (floating pier), diat provides access ro d1e water. r303:3.3. I 7] (CMP-7) Pier, Fixed. Pier co11SU-ttcted on a permanent. fixed fow1dation, such as on piles, that permanently establishes the eJevation of the strucltlre deck 1vitll respect lo land. f3 03:3.3.1 7.2 l (CMP-7) Pier, Floating. Pier designed with inherent no tation capability that allows th e struct:1.11·e to float on the water su rface and rise and faU with W,lter level changes. [303:3.3.17.3] (CMP-7) P]enum. A compartment or chamber to which one or more air d u cts are connected and that forms part of the air disu·ibution system. (CMP-3) Power Outle t. An enclosed assembly that may include receptacles, circuit breakers, fuseholde1·s, fused switches, buses, and watt-ho ur merer mounting means; intended to supply and control power to mobile homes, recreational vehicles, park trailers, or boats or to serve as a means for disti·ibuting power required to operate mobile or temporarily installed eqttipment. (CMP-7) Powe r Production Equipment. Electi-ical generating equipment supplied hy a ny source other tJ1a.11 a utility servi.ce, up to the source system disconnecting means. (CMP-4) ln fonnational No Le: Examples of power production equipmenL include such jLems as generaLors, solar phomvoltaic systems, and fue l cell sysLems. Power-Limited Tray Cable (PLTC). A factory assembly of two or more insulated conductors rated at 300 volts, with or without associated bare 01· insulated equipment grotu1.din.g conductors, under a nonmetallic j acket. (CMP-3) Premises Wiring (System). l nterior and exterio r 1viring, inch.tding powe1~ lighting, control, and signal circu.it wiring together wid1 all their associated hardware, fittingi;, and wiring devices, both permanently and temporarily installed. Thi~ includes (a) wil"ing from the service point or powet· source to die outlet~ or (h) wii-ing from and including the power source to the outlets where there is no service point. 2020 ll\lirjon NATIONAL ELECTRICAL CODE DEFINITIONS CHAPTER ! Such wiri ng does not include wiring intern al to applia nces, lurninaires, motors, controllers, motor control centers, and similarequipmenl. (CMP-1) l n.forrn<1riona l Note: Power source.;, include, but are not limited LO, imerconnected o r stand-alone hatLeries, solar phowvoltaic systems, oLher dis1ributefl generation systems, or generacors. Prime Mover. The machine diat supplies die mechanical horsepower to a gen erator. (C...MP-13) Qualified Person. One who ha.5 ski lls and knowledge rel:;1ted to ~he construction and oper-ation of tJ1e elecu-ical equipment and installations a nd has received safety training to recognize and avoid tJ1e hazards involved. (CMP-1) I nfrurna1fonal Note: Refer to NJ•PA 70£'.!()18, S1a11d(m/Jhr Elerlrical Srt{f.ly in 111,, Worhpia,,,, for electrical safety u-aining requiren1ents. Raceway. An enclosed channel designed expressly fo r holding wit-es, cables, or busbars, with additional functions as pern1.itted in thi~ Cod6. (CMP-8) Informational Note: A raceway is identified within specifi c anicle rlefinitions . Raceway, Communications. An enclosed chan nel of nonmetallic mate1ials designed expressly for holding communications wires and cables; optical fiber cables; data cables associated 1vith i.n formati.on technology and communications equipment; Class 2, Qass 3, and Type PLTC cables; a nd power-litUited fire a larm cables in plenum, rise1~ and general-purpose applications. (CMP0 J 6) Rainproof. Constructed, protected, or treated so as to prevent rain from in Lerfering witJ1 the su ccessful operation of the apparatus under specified test conditioJ1s. (CMP-1) Raintight. Consu·ucted or protected so d1ar exposw·e to a beating rain will not result in the entrance of water tmder specified test conditions. (CMP-1) Receptacle. A contact device installed at die outlet for the connection of an attachment plug, or for the d irect connection of electi·ical 1Jti.lization equipment designed to mate with die corresponding contact device. A single recept:acle is a single contact device with no od1er contact device on the same yoke o r su-ap. A multiple receptacle is two or more contact devices on the same yoke or su·ap. (CMP-18) Informational No1e: A duplex receptacle is an example of a multiple r eceptacle that has rwo receptacles on the same yoke 0 1· s1rap. Receptacle Outle t. An outlet where one or more receptacles are i11Stalled. (CMP-18) Reconditioned. Electromechanical systems, equipment, apparatus, 01· components d1at are restored to operating conditio ns. This process differs from normal servicing of equipment that remains within a facility, or replacement of listed equipment on a one-to-one basis. (CMP-10) rnformationa l Note: The term reco11dili01ied is frequenrly reterred Lo as relntill, ntf'ud1ishnl, or w1t1m.11fm:tured. Remote-Control Circuit. Ail)' electrical circuit U1at controls any other circuit through a rela)' or an eqttivalem device. (CMP-3) 70-39 CHAPTER l ARTICLE 100- DEFINITIONS Retrofit Kit. A gen eral term for a complete s uha~sembly of part~ and devices for field conversion of utilization eq uipment. (CMP-18) Sealable Equipment. Equipment enclosed in a case or cabinet tJ1at is prnvided with a m eans of sealing or locking so that live parts cannot b e m ade accessible without opening the e nclosure. (CMP-1) Informational Nme: The equipment may or may not be operable wiL110L1t opening th e enclosure. l nformaLiona l Note: TI1e service poim can be descl'ibei;I as the point of dernarcaLion becween whe,·e che serving utility e ncl!; and the premises wiring begins. The serving utility generally speci fies the location of' the service point based o n Lhe conditions of service. Short-Circuit Current Rating. The pros pective w mmetrical fault cutTen t a t a nominal voltage to which an apparatus or system is able to be connected without sustaining damage exceecling defined acceptance criteria . (CMP-10) Separately Derived System. An electrical source, other than a service, h avi ng n o d irect connection. (s) to circLtit conductors of any other e lectrical source other th a n those establ ished by grounding and bonding connections. (CMP-5) Show Window. Any window, including windows above doors, used or designed to be med for the display of goods or advertising mate1-ial, wh e U'ler it is fully or partly e nclosed or e n tirely open at U1e rear and wheU1er o r· not it has a platform rai~ed higher than the st1-eet floor level. (CMl'-2) Service. The conductors and equipment con necti ng the sen'ing utility to the wiring system of the p1·emises ser ved. (CMP-10) Signaling Circuit. An y electrical c ircuit that ene,-gizes sig na ling equipm ent. (CMP-3) Service Cable. Service conductors made up in the forn1 of a cable. (CMP-10) Service Conductors. The cond uctors from the service point to the service di,~con necting m eans. (CMP-10) Service Conductors, Overhead. The overhead conductors between the service point a nd the first point ol' connection to the service-entrance conducrm-s at the building o r othe r structure. (CMP-10) Service Conductors, Underground. The underground conduc,. tors between the service point and the first point of connectio n to the service-entrance conductors in a terminal box, meter, or other enclo~ure, inside or outside the buildi11g wall. (CMP-10) Informational Note: Where there is no terminaJ box, meter, or oLher enclosure, che poini of connecLion i$ considered to be I.he point of entrance of the service condltctors imo the building. Service Drop. T he overhead conductors between the serving utility and U1e service point (CMP-10) Service-Entrance Conductors, Overhead System. The service condu ctors b etween the termina ls of the service equipment and a point usually o u tside the building, clear of building walls, where j o ined by tap or splice to U1e serv ice drop or overhead service conductors. (CMP-10) Service-Enttance Conductors, Underground System. The service conductors b etween th e terminals of the ser vice equipme nt and the point of connection to the sen~ce lateral or undergrou nd ser vice conductors. (CMP- 10) lnformacional Note: Where service equipment is locmed out~ide the building walls, there may be no -erv ice-entrance conductors or chey may he enLirely ouLside che building. Service Equipment. The necessary equipme nt, consisting of a ci rcuit breaker(s) or switch(es) and fuse(s) and their accessories, connected to the serving utility and intended to constitu te the ma in con trol a nd clisconnect of the se1v ing utility: (CMP-10) Service Lateral. The unde rground conducto rs between th e utility elecn-ic su pply system and the service point. (CMP-:10) Service Point. The point of connection between the fac ili ties of the sensing utility and tl1e premises wiring. (CMP-10) Single-Pole Separable Com1ector. A device that is installed at the e nds of portable, fl exible, si ng le-conductor cable tha t is LL~ed to establish conneCLion or d isconnection b etween two cables or one cable and a single-pole, panel-mounted separable connector. (CMP-18) Special Permission. The written consent of th e a uthority havingjw-isdiction. (CMP- L) Stand-Alone System. A system that i.~ capab le of supplying power independent of an electric power production and d.istr:ibution network. ( CM P-4) Structure. T hat which is built or constructed, other than equipm ent. (CMP-1) Surge Arrester. A p rotective device for limiting su rge voltages by di,~chargi ng or bypassing sm·ge cunent; it also prevent~ continu ed flow of fo llow current while r emaining capable of repeating these .func tions. (CMP-10) Surge-Protective Device (SPD) . A protective device for limiting trarL~ient voltages by diverting o r limiting surge curre nt; it also pi-event~ continued flow of fo llow current while remaining capable of repeati ng these functio ns and is desig n ated a.~ follows: Type 1: Perman enLl)' conn ected SPDs intended for installation between the secondary of the se rvi ce u-ansformer and the line side oJ the service cli~connect overcurrent device. T)'Pe 2: PennanenUy conn ected SP Ds intended for installatio n o n the load side of rh e service disconnect overcurre n t device, including SPDs located at the branch panel. T ype 3: Po in t of utilization SPDs. T ype 4: Compone nt SPDs, including discrete components, as well as assemblies. (CMP-10) lnfr1m1ationa l Nore: For farther information on Type 1, Type 2, Type 3, and Type 4 SPDs, see UL 1449, Slllndard.for S11rge Pmtci:ti.Vl! Devicl!S. Switch, Bypass Isolation. A manual, nonautomatic, or a L1tomatic operated device used in cortjun ction wi th a transfer switch Lo provide a means of directly co11.11ect:ing load tonductors to a power soLtrce and of d isconnecting tl1e transler switch. (CMP-13) Switch, General-Use. A switch inte n ded for use in gen eral disuibution and branch circuits. It is rated in amperes, a nd it is 70-40 NATIONAL ELECTRICAL CODE 2020Edition AITT'ICLE 100-DEFINITlONS capable of interrupting its rated c urrent at its rated voltage. (CMP-9) Switch, General-Use Snap. A form of general-use switch constructed so that it can be instaJled in device boxes or on box cover·s, or od1erwise used in c01tjun ction with wiring systems recognized by this Code. (CMP-9) Switch, Isolating. A switch in tended for isolating an electrical circuit from the source of power. It has no interrupting rating, and itis intended to be operated only after tJ1e circuit ha~ been opened by some od1er means. (CMP-9) Switch, Motor-Circuit. A switch rated in horsepowe r that is capable of intermpting tJ1e maximLtm opernting overload current of a motor of the same horsepower rati ng a~ the switch at the rnted voltage. (CMP-L1) Switch, Transfer. An automatic or nonautomatic device for transferring one or more load conductor con nec tions from one power source to another. (CM P-13) Switchboard. A Large single panel, frame, or assembly of panels on which are mounted on the face, back, or both, switches, overcurrem aml othe.r protective d evices, buses, and usually instrument~. These a~semblies are generally accessible from the rear as well as from dle front and a re not intended to be installed in cabinets. (CMP-9) Switchgear. An assembly completely e nclosed on all sides and top with sheet metal (except for ventilating openings ru1d inspection windows) and containing prima.r)' power circuit switch ing, interrupting devices, or both, with bmes and conuections. T he assembly may include control and auxiliary devices. Access to the intetior of tJ1e enclosure is provided by doors, removable covers, o r both. (CMP-9) lnfortnational Note: AU switchgear subject LO NEC requiremenu; is metal enclosed. Switchgear rared below 1000 V or l~ss may he ide nLitied as "lmv-vohage pmver circuit breaker swiLcl1!\"ea1:" Switchgear rated over LOO() V may he identified as "metalenclosed switchgear" or "meLal-clad switchgea1:'' Switchgear is av~1jJable in non- arc-resisrant or an;:-resistnnL C(u1su·uc6ons. Thermal Protector (as applied to molors). A protective device for assembly a5 an integral part of a motor or motorcompressor that, when properly applied, protects dle motor against dangerous overheating due t.o overload and failure to stan. (CMP-Ll ) Informational Note: The thermal protector may consist of one o r more sen.sing elemenlS imegral with the motor or motorcom press or and an exrernal comrol device. Thermally Prolected (as applied to motors). A motor o r motor-compressor tlrnt is provided with a tl1ermal protector. (CMP-11) Ungrounded. Not connected ro grotmd or to a conductive body dlat extends tl1e ground connection. (CMP-5) Uninterruptible Power Supply. A power supply tL5ed to provide a lternating ctuTent powe1· to a load for some pe1·iod of ttme in tl1e event of a power failure. (CMP-13) Informational Note: In addition, it may provide a more constant voltage and frequency s,1pply to the load, reducing the elfecLS of voltage and frc<Juenc y variations. CHAPTER! Utilization Equipment. Equipment tl1at utilizes elecu·ic e nergy for electronic, elecu·omechanical, chemical , heating, Lighting, 01· simil,u· pmposes. (CMP-1) Voltage (of a circuit). The greatest root-meai1-sqt1are (nns) (effective) difference of potential betwee n any two conductors of tl1e circuit concerned. (CMP-1) lnfrmnational Note: Some systems, such as :>-phase 4-wire, single-phase 3-wire, and 3-wire direct current, may have vrn·ious circuiL~ ofv.-1rious vo ltages. Voltage, Nominal. A nominaJ value assigned to a circuiL or system for tl1e pLtrpose of conveniently desig nating its voltage cla5s (e.g.. 120/ 240 volts. 480¥/ 277 volts, 600 volts) . (CM P-]) ln'lormarlonal Note No. 1: TI,e actual voltage a1 which a circu iL opera1es can v,u-y from the nominal within a range that permit$ smisfactory operation of equipment. Informational Nole No. 2: See ANSI C84.l-201I. Vnl/flr;t Haling.\ for Eie1;1rir Power Systems a11d Eqttifnnent (60 1-li). Informatio nal Note No. :I: Certain bar.tery uni LS may be con sidered Lo be rated a1 nominal 48 vol IS de, bl.IL may have a chai:ging tlom voltage up to 58 volts. In de applications. 60 vohs is used t0 cover Lhe entire range oHloat voltages. Voltage to Ground. For grounded circuits, the voltage between the given conductor and tlrnt point or conductor of the c ircuit tJ1at is grounded; for ungrounded c ircuits, the greatest voltage between the given conductor and a ny other conductor of dle circuit. (C..MP-] ) Watertight. Constructed so that moisture will not en ter the enclosw·e under specified test condition,,. (CMP-1 ) Wead1e rproof. Constructed or protected so that exposLLre to the weather will not interfere with successfiil operation. (CMP-1) Informational Nme: Rainproof", rainl.ight, or watertight equipmem can l\.tllill the requirements for weatherproof where varying weather conditions 01J1er than wetness, such as snow. ice, dust, or r.emperawre exr.rernes, are nola factor. Part II. Over 1000 Volts, Nominal Electronically Actuated Fuse. An overcLUTent protective device that generally consists of a control module that provides current sensing, electronically derived time-curren t characteristic$, e nergy to initiate u·i pping, and a n interrupting module that interrupts current when an overcurrent occurs. Electronically actuated fuses may or may not operate in a currentlimiting fa5hion , dependi.ng o n the type of control se lected. (CMP-10) Fuse. An overcurrent protective device with a circuit-opening fusible part dlat. is heated a nd severed by tl1e passage of overc w-re n t through it. (CMP-10) lnforrnat.ional Note: A fuse comprises all 1:he pans thar. form a unit capable of performing Lhe presc ribed functions. ILm,1y or may not be the complete device neces.sary LO connect ir into an electrical circuiL Con/rolled Vtmtecl Power h.1sf. A !i.tse wit11 provi.~ion for controlling discharge circuit interruption $uch Lhat no solid matedal may be exhausted into th e surrounding atmosphere. Informational No1e: The ti.,se is designed so chat discharged gases ,,~II noL ignire or damage insulation in the path or 1.he 2020 ll\lirjon NATIONAL £LllCTRICAL CODE 70-41 CHAPTER I ARTICLE 100-DEFINlTIONS Part m. Hazardous (Classified} Locations (CMP-14). discharge or propagate a flashover LO or berween grounded members or conducl.io n membe rs in Lhe palh of d1e discharge whe re che distance be1ween the vcnL -and such insulaLion or tonducl.ion members conforms to manufacturer's recommenda-tions. Aircraft Painting Hangar. An aircraft hangar co11.~tructed fo1· d1e express purpose of spray/ coating/ dipping applications and provided widi dedicated ventilation supply and exhaust. J,,,.1n1lsion.Fuse Unit (E,;pulsion Fusr). A vented fuse unit in which the expulsion effect of gases produced by the arc and lining of the foseholde1~ either alone or aided by a s pl'ing, extinguishes the arc. Associated Apparalus. Apparatus in which t he circuits are nol necessarily intrinsically safe themselves but that affects the energy in the intrinsically safe circuit~ and is relied on to maintai n intr.insic safety. Such app::u-at1.ts is on_e of the following: Nonvented Power P1tse. A fuse without i11tentional provision for (l) the escape of arc gases, liquids, or solid particles to the atmosphere during circuit interruption. Power Puse Unit. A vented, nonvented, or con u·olled vented fuse (2) unit 'in whicl1 the ar·c is extinguished by being drawn through solid material, granular material, or liquid, eithe1· alone or a ided by a spring. lnformatjonal No1.e No. 1: AssociaLed apparatus has idemified inu:insically safe connection.5 for inuins.icaJly safe apparatus and also may h;we connections for nnnintrinsically sale apparatus. Vented Power Fuse. A fu5e with provision for die escape of arc gases, liquids, or solid paxticles LO the surrounding am1osphere during circuit interruption. lnfom1a1.ional Nme No. 2: An example of associated apparatus is an in1rinsic safety barrier, which is a network designed to limi1 the energy (vohage and curre111) available r.o the protected cirnLil in Lhe hazardous (classitied) locmjon, w1der specifiecl fuul1 condi1Jo11s. Multiple Fuse. An assembly of Lwo or more single-pole fuses . (CMP-10) Substation. An assemblage of e<]uipment (e.g., switches, intern.1pting devices, circuit breake1·s, buses, and transforme1·s) through which electric energy is passed for the pw-pose of distribution, switching, or modifying its characteristics. (CMP-9) Switching Device. A dev ice designed to close, open, or both , one or more elecu-ical circuits. (C'MP-l ) Cirmit Breake,: A switching de1Tice capable of making, carrying, and interrupting c urrents under normal circui t conditions, and also of making, carrying for a specified time, and interrupting current~ under specified abnormal c ircuit conditions, such as th ose of short c ircuit. Ciilont. An assembly of a fuse support wid1 e idler a fuseholder, f·use carrie1~ or disconnec ting blade. The fuseholder or fLL5e carrier may include a conducting elemem (fuse link) or may act as the disconnecting blade b y the incl1.L5ion of a non fusible member. Discrmnecting Means. A device, group of devices, or 01.her means whereby the conductors of a cir·cuit can be disconnected from thei1· source of s upply. Disconnecting (or isolating) SwiU:h (Di.sconnector, Isolator). A mechanical switching device used for isolating a circuit or equipment from a sou1·ce of powe r. lntern.t/1/er Switch. A switch capable o-f making, carrying, and inlerrupting specified current.5. Oil Cit/out (Oil-Filled Culo1.1t). A cutout in wh ich all or part of th e fuse support a nd itq fuse li.nk. or d isconnecting blade is mounted in o il with complete immersion of the contacts and the fusible portion of the conduning e le m em (fLt5e link) so that arc intern.1ption by severing of the fuse link or by opening of the contacu wi ll occur under oil. Oil Switrh. A swilch having contacts that operate unde 1· o il (or askarel or other suitable liquid). Regulator Bypass Switch. A specific device devices d es.igned to bypa~s a regulator. 70-42 01· combination of Electrical apparatus that h as an a lternative type of protectio n for use in the appropriate hazardous (classified) location Electrical apparatus not so protected that shall not be used within a hazardous (classified) location Associated Nonincendive Field Wiring Apparatus. Apparnms in which the circuits are not necessarily nonincendive themselves but that affect the energy in nonincendive field wiring circuit~ and are re lied upon to maintain noni.ncendive e nergy leveL5. Such apparal1.t5 are one of the following: (] ) (2) Electrical apparatus that has an a lternative type of protectio n for use in the appropriate hazardous (cl,1.ssified) location Electrical apparatus not so pr<>tected dial shall not be used in a hazardous (classified) location lnfom,ational Note: Associa1.ed nonincendive field wiring appa· ra1 us has designated associated nonincendive fie ld wiring apparallls connecLions for nonincendive fi e ld wiring apparatus and may also have connections for OLher e lectrical apparaLus. Combustible Dust. Dust particles that are 500 microns or smaller (i.e., material passi.ng a U.S. No. 35 Standard Sieve as defined in ASTM Ell-2015, Standard Specification for WoVfm Wire Test Sieve Cloth 1.ind Tesi Sieves) , and preseut a fire or explosion ha7..ard when dispersed and ignited in air. ln fom1aLional Nore: See ASTM EI22!:>-2012a. Sllmdard Test Method for E~plosil>ility qf Dust (,"[111uLs, OI' ISO 6184-1, Explosion /1ro/./!cli01, sysllims - Port I : Di'/em,inalicm of f!Xf,losio1r iudiUIS of combustible dust, in air. for procedures for deLermining the explosibility of dusLS. Combustible Gas Detection System. A protection technique utilizing stationary gas detectors in indLL~u·ial establishments. Control Drawing. A drawing or od1e1· document prnvided by the manufacturer of the inu·insically safe or associated apparatus, or o f the noni.ncen dive field wiring apparatus or associated nonincendive field wiring apparatus, that details 1.he allowed intel'Connections b et.ween the inu·insically safe and associated apparan1s or between the nonincenclive field wiring apparatus or a~sociated nonincendive fie ld wiring a pparatus. Cord Connector. A fitting intended to term inale a cord to a box or simila1· device and reduce the strain at points of term.ination and may include an explosionproof. a dustigni1.ionproof, or a Ila me proof seal. NATIONAL ELECTRICAL CODE 2020Edition ARTICLE IO0 Different Intrinsically Safe Circuits. Inrrinsically safe circ uiL~ in which the possible imerconnections have not been evaluated a nd identified as intrinsically safe. Dust-Ignitionproof. Equipme nt enclosed i.n a manner that excludes d1_1sts a nd does no t permit arcs, sparks, or heat otherwise generated or liberated inside of the enclosure Lo cause ignition of exterior accumulations or atmqsphe ric suspensio ns oh1 specified dust on or in the vicinity of t he enclosw-e. Informational Note No. 1 : Fo r furth e r information on duslignirionproof e nclosm es, see ANSI/ UL 120'.>-201 5, Exf1losionProof" n,•11d Duslrlff11ilion ..Pmof Ei,,;Jrica/ Eq11i/mie11.t foi Hazarr/011.s (Classified) Lowtions. Jn formational Nore No. 2: Dust-igniLionprnof e ,1closures are sometimes additionally marked Type 9 pe r NEt\llA 250-2014, E11c/osuresfar E/er1trfral Equ ipmnl.l. Dusttight. EnclosLtres consu·ucted so that dust will not enter under specified lest conditions. lnfom1ational Nole No. I: For furth e r informa tion, see ANSI/ UL 121201-2017, Noninrendit1e Ell!Clricat Eqttl/nnm1 for Ufe in Closs I mu/ II, Division 2 and (,"lass ill, Division.< I mill 2 H azc,rdm,s (Classified) Localions. lnl'ormati<mal Nme No . .2: Enclosure Types 3, 3X, 3S, 3SX, 4, 4X, 5, 6. 6 P. 12, 121<, and 13, per N EMA :!W-20.14., Er11:losur'"'' .fin· lilectrical Equipment a nd ANSI/UL 50£-2015, E11r/Qswr.1 far Eleclrital .t:quipment, Envim,1r11m1r!I Ccmsidemtim,s, are conside red dusttighL Electrical Resistance Trace Heating "60079-30-l ''. Type of pro tection for the purpose o f producing heat on the principle of e lectrical resL5tance a nd typically composed of one or mo re metallic conductors and/ or an elecu-ically conductive m.aterial, suitably electrically insulated and protected. Informational Note: See ANSI/ UL 600?!)-30-1-2017 . l:.'.>:plosiv; At1110Jt1!11:res - Pm·/ 3(J.l: Elertriml R esislance Trace Healing General rmd Testing Requiirwwnl<. Encapsulation "m". Type of protection where e lec □·i cal p,u-ts tha t cou ld ign ite a n explosive atmosphere by either sparking· or heating are e nclosed in a compotmd in such a way that d1is explosive atmosphe re cannol be ignited. Informational Nole: See ANSI/U L i\0079- 18--2015. Ex/!losive atuwspheres - Pn,rl 18: Eq11i/mw11protec1;on IJ)• enCO;psulalion "m". Explosionproof Equipment. Equipment endosed u1 a case d1at is capable of withstanding an explosio n of a specifie d gas 01· vapor that may o ccur within it and of preve nting d1e ign ition of a specified gas or vapor surrounding die enclosure by sparks, flashes, or explosion of the gas 01- vapor within, and that operates at such an exten1al temperature that a surrounding flammable a □nosphere wi ll not be ignited th ereby: (CMP-14) Informational Note Nu. 1, For further informaLion, see ANSI/ UL 120'.~2()1!",. t:x/ilusio,1-Proof and Dtt.1l-lg11ition-Pmof El✓:tt1fral E,r,,ifmwntfor UsP in Haz.1Lrduus (Classifiul) L ocation\. Infonnadonal Note No. 2: Explosionproof enclosures are som eLimes addi1fonally markec! Type? per NEMA 250-2014, Et,dosums for EiJJLlriwl Equipm,ml Flameproof "d". Type o f protection where the e nclosure will withstand an internal explosion of a fl ammable mixture d1a l ha~ p enetrated into the interior, wid1ouL suffering damage and without causing ignition, through anyjoints or structural openings in the enclosure o f an external explosive ga~ a unosphe 1·e 2020 ll\lirjon NATIONAL E LECTRICAL CODE DEFlNrTJONS CHAPTER I consisting of o ne o r more of d1e gases or vapors for which it is desig ned. Informationa l Note: See ANSl/UL 60079-1-20 15, lix/>losive AtnwsJ>hrres-Par/ I , Equip111r11tPmtn:1i01, l>y i'1mneproo(Endosw~s ·rt •. Hermetically Sealed. Equipment sealed against the en trance of an external atmosphere where the se<1l is made b yfmion, for example, solde ring, b razing, welding, or the fusio n of glass to metal. Informational Note: Fo r forLher in formation, see ANSI/ ISA- 12. 12.01-2013, Nonincendive Elerlrirnl Equip11umt for Us, h, Class I and ll, Division 2, and Clr1ss Ill, Divisionr 1 rmd 2 Hrtz.rmio11~ (Classifml) Lotations. Increased Safety "e". Type of protection applied to elecn-ical equipme n t that does not p roduce arcs or sparks in normal service a nd under specified abnormal conditions, in which additional 1Tteasures are applied so as to g ive increased senu-ity against the possibility of excessi,7 e temperatures and of the occ w-rence of arcs and sparks. Informational Note: See ANSI/UL 60079°i- 2()17, E.-,:fllOSiVP. Atmospheres- Parl 7: Eq11i/>menl,Prolei:l;on IJ)• lnr,rer1.,ed Safely "e". Inherently Safe Optical Radiation "op is". Type of protection to min imize the risk_ of ignitio n in explosive atmospheres from optical radiation where vi~ible o r in frared radiation is inca pable of producing sufficien t ene1·gy unde1· normal or specifi ed fault cond itions to ig ni te a specific explosive a tmosphere. l nformaLional Note: See ANSI/U L 60079-28-20 17, E.,;/ilosiVII Atmospherns - Part 28: Protec/ion of i1'quipnumt and 1hinsmission ,\)'sl.t.ms U1ing Opticitl Rruliatim,. Intrinsic Safe ty "i''. Type of proteclio n where a ll)' spark_ or th ermal effect is incapable of causing ignitio n of a mi'Xtu re of flammable 0 1· combustible material in air unde1- prescribed test conditions. l nformariona l Note: See UL !)13-201.5, lntriusicalty Srife Appamluo an cl Associated A}1/10:mlns .for Use h1 Cla.1.1 I, rI, and IfI, Division 1 Hriumlott.S (Classified) Locotim1s; and ANSI/ UL 6007!J- l l-2013, Exjilnsive Atm,,1phereJ - Pnrl JI: Equipmm1 protarliM, lry intrinsi, safely "i ". Intrinsically Safe Apparatus. Apparatus in which all the c ircuits are inu·insicalJy safe. Intrinsically Safe Circuit. A circuit in which an y spark o r the1-rnal effect is incapable of causing ignilion of a mixture of flamma ble or comhLL5tible material in a ir tmder prescribed Lest conditions. lnfonnational Note: TesL condil ions are described in ANSI/ UL HJ 3-20 I 3, Standard for Saft (\', lnl,insically Safe Af1(1aralt1S aud A<sociattld. ApfJamltlS far Us; in Class I, II, and Ill, Div~rion 1, I-lr1zardo11s (C/11ssijii:rl,) Locations. Intrinsically Safe System. An assembly of it1terco1rnecLed inu-insically safe apparatus, associated apparatus, and u1tercon11ec ting cables, in that Lhose part~ of the system that may be used in hazardo us (classifi ed ) locations a1·e u1u·insically safe c ircuit~. lnformaLio nal Note: An inu-insically sale system may include mnre than o ne inLrinsically safe ci rcuiL. Limited Finlc;hing Workstation. An apparatus that is capable of confining d1e vapors, mist~. residues, d LL~ts, 01- deposiL~ that a re generated by a spray applicatio n process but does not meet Lh e 70-43 CHAPTER I ARTICLE 100-DEFINlTIONS requirements of a spray booth or sp ray room , defined. f33:3.3.18.l] ~ herein Informational Nole: See Section 14.'.{ of NFPA 33, !:,~fmt/mrl Jin· Spray Appiicalion ll.<il,g 1'Y{1111.11111bfPor Co-mlnirlih!;, JWa,t,,.ria/s, fo r limited lini$hing worksl,ltions. Liquid Immersion "o" . Type of protection where e lectrical equipmenL is immersed in a protective liquid in such a way that an explosive atmosphere that may be above tl1e liquid or out5ide the enclosure catrno t b e ignited. Informational Note: See ANSI/ UL fi007V-6-2lH 6, ExplvsiveAt111osPart 6: Equipmrnt prolectio" /})' liq1tid immHsion "o ". f1lwres - Major Repair Garage. A building or portions of a bldlding wh e re major repairs, such as engine overhauls, painting, body a nd fender work, and repairs thaL requi1·e draining of Lhe motor vehicle fuel tank are performed o n m otor vehicles, including associa ted floor space used for offices, parking, or showrooms. l"30A:3.3.l2.1l Membrane Enclosure. A temporary e nclosure used fo r th e spraying of workpieces that cannot be moved into a spray booth wh ere open spraying is not practical due to the proximity to other operations, finish quality, or concerns su ch as the collecrion of overspray. lnformational No te: See Ch apler 18 of NfPA 33-201 6, Slandard for S/Jmy Apfilil:ation U.1ing Flam·11,ab{1• ur Combusti/ilP Moteriat,, fo r in formation on the constructio n anct use of membrane enclosures. Informational NOLe: For further informacion, see ANSI/ IS,.\-1 2.12.01-2013, Nm,i111:,ndi:0P Elatrical Eqnipuuml for Usr1 in Closs I awl fl, Dillision 2, rmd Clr•rs Ill, Divisil)ns J m,d 2 Hr,.zardous (Classified) Locr!.lfom. Nonincendive Equipment. Equipment h aving electrical/e lectronic circuitry that L~ incapable, un.de1· 1101·mal o perating conditions, of causing ig nitio n of a specified flammable gas-air, vapor-air, o r dust-air mixture due to arcing o r thermal means. lnfom1aLional Nme: For fitrd1e r informatio n, see ANSI/ ISA-12.12.01-2013, Nuni>1cendiv, .Electrical Eqaip111enl for Use ill Class l a-nd If, Diliisio11 2, rmd Clr1s.1 Ill, Division,r 1 amt 2 Hr1.zardous (Classified/ Loaitions. Nonincendive Field Wiring. \ 1Viring thal enters or leaves an equipment enclosure a nd, under normal operating conditions of the equipment, is n ot capable, rlue to arcing or the rnial effect~, of igniLing the flammable ga~-a.ir, vapor-air, or dtlSt-air mixture. Normal operatio n includes opening, sho1·ting. o r grounding the field wir ing. Nonincendive Field Wiring Apparatus. Apparatus intended w be connected Lo nonincendive field wiru1.g. l nformatio nal Note; For further infom1ation, see ANSI/ ISA-12.l'.:!.0l-2013, Noninr.endiv, Ei£ctrical Eqai/mwnt fur Use in ChL,~ I and fl. Division 2. awl Ctr.-. ill, Divi.,iow; 1 and 2 Ha.u,mlou; (Classijitd) Localions. Minor Repair Garage. A building or portions of a bttilding used fo1· lub1·ication , i1L~pectio11, and mu1o r automotive mainten,rnce work, such as engine tune-ups, replacerne:nt bf parts, flttid changes (e.g., o il, antifreeze, transmission fluid, brake fluid, aiL conditio11ing refrigerants) , bra ke system repairs, tire rotation, a nd similar 1-outine maintenance work, including associated floor space used for offices, parking, or sh owrooms. 0 [30A:3.3. l 2.21 Mobile Equipment. Equipment with electrica l component~ sLLitable to be moved only with mechanical a ids 01· is provided with wheels for movement by per~on (s) or powered devices. Motor Fuel Dispensing Facility. That portion of a property wh ere motor fue ls are stored a nd dispensed from fixed equipme nt into tJ1e fuel tanks of motor vehicles or marine craft or into approved containers, including a ll equipment used u1 connection therewith . f30A:3.3 .1 l1 lnforrnauonaJ Nme: Refer Lo Articles ,,10 and 511 with respecr m e lectrical wiring and equipment for ocher areas 1Jsecl as luhri1.Qriums, service rooms, repair rooms, ofl-lces. salesrooms, cc1mpressor room s, and similar locations. Nonincendive Circuit. A circuit, oth e r than fie ld wmng, in wh ich any arc or the rmal effect p rodu ced unde1· inte nded operating co nditions of tl1e equipme n t, is not capable, under specified test conditions, of igniting the fl ammable ga~-ai,~ v-apor-ai1~ or d usl'-air m ixtLtre. lnfo,·macional Note: Condit.ions a re de.scribed in ANSI/ ISA-] 2.12.01-2013, Nonim:endh!II Elecllfral Equijmient for l'se i n Class I and II, Division 2, (IIUl Class Ill, Dillisions I and 2 Ha:umlous (Classi/iarl) Lomlio11.1. Nonincendive Component. A compon en t having conracL~ for making or breakin g a.11 in cen d ive circuit and the contac ting mechanism i.~ constructed so that the compon e nt is incap able of ign iting th e specified flammable gas-air or vapor-air 70-44 mixture. The housin g of a nonincendive com pon elll is not u1tended to exclud e the flammable a tmosphere or contain an explosion. Oil Immersion. Electrical equipme n t imme rsed in a protective liquid i11 su ch a way that a n explbsive atmosph er e tJ1at may be ab ove tJ1e liquid o r o utside the enclosu re cannot be ig nited. Optical Radiation. Elecu-omagnetic radiation at wavelen gth.~ u1 vacuum b etween the region of tra nsitio n to X-rays a nd th e region of transition to radio waves, that is a pproximately between l nm and J000 µm. In.fom1arional Nole: Fo,· acldicional inforn1:11ion on rypes of prmecrion chat can be applied to minimize che risk of ignilion in explosive aunospher~ from oprical racUatio n in the w,wele ngrh range J'rorn '.180 nm ro LO µm, see ANSI/ UL 6007!}-.28-2017, ExjJ/osivPAtm.o:,ph.eres - Prm 28: Protedio11 ofb"'quipmerit (rnd 1immnission Systems Using O/ilia,l R,;uiiafio,1_ Optical System With Interlock "op sh". Type of protection to minim ize th e risk of ig nitio n in ex-p losive a mmspheres fro m opticaJ radiation where visible or infra red radiation is confined inside o ptical fibe r o r other transm.issio n medium with inte rlock cu t-off provided lo relia.bly redu ce tl1e rmconfin ed beam su-ength to safe levels within a specified tim e in case tJ1.e confineme nt fails and th e radiation becomes uncon fined. Informalional Noce: See ANSI/ U L (i0079-28-20l7, Exj)/osi,Jf• AlnWS/Jhere., - Part 28: Proteclim,. qj' Equipnw-111 mu/ Tm11s11,issitm Sy.<lenLI U,irrg O/ilical Radinlion. Outdoor Spray Area. A spray area d1at is o utside the confines of a building or that has a canop)' or roof th at does no t limit the dissipation of the h eat of a fi re o r dis persion of fl ammable vapors and does not resD·ict fire-fighting access and control. For d1e purpose o f this standard, an ou tdoor spray area can be tre,ited as an un enclosed spray area. [33:3.3.2.3.1 l Portable Equipment. Equipment with e lectri cal components suitabl.e to be moved by a su1gle pe1·son witho ut mech a nical aids. NATIONAL ELECTRICAL CODE 2020Edition AITTICLE 100-DEFINITlONS Powder Filling "q". Type of protection w here elecu-ical part5 capable of ig niting an explosive atmosph ere are fixed in position and completely surro unded by filling ma ter ial (glass o r quartz powder) to prevent the ign ition of an external explosive atmosphere. a nd 25 mW, o r a passive component tliat does not rli~sipate more tJian 1.3 watt5 a nd is compatible with the inu·insic safety of the circuiLin wh ich it is used. l n.frirmational Note No. 1: The following apparatus are examp les of simple apparatus: Informaci0nal Note: See ANSI/ U L 60079-5-2016. Ex/ilns;V(,Atmosplwre,<- Part 5: Eq1iijmum1 /mJWlion IJy /1owd1:rjillinK "q ". (I ) Pressurized. The process of supplying an enclosw·e wiJh a prntective gas with o r witho ut continuous flow, at sufficie nt pressure to prevem the eno·ance of combustible dmt or igniLible fib ers/ flyings. (2) Pressurized Enclosure "p". Type of prntection for e lectrical equipment tha t use s the tech nique of g uarding against the ingress of the external atmosphere, whic h may be explosive, into an e nclosw ·e by maint<\ining a protective gas tJ1ere in at a pressure above that of the exte rnal aonosphere. Informational Note: See ANSI/ UL~0079-2-2017, Explosil!l•Atmospheres - Part 2: Equ.ipment protfttion l,y pressurized enclosures "p ··. Process Seal. A seal between electrical systems a nd flammable or combustible process fluids ,vhere a failure could allow the migrntion of process fluids into tl1e prem ises' wiring system. Protected Optical Fiber Cable. Optical fiber cable protected from relea~ing o ptical radiatio n into the atmosph ere during normaJ operating conditions and foreseeable malfun ctio ns by additional armoring, concluiL. cable u·ay, or raceway. l nfom rntional N ote: See ANSI/ UL 60079-28-2017, Ex/1!0.<ive Al111osp1im,f - Part 28: Protection of Equi/nnent rmd 7'rrmsrnissiou S_rs1,m,s Using Optical Radiation. Protected Optical Radiation "op pr". Type of protection to minimize the risk of ignition in explosive atmosph e res from optical radiation where visible o r infrared radiation is confined i11side optical fiber ox other u·ansmL5sion m edium Lmrler normal consu·uctions or constructions witl1 add itional mechanical protectio n based o n the assumption that there is no escape of radia tion from the confinement. Informational Note: See ANSI/ UL 60079-28-2017, E,plosive Atmosfiherl'f - Part 28: Protertion of Eq11i/111u1nt m,d n-m1smissio1, Systems Using O/ilical H(U[ialim,. Protection by Enclosure "t". Type of protection for explosive dLL~t atmospheres whe ,-e elecn·ical eq uipment is provided with a n e nclosure providing dust ingress protection and a m eans to limit stu-face tempern,tures. Informatio nal Note: For additio nal in fo nn.ation, see ANS1/ UL 6007\l-~ 1-2015, fa/J/osive Atmospheres - Part 3 1: Eqrtipment Dmt Ignition Pmtel'lio11 t,y Endo,rnm "l". Purgecl and Pressurized. T he proce~s of ( I ) purging, supplying an e nclosw·e with a proLective gas at a sufficie nt flow a nd positive p1·essure to reduce the concenu·ation of an y fla mmable gas or vapor initi.aUy presem m a n acceptable level; and (2) press1u-ization, supplying an enclosure with a protective gas with o r witho uL con tinuo us fl ow at sufficient pressure to preve nt tJ1e e nu·ance of a flamma ble gas o r V'ilpor, a combustible dust, or an ignitibl.e fiber. Informational Note: Fo r furd1er in formation, see ANSJ/ NFPA -l 96-2013. Purged and Ptt:ssttJ"k.erlEndum1nforEl,:tlrical b,r1uipmenl. Simple Apparatus. An e lecn·ical component o r combina tion of component5 of simple constructio n. with well-defined e lec lxical parameters tha t does nol generate more than 1.5 volt~, 100 mA, 2020 Edition NATIONAL ELECTRICAL CODE CHAPTER I (3) Passive compone nt~; for example, switc hes, instrum enL connecrors, p)ugs and sockets, junction boxes, resistance temperature devices. and simple semicond uctor devices s uch as LEDs Sources of stored e nergy consist.ing of single components in simple circuits 1viLh well-defined para meters; for example, capacitors or inductors, whose values are considered when determining 1.he overall safety of the syscem Sources of generated energy; for examp le, thermocouples a nd phoLOceUs. rJ1at do not generate more dian 1.5 vohs. l00m.A, and 2.~ mW [nformationaJ Note Nu. 2: Fo r funher information, refer ro ANSI/UL 9 1:1-2013. Jntiinsically Safe f l jJ/J(lralus ancl Assor:iawd Alif;amllls for U.e i11 Chu I, II, III. Divi,io11 1, Hazardo11,· (Clr,ssijifd) L ocaLions; and ANSI/ U L 60079- 11-110 13. £:>.-plosive Atmosphems Pm·t 11: Eq,.tipmeul Prottction l>y Intri·,1stc Safely ·;," Spray Area. Any fully enclosed, par1Jy enc losed, or unenclosed area in which dangerous quantities of fl a mma ble o r combtL5tible vapors, mist5, re.5idu es. dlL5ts, o r rleposit~ are present due to the ope ration of spray processes, including ( 1) an y area in tl1e d irect path of a spray applicatio n process; (2) the inte rior of a spray bootJ1, spray room, or limited finishing workstatio n , as herein defined; (3) tJ1e interior of an y exhaLL5t plenum, elimina tor section, or scrubber se ction ; ( 4) the interior of <1.ny exhaLL5t d uct o r exhaust stack leading from a sprny app li.catio n process; (5) the interiot· of a ny air recirculation patJi up Lo and includ ing recirculatio n particu late fi lters; (6) a ny solvent concentrator (pollu~ion abatement) unit or solvent recovery (distillation) un it; and (7) the inside of a membrane enclosure. The following are not part of the spray area: ( 1) fresh a ir ma keup LLl1it5; (2) a ir snpply duc t5 and a ir supply plemuns; (3) recirc ula tio n a ir supply d ucts downsu-earn of recirculation particulate fil ters; an d (4) exhatL5t ducts from solvent concenu·aLOr (po llution a batement) LUlit~ . r33:3.3.2.3l lnfi;irmatio nal Note: Une nclose~l spray areas are locations o utside of buildings or are localized operations within a larger room or space. Such are normally provided with some local vapor extraction/ ventilation system. In automated operations, die area lim.iti; are the maximum area in th e direc1 path of spray operations. In man11al operatio ns, the area lin:Lii:s are the m aximum area of spray when aimed a1 90 deg~'ees to the applicatio,1 surface. Spray Booth. A power-ventilated e nclosure for a spray a pplication operation or process tJ1at confines and limits the escape of th e material being sprayed, including vapors, mist~. dusts, and residues tha t are produced by tJ1e .~praying operatio n and conducts o r d irects these mate1-ia ls to a n exhaust syste m. r33:3.3.15l l nfrirmatfo naJ Note: A spray bomh is an enclosure or insen wiLhin a larger room used for spray/ coating/ dipping applicaLions. A spray booth L,t ll be ti.illy e ncloserl or have open front or face and can include separate conveyor enu·ance and exit. The spray booth ,s prol'ided with a ded icated venti lation exh aust 1vi1h supply ai r fro m rJ1e larger room or from a dedicated air supply. Spray Room. A power-ventila ted fully enclosed room used exclusively for open spraying of fbnunable or combustible mateiials. r33:3.3.16l 70-45 110.l ARTICLE 110- REQUIREMENTS FOR ELECTIUCAL INSTALLATIONS o r 01.h er Iimital.ions and o the r peninem informal.ion may be marked o n rhe equipment. included in rJ1e product inslructions, Qr included in che a ppropriate listing and labeling Information. Suitabilicy of equipmen t ma)' be evidenced by listing or labeling. Type of Protection "n". Type of protect.ion where electtical equipment, i.n normal operation, is not capable of igniti.ng a surrow1ding explosi.ve gas atmosphere and a fault capable of causing ignition is not likely to occur. lnfonnal.ional NOLe: See ANSI/ UL 60079-15-2013, Explo,;iw Atmosph,'11/S - Parl 15: Eqt1ifmum1 ProlffliOfl iJy Ty/>e of Prolt!l:/ioll ..,,, ". Unclassified Locations. Locations determined to b e ne ither Class I, Di.visio n l ; Class I, Division 2; Zone O; Zone 1; Zone 2; Cla5s JJ, Division I ; Class Il, Division 2; Class III, Divisio n I ; Cla~s Ill , Division 2: Zone 20; Zone 2 1: Zone 22: nor a nr combina tion the1·eof. Unenclosed Spray Area. Any spray area that is n ot confined by a limited finishing work.~ta1.ion, spray booth , or spray room , as herein defined. [33:3.3.2.3.21 Ventilated. Provided with a means to permit c irculation of air sufficient to 1·emove an excess of heat, fumes. or vapors. Volatile Flammable Liquid. A flammable liquid having a fla~h po int below 38°C (I00°F), or a flammable liquid whose temperau.u·e is above its flash point, 01· a Class TI combu~tible liqLtid that has a vapor pressure not exceeding 276 kPa (40 psia) at 38°C (l00°F) and wh ose temperature is above its flash point. (2) (3) (4) (.5) (6) (7) (8) Mechanical strength a nd durability, including, for parts designed to enclose a nd protect o ther equipment, the adequacy of the protection drns provided Wire-bending a nd connect.io n space Electrical insulation Healing effec~ under norma l conditions of use and a l50 under abnormal conditions likely to a rise in service Arc ing effects Classification by type, size, voltage, curre nt capac ity. and speci fie tt~e Other factors d1at contribute to the practical safeguarding o f pe1·sons using o r likely to come in contact with the equipment (B) Installation and Use. Equipment that is listed, la be led, or both shall be installed and u~ed in accordance with any instructions included in the listing or labeling. (C) Listing. Product testing, evaluation, and listing (product certification ) sha ll be performed by recognized qualified electrical testing la boratoi-ies a nd shall be in accordance with applicable product standards recognized as achieving equivalent and effective safety for equipment installed to comply with this Coda. .ARTICLE 110 Requirements for Electrical Installations Part I. General 110.l Scope. This article cove1·s general requireme n ts for the examina tion and approvaJ, installation and use, access to and spaces about electrical conductors and equipment; enclosures intended for personnel enu-y; and tunnel in~talla t.ions. lnformar.ional Note: See l nformaLil'e Annex J fm information regarding ADA accessibili ty design. 110.2 Approval. The conductors and equipmem required o r permitted by this Code shall be acceptable only if approved. l.nformal.io nal Note: See ~J0.7, Examination of Equipme m to r Safety, and 110.3, Exam.inalion, Identific:uion, Installatio n , and Use of Equipmen L See definitions of Apprrroed, ldmtifi,d, Labet,,d, and Ust.nf. 110.3 Examination, Identi.lication, Installation, Use, and Listing (Product Certification) of Equipment. (A) Examination. In judging equipm.ent, co11..~ide rat.ions s uch as the following shall be evaluated: (1) Suitabi.Litv for installation a nd use in con forn1 ity wid1 d1is Code ' · ln fo rma lio nal Note No. I : Equipmem may be new, recondi.tioned, refurbished , or remanufacrnrerl. Lnfo nnal.ional Note No. 2: Suitabili ty of equipme m use may be identified by a descripl.ion ma rked o n or provided wi1h a produce LO idenLify rhe snitabili1y of the product for a specific purpose, environment, or applical.ion. Special conditio n.5 of use 70-4fi lnJ-ormatio nal Note: The O ccupal.ional Satecy and HealrJ1 Aclminisu-al.ion (OSHA) recognizes qualified electrical ces1ing laboratories lhat per form evaluat.ions, LeSLing, and cerlifical.io n of certai11 produces tn e ns ure (ha t Lhey meet the requireme n ts of both the construcl.io n a nd gene ral indusCT)' OSHA eleccrical standa rds. If the listing (product cer1jficarion) is done unde r a C)Uali.fied e lectrical testing laborarory p rogram, t.his listing ma1'k signifies tha1 the tested and certified prod1.1ct m m plies with th e requireme nts of o ne or more appropriate product safecy rest standards. 110.4 Voltages. Throug ho ut this Code, d1e voltage conside red shall be that at which the circuit operates. The voltage rati ng of elecu-ica l equipment sha ll not be less than the nominal voltage ofa circuit to which it is connected. 110.5 Conductors. Conductors LLsecL to carry current shall be of copper, aluminum. o r copper-clad a luminum unless otherwise prnvide d in th is Code. Where the conductor materia l is not specified, the sizes given in th.is Code sha ll apply to copper conductors. Whe re o d1e r materials a re used, the size shall be changed accordingly. 110.6 Conductor Sizes. Conductor sizes are expressed in American Wire Gage (AWG) or i.n circular mils. 110.7 Wiring Integrity. Comple ted wiri ng installatio ns shall be free from sho rt c ircuit~, grmrnd faults, or an y connect.ions to ground othe r than as required o r permitted elsewhere in d1is Code. 110.8 Wiring Methods. Only wiring methods recognized a.~ suitable are included in this Code. The recogn izecl me thods of wiring shall he permitted t.o be installed in a ny type o:fhuilding or occupancy, except as otherwise provided in this Code. 110.9 Interrupting Rating. Equipment intended to interrupt current at fault levels shal l have a n i.nterrupting rating at nominal circuit voltage at least equal Lo the curre nt that i.s availa ble at the line terminals ofd1e equipment. NATIONAL ELECTRICAL CODE 2020 EdiLion ARTIC LE 110 - REQUIREMENTS FOR ELECTIUCAL INSTALLATIONS Equ_iprne nt intended to inten upl current at other than fa ult levels sha ll have an inte1Tupting rating at nominal circuit voltage at lea5t equal to the ctu-rent that mtist h e inten-upted. ll0 .10 Circwt hnpedance, Short-Circuit Current Ratings, and Other Characteristics. The overcurrent prntective devices, the total impedance, the equipment short-circuit curren t ratings, a nd other characteristics of the circuit to be protected s hall be selected and coordinated to permit 1..he circuit protective devices LL~ecl to clear a fault to d o so without extensive damnge r.o the elecu-ical equipment of the circuit. This fault sh all be assumed to be eithe r be twe en two or more of the circuit conductors or between any circuit conduccor and the equip1ne nt ground ing co nductor(s) permitted in 250.118. Listed equipment applied in accordance with their listing shall be conside1·ed to meet the require ment5 of th is section. 110.ll D eteriorating Agents. Unless identified fo r u se in the operating e nvironment, no conductors or eq uipme nt shall he located in d a mp or wet locations; where exposed to gases, fumes, vapors. liq uid5, or o ther agent5 that have a deterio ra ting effect o n the conductors o r equipmen t; or whe re exposed to excessive temperatLu·es. InformaLionaJ Note No. I : See 300.6 for pro1ecLion against corrosion. Informational Note No. 2: Some c lea ning a nd luhrirnti ng compounds can cause severe deLe1iormio n o r many plastic materials u sed for insulaLing a nd scrnccural applicaLion s in eqLtipment. Equipment not ide ntified for 01.1tdoor u se and equipment ide ntified only for indoo1· u5e, such as "d.ry locations," '"indoor use on ly," "damp locations," or e nclosure Types l , 2, 5, 12, 12K, and/or 13, shall be protected agains t c;lamage from the weather during construction. Informational Note No. 3: See Table 110.28 for appropriate e nclosure-Lype designations. ln fom1atio nal Note No. 4: Minimum Hood p rovision s are provid ed in NFPA 5000-201 5 Building Construclion mul Saftly Code, 1he lnltrm(iliurwl Building Code (!BC), and the Intemalional Residenlial Cud1:jar One- c,11(( Ttua-F11mi(v Dwellings ( m C). 110.12 Mechanical Execution of Work. Electt·ical equipment shall be installed in a neat and workman like manner. Informational Note: Accepted indusu-y practices are described in ANSI/NECA. 1-20 15. Sta11drml Jnr Good WorkmcmshijJ in Eleclrirnl Cnnst,w:lion, and o l.he r ANSI-approved installa tion standards. (A) Un used Openings. Unused openings, oth er tforn those intended for the operation of equip ment, those intended for mounting ptu-pose$, or tJ1ose pe rmitted as part of tJ1e desig n for listed eq uipment, shall be closed to afford protec tion substantially eqttivalent tO the wall of the equipme nt. Whe1·e metallic plugs or plates a re LL~ed wi tJ1 nonmetallic enclostu·es, they shall be recessed at lea~t 6 mm (1/,1 in.) from the o ute1· sudace of the e n.closw·e. (B) Integrity of Electrical F.quipmenl and Connections. Internal parts of e lecb·ical equipme nt, incJuding busbars, wiring terminals, insulawrs, and othe r s u rfaces, shall not be damaged or contaminated b y foreign materia ls such as paint, plaster, cleaners, abrasives, or corrosive residues. The re shall be no damaged parts that may adversely affect safe oper a tion or mechanical strength of the equipment such as parts U1at are broken; bent; cut; o r deteriorated b)' cor rosion, c he mical action, 01· overheating. 2020 Edition NATLONAL E LECTRICAL. CODE 110. 14 (C) Cables and Conductors. Cables and conductors insta ll ed exposed on the surfaces o f ceilings and sidewalls shall be supported by the building structure in such a manner tJ1at tJ1 e cabl es a nd conductors will not be damaged by normal building use. Such cables and conducto rs shall be secured by h ardwa1·e incluiling straps, staples, cable ties, hangers, or similar fittings designed and installed so as n ot to damage tJ1e cable. The installatio n shall also conform with 300.4 a nd 300. ll. Nonmetallic cable ties and o ther non metallic cab le accessories u5erl to secure a nd support cables in other spaces used for e n vironme n tal air (plenum;;) shall be listed as having low smoke and heat release properties. Informationa l NOLe No. I: Accepted inclusuy prac1ices a re described in ANSI/ NECA/ FOA :101-2009, Strmdaid for Im,lalli11g ,mil 71!sting Fiber OJ;tic Cnh/Ps, and other ANSI-approved ins1allacion smndarcls. lnformarfo nal Note Nn. 2: See 4.3.IL2.6.5 a nd 4.'.3.11.5.5.fi of NFPA. 90A-2018 , Standard for //,e l nstallatio11 qf Air-Gorulitioning cmrt Ve111ilali11g Systems, for discrete co mb1JsLible com ponenrs ins1alled in accordance with 300.22 (C). lnf-ormaLional Note No. 3: Pa int, plaHe•~ cleaners, abrasives, corrosive residu.es, or oth er contaminanLS n1ay resulLin an unde- lermined alteration of optical liber cable properties. 110.1 3 Mounting and Cooling of Equipment. (A) Mounting. Elec trical eq1.1ipme nt shall be firm ly secure d to the surface on whicl1 it is mow1ted. Wooden p lugs driven into ho les in mason ry, con □-ete, plaste1; o r similar materials shall not be used. (B) Cooling. Electrical equipment that dep ends on Lhe natural circulatio n o f a ir and convection principl es for cool ing of exposed surfaces shall be i nstalled so tha t room airflow over s uch sm·faces is nor preven ted by walls o r by adjacent instaUed equipment. For e qu.i.pmem d esigned for fl oor mounting, clearance be t\veen top surfaces a nd adj acent surfaces shall be provided to dissipaLe rising warn1 air. Electrical equipmen L provide d witJ1 ventila ting openings shall be installed so that walls or oth e r obstructions do not prevent the free circulation of air through lhe eq uipment. 110.14 Electrical Connections . Becau se of d iffe re nt c haracteristics of dissimilar metals, d evices sud1 as pressure te rmi nal or pressure splicing conneccors and solde ring lugs sha ll be ide ntified for tJ1e material of the conductor a nd sh all be p roperly installed and u~ed. Conductors of d issimilar metals shall no t. be intermixed _in a term.inaJ or splicing connector wh ere physical c0t1.tact occurs bet\vee n dissimila r conductors (such as copper and a luminum o r altrn1inum and coppe1~clad a luminum), unless the device is identified fo r the purpose and con d itions of use. Materials such as solde r, fluxes, inhibitors, and com pounds, where employed, shall be suitable for the use and shall h e of a type tha t will no t adve rsely a.fleet the conductors, installatio n, or equipmen t. Con nectors and termina ls for conduc to rs more fin e ly stranded tJ1a.n Class B a nd C lass C stranding as shown in Chapte1· 9, Tobie 10, shall be iden tified for the specific conductor class or classes. 70-47 110.14 ARTICLE 110-.REQUIREMENTS FOR ELECTIUCAL INSTALLATIONS (A) TerminaJs. Connection of conductors to terminal parts shall ensure a thoroughly good connection withoul damaging the conductors and sha ll be made by means of pressure connectors (including set-screw type), solder lugs, or splices to flexible leads. ConnecLion by means of wire-binding screws or studs and nuts that have upturned lugs or l11e equivalent shaU be permitLed for LOAWG o r smaller conductors. Terminal~ For more Ll1an one conductor and termi nals used r.o connect a luminum shall be so identified. (B) Splices. Conductors shall be spliced o r joined with splicing <levices identified for Ll1e use or by b razing, we lding, or soldering with a l"LL~ible metal or alloy. Soldered splices shall first be spliced or joined so as to be mechanically and electl"ically secure without solder and then be soldered. All splices and joints and the free ends of conductors shall be covered with an insulation equivalent to that of the conductors or with an identified insulating device. l nformaLional No1e: WiLh respect m 110.14(C) (1) anc;I (C) (2), equ.ipmenL markings or lisLing informal.ion ma)' addiLionally resuict the sizing and temperature ratings of connected conductors. (D) Terminal Connection Torque. Tig hte ning torque values for termi na l connections shall h e a~ indicated on equi.pment 01· in insta llation insu-·uctions provided b)' the manufacturer. An approved means sha ll be u.~ed to achieve the .indicated torque value. l nformaLional Note No. I: Examples of approved means of achieving· L11e indicarecl 1orque vaJ11es include torque rools or devices such as s hear bolts o r breakaway-style devices wiLh ,~sual indicators chat demonstra1e 1hat 1he proper tqrque ha$ been applied. Informational Nme No.~: The equipmem mam1fac1urer can be contaCLed if numeric torque values are 1101. indicaied on the equipment or if the inscallation instrucLions are not available. Informative An nex J of UL Standard 486A486B, Sllmdard .fnr Sapty-WirP Cm,nedars, provides torque values in the absence or manufacturer's recommendations. vVire connectors or splicing means inMalled on conductors for direct bw·ial shall be listed for such use. (C) Temperature Limitations. T he temperature rating associated with the ampacity of a conductor shall be selected and coordinated so as nol to exceed the lowest temperatLtre rating of any connected Lermination, conducwr, or device. Conducto1·s with temperature ratings hig her man specified for terminations shall be pem1 itLed to be used fo r ampacit)' arljustment, correction, o r both. ( 1) Equipment Provisions. The detennination of ter mination provisions of equipment shall be ba~ed on l I 0.l 4(C) ( J) (a) or (C)( l )(b). Unless the equipment is listed and marked otherwise, conductor ampacilies used in determining equipment termination provisions shall be based on Table 3J O. I 6 as appropriately modified by 310.l 2. (a) Termination provisions of equipment for circuits raLed JOO amperes or less, or marked for 14 AWG through l AWG conductors, shall be used on ly for one of the follmvin g: (l) (2) Conductors rated 60°C (140°F). Conductors with higher temperatme ratings, p rovided the ampacity of such conductors is determined based on me 6D°C ( 140°F) ampacity of the conducto1· size LL~ed. (3) Conductors with h igher temperature ratings if the equipment is listed and identified for use wiLh such conductors. (4) Fo1· motors marked wiili design letters B, C, o r D, conductors having an insu lation rating of 75°C (l 67°F) or hig her shall be permitted to be used. provided the ampacity of such conductors does not exceed the 7!'i°C ( l 67°F ) ampacity. (b) Termination prov1s10ns of equipment for circuits rated over LOO amperes, or marked for conductors larger than l AV•lG, shall b e used o nly for 011,e of the fo Llo,ving: (l ) (2·) Conductors rated 75"C (l67°F) Conductors with h igher temperatme ratings, provided rl1e ampacity of such conductors does not exceed the 7.5°C (167"F) arnpacity of the conductor size used, or up to their ainpacity if t11e equipment i.~ listed and identified for use wirl1 such conductors (2) Separate Connector Provisions. Separ:;1tely installed pres, sure connectors shall be used with conductors at the arnpacities not exceeding the ampacity at the listed a nd identified temperamre rating of l11e connector. lnformationaJ Nme No. 3: Additional information for torquing tJ1readed connections and terminations can be found in Section 8. 11 of NFPA 70B-20] 9, H,rom11li!"nded Pmllire }or Eleclrictil J:,r/ttifr men/ l\1ai1tll'l'1anu. 110.1 5 Hig h-Leg Marking. On a 4-wi,·e., delta-con nected ryste m w he 1·e the rnidpoi.nt o f one phase winding is g rounded, o nly the conductor or bLL~bar having rl1e highe r phase voltage to ground shall be durably and permanemly marked by an outer fin ish that is o range in color or by othe r effective means. Such identification shall be placed at each point on the system where a connection is made if me grounded cond uctor is al50 present. 110.16 Arc-FJash H azard Warning. (A) General. Electrical eqLtipment, such as switchboards, S\vitchgear, pa ne lboards, industrial contro l panels, meter socket en closw·es, an d motor comrol centers, that is in other thai1 dwelling unit.~, and is likely to req11ire examination, adj ustment, se1·vicing, or ma.intenance while e nergized, shall be field or factory marked r.o warn q ua lified persons of potential elecuic arc flash hazards. The marki11g shall meet the requireme nt~ in 110.21 (B) and shal l be located so as to be clearly visible to quali fied persons before exam ination, acljustment, servicing, Dr maintenance of the equipment. (B) Service Equipment. In other l11an dwelling wuls, in addition to the requirement5 in 11 0.16(A) , a permanent la be l shall be fie ld or factory applied to se1·vice equipment i-ated 1200 amps 01· more. The label shaU meet the requirements o f 11 0 .2 1 (B) and contain t11e following inforn1atio n: (1) (2) (3) (4) Nom ina l system voltage Avai lable fau lt curre nl al the service overcurrenl p rotective devices The cleai·ing time of se1v ice overc,:urrent protective devices based o n rl1e available fau lt curre nt a t the service equipment The date the label was applied Excl'{1tio_n: Servic.R equipment labeling shall not be required if an arr flash la.bet is af1plir.d in atcordrm1;e with aw1ptable indusl1y pmdia. l nformationaJ Note No. 1: NFPA 70&201$, Slandrml.for lilectricat Safety i'II lhe Workplare, provides guidance, such as cerermining severity of pmential exposure, planning sate work practices. arc Has h labeling. and selecting personal protective equipmen1. 70-48 NATIONAL ELECTRICAL CODE 2020Edition ARTICLE 11 0 - REQUIREMENTS FOR ELECTRICAL INSTALLATIONS Jnfomrncional Note Ne,. 2: ANSI 2535.4-2011, Pmduc/ &ifi!ty Signs and Labefr, provides guidelines for Lhe des.ign of safety signs and labels for application 10 products. lnfo1111acional Note No. 3: Acceptable indusrry practices for equipment labeling :ire described in NFPA 70£-2018, Slrmdard jor Elei'lrir'al Softly i11 lite Worhji/arn. This sw11dard provides specific criLeria for developing arc-flash labels for equipment chac provides nominal system voltage, incidem encrg)' levels, arc-l'lash bou.ndaries, minimum required levels of personal protective equipmem, and so lhrth, 110.18 Arcing Parts. Part~ of e lectrica l equipment. that in ordinary operation produce arcs, sparks, fl ames, or molten metal sh all be enclosed o( separated and isolated from all co1nbustible matet-ial. l nfomrndonal Note: For hazardous (classified) locations, ~ee Ankles 500 1hrough 517. For motors, see 430. 14. 110.19 Light and Power from Railway Conductors. Circuits for lighting and power shall not be connected to any system that contai n.~ trolley wires with a ground rettu-n. Exce/Jlion: S,ach. circuit connections .~hall be perrnilled in car houses, potvff houses, or pas.w;nger and freight stntirms opera/eel in umnrction wi.ll1 elecl1ic milways. 110.21 Marking. (A) Equipment Markings. (1) General. Th e manufactm·er's name, u·ademark, or other descriptive marking b y which the o rganization responsible for the product can be identified sha ll be placed on a ll electrical equipment. Othe1· ma_rkings that indicate voltage, current, wattage, or other ratings shall be provided a5 specified e lsewh ere in this Code. Th e marking o r labe l shall be of sufficient rhu·ability co withstand the e nviro n ment involved. (2) Reconditioned Equipment. Reconditioned equipment shall be mai-ked with the name, trademark, or other descriptive m,u-king b y which the 01·gan.ization responsible for reconditioning the elecu·ical equipment can be identified, a lo ng with the date of the reconditio ning. Reconditioned equipment shall be ide ntified as "reconditioned" and the original listing mark removed. Approval of rJ1e reconditioned equip me n t shall not he b ased solely on the equipment's o riginal listing. Exteption: I n industrial o/'l'·uj)ancies, 1/Jh(II·~ conditions of 11winlenan('(1 and supr>rvision ensure that only qualified f1mons service lhe equiprnrmt, the markings indicaled in 110.21 (A)(2) ,hall no/ be mruired for ~q·ui/nnent lhal i5 reconditioned by 1h11 01.,m.11r or operator as /1art of a ,egular equi/nnent mainlenmu:e Jnvgmm. Informational No1e No. l : Industry standards are available for application of recondii:inned and refurbished equipmenL ln fonnarional Note No. 2: The rerm m;rmditioued may be incerchangeable wirh the rerrns rebuill, re.f11rbisl111d. or remar,i!flltlumd. Informational Note No. 3: The original listing mark 11lfl)' include the mark of the certifying body and not the emire equ ipmem label. (B) Field-Applied Hazard Markings. Where caution, warning, or clanger sig ns or labe ls are required by this Code, the labels slcal l meet the following requiremen t~: ( 1) The marking shall •.varn of the hazards using effective words, colo rs, symbol~, or any combination the reof. 2020 ll\lirjon NATIONAL ELECTRICAL CODE 110.24 Informational Nme: ANSI 2535.4-20 11 , Prod11ct Safety Signs m,r/ Label;, provides guidelines for suitable fom sizes, words, colors, symbols, and location requiremenLS for labels. (2) 171e la be l shall be permanently affixed to the equipment or wiring method a nd shall not be handwritten. Exce/Jti<m to (2): Portions of lrlbels or markings that are variable, or tltal could b11 subject to changes, shall be /1ermitled lo bf handwrilten and shall be legible. (3) 171e la bel shall be of su.fficien l d urability to w ithstand the environment involved . Informational Note: ANSI 2,,%.4-201 l, Product Sa,(i:ty Sig11s a11d Lal/Ills, provides guidelines for che design and durabili Ly of safety signs and labels for application ro electrical equipmenc. I I 0.22 Identification of Djsconnecting Means. (A) General. Each d isconnecting means shall be legibl)' marked to indicate it~ p urpose unless localed and arranged so the purpose is evident. In other than one- o r two-family dwellings, 1.h e marking sha ll include the identification of th e c ii·cuit source th at su pplies the d isconnecting means. T he marking shall be of sufficie n t durability to withstand 1,.he envi ronment involved. (B) Engineered Series Combination Systems. Equipment enclosu res for circuit breakers 01- fuses appl.ied in complia nce with sei:ies combina tion ratings selected under eng i.neering s upetvision in accordance with 240.86(A) shall be legibly marked in the field as d irected by th e engineer to indicate the equipment h as been applied with a se r·ies com bination rati11g. T he marking shall rneet the requirements in 110.2l ( B) and shall be readily visible and state the following: CAUTION - ENGINEERED SERIES COMB!NATION SYSTEM RATED _ _ _ .AJ.\1PERES. IDENTIFIED REPlACEMENT COMPONENTS REQUIRED. (C) Tested Se ries Combination Systems. EqLtipm.ent enclos ures for circuit b reakers o r fuses applied in compliance with 1.he series combinatio n rati ngs marked o n th e equipment by rhe manu factu rer in accordance with 240.86( B) shall be legibly ma rked in the fie ld to .indicate th e equipme nt has been appli ed wi1.h a series com bination rating. T he marking sha ll meet the requiremem~ in l 10.21 ( B) and shall h e readily visible and state the following: CAUTION-SERIES COMBINATION SYSTEM RATED AMPERES. IDENTIFIED REPLACEMENT COMPONENTS REQUIRED. Informational Note: See I EEE 3004.5-2014 Recomm,m,rlecl Pmcliu' for lhl' Jlfi!ilicaliun of Luw-\lollag, Cin;uil Breakers ill hulu,tlrird rmd Cmn•111en·ial Power Systems, for funher infonnar..ion on series cested systems. 110.23 Current Transformers. Unused cw-rent n-a.nsformers associaced with pocentially energ ized circuits sh all be shortcirc uited. 110.24 Available Fault Current. (A) Field Marking. Serv ice equipment at other than dwelling Lui.its shall be legibly ma rked in the fie ld with the available fault c mrent. The field marking(s) shall inc.lnde the date the faultcurre nt calculatio n was pei-fonned a nd be of suffkient durability to withstand the e.nviro1m1e nt involved. The calculation shall 70-49 110.24 ARTICLE 110 -REQUIREMENTS FOR ELECmJCAL INSTALLATIONS be documented and made available w those authorized to design, install, inspect, maintain, or operate the system. lnfomrntional Note No. 1: The available fauh--currenl mark-ing(s) addressed in l l0.24 is related Lo required sho[t--ci rcuir curren1 and internqxing ratings of eqttipmen1. MPA 70J.;.2018, Sirmdcml far J:.:/ew-;rr,[ Safaty in the Wurkpla.a, provides assistance in determini11g 1.he severity of pote ntial exposure. planning safe work practices. and selec1ing personal protective equipment. Lnformational Note No. 2: Values of available fau lt current fc11· use in determining appropriate minimum shon--circwL current and interrupting ratings nfservice eqwpment are availal,le from electric utilities ·i n published o r o tl1er forms. (B) Modifications. ',i\lhen modifications to the electrical installation occur that affect the avai !able fault current at the service, the availabl e fault current shall be verified or recalculated as necessarr to ensure the service equipment ratings ru·e sufficient for the available fau.lt current at the line terminals of the equipmenL The requi.red field marking(s) in l l0.24(A) shall be aclju~t.ed to renect the new level of available fault current. Exceptioii: The jiPld m.arhing requiremenLt in 110. 24(AJ and l 10.24(B) shall not be mquired in indust1ial installations tvhl'/"e conditions of nwinlenance and supervision rnsui-e tlwt only q11alijied pm:wns seruir:e the 11q(li/1mt:nl. 110.25 Lockable Disconnecting Means. If a disconnecting means is required to b e lockable open elsewhere in this Code, it shall be capable of be ing locked in the ope n position. The provisions for locking shal l remain in place with or without the lock i.mtallecl. t:xl'eption: Lod1ing provisions for a rnrd--mul--plug connettio-n shalt no! /)p rnquii"l!d to remain in plac,, witho1tl the lol'k installed. Part II. 1000 Volts, Nominal, or Less 110.26 Spaces About Electrical Equipment. Access and working space shall be provided and m.aintained about all electrical equipment to permit ready and safe operation and maintenance of such equ.ipmenl. (A) Working Space. Working space for equipment operating at 1000 volt5, nominal, or less to ground and likely to req ui.re examination, adju~011ent, servicing, or maintenance wh ile energized shall comply with the dimensions of 110.26(A) ( .1 ), (A) (2), (A) (3), and (A) ( 4-) or as required or permitted elsewhere in this Corti'. Informational Note: NPPA 70E-2018, Stancl,inl for- t:lettrir«l Srl/i-ly i n Lhe l¼1rk/1Lar.e, provides guidance, such as deLern1ining severi1y or potential exposure, plauning safe work practices including establishing an eleCLrically sal·e work condition, arc flash labeling, and selecting pe1·sonal protective ec1uiprnem. ( 1) Depth of Working Space. The d e ptJ1 o f the working space in tJ1e dfrection af live part~ shall not he less than Lhat specified in Table 110.26(A) ( 1) unless the requirements of 110.26(A) (! ) (a). (A)( l )(b), or (A)(J )(c) are met. Distances shall be measured from the exposed live part~ or from the e.nclosw·e or opening if tJ1e live parts are enclosed. (a) Dead--Fro11.l Assnn/Jli1.1, Working space shall not be required in the back o r sides of assemblies, such as d e ad--front switchboards, s,vitchgear. or motor control centers, where all connection,~ and all renewable 01- acljustable part~, such as fuses or switches, are accessible from locations other than the back nr sides. , ,vhere rear access is required to work on nonelectrical 70--50 parts on the back of enclosed equipmem, a minimum horizon-t;_'ll wodang space of762 mm (30 in. ) shall be provided. (b) Low Vollage. By special permi.~sion, smaller working ~paces shall be permitted where a ll exposed live part~ operate at not greater than 30 volt~ rms, 42 volts peak, o r 60 volts de. (c) l!,m sting Buildings. In exi,~ci.ng buildings where elecu·i-cal equipment is being replaced, Condition 2 working clearance shal l be perm itted between dead--front switchboards. s1vitchgear, panelboarrls, or mot01- conu-ol centers located across the aisle from each other where conditions of maintenance ,rnd supervision ensure that written procedures h rwe been adopted to prohibit equipment on both sides of the aisle from being open at tJ1e san1.e ti.me and qualified pe1·sons who are authorized will service tl1e instal lation. (2) Width of Working Space. The width of tJ1e working s pace in front of the elecu·ical eq uipment shall he the wicltJ'l of tJ1e equipment or 762 mm (30 in.), whichever is greater. 1n all cases, the work space shall permit a t lea~t a 90 degree opening of equipment doors or hinged panels. (3) Height of Working Space. The work space shall be clear and extend from the grade, floor, or platform to a height of 2.0 m (6½ ft) or tJ1e height of tJ1e equipment, wh ichever is g reater. Within tl1e he ight requirements of th.is section, other equipment or support structures, such a,5 concrete pads, associated witJ1 the e lectrical i.t1sLallation and located above or below the electrical equipment shall be pem1itted to extend not more tJ1an 150 mm (6 i.t1.) beyond the front of the electrirnl equipment. E-:cej>lion No. I: On batle1y systems mounted on open racks, lh.P top dJ<armu:p shall comply with. 480.1 0(D ). i',xception No. 2: In existing dwelling 1.1nils, service equipment or /Janel-boards that do not exceed 200 amf>eres shall bP pmnittell in sf){trl/S where the height ofthe wo,d1ing sf1ar:e is ll/Ss than 2. () 111 (61/2 ft ), E.-:cf'f1tion No. 3: Nltters that 1Jre imtalled in 11/Pter sachets shall bP f1ennittPd to e:A1end b1yond the olhm· equifmu"nt. The m.elfr socket shall be required to follotv the rules of this section. Table 110.26(A)(l) Working Spaces Nominal Voltage to Ground 0-l/'JO 151--600 601-1000 Min:inuun Oear Distance Condition l Condition 2 Condition 3 900 nill1 (3 l't) 900 mtn (3 ft) 900 mm (3 ft) 900 lllm (3 ft) l.Om(3ft6io.) J.2 Lil (4 lt) 900 mm (3 ft) l.2 m (4ft) 1.5 m (5 ft) Note: Where the condi Lions are as follows: Condition 1 - Exposed live parts on one side of the working space and no live o r gronnded parts on the other side of the working space. or exposed live parts on holh ~des oft he working space 1hm are effectively guar<led by insulating materials. Condition 2 - Exposed live parts o n crne sicle of the working space and gro11nded part~ on tJ1e other side of the working space. Concre te, brick, or tile walls shall be. considered a~ groun<led. Condition 3 - Exposed live part~ on both sides of th e working space. NATIONAL ELECTRICAL CODE 2020Edition ARTICLE 11 0 - REQUIREMENTS FOR ELECTRICAL INSTALLATIONS (4) Limited Access. '1\'here equipment operating at LO00 volt5, norninal, or less to ground and likely to require examination, acljustment, se1vicing, or maintenance wh.ile energized is required by installation instructions or function to be located in a space with limited access, all of the following shall a pply: (1) (2) (3) ( 4) Where equipment is installed above a lay-in ceiling, there shall be a n o pening not smaller than 559 mm x 559 mm (22 in. x 22 in.) , or in a crawl space, there shall be an accessible opening not smaller than 559 mm x 762 mm (22 in. x 30 in.) . The width of the working space shall be the width of the equipment enclosure or a minimum of 762 mm (30 in.), whichever i.~ g reater. All enclosure doors or hinged panels shall be capable of opening a minimum of90 degrees. The space in front of the enclosure shall comply with the depth requirement5 of Table ll0.2fi(A)(l ) . The maximum heig ht of the working space shall be the height necessary to install the equipment in the limited space. A ho rizontal ceiling structural member o r access panel shall be permilted in this space . (5) Separation from High-Voltage Equipment. Where switch es, cutout5, or other e(]ltipment operating at 10Q0 volt5, nominal, or less are installed i n a vault, room, or enclosure wh ere the1·e are exposed Jive part~ or exposed wiring operating over I 000 volts, nominal, the high-voltage e(]uipment shall he effectively separated from tJ1e space occupied by the low-voltage equipment by a suitable partition, fence, or screen. (B) Oear Spaces. vVorking space required by this section s halJ not be used for storage. Vlhen normaUy enclosed live parts ,l!'e exposed for inspection or servicing, the working space, if in a passageway or ge neral open space, shall be suitably guarded. (q Entrance to and Egress from Working Space. (I ) Minimum Required, At least one entrante of sufficient a1-ea shall be provided LO give access to a nd egress from working space about elecu-ical eqttipment. (2) Large Equipment. For large eq uipment that contains overcurre nt devices, switching devices, or control devices, rl1ere shal l be one entrance co and egr·ess from the required working space not less than 610 mm (24 in.) wide and 2.0 m (6½ ft) high at each end of the working space. This ref]LLirement shall apply to either of the following conditions: ( I) (2) For e(]uipment rated 1200 amperes or more and ove1- 1.8 m (6 ft) wide for service disconnecting n1eans installed in accordance with 230.7 1 where the combined ampere rating is 1200 amperes or more a nd over 1.8 m (6 ft.) wide Open equipment rloors shal l not impede the e nuy to or egress from the working space. A single enu·ance to and egress from the required working space shall be permitted where e ither of the conditions i.J1 I 10.26(C)(2) (a) or (C) (2)(b) is met. (a) UnnbstrttcfPd Lgress. '"'here the location permits a continuous and unobsu·ucted way of egress u·avel, a single en trance to the working space shall be permitted. (b) Extra Working Space. Whe1·e the depth of the working space is twice that reqtLi.J-ed by ll0.2fi(A)(I), a single e no-ance shall be permitted. It sha ll be located such chat the clistante from the equipment to the nearest edge of the e ntrance is not less than the mininuun clear distance specified in Table 2020 Edition NATLONAL ELECTRLCAL CODE 110.26 11 0.26(A) ( I) for equipmem operating at that voltage and in that condition. (3) Personnel Doors. Where equipment rated 800 amperes or more that contai11s overcurrent devices, s,vitch.ing devices, or control devices is installed and there is a personne l door(s) intended for enu·ance to and egress from the working space less than 7.6 m (25 fl) from the nearest edge of the working space, the door(s) sh all open in the direction of egress and be equipped with listed panic hardware or listed fire exit hardware. lnfrumariona l Note: For informarfon on panic hardware, see UL Standanl Fur Safrly Fur Pa11ir Hartl,ll(m. for lire exit hardware, see U L 305, Slmuiard For Panic Hm,lware, and UL IOC, Sl/'i-nrlanl for Sll{ely for Pos:irive Pmss wi Fin, Tests of Door Assemhlies. gor,. (D) Illumination. Illumination shall be provided for all working spaces aboul se1v ice e(]uipmen t, switchboards, switchgear, panelboards, or motor control centers installed indoors. Control by a utomatic means shalJ not be permitted to control al l illumination ,vithin the working space . Additional lighting outlet~ shall not be required where the work space is illuminated by an adjacent light source or as p ermitted b)' 210. 70(A) (I), Exception No. I, for swi tched receptacles. (E) Dedicated Equipment Space. All swi tchboards, switchgear, panelboards, and motor control centers shall be located in dedicated spaces a nd protected from damage. Exoption: Control equipment that by its very ·11.at·ure or becanse of other ruLPs of the Code must be adjru:ent lo or within sight of its opemting marhinery shall be /1ermilted in lhnse locations. (1) Indoor. lndoor installations shall comply with LJ0.26(E) ( l) (a) through (E)( l )(d ) . (a) Dedicated I!.'lec('ricrzl S/xu;e, Th e space equal LO the ,vidth and depth of the equipment a nd extending from the floor to a hei ght of 1.8 m (6 ft) above the equipment or w the structural ceiling, whichever is lower, shall be dedicated to tl1e elecn-ical installation. No piping, ducts, leak protection appai:atus, or other equipment foreign to tJ1e elecn·ical installation shall be loca ted in th.is zone. E,cceptinn: Suspended ceilings with rernovable paneL.1 shall be /1ermilled wilhin the lJ/,m (6-Ji,) z1me. (h) Fonign Systems. The area above tJ1e dedicated space re(]uired by I 10.26(E) (1) (a) shall be permitted LO contain foreign systems. provided protection is installed to avoid damage to the electrical equipment from condensation, leaks, m- breaks in such foreign systems. (c) Sprinhler Protec/ion. Sprinkler protection shall be permitted for the dedicated space where the piping compli es with this section. (cl) Stts/1mdPd Ceilings. A dropped, suspended, or similar ceiling that does not add strengrl1 to the building structure shall not be considered a su·uctural ce iling. (2) Outdoor. Outdoor installations shall comply with ll0.26 (E)(2)(a) throug h (E)(2)(c) . (a) hlst(l.llettion Requimnenls. Outdoor electrical equipment shall be the follmving: ( 1) (2) (3) installed in identified e nclosw·es Pro tected from accidental contact by unauthorized personnel or by vehicular u-affit Pro tected from accidental spillage or leakage from piping systems 70-51 110.26 ARTICLE 110- REQUIREMENTS FOR ELECTIUCAL I NSTALI.AT IONS (h ) Woth Space. The working clearance space sh all include the zon e d escribed in 110.2fi(A) . No a rchitectural app u rten ance or o ther equi p ment sh a ll be located in t hi~ zone . (c) DPdicaled Equipmmt Space. T he space equal to the width and dep th o f th e equipme n t, a nd exte nding fro m grade to a heig ht o f 1.8 m (6 ft) above th e e quipment, sh all be dedicated to the e lectrical installa tio n. N o piping or oLher eq Ltipment fore ign to the e lectrical installatio n sh a ll be located in tJ1is zone . Table 110.28 sh all be used for selecting these en closures for use in specific locatio ns oth er th ar1 h azanlous (classified) locations . Th e e n clostu-es are not intended to protect against condition s such as condensation, ic ing, cor rosio n, or con tamination th at may occu r within tl1e enclosure o r e n ter via tJ1e raceway or un$ealed openings. Exception: Structural overhangs or mof extensions shall /JP pennitted in th.is zone. Part IlL Over 1000 Volts, N ominaJ (F) Locked Electrical Equipment Rooms or Enclo sures. Electrical equipm ent rooms or e nclos LLres housing e lectrical apparatus th at are controlled by a lock(s) shall b e considered accessible to q u al ified persons. 1 10.27 Guarding of Live Parts. (A) Live Parts Guarded Against Accidental Contact. Except a5 e lsewh ere required or permitted b y th is Corle, live pat-ts of elecu·ical equip m em operaLing a l 50 to 1000 volL5, nominal sh a ll be gu arded against accidental contact by approved e nclosu res o r by any of the following m eans: (1) (2) (3) (4) By location in a room , vault, or similar en closure thaL is accessible o nly to q ua li fied persons. By p e n mment, substantial part.itions o r screens arran ged so tJ1a L only qualified pe rsons h ave access to Lhe space wi thi n reach of the Live parts. Any openings in such partition s or screens shall be sized a n d localed so that persons a1-e n ot likely to come into acciden tal con tact with the Live parts or to bring cond u cting o bjects into contact wiLh them. By location on a balcony, _gallery, or p latform e levated and arran ged so as to exclu de unqua lifi ed persons. By e levaLi.on above the floor or olher workin g surface ,;t.5 follows: A minimum of 2.5 m (8 ft) for 50 vol ts to 300 voltq between ungroun ded cond uctors b. A 1ni.nim um of 2.6 111. (8 ft. 6 i n.) fo r 301 volL5 to 600 volt5 between 1.mgroLm ded conductors c. A m in i.mum of 2.62 m (8 fl 7 in .) for 60 1 volLs to 1000 v0IL5 between m1.groundecl conductors a. (B) Prevent Physical Damage. In locations wh e re e lectrical equipme nL i5 likely to be exp osed to physical da mage, e n closu res or g uards shall be so arranged a nd of such strength a5 to prevent su ch dam age. (C) Warning Signs. En trances to room s an d o ther gua rded locations that contain exposed live part5 shall be marked wi th conspicu o u.5 warning signs fo rbidding unqualified pe1·so ns to enter. Th e marking shall meetthe req uiremen ts in 110.21 (B) . Informational Nole: For motors, see 4:l0.2'12 a nd 4'10.2'1'!. For over l000 volt.,, see 110.34. 1 10.28 Enclosure Types. E nclos tLres (otl1er than SlUTound ing fences o r wal ls covered in 110.31) of switchboards, switch gear, panelboards, industrial control panels, motor con u·ol centers, me ter socket5, e nclosed switches, tramfer switch es, power o u tlets, circuit b reakers, adj ustable-speed d rive systems, p ullo u t switches, portable power d istrib ution e q u ip ment, termination boxes, general-pu rpose u·ansfo.rme1-s, fire pum p con trolle rs. fire p u mp motors, a n d motor con tro llers. rated n ot over 1000 volt5 nomina l and intended for su ch locations, sha ll be 70-52 marked wi th an enclosu re-type number as shown in Table 11 0.28. 110.30 General. Cond u ctors a n d eq uipment used o n circui L5 over 1000 volts, n om ina l, sh a ll comp ly with Part l of tJ1is article and with 110.30 through 11 0.41, which sup ple mem o r modify Part r. In no case sh all tliis part apply to eqLLipm en t o n the supp ly side o f the se1v ice po int. 110.31 Enclosure for Electrical Installations. E lectrical insta1lati.01L~ i n a vaulL, 1-00111, o r clo.~el or in a n area SLUTounded by a wall, screen, or fe nce, access to whic h is co ntrolled by a lock(s) or o ther approved means, sh a ll be consid e red to be accessible to q ualified persons o nly. The type of enclosure LL5ed in a given case sha ll be design ed and c onSUTLcted according to 1J1e natu re and d egree o f Lhe h aza1"d(s) associated with the installation. For installations othe r drnn equip ment as described in 110.31 ( D), a wall, screen, or fence sh a ll be used to enclose an OLLtdoor elecu-ical in stal lation lo deter access b)' persons who are no t q ua lified. A fe nce sh a ll not be less th a n 2.1 m (7 ft) in h eight or a co m b ination of 1.8 m (G ft) or m ore of fen ce fab1-ic an d a 300 mm (1 tl) o r more exLensio n. u ti lizing lhree or more so-a nds of barbed w ir e or eqLtivalen t. The di.stan ce from tl1e fe n ce Lo live parts sh all h e n ot less Lha.n given in Table 110.:~ I. lnformationaJ No te: See Article ,150 for conw·uction requ ire, rnenrs for transformer vau lrs. {A) Electrical Vaults. Whe re a n electrical vau lt is requ ired or specified for con du ctors a nd equipme n t JI 0.31 (A) (1) to (A)(5) shall apply. (l ) Walls and Roof. 1l1e walls a nd roof shall be constructed of U1ater ials th a t h ave adeq1.1ate structura l strengtli for the conclitio ns, wi.th a minimum fire rating of 3 h m ll's. For tJ1e p urpose o f tl1L5 section, studs a n d wall board consu·uction sh all n ot be permitted. (2) Floors. The floors of vault5 in contact witli die earth sh al l be o f concrete tl1at is n()t less than I 02 m m (4 in.) t11ick, but wh e re the vaulL is constn1cLed witli a vaca.nL space or o th e1" stories below it, die floor s ha ll have adequ ate structural stren gth for the load imposed on iLa n d a m inimum fire resisLance of 3 h o u rs. (3) Doors. Each d o o rway lea.ding into a vault fro m th e building interior shall be pro~ided with a tigh t-fi tting door that has a min imu m fire rating of 3 h ou rs. The au th ority havingjurisclicLio n sh a ll b e pe rmitted to requ.i.re such a door fo r an exLerio r wall o pening wh ere conditions warran t. l!.xrej>tion l.o (1 ), (2), and ( 3): Where the vault i,s f.rmtectPd with automatfr spri.nkler, wal.er ,ij1my, car&on dioxide, fir halou, constrtlclifln with rt 1-lwur mting shall he p,1rmiU1'd. NATIONAL ELECTRICAL CODE 2020Edition 110. 31 ARTICLE 11 0- REQUIREMENTS FOR ELECTRICAL INSTALLATIONS Table ll0.28 Enclosure Selection For Outdoor Use Provides a Degree of Protection Against the Following Environmental Conditions Incidental contact with the encloscc.l eqttipnlC'nt Ra in, snow, and sleet. Sleet* Windblown dtL,t Hoscdown Con-osive agents Temporary submersion Prolouged submcrsiou Enclosure Type Number 3 3R 3S 3X 3RX 3SX 4 4X 6 6P X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X Provides a Degree of Protection Against the Following Environmental Conditions Incident.al contact. with the enc:losed equiprncnt Falling d irt Falling liquids and light s plashing Circulating d us t, lj11t, fibers, X X X X X X X X For Indoor Use Enclosure Type Number 2 4 4X 5 6 6P L2 12K 13 X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X and !Iyit1gs Settli ng airborne dust, li n t, fibers, and !lyings I-Ioscdown and splash ing water O il aud coola11 t seepage Oil or coolant spraying and spl~bing Corrosive agents Tempor,u-y submersion Prolonged sub,1,ersion X X X X X X X *Mechanism shall be operable when ice covered. Informational No 1e No. I: The cerm rain.tight is tY)lically used in coruunction wid1 EncloSLLre Types 3. 3S, 3SX, '.1X, 4, 4X, 6, and 6P. The term mfoproof is typically LLsecl in co,~junction v,,ith Enclosure Types 3R and 3RX. The Lerm watertight i.s typicall)' used in co1~junction wiLh Enclosure 1:vpes 4, 4)(. 6, and 6 P. The term rlrif!tigltl is typically used in co,tjunction wi1.h E:nclosure Types 2, 5 . 12. 12K, and 13. The term d11slli{{hl is cypically used in conjunction wiLh Enclosure Types :I, 3S, :ISX, '.3X, 4, 4X, .~, 6, 6P, 12, 12K, and 13. Informational Note No. 2! Ingress protection (LP) ratings may be found in ANSI/IE:C 60529, Degrusof Protection Pmvided try Enclosures. IP ratings are nm a substitute for Enclosure Type racings. Informational Note No. 3: Dust tight enclosures are suitable for use in hazardous lc,carions in accordance with 502.10(B)(4), 503. lO(Al (2), and 506.l!:i(C)(U). Informational No1e No. 4: D1.1sttigh t enclosc1res are suitable for use in unclassified localions and in Class tr, Divisio n 2; Class UI.; and Zone 22 hazardous (classified) locations. (4) Locks. Doors s hall be equipped with lock~, and doors sha.11 be kept locked, with access allowed only to q ualified persons. Personnel doors shall open in tl1e direction of egress and be equipped with listed panic hardware or listed fire exit ha rdw,u-e. (5) Transformers. Where a u·amformer is inst.ailed in a vault as r equired by Article 450, the vault shal l be consO'ucted in accordance witl1 the requirements of Part TII of Article 450. Informational Nore No. l : For additional information, see ANSI/ ASTM E 11 9-20 1Sa, M11thorl/Qr Fim Te.Sis of"Bnildiug ConstTUreion and Materlalf, and N FPA 80-2019, Standanl for Fitf Doors mul Table 110.31 Minimum Distance from Fence to Live Parts Minimllill Distance to Live Parts Nominal Voltage m ft JO l.'i 18 I 001- 13, 799 3.05 J 3,800- 230,000 4. .':i7 Over 230,000 5.49 Note: Fo r cle,u.rnces of co nductors for specific system voltage.:; anrl typical BIL ratings, see ANSI/ IEEE C2-2017, Nrtlimw/ Efeclrical Sa{fly Co([c. Ollu:r 0/1e11ing Piu/JitliVPs. Informational Note No. 2: A typical ;}hour construction is 150 mm (6 in.) thick re in-fi;m;:ed c() ncreie. 2020 ll\lirjon NATIONAL ELECTRICAL CODE 70-53 1 10.31 ARTICLE 110- REQUIREMENTS F'OR ELECTiliCAL INSTALLATIONS (B) Indoor Installations. 110.33 Entrance to Enclosures and Access to Working Space. (1) In Places Accessible to Unqualified Persons. Indoor electrical installations that are accessible to unqualified person5 shall be made with metal-enclosed e quipment. Switchgear, transformers, pull boxes, connection boxes, a nd oth e 1· similar a5sociated e quipment shall be marked with appropria te caution signs. Openings in ventilated d.ry-t-yp e transformers or similar openings in othe1· equipment shall be designed so th at foreign objects inserted th ro ugh these o pen ings are deflected from energized parts. (A) Entrance. At least one entrance to e n.closu1·es for elecu·ical instal lations as described in ll0.31 not less than 610 mm (24 in. ) wide and 2·.o m (6½ ft) high sha ll be provided to give access to the working space a bolll electrical eq uipment. (2) In Places Accessible to Qualified Persons Only. Indoor electi-ical i.nstallacions considered accessible only to quali fied persons in accordance with this section shall comply with l 10.34, l 10.36, and 490.24. (C) O utdoor Installations. ( 1) In Places Accessible lo Unqualified Persons. Outdoor electrical installations that a.re open to unqualified pe rsons shall comply with Parts I., IT, ,lnd UI of Article 225. (2) In Places Accessible to Qualified Persons OnJy. Outdoor elecu·ical installations that have exposed live part5 sha ll be accessible to qualified pe,·sons only in accordance with d1e first paragraph of this section a nd shall comply wid1 110.34, 110.36. and 490.24. (D) En closed Equipment Accessible to Unqualified Persons. Ventilating or similar openi11gs in eq uipment shal l he designed such that foreign o bjecL~ inserted throug h these openings are deflecLed from energized parts. Whe,-e exposed to physical damage from vehicular tsaffic, suitable guards sha ll be provided. Equipment located outdoors and accessible to unqualified persons shall be designed su ch that exposed nuts o r bolts cannot be readily removed, permitting access to live parts. Where equipme nt is accessible to unqualified persons and the bottom of the enclosme is less than 2.5 m (8 fl) ab ove the fl oor or grade level, the enclosure door o r hinged cover sha ll be kept locked. Doors and covers of e nclosures used solely as pull boxes, splice boxes, or junction boxes shall be locked, bolted, or screwed on . Underground box co vers that weigh over 45.4 kg ( 100 lb) shall be conside red ,is meeting this requi re1ne nl. 110.3 2 Work Space About Equipment. Si1fficient space s ha ll h e provided a nd maintained abou t electrical equipment to permit ready and safe operatio n and maintenance of such equipme nt. \<\'here energized parts are exposed, the minimum clear work space shall be not less than 2.0 m (6½ ft) h igh (measlU·ed vertically from die noor o r platform) and the width of Lhe equipment or 914 mm. (3 ft) wide (measured parallel to th e equipme nt), whic hever is greater. The depd1 sha ll be as required in 110.34(A). In all cases, the work space shall perm.it at least a 90-degree opening of doors or hinged panels. Within rJ1e he ight requirements of d1is sectio n, o ther equipme nt that is associated wid1 the e lectrical installation and i.5 located above or below the electrical equipment shall be permitted to extend not more than 150 mm (6 in. ) beyond the front of tile e lecu·ical e quipment. Working space required by this section shall not be used for storage. When normal.ly enclosed live parts are exposed for inspection or servicing, the working space, if in a passag·eway 01· general open space, sha ll be suitably g ua.i·ded. 70-54 ( 1) Large Equipment. On switchgear and control pa nel~ exceeding 1.8 m (6 ft) in widtl1, tl1e re shaU be one e ntrance at each end of the equipme nt. A single entrnn ce to the required working space shall be pe rmitted where e ith e1· of the conditions in l.10.33(A) (1) (a) o r (A) ( 1) (b ) is met. (a) Unobst,w:ted Exit. Where tl1e location permit~ a continuous and tU1obsu·ucted way of ex.it travel, a single enu-ance to the working space shall be permitted. (b) Exira Working Space. Whe,-e the depth of the worki ng space is twice t hat required by l 10.34(A) , a single enu-a nce shall be pe rmitted . It sh all be located so that the dist,ince from the equipme nt to tl1e nearest edge of th e entrance is nor. less than the minimum clear distance specified in Ta ble I l0.34(A) for equipment open1ting at d1at voltage a nd in that condition. (2) Guarding. Where bare energized pa rts at a ny voltage or insulated energized parts a bove 1000 volt~, nominal, are located adj acent to suc h entrance, they shall be suitably guarded. (3) Personnel Doors. Wh ere ther e are personne l doors inte nded for e nu-ance to and egress from the working space less tl1an 7.6 m (25 ft) from the nearest edge of the working space, the doors shall open i11 the direction of egress and be equipped with listed panic ha rdware or lisLecl fire exit ha.i·dware. (B) Access. Perma nent ladders or stairways sh all be provided to give safe access to the wo1·king s pace around el.ecu·ical equipment instal led on platforms, balconies, or mezzani.ne floors or in attic o r roof rooms or spaces. 110.34 Work Space and Guarding. (A) Working Space. Except as elsewh ere required or permitted in this Code, equipment like ly to require examinatio n, adjustmen t, servici.ng, o r maintenance while ene1·gizec;l shall h ave clear working space in the direcLion of access to live parts of the e lectrical equipment a nd shal l he not less than specified in Table l l0.34(A) . Distances sha ll be measu red from tJ1e live parts, if such are exposed, o r from the enclosure fro nt or opening if such are enclosed. ExcejJtion: Wor/1ing sfiru;e shall not be required in back of equipment SI.I.Ch as switchgear or control assemblies where lhere are no renewablt or adjustable /1ar/s (such as fuses or switches) on the back and where all wnnections are accessible fmm locations othrr than the badl. Where rl'.ar access is mquirnl lo work on nondrct1i1:ol parts on the bark of rmtlosed eqnipmenl, a minim11111. working spar.e of 762 mm (30 in.) h.01--i:z,ml.ally slwll b~ provided. (B) Separation from Low-Voltage Equipment. Where switches, cuto uts. or other equipm ent operating at 1000 volts, no mina l, or less are installed in a vaul t, room, o r enclosure where tl1ere are exposed li.ve part~ or e xposed wiring operating a t over 1000 volts, nom ina l, the hig h-voltage equi pmen ohal l be effectively separated from the space occupied by the low-voltage equipment by a suitable partition, fence, or screen. .ExrPj1tion: Switches or oi,her nr1tijmumt operating at 1000 volts, nmn.inal, or ll'ss and se'IVing only r.quipmml. within, the high-llOltagf vault, room, or endosure shall bf jJem1ittl'd to bf inslallPd in the high-voltage vault, rornn, or enr;/nsare tvithout rt f1artition, Jenee, or screm if aci:essiblr to qualified fJl'rsons only. NATIONAL ELECTRICAL CODE 2020Edition ARTICLE 11 0 - REQUIREJvlENTS FOR ELECTIUCAL INSTALLATIONS Table 110.34(A) Minimum Dep1h of Clear Working Space at Electrical Equipment Nominal Voltage to Ground 1001-2500 V 2501-9000 V 9001-25,000 V 25,001 V-75 kV Above 75 kV Minimum Clear Distance Condition l Condition 2 !:JOO mm (3 ft) l.2m(4ft) 1.5 Ill ( 5 ft) l.8 111 (6ft) 1.2 m 1.5 rn l.8 m 2.5 m 2.5 m (8ft) 3.() lTl (·Ht) (5 ft) (6 ft) (8 fl) (1() ft) Condition 3 1.5 Ill (5 ft) 1.8 n, (6 ft) 2.8 Ill (\J !'t) 3.0 m (JO rt) 3.7 m ( 12 ft) Note: Whe re the conditions are as follows: ( l ) Condition I -.Exposed live pans on one sid e of rl1e working space and no live or g1·01.111ded pans on rJ,e orJ1er side or the working space, o r exposed live pans on bo1h sides of the working space th at are effectively guarded by insulating materials. (2) Condition 2 - Exposed live parn on one s ide of the working space anrl grounded parts on I he other side of the working space. Concrete, brick, or tile wall s shall he considered as grounded. (3) Condition 3 - Exposed live part~ on both sides of the working space. (C) Locked Rooms or Ehclosures. The e n trance tO all buildings, vaults, rooms, or enclosures containing exposed live part~ or exposed condu ctors operating at over J 000 volts, nomi11al, shall be kept locked unless such e ntrances are under the o bservation ofa qualified person at all times. Permanent and conspicuous danger signs shaU be provided. The danger sign shall meet th e requirements in I 10.21 (B) and shall read a5 follows: DANGER - HTG HVOLTACE - KEEP OUT (D) Illumination. mumination shall be provided for a ll working spaces about electrical equipment. Conu-ol b y a utomatic means only shal l n ot be permitted. The lighting outlets shaJJ be ai:ranged so that. persons ch anging lamps or mak.in g repairs on d1e lig hti.ng system are not endangered by Live parts or other equipment. The points of control shall be located so that persons are n ot likely to come in contact with any live part or m oving pan of the eq uipment while turning o n the light5. (E) Elevation of Unguarded Live Parts. Unguarded Jive parts above working space shall be maintained at elevations not le5,~ than required by Table 11 O.,H(E). 110.51 {F) Protection of Service Equipment, Switchgear, and Industrial Control Assemblies. Pipes or duct5 foreign to tl1e electrical installatio n and requiring periodic maintenance 01- whose malfunction would endan ger th e operation of the electrical system shaU not be located in tl1e vic inity of the service equipment.., switch gear, or i ndustrial control assemblies. Protection shall be provided where necessary to avoid d;;unage from condensation leaks a n d breaks in su ch foreign system~. Piping and other facil ities shaU not be consid ered foreign if provided for fire protection of the electrical instaUation. 110.36 Circuit Conductors. Circuit conductors shall be perm.itted to be installed in raceways; in cable trays; as metal-clad cable Type MC; as ba1·e wire, cable, a nd busbars; or 35 Type MV cables or conductors as provided in 300.37, 300.39, 300.40, and 300.50. Bare live conductors shaU comply w ith 490.24. Insulators_, togetl1er witJ1 the ir mounting and conductor ,;1tta.clu11em s, where LL5ed as supports for wires, si11g le-conductor cabl es, t,r busbars, shall be capable of safely witl1standing the maximum magnetic forces cha t would prevail if two or more conductors of a c ircuit were sul~ected to short-circuit current. Exposed runs of insulated wires and cables tl1at have a bare lead sheath or a braided o uter covering sh a ll be supported in a manner d esigned to prevent physical damage to the bra id or sheath. Supports for lead-covered cables shall be designed to prevent electrolysis of the sheatl1. 110.40 Temperature Limitations at Terminations. Conductors shall b e permiued to be terminated ba~ed on the !)0°C ( 194°F) temperature rating and ampac.ity as g iven in Table 3 1 l.60(C) (67 ) through Table 3ll.60 (C) (86), Lmless o tJ1erwise identified. 110.41 Inspections and Tests. (A) Pre-energization and Ope.rating Tests. Whe1·e required elsewhere in tl1is Code, the complete e lecu·ical system des ign, including settings for protective, switch i11g, and control circuits, sh all b e prepared in advance and made available on request to the autho1-ity havingjurisrliction and shall be tested when first in.staUed on-site. (B) Test Report. A test report covering the results of tl1e tests required in 110.41 (A) sh all be availa ble to tl,e autl101-iry having jw-isdiction prior to energization and made available to tl10se authorized to install, operate, test, and ma in tai.n the system. Part IV. Tunnel Installations over 1000 Volts, Nominal 110.51 General. Table l 10.34(E) Elevation of Unguarded Live Parts Above Working Space Elevation Nominal Voltage,_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ Between Phases m ft 1001-7500 V 7501-35,000 V Over 35 kV 2020 ll\lirjon 2.7 ~-!:) A dd 9.5 mm per kV above 35 kV NATIONAL ELECTRICAL CODE 9 9ft6 in. Add 0.37i.n. per kV above 35 kV (A) Covered. This part sha ll appl)' to the installation and use of high-voltage power d istribution and utilizatio n equipment that is p ortable, mobil e, or bo tJ1, such a~ substations, trail ers, cars, mobile shovels , draglines, hoists, drill5, dredges, compressors, pumps, conveyors, underground excavators, and th e like. (B) Other Articles. The requirements of tl1is part sha ll b e additional to. or arnemla to 1·y of, those prescribed in Articles 100 through 490 of this Code. (C) Protection Against Physical Damage. Conductors and cables in trnmels shall be located a b ove the t1.u me l floor and so p laced or guarded to protect them from physical damage. 70-f,5 110.52 ARTICLE 110- REQUIREMENTS FOR ELECTIUCAL INSTALLATIONS 110.52 Overcnrrent Protection. Motor-operated equipme nt shall be protected from ove1·curre nt in accordance with Part5 III, IV, and V of Article 430. Transformers sh.all be p rote cted from overcurrenr in accordance with. 45 0.3. 110.53 Conductors. High-voltage conductors in tunne ls s hall be installed in meta l conduit or other metal rnceway, Type MC cable, or o ther approved multicondu ctor cable. MulticonducLo r portable cable shall he pe rm.irted to supply mobile equipment. 110.54 Bonding and Equ.ipment Grounding Conductors. (A) Grounded and Bonded. All non-curre nt-can-yi ng metal parts of elecu-ical equipment and all m e tal raceways and cable sheaths shall be solidly groLU1ded a nd bonded to all me tal pipes and rails at the portal and at intervals not exceeding 300 m (1000 ft) throughout the tunnel. (B) Equipment Grounding Conductors. An equipment grnunding conducto1· shall be 1·un with circuit conductors inside the metal raceway or inside the multiconductor cable jacket. The equipment grounding conductor sh all be permitted to be insulated or bare. 110.55 Transformers, Switches, and Electrical Equipment. All transformers, switches, mo tor conu·ollers. motors, rectifiers, and other equipment installed belowground shall be protected fro m physical damage b y location o r g uarding. 110.56 Energized Parts. Ba.re terminals of u, msfonners. switches, motor cono·olle rs, and othe r equipment shall be e nclosed to prevent accidental contact with e nergized parts. 110.57 Ventilation System Controls. Electrica l controls for the venti lation system shall be arranged so that the airflow can be reversed. 110.58 Disconnecting Means. A swi_rch or circuit breaker that simultaneotL5ly opens a ll ungrounded conducto rs of the circuit shall be installed with in sight of each transformer 01· motor location for disconnecting the o-ansforme r o r motor. The switch or circuit breaker for a transformer sha ll have an ampere rating not less than the ampacit)' of tJ1e transformer supply conducto rs. The switch or c ircuit breaker for a n1.oto r shall comply with the applicable reqLtiremenL5 of Article 430. 110.59 Enclosures. Enclosures for u se in tunnels shall be dripproof, weatJ1erproo£; or subme rsible a-. required by the e nvironmental conditions. Switch or contactor e nclosures shall not be used as junction boxes or as raceways for conductors fe eding tJ1roug h o r tapping off to othe r switch es, unless the en cloStires comply witJ1 312.8. Parl V. Manholes and Otl1er Electrical Enclosures Intended for Personnel Entry 110.70 General. Electrical e nclosures inte nded for personnel e ntry and specifically fabricated for this purpose shall be of sufficie nt size ro provide safe wo1·k space about e lectrical equipment with live parts that is likely to r equire examination, adjustment, servicing, or maintenance while energized. Such enclosures shall have sufficient s ize to permit read y instal lation or withdrawal of the conductors employed without da mage to the conductors o r to tJ1ei.r insulation. 111.ey sha ll comply wi th this part. Exci>fllion: Whl're electrical enclosures covered by Part V of this artirle r1re part <if (In indmtrial wi1·ing ;ystem operating under m11ditiorrs of rn.aintencmce and s·uperuision that ensure that only qualiji,Pd pe1;mm monitor a.nrl sufm,.JisP th,, system, they shall be fJPm1iUer.l to be designed and installed in accordance wilh npproprialt rngineering jm1ctice. If mquirrrl by lite r.111lho1ity having jmisdictirm, rlr:sign do1wr11mtation shall /J,, fmwided. 110.71 Strength. Manholes, vaulL5, and their means of access shall be de.signed unde r qualified e ngin eering supervisio n and sha ll withstand all load~ likely to be imposed 011 the su-uctures. InformaLio nal No1e: See ANSI C2-20()i, National Eleclrlml Srfely Codi!, for additional info rma tio n o n (he loading Lh ar can be expected LO bear o n underground e nclosu res. 110.72 Cabling Work Space. A dear work space not less than 900 mm (3 ft) wide shall. be provided where cables are located on both sides, and no t less than 750 mm (2½ ft) where cables are o nly on one side. The vertical headroom shall be not less than 1.8 m (G ft) unless the open ing is within 300 mm ( 1 fr), measured ho1izontaUy, of the adjacent interio1· side wall of the enclostu·e. Excej1tion: A manhole mnlciining only o·,u, or 11!011' of thr following shall he perm.it/ea IO have ont of the horizontal worh spare dirnensiom reduced to 600 mm (2 fl) where the other horizontal dear wm-/: space is incrrased so the IWn of the two dimensions is not less than I.8 111 ( 6 fl): (l ) (2) ( 3) Optical film· rables as cover/id in A rtide 770 Pmuei•limiled fire alarm tircuils supplie,t in accordance tuitlt 760.121 Class 2 or Class 3 rernotf-i:Onlrol and signaling circuils, or bot.h, supplied in r.u:conhince with 725.121 110.73 Equ.ipment Work Space. Where elecu·ical e quipment with live parts that is likely to require exam.ination, adjustment, servic ing, or maintenance whi le e nergized is instal led in a manhole, vault, or o ther enclosw·e d esig ned for personne l access, the work spate and associated requirements in 11 0.26 shall be met for installations operating at 1000 volts or less. '"' her e the installa tio n is over 1000 volt5, the work space and associated requirement~ in 110.34 shall be met. A ma nhole access cover that weighs over 45.4 kg (100 lb) shall be considered as meeting the 1-equire ments of 11 0.34(C). 110.74 Conductor Installation. Conductors installed in manh oles and other e nclosures intended for personnel enu)' shall be cabled, racked up, or a rranged in an approved manne1· that provides read y and safe access for pe1·sons to enter for installation and maintenan ce. The insta lla tio n shall comply with ll0.74(A) or l 10.74(B), as applicable. (A) 1000 Volts, Nominal, or Less. Wire be nding space for conductors operating at JOOO volts or less sha ll be provided in accordance with the requirements o f 3 l 4.28. (B) Over 1000 Vohs, Nominal. Conductors o perating a t over 1000 volts shall be provided with bending space in accordance with 314 .71 (A) and (B), as a pplicable. ExrPJ>lion: " 'lwre 314. 71(B ) applies, eath row or column of dtwts on one wall of Ote m/Jlosure shall be ral1:ulated inriivitlttally, and the single row or column /hat fn-oviries lhP maximum distance shall be used. 110.75 Access lo Manholes. (A) Dimensions. Rectangular access ope nings shall no t be less than 650 mm x 550 mm (26 in. x 22 in.) . Round access o pen- 70-!ifi NATIONAL ELECTRICAL CODE 2020 Edition ARTfCLE 11 0 - REQUIREMENTS FOR ELECTRICAL INSTALLATIONS ings in a m anho le sha ll h e not less th a n 650 mm (26 i.n. ) in d iameter. Exception: A rnrmhole that has fl fixed laddn· thrrt does nol obstnu;J the op,m-i.ng or that contains only one or mrn·e of lhf. following shall be permillnl to reduce tllf rninirrmrn wver diamP/.ttr to 600 rnrn (2 fl): (1) (2) (3) Oplica,l fibn· cables ar covered in Article 770 Powe1°limitfd fire alarm r·hrnits supplifd in accmrlanCf with 760. 12 1 Class 2 or Class 3 renwte-contml ancl signuling cin;uils, or both, supplied in accordance with 725. 121 (B) Obstructions. Manho le ope nings sh all be free o f pro n·usio ns that could injure pe rsonne l 01· prevent ready egress. (C) Location. Manhole o penings fo r personnel shall be located wh e re th ey are n o t d ire ctly ab ove ele cn·ical equipme n t o r condu ctors in the e n closu re. Whe re this j s not practicable , eitl1er a pro tective barrie r or a fixed ladder shall be p rovided. (D) Covers. Covers shall be over 4fi kg ( HI() lb) or o tl1en ~ise d esign ed to re quire the LL5e o f too l5 to o pe n. T h ey sha ll be d esign ed or restrained so tlley canno t fall into the m anho le o r prnn·ude su fficie ntly to contact electrical condu ctors or equipm e nt w ithin the 111.anh ole. (E) Marking. Manh o le covers sh a ll have a n iden tifying m ark or logo that promin ently indicates tl1eir functio n, su d 1 as "elecu-ic ." 2020 ll\lirjon NATIONAL E LECTRICAL CODE 110.79 110.76 Access to VauJts and TunneJs. (A) Location. Access o penings for personne l sh all be located wh ere tlley ru·e n o t d irectly above e lect1i cal equipmen t OT con d u ctors in the e nclosure . Otlle r o pe nings shall be pe rmitted over equipme n t to fac ilitate instal la tio n , ma intena nce, o r replacement of e quipment. (B) Locks. Tn adilition to compliru1ce with the re quire me n ts of 110.34, if applicable, access o pen ings for personnel sh a ll b e an-an ged su ch tha t a person o n the i nsid e cru1 ex it wh en tl1.e access doo r i,.~ locked fro m th e outs ide, or in the case o f no rn1ally locking by padlock, tl1.e lock in g ru-ra n gemen t shall b e such that the padlock can be closed on the locking syste m to preven L locking from the o u t~ide . 110.77 Ventilation. Whe re ma nho les, tunnels, and vaults h ave communicating op e nings into e n closed are as used b y th e public, ventilatio n to open a ir sh all be provid ed whe rever pract icable. 110.78 Guarding. v\7h ere con d uctors o r equipm ent, or both , cQuld be contacted by o bject~ falling or be ing push ed t h rough a ven tilatiJ1g grating, both co n d u ctors a nd live part~ sh a ll b e p rotected iJ1 accordance wi tl1 the requirements o f J l0.27(A) (2) o r II0.3 l (B)( l ), d e penilingon the voltage . 110.79 Fixed Ladders. Fixed lad der s sh all be co rrosion resistant. 70-57 CHAPTER 2 ARTICLE 200- USE AND fDENTIFICAT ION OF GROUNDED CONDUCTORS Chapter 2 Wiring and Protection Ewi,ption No. I: The requirement for grouping or identifying shall not aptJly if the branch-circuit or feeder conductm:~ enter Ji-om a mble (rr a rai:1Jwa:y uniquf tn the rimuit that rnalies tht gnntping obvious. ARTICLE200 Use and Identification of Grounded Conductors 200.1 Scope. This article provides requirements fort.he following: (1) (2) (3) Ide ntification of terminals Grounded conductors in premises wiring systems Identification of grounded conductors 200.6 Means of Identifying Grounded Conductors. (A) Sizes 6 AWG or Smaller. An irm.tlated grounded conductor of 6 AV1IG o r smaller shal l be identified by one of the f-o llowing means: In fo rmatio nal Note: See Article 100 for definitions of Crom,de/t Con(l11-rto1; .equipment Orom,ding C',,md'llclm; and Oro11ndil1g E/,;ctrorlr ( I) G'ond1u:to1: 200.2 General. Grounded 200.2(A) and (B) . Exre/>Lion No. 2: Thr requirement Jiir gnmping or irl1mtifying shall not apply where br(l.m:h-cirruit conrl-uctors /Jass through a box or co11du.it body without a loop as rlemiberl in 314.16(8)(1) orwitluml a splice or termination. (2) conductors shall comply with (3) (A) Insulatio n. The grounded conductor, if insulated, shall have insulation that is ( I ) suitable, other than color, for any ungrounded conductor of the same circuit fo r sy~tems of 1000 volts or less, or impedance grounded neutJ.·,l l systems of over 1000 volts, or (2) rated not less than 600 volt~ for solidly grounded .neutral systems of over I 000 volts as described in 2.'i0.184(A). (4) (5) (B) Co ntinuity. The continuity of a grot.mded conductor shall not depend on a connection to a metallic enclosure, raceway, o r cable armor. (6) lnfo nmuional Nore: See 300.l3(B) for Lhe conrjnuity or grounded conduclors used in mu.lliwire branch circui ts. 2 00.3 Connection to Grnunded Sys tem, Grounded conductors of premises wiring systems shall be electrically connected to the supply system grounded conductor to ensure a common, continuous grou nded system. For the purpose of this section, elPctricrtlly connected shall mean making a direct e lectrical connection capable of carrying current. as distinguished from induced cmrents. (7) (8) T he insulated conductor shall have a continuous white outer finish . The insulated conducto,- shall have a con tinuous g ray outer fi n.ish. The insulated conductor shall have three continuous white or gray stripes along the conductor's entire length on other th an green insu lation. Insulated conductors that have the ir o uter covering finished to show a white or gray color but have colored u-acer threads in the braid idemifying the source of mam tfacture are acceptable means of identification . A single-conducto1~ sunlig ht-resistant.. outdoor-rated cable used as a solidly grounded conductor in photovoltaic power systems, as permitted by 690.41, shall be identified at the time of installation by markings at terminations in accordance with 200.fi(A) (J ) through (A) ( 4) . The grounded conductor of a mineral-insulated, metalsheathed cable (Type Ml) sha ll be identified at the rime of installation by d istinctive marking aL its terminations. Fixture wire shall comply with the requiremenL~ for groLmded conductor identification as specified in 402.8. For aerial cable, the identificarjon shall comply with one of the methods in 200.6(A)(l) th rough (A)(5), or by means of a ridge located on the exterior of the cable so a~ to identify it. Exceplion: Listed fr1.tl!rartivl' invertn:s identified for LISP. in distrilnllrd rrsowre g1mmntion !fJSl.nns ~Ul'lt. as photovoltaic and fi.wl eel/, f1ower (B) Sizes 4 AWG or Larger. An insulated grounded conductor 4 AWG or large1· shall be identified by one of the following means: sy.wms shall IHi /iermittel/ to be connP.cted Lo premises tviring with.out a gnnmded rnndw;tnr if the connected premises tuiring or utility system includes a grrnmded conduclm: (1) (2) (3) 200.4 N eutral Conductors. Neuu·al conductors installe d in accordance with 200.4(A) and (B) . (4) shall be (A) Installation. Neutral conductors shall not be lL5ed for more than one branch circuit, for more than one mulliwi.re branch circuit, or for more than one set of ungrnunded feeder conductors unless specifically permitted elsewh ere in this Corle. (B) Multiple Circuits. Where more than o ne neutral conduct.or associated with different c.ircuit5 is in an enclosure, g round ed circuit conductors of each circuit shall be ide ntified or grouped to correspond with the ungrounded circuit conductor(s) b y wire markers, cable ties, or sim ilar means in at lea~t o ne location within the e nclosure. 70-58 A continuous white outer fi n ish . A continuot.L5 g ray outer finish . Three continuous wh ite or gray stripes along the conductor's entire length o n other than green insu lation. AL the time of instal lation, by a distinctive white or g ray marking at its term inations. This marking sha ll enc ircle d1e conductor or insulation. (C) Flexible Cords . An insulated conducto,- that is imended for LL5e ai, a grcmnded conductor, where contained withi n a flexible cord, sha ll be idemified by a white or gray outer finish or by methods permitted by 400.22. NATIONAL ELECTRICAL CODE 2020Edition ARTICLE 200- USE AND IDENTIFICATION OF GROUNDED COND UCTORS (D) Grounded Conductors of Different Syste ms. Where grou nded conductors of d iffe1·ent systems are installed in the same raceway, cable, box, aLLxiliary guller, or other type of enclosu re, each grounded conductor shall be identified b y system. Ide ntification that distinguishes each system grow1ded conductor shall be permitted by one of the fo llowing means: ( 1) (2) (3) O ne system grounded conductor shall have an ouler cove1·ing conforming to 200.6(A) or (B) . The grounded concluctor(s) of olher syste ms shall have a different outer covering conforming to 200.6(A) o r 200.6( B) or by an outer covering of white or gray wi1.h a readily disti.nguishable colored stripe other than green running a lo ng the insulation. Other and different means of identification allowed by 200.6(A) or (B) shall distinguish each system grounded conductor. ( I) (2 ) The means of ide ntification sha ll be docmnented in a mam1er that is readily available or shall he permanently posted where the conductors of differenL systems o riginate. Excrption No. 1: Conductm:t with.in rnulticonductor cables shalt be pr:rmitled lo /Jp rr-irl!!ntifir,rt nt their tirrminations at the tinw of instnltation by a distiru;tivt white ar gray rnm'hing or other equal!J ejfr'r.t.ivt If part of a cable assern bly that has the insulation permanently reidentified to indicate it~ use as an ungrounded conductor by marking tape, painting, or o ther effective means at its termination and at each location wh ere the conductor is visible a nd accessible. Iden tification sh al l e ncircle the insulation and sha ll be a color o ther than white, gray, or green. If used fo.r $ingle-pole, 3-way or 4-wa)' switch loop s, the reidentifi ed conductor with white 0 1· gray insulatio n 0 1- three conti11uous wh ite or g ray stripes shall be used only for tl1 e suppl)' to the switd1, but not as a return conductor from the switch co U1e outlet. A fl exible cord having one conductor identified by a white or gray ol.ller finish or three continuous white o r g ra)' stripes, or by a ny other m eans permitted b y 4-00.22, tl1at is tL5ed for connecting an applian ce or equipment pe rmitted by 400. l 0. Th is shall a pply to flexible cords connected to outleL5 wheth_e r o r not the outlet is suppli ed by a circuit that has a grow1ded conduc tor. Informational Nme: T he color gray may have been Ltsed in the past as an ungrounded conducto ,: Care s hould be mken whe n working o n existing sysLems. (E) Grounded Conductors of Multiconductor CabJes. The insulated grounded conductor(s) in a multiconductor cable shaJI be identified by a continuous white or gray outer finish o r by three continuous white or gray stripes o n other than green insulation a long its entire length . For conductors that are 4 AWG or larger in cables, identification of the grow1ded Cl) nductor shall be permitted to comply with 200.6(B) . For multiconductor flat cable with cond uctors that are 4 AWG o r larger, an external ridge shall be permitted to ickntify the g rounded cond ucto1: 200.10 200.9 Means of Identification of Terminals. In devices or u tilizatio n equipme nt with polarized connections, identification of lerminaJs to which a grounded conductor is to be connected shall be substantially wh ite or silver in color. The identification of oth er tenn inaJs shaJl be of a readily d isti.ng1.1ishable different colo r. Exception: Whae the ronditions of maintmana and supervision enswre that only qMlijied /1ersrms servire the in.'ila.llatians, tl'l'nunalr for gn:mnded conductors shal.l be permitted lo be permanently identified at the tirne of installnlion by a distinctive white marking or 0//11,r eq1ially ejfective mPans. 'lnf'111lS. 200.10 Identification of Terminals. Excef>tion No. 2: The grounded cond'I.Lctor of a multii:1m.ductor vamisherl-cloth-insulalNl cable shnll be /Jenni/ te,t to be identified a:t its t1<r111inations at the time of 'mstallatio11 by rt rlisti111;tive while marking or other equally effective means. (A) Device Terminals. All devices, excluding pane lboard s, p rovided witJ1 terminal5 for the attachmenl of conductors and intended for corrnection to more tJ1an one side of the c ircuit shall have terminals prope rly marked for identificalion, unless the electrical connection of the termjna l intended lO be connected to the grounded conductor is clearly evident. Informational Nore: The color gray may have been used in the pasL a;; an ungrounded conductor. Care ~h ould be 1.aken when working on existing ysLems. 200.7 Use of Insulation of a White or Gray Color or with Three Continuous White or Gray Stripes. (A) General. The following shall be used only fo1· the grou nded circLtit conductor, unless otherwise permitted in 200.7(B) and (C) : (l) (2) (3) A conductor with continuo us white or g ray covering A conductor with th ree continuous white or grn.y stripes on other than green insulation A markiJ1g of white or gray color at the termination (B) Circuits of Less Than 50 Volts. A conductor with wh ite o r gra)' color insulation or three co11tinuo11s white stripes or having a marking of white o r gray at the termination for circuits of less than .50 volts shall be required to be grounded only as required by 250.20(A). (C) Circuits of 50 VoJts or More. The use of insulation that is white or gray o r thal has three continuous white or gray stripes for other than a grounded conductor for circuits of 50 volts or more shall be permi creel only as in ( I ) and (2). 2020 ll\lirion NATIONAL E LECTRICAL CODE Excr,ptitm: Tenninal identificat ion shall not bP required for deuices lhitt haue a normal rnrrent rating of over 30 am/>eres, other than jJolari:z.erl rittadirnenl plt1g~ and /JOlarized receplades for attachment j1lngs flS requ,ired in W0.J0(B). (B) Receptacles, Plugs, and Connectors. Receptacles, polarized attachme nl plugs, a nd cord connectors for plugs and polarized plug·s shaJI have the terminal intended for connection to the grounded cond uctor identified as follows: ( 1) (2) l clenlification shall b e hy a metal Qr metal coating tl1a t is substantially white or silver in colo1· or by the word "white" or the letter "Vv' located adj acent to the identified term.inal. If the terminal is not visibl e, the conduc tor e n trance hole for the connection shall be colored white or marked with the word "white"' o r the letter ''W." Informational Nme: See 2!i0. J 26 for ide ntificatio n of wiring device equipm e ll r grounding conducto r rerminals. (C) Screw Shells. For devices witJ1 screw shells, the terminal for tl1e grounded conductor shaJ l be the one connected to the screw shell. 70-59 200.10 ARTICLE 210- BRANCH CIRCUITS (D) Screw Shell Devices with Leads. For screw s h e l.l devices with attached leads, the conductor attached to the screw shell shall have a white or gr:ay finish. The outer finish of the other conductor shall be of a solid color that will not be confused with the white or gray finish used to identify 1.h e g rounded conductor. Informational Note: The color gray may have been usi;d in the past as an ungrounded cond11cror. Ca.re should be taken when wor'king on existing sys1ems. (E) Appliances. Appliances that have a single-pole switch or a single-pole overcurrenl. device in the line or any line-connected screw shell lampho lders, and that are to be connected by (1) a permanent wiring met.hod or (2) field-installed attachment plugs and cords with three or more wires (including the equipmenl. grounding con.duel.or), shall have means to identify the terminal for tJ1e grounded circuit conductor (if any). 200.l l Polarity of Connections. No grounded conductor s haU be attached to any rermi1ial or lead so a~ to reverse th e designated polarity. 210.4 Multiwire Branch Ci.i-cwts. (A) General. Branc h circuits recognized by thi~ article shall be permitted as mltltiwi.re circuits. A multiwire circuit shall be permiued lo be considered a5 mulliple circ uits. All conductors of a multiwire brancl1 circuit sha ll orig inate from the same panelboard or similar distribution equipmenl.. Informational Note No. 1: A 3-phase, 4.-wire, wye-<:onnected power system used ro suppl)' power to nonlinear loads ma~ necessitate that Lhe power system d esign a llow ror the possibility of high hanuonic currenis on the nemral conducwr. Informational Note No. 2: See 300.l 3(8) for continuity of grounded cond11ctors on mu! tiwi re ci rcu iL~- (B) Disconnecting Means. Each multiwi.re branch c ircuit shall be provided with a mearrn that wi ll simultaneously disconnect all ungrounded conductors at the point where the branch circu il. originates. Informational Note: See 240.15 (B) for information on the use of single-pole circuit breakers, a5 the disconnecting means. (C) Line-to Neutral Loads. Multiwire brancl1 circuits shall supply o nly li ne-to-neutral loads. 0 l!.'xi:.ption No. 1: A mnUiwirr branch cin;uit thal S'1tf>plies only ulilb.nlirm 1'quipmenl. ARTICLE 210 Branch Circuits 011P E-,;ce/J/ion No. 2: Where all ungtnunderl cnndi1dor.r of the rmiltiwirf branch ci1ritit are n,penerl simultlmPmtsly by 1h11 bmnch-drmil ovrrcu, rent rievicP. 0 Part I. General Provisions 210.1 Scope. This article provides the general requirement~ for branch circuit~. 210.3 Other Articles for Specific-Purpose Branch Circujts. Table 210.3 list~ references for specific equipment and applica1.ions not located in Chapters 5, 6, a11d 7 tl1a1. amend or suppl ement the requirements oftl1is article. (D) Grouping. The ungrounded and g1-ounded c ircuit conducto1-s of each multiwire branc h cit-cLtit shal I be grnu ped in accordance with 200.4(B). 210.5 Identification for Branch Circuits. (A) Grounded Conductor. The grotu1ded con c;htcl.or of a branch circuit shall be identified in accordance with 200.6. (B) Equipment Groundmg Conductor. The equip1nent grow1ding conductor shall be identified in accordance with 250.119. (C) Identification of Ungrounded Conductors. UngroLmded conductors shall be identified in accord,rnce with 210.5(C) (] ) or (2), as applicable . Table 210.3 Specific-Purpose Branch Circuits Equipment Article Air-conditioning anrl refrigerating equipment •140.6, 440.3], 440.32 368.17 422.12 Busways Central heating equipment <1thcr than fixed e lecti-ic sp ace-healing equipment Fixed clcc:tric heating eq uipmen t for pipeline, and vcsseb Fixed electric s pacc-hca1.i,,g eq uipme nt Fixed o utdoor elecuical dcicing and snow-melting equipment Infrared lamp industria l h eating equipment :vlolors, mot.or circuits, and controllers S1,~tchbo<1rds and '])anelboards 70-60 Section 427.4 424.3 426.4 422.48, 424.3 430 408.52 (1) Branch Circuits Supplied from More Than One Nominal Voltage System. Where the premises wiring system has bra nch circu it5 supplied from more thai1 one nominal voltage syste m , each ung rounded conduc;1.o r of a branch circ uit shall he identified by phase or Lin e a.nd by system voltage class at a ll termination, connection, and splice points in compliance with 210.5(C) ( 1) (a) and (b ). Different systems within the same premi~es that hrwe the same system voltage class shall be permitted to u se tl1e same identification. (a) Means <rf identification. T he means of identification s hall be pe1-mitted to be by sepai-ate color coding, marking tape, 1.agging, or other approved m ean s. (b) Posting of ldentijicatirm Means. The method utilized for conductors origiJ1al.ing within each brai1ch-circuit pane lboa rd or similar brai1ch-circuit d istribution eqttipment shall be documented in a manner that i.~ readily available or shall be permanently posted at eac·h branch-circuit panelboard or similar branch-circuit distt·ihution equipment. The label shall be of s ufficient durability to withstand tl1e environment invo lved an d s hal.l n ot he handwritte n. NATIONAL ELECTRICAL CODE 2020Edition ARTIC LE 2J O - Exception: In eJdsting install«tiom tvhe:rl' a voltage systern(.t) already e,xisls and rt difjPrent voltage syslem is bPing added, ii s/t(lll be pennissible lo marh only the -new system vollage. Existing unidentified syslems shall not be requin,d to be identified al each termination, connection, and s/1licP point in compliance with 2 / 0.5(C)(l)(a) and (h). Ln,beling .ihall br, required at mrh voltng/1 systmn distriln1tion equi/nnent to identify that only one voltage system has been rnarfled for n new systnn(s). ThP new system lr1bel(s) shctll includr, the words "olht!r unidentified systems exist on thl' /m•mises. " (2) Branch Circuits Supplied from Direct-Current Systems. ·whe re a bran ch ci rcuit is supplied from a de system ope rating at mo re tha n 60 volts, each ung rom1de d conductor of 4 AWG o r larger shall be idenl.ified by polarity at all termina l.io n , connection, and splice poin~ by ma rking ta pe, tagging, o r o ther a pproved means; each unground e d conduc to r o f (j AWG or smaller sh all be ide ntified hy po larity at all te rminatio n, connection, a nd splice point5 in complian ce with 2 I0.5(C) (2 ) (a) and (b) . The ide ntificatio n me tJH)dS utilized for conductors o rigina ting within each bran ch-circuit pane lboard o r simihu- bran ch-circuj t d i5tributio n e quipme nt shall be docume nte d in a ma nner that ~~ readil)' available o r shall be pe rmane ntly posted at each bran ch-circuit panelboard or simila r branch-circuit dist1·ib1.1tio11 equipmen t. (a) Positive Polarity, Sizes 6 A WC ar S1nalle1: Where the positive p ola rity of a d e syste m d oes not serve as the connection po int for the gro unded conducto 1~ each positive ungrounded conductor shall be id entified by on e of the fo llowi ng means: A continuous redome rfinish A contin uou s red stripe durably 1mu·kecl a lo ng the conductor's e ntire lengtl, on insula tion of a color other than g reen , white, gray, or black (3) lmp1inted plus signs (+) o r tl1e word POSITIVE o r POS dura bly ma rke d o n insulation of a colo1· oth er than g reen , white, gray, or black and re peated at inte rvals no t exceeding 610 mm (24 in.) in accordance with 310.S(B) ( 4) An approved permane nt marking mea ns su c h as sleeving or sh.rink-tubing th a t is suitable for the conductor size, a t qll termination, connen io n , a nd splice po ints, wit!, imprinted plus sign s (+ ) o r the word POSITrvE o r POS durably marke d on insulation o f a color o ther tha n green , white, gray, or black (b) Negative Polarity, Sizes 6 A WG or S111.alle1: Wh ere tJ1e negative polarity o f a d e system d oes no t serve a~ th e co nne ction po in t fo r the g ro w1ded conclucto 1~ each negative ung ro und ed conducto r shall be ide ntified by o ne of Lhe followin g mean s: ( 1) (2) ( 1) (2) (3) (4) A conLinuous black outer fini sh A conl.inuo us black su·ipe dm'ably ma rked alo ng the cond uctor's e n ti re le ngtl1 on insulation of a color o ther tl1an g ree n, white, gray, or red Imprinted minus sig ns (-) or tl1e word NEGATNE or NEG d mably marked o n insulatio n of a colo r otJ1e1· tha n g reen, white, gray, or red and repeated at inter vaL5 n ot exceeding 6 10 mm (24 in .) in accorda nce with 310.8(B) A..n ap proved pe rmanent marking means suc h as sleeving or sh rink-n.1bi.ng tha t: is suitable for the conductor size, at all termi nation, conn ecri o n, and splice po in ts, with im p rinted minus signs (-) o r the word NEGAT[VE o r NEG durably ma rked o n insula tio n o f a colo r other than green , whi te, gray, or reel 2020 ll\lirjon NATIONAL £ LllCTRICAL CODE 210.6 BRANC H CIRCUITS 210.6 Branch-Circuit Voltage Limitations. The no minal voltage of branch circui t~ shall not exceed the values pe rmitt ed by 210.fi (A) tlu-oug h (E) . (A) Occupancy Limitation. In dwelling units an d g uest ro oms o r guest suites of hotels, mote ls, a nd simila r occupa ncies, the voltage shall n ot exceed 120 volts, n o mina l, be tween conductors that supply Lhe ten n i na ls of tl,e foll owing: (J ) (2) Lurninafres Cord-and-plug-connec ted loads 1440 volt-amperes, nominal, or less o r less tban 1/, hp (B) 120 Volts Between Conductors. Circuits not exceed ing 120 volts, nominal, between conductors sh all be pennitte d to supply the fo llowing: (J) (2 ) The terminals of lampho lde rs applied within tl1e ir voltage ratings Auxil ia1)' eg ui pment of elecu·ic-clischa rge lamps Information a l Note: See 410. 137 f'or awdJiary equ ipme111 limita• rions. (3) Cord-and-plug-connected utili zal.io n e quipme nt or permaJ1 en tly co1rnected (C) 277 Volts to Ground. Circuits exceed ing 120 volt~, no mina l, be twe en co nductors but no t exceeding 277 vol t5, no mina l, g round sha ll be permitted to supply cord-and-plugco nnecte d o r perma ne ntly connected u til izati on egLLipme nt, o r the following types of IL~ted ILmtina'ires: to (l ) (2) (3) Electric-discha rge lumina ire~ witl1 integral ba llasts LED luminaires witJ1 LED drivers bee-ween the bra nch circuit a nd tl1e la mpho lders Incandescent or LED lumina ires, equipped with mediumbase o r smaller screw she ll lampho lders, whe re the la mpholders are supplied at 120 volts o r less from l11e output of a ste pd own autou·a nsform e1; LED driver, or oth e r type o f p ower supply tl1at is a n integral compo ne nt of the luminaire ln!ormaLio na l Note: See 410.90 for requiremen ts regarding the connect.ion of screw sh e ll lampholders to grounded conducto rs. (4) (5) (6) Luminaires e quipped with mogul-base screw sh ell la mp• holders Luminaires equipped with la mpholders, otl1e r than the screw sh ell type, whe n u sed within tl1eir voltage ratings of tl,ei r la m pholders Luminai res witl1out la.mp holders Informatio na l No1e: Luminaires wid1 no nserviceable LEDs a re examples of ILm1inalres withow lampho lrlers. (7) Auxilia ry equipment of e lectric-discha rge or LED-type la mps Informatio na l Noce: See 410. 137 f'o r auxiliary eq u ipmen t limita1.ions. (8) Luminai res converted witl1 listed retrofit kits incorpo rating integral LED lig h t som·ces or accepting LED lamps that also con.fo rm5 witl1 210.6(C) (J ), (C) ( 2), (C) (3), (C) (4), or (C) (5) 70-61 210.6 ARTICLE 210- BRANCH CIRCUITS (D) 600 Volts Between Conductors. Circuits exceedin g 277 vol t~, nominal, to ground a nd not exceeding 600 volts, non1inal, b enveen conductors shall be permitted to supply the fo llowing: (1) The arndlia ry equipm.ent of elecu-ic-clischarge la mps mounted in permanently installed lumina ires where the luminaires are mo unted in accordance witl1 one o f the following: a . Not less than a height o f 6 .7 m (22 ft) on po les or similar sn-ucLUres for tl1e illumination o f outdoor areas su c h as. highways, road~, bridges, athletic fields, o r parking lot~ b. Not less tha n a heig ht of 5.5 m ( 18 ft) on other srructures su ch as tunnels ln forma1jonal Note: See 410. 137 for auxiliary equipmen t limi tations. (2) (3) Cord-and-plug-connected or permanently connected utilization equipment other than luminaires Luminaire.~ powered from direct-curre nt systems where eimer of the followi11g apply: a . The luminaire contains a listed, de-rated ballast mat provides isolation be l"\vee n the d e power source and the lamp circuit and prmection li·om electric sh ock wh e11 c ha.ngi ng lamps. b. The luminair·e contains a listed, dc-nlted ballast a nd has n o provision for changing lamps. Excef>lion No. 1 to (B). (C), rmrl (D): For larnpholders of infrared indiistrial heating a/Jpfiances r1s provided in 425.14. Fo r the p urposes of this sectio n, when determini11g tJ1e d istance from rece ptacles the distance shall b e measu red as the s hortest patl1 the supply cord of an appliance connected to the receptacle would follow witho ut piercing a floo r, wall, ceiling, or fixed barrier, o r the shortest path without passing mrnugh a window. (A) Dwelling Units. Ali l 25-volt through 250-volt receptacles installed i11 t:he locations spi:cified in 2 l0. 8(A)( I ) through (A) (11) a nd supplied by single-phase branch ci1·cuits rated 150 volts or less Lo ground shall h ave ground-fault circuiti.nterrupter protection for personnel. (1) Bathrooms (2) Garages a nd a l~o accessory buildings tha t have a fl oor located at or below grade level not inte nded as habitable roo ms and limited to storage area5, work a re.'ls, an d a rea5 of similar use ( 3) Outdoors f.xcej1lio11 to (3): Rr!f:11ptades th(l.t rm· not rPadily accessible and rm· supplied by a branch circuit rlerlicalerl lo electrir snow-melting, deicing, or pipeline rmrl vessfl heating equifnnent slwll be permitted to be ins/rifled in accord.anu with 426.28 or 427.22, CL~ n/1plicable. ( 4) (5) Informational Note: See 760.41 (.8) a nd 760.121 (B) fo r power supply requirements fo r fire a la rm systems. (6) (7) (8) 210.7 Multiple Branch Circuits. Where two or more branch circuits supply devices o r e quipment on me sam e yoke or mowHing stra p, a m eans to simultaneously disconnec t the ungTOLmded supply conductors sha ll be provided at th e point at which the branch circuits 01-igin ate. 210.8 Ground-Fault Circuit-Interrupter Protection for Personnel. Ground-fault c ircuit-interrupter protectio n for personn el shall be provided as required in 2 10.8(A) throu g h (F). The grow1d-faull circ uil interrupte r sha ll be installed in a readily accessible location . Informational Note No. 1: See 215.9 for ground-faLtlt circuit.interrupte r protection for personnel o n feeders. Informational Note No. 2: See 4225(A) fo r GFCl requfrernems for appliances. Informational Note Nn. 3: See 555.9 fo r GFCI reqLLiremen rs for boat ho ists. l.nfonnational Nme No. 4: Additional G FC I require rn enL~ for specific circuit,~- and equipme m are contained in Ch apters 4. 5, a nd 6 . at or below grade level Exce/1tion lo (5): A re1;r,ptacle s1.1f1plying only a /Jemumently installer.t fire 1Jl0:rrn or l;wglar alarm S')l/ilfl1n shall no! be requi:red to have groundfmtli cirntit·internJ41ter protel'lion. Excrption No. 2 to (B ), (C), and (D): For railru1iy profH1rlies ris descri.bed in 110.19. (E) Over 600 Volts Between Conductors. Circuits exceeding 600 volts, no mina l, between conductors shall b e permitted to suppl y utilizatio n equipment in installations where conditions of maintenance and supervision ensure tl1al only qualified persons .~ervice tJ1e instal lation. Crawl spaces Basemen ts (9) ( 10) Receptacles installed under d1e exceptio n to 2 I 0.S(A) (5) sh all not b e cons idered as meeting the requirements of210.52(G) . Kitchens - where the receptacles a re insta ll ed to serve the countertop surface s Sinks - where recepta cles a re installed within 1.8 m (6 ft) from th e top inside ed ge of tl1e bowl of m e sin k Boatho uses Ba thtubs 0 1· showe r stalls where receptacles are installed wi tllin 1.8 m (6 ft) of the o u tside edge of the barn tub o r s hower stall Laundry areas I:.):r:ff1lion to (I) through ( 3 ), ( 5) through ( 8), and ( I 0): Li.ste1l locking .mpport and mowit,ing 'lrt!'('/1tades utilized in /'0111bination with com/Jatible auachment fittings installed for the pu>-pose of serving a ceiling lwninain: or t:eili ng Jan shaft not bf required Lo be ground-fault dn:ititinterrnpler f1mlected. if a gmeml-putj1ose ronvPni,mc11 ree11ptacle is inllfgml Lo Liu, ceiling fmninaire or l'eiling fan, GFCJ /nvteclion shall be />mvided. (11) Indo or d a mp and wet locations (B) Othe r Than Dwelling Units. All 125-volt d1rough 2 50-vol t receptac.les s upplie d by single-phase brancJ1 circuits 1-ated 150 volts or less to ground. 50 amperes o r less, and all receptacles supplied by three-phase bra n ch circllits rated 150 volt~ or less to groun d. 100 amperes o r less, installed in the locations specified in 2 l0.8(B)( l ) tluoug h (B)( l 2) sh all h ave groundfault circuit-inte rrupter prntection for personnel. ( l ) Batlu·ooms (2) Kitch ens or areas witn a sink ai1d perman e nt provi~ions for eime r food p reparation or cooking 70-62 NATIONAL ELECTRICAL CODE 2020Edition ARTICLE 210 - BRANCH CIRCUITS (3) Rooftops Exception: Recrptacles on rooftops shall. not be required to he readily affessiblR other than fmm thR mofl(}jl. (4) Outdoors E~1;eption No. 1 to ( 3) and (4 ): Rrrep!ades that mw not rmrlily llCtessible and ar,J .m/Jf>lied 0,, a branch circuit dedicatPr.l to Plectric snnwrnelting, deicing, m· pipPline and vessfl luating equipnuml shall be permilled to bP installed in aceori:lmu;p with 426.28 or 427.22, as appliwblR. Exce/ilion No. 2 lo (4 ): in ind1.1,Strial estoblislwu:nts only, wherP lhP conditions of 1naint11nanct1 ancl suf11/rvisinn 1111si1re that only qualified /Je1:sonnl!f are involved, an asmred equifmient gmunding cmulw·tor program os specified in 590.6(8)(2) shall be perrnif/edfor only those m;eptade millets its11d ta supp!,y equipment that would 1Tentr r1, grmler hazard if f>awer is interrupt.ed or having a design Iha! is not mmj1atible tvith GFCJ f1rotection. (5) Sinks - where receptacles are installed within 1.8 m (6 ft) from the top inside e dge of the bowl of the sink ExcPption No. l to (5): In industrial laboratories, rPl'epi.acles ll5ed lo rnp/11:y equipment wfwrf' removal rif poruer would iritmdw;r a 6rrmter hazard shall bf' permitted to be imtalled wWtO'Ul GFCJ pmtertion. ExCPption No. 2 Lo (5): Remptadfs localed in fJOlient bed locations qf Cal.egcn-y 2 (genrml care) or Clltegcny I ( critirnl atrP) spar.es of hmll/1, careJacililies shall be pennilled to comply tuith 517. 21 . (6) (7) (8) (9) (LO) Indoor damp and wet locations Locker rooms with associated showe1·ing faciliti es Garages, accessory buildings, service bays, and sim.ilar a reas othe r tha n vehicle exhibition h alls and sh owrooms Crawl spaces - a t or below grade level Unfinished areas of basements Exception to (1) through (5), (8), anrt (10): ListPd lod:ing supporl. rmd -mounting rP.cPf>lades ttlW.ud in combination with compatible attachm,e11i fittings inst11fled for the fni.rpose of serving a ceiling lwminaire or ceiling Jan shall not. be requi rerl lo be gm·u.11.tlfa·ull cirruit-intemipter f1mteded. If 11 geneml-pwfJOSP convenience rewptatlP is integral lo th~ ceiling lurninaire or chlingJan, GFf'J /1rolection slrnll be fJrOvided. ( 11 ) Law1dry area~ ( 12) Bathn,1l;s and shower stalls - whe re receptacles are in.stalled with in 1.8 m (fi ft) of the o uLside edge of the bathtub or shower stall (C) Crawl Space Lighting Outlets. GFCI p rotection sh all be provided for lig hting outlet~ not exceedi11g 120 vol es installed in c.rawl spaces. (D) Specific Appliances. Unless GFCI protection is provided in accordan ce with 422.5(B)(3) th rough (8 )(5), the outlet5 supplying t11e appliances specifi ed in 422.5(A) shall have C FCI protection in accordance with 422.5(8 ) ( J ) o r (B) (2) . Where the applia nce is a ve nding machi.11e as specified in 422.5(A) (5) and GFCI p rotection is n ot provided in accorda nce with 422.5(B)(3) or (B)(4), bra nch circuiLs supplying vending machines shall have CFC! protection in accordance with 422.5(B) ( I ) o r (B) (2) . (E) Equipment Requiring Servicing. GFCI p rotection shall he provided fix the receptacles required h y 2 10.63. 210.11 supplied by single-phase branch ci.rcuits rated 150 volts to ground or less, 50 amperes o r less, shall h ave ground-fault circuit-interrupter protection for personnel. Exception: Grou,nd-Jaull. cirtuit-inlr.rmpter fJrof.ecti.on shall not bf rpquirnd on lighting oullets other than those rnvered in 2 10.8(C). 210.9 Circuits Derived from Autotransformers. Bran ch c ircuit~ shall no t be derived from autou·a11.5formers unless the circuit supplied has a g rounded conductor tl1at is e lectrically connected to a grounded conductor of the system supplying the au totransformer. Excepti<m No. 1: An 1mtotransfonncr shall be f.>errnitted without the connection to a gimmded conductor where tmnsforrning Jrcmi a nmniual 208 volL1 to o, nominal 240-voll suj1ply or similarly fiwn 240 volts lo 208 volLt. Exception No. 2: in industrial occ:ujJanries, where conditions of maintenance antl si1pervision ens'!tre that only q1a1lijifd persons srrvice the installation. mit0Lraniforn1n~ sh.all be permit/Pd to supply nominal 600-volt loads from -nominal 480-voll systnns, r.md. 480-volt loads Jivrn nominal 600-volt syst-em.s, without th.P tO'll'nt!Cliou, to a similar gmund,er.l cmul1u·to1: 210.10 Ungrounded Conductors Tapped from Grounded Systems. Two-wire de circuit5 a nd ac circuits of two or more ungrow1ded conductors shall be permitted to be tapped from the ungrounded condL1ctors of circu.it5 that have a g1·ounded ne utral conductor. Switching devices in each tapped circu it sha ll have a pole in each w1grou11ded conductor. All poles of rnultipo le switching devices shall manuall)7 switch together whe1·e such switching devices a lso ser·ve as a d isconnecting means as required by Lhe following: (l ) (2) (3) (4) (5) (6) (7) 410.93 for double-pole switd1ecl la mpholders 410.1 04(B) for electric-discharge lamp a uxi lia ry equipme nt switching devices 422.3 1(8 ) for an applia nce 424.20 for a fi xed e lecu·ic space-h eating unit 426.51 for e lectric deicing and snow-me] ting equipme n t 430.85 for a motor conu·oller 430.103 for a motor 210.11 Branch Circuits Required. Branch circuiL5 for lig hting and for appliances, including motor-operated appliances, shall be provided to supply the load s calculated in accordan ce with 220.10. In addition, branch circuits shall be provide d for specific loads not covered by 220.10 where requi1·ed elsewhere in this Code an d fo r dwelling unit loads a5 specified in 210.l l (C) . (A) Number of Branch Circuits. The mmmmm number o[ branch circuit5 shall be determined from the tocal calculated load and the size or rating of the ci.rcuiL5 used. In a ll installatiom, the number of circuits shall be sufficie nt to supply the load ser ved. In no case shall the load on a ny c ircuit exceed the maxi mum specified by 220. 18. (B) Load EvenJy Proportione d Among Branch Circuits. Where the load is calculated o n the basis of' volt-ampe res pe1· square meter or per square foot, the wiring syste m up to and including the branch-c ircuit panelboard(s) shall be provided to serve not less than d1e calculated load. This load sha ll be evenly proportioned among multioutlet branch circuit5 within die pa.nelboard(s) . Bra nch-circuit. overcurrenr devices a nd c ircuiL5 shall be required to be installe d o nly to serve the connected load. (F) Outdoor Outlets. All outdoor o utlets for dwellings, other than tl10se covered in 210.8(A)(3) . Exception to (3), that are 2020 Edition NATIONAL ELECTRIC.AL CODE 70-63 210.ll ARTICLE 210- BRANCH CIRCUITS (C) Dwelling Units. (1) Small-Appliance numbei- of branch section, two or mm-e shall be provided 21052(B). Branch Circuits. In addition to the circuits reguired by otl1e1· parts of this 20-ampere sma U--appliance branch circuit5 for all receptacle outlets ~pecified by (2) Laundry Branch Circuits. In addition to the number of ( 4) branch circuit5 required b)' oilier pat-L5 of th is section, at Least one additional 20-ampere branch circuit shaU be provided to supply the laundry receptacle outJet(s) required b y 2 10.52(F). This ci.rcuiLShall have no other outlets. (3) Bathroom Branch Circuits. In addition to the number of branch circuit5 requi.red by other pans of tliis section, one or 11101·e 120-volt, 20-ampere branch c ircuit shall be provided to supply bathroom (s) receptacle outlet(s) required by 210.52(D) and any countertop and sin1ilar work srn·face receptacle outlets. Sucl1 circuit5 shall have no otl1er outlets. Exreptivn: When, lhR 20-mnpft-e circuit supplu:s ll singl,r. bathroom, rmtlets for other pq•uipment within the satnP hath.room shall b,, fiermilfed to be snpfJliPd in acrordana with 210.23(A)( I) and (A)(2). (4) Garage Branch Circuits. In addition to the mui1ber of branch circuits reguired by otl1er pans of tl1is section, at least one 120-volt, 20-ampere branch cirrnit shall be installed to supply receptacle outleLS required by 2 L0 .52(G) ( I ) for attached ga1·ages and in detached garages with electric powei-. This circuit shall have n o other outlets. (5) 1.-.'xcefilion: This circuit shall be pemiilled to ,51.1.pfJfy readily accessible outdoor receptaclt outlets. b. The maximum le ngth of the branch-circuit w1rmg from the branch-ci1·cui t overcurrent device to the firsc outlet shall not exceed 15.2 m (.'50 ft) for a 14 A\lllG conductor or 21.3 m (70 ft) for a 12 AV·iG conductor. c. l11e first outlet box in the branch circuit sh a.11 be marked to indicate tl1al il is the first outlet of the circuit. A listed outlet branch-circuit-type arc-fault circuic interrupter installed a t the first outlet on tl1e branch circuit in combination witl1 a listed bnu1ch-circuit overcurrent protective device where all of the following conditio ns are m et: a . The branch-circuit wiring sh a ll he continuous from the branch-circuit overcurrent device to the outJet branch-circ uit arc-fault circuit interrupte1: b. The maximum le ngth of tlie branch-circuit wiring from the b ranch-circuit overcurrent device to the first outlet shall not exceed 15 .2 m (50 ft) for a 14 AWG conductor or 21.3 m (70 h) for a L2 AWG conductor. c. The first o utlel box in the branch circuit shall be marked to indicate that it is tl1e first outlet of tJ1.e circuit. cl. l11e combination of the branch-circuit ove1-ctuTent device and o utlet brancb-circu.iL A.FCl shall be identified a.5 meeting tl1.e requirements for a system combination-type A.FCl and shall be listed as su ch . If metal raceway, metal wireways, metal a uxiliary gutters, or Type MC, o r Type AC cable meeting tlie applicable requirement~ of 250. l!S, witli metal b oxes, metal conduit bodies, and metal e nclosures are installed for tlie portion of the branch circuit between the branch-cirCLtit overcurrent de,,ice a nd tl1e first outJet, it sh all be permitted to imtall a listed o utlet branch-circuit-type A.FCl at tlie first outlet to provide protectio11 for the rema ining portion of tlie branch cit-cttit. v\1here a listed m etal or nonmetallic conduit or tubing or Type MC cable is encased in not less tl1an 50 mm (2 in. ) of concrete for the portion of the brallch circuit between the branch-circuit overcurren t device and the first outleL. it shall be permitted to install a listed outJet branchcircuit-Type AFCI at tl1e first o utlet to provide protection for the re maining portion oftl1e branch circuit. 210.12 Arc-Faull Circuit-Interrupter Protection. Arc-firnlt circuit-interrupter protection shall he provided as required in 210.l2(A) , (B), (C), and (D) . The arc-fault cirrnit interrupter shall be installed in a readily accessible Location. (6) (A) Dwelling Units. AU 120-voll, single-pha~e, 15- and 20ampere branch circuits supplying outlets or devices installed in dwelling unit kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sun rooms. recreation rooms, closet~, hallways, law1cl1-y areas, or similai- rooms or areas shall be protected by a n y of the means described in 2 L(). 12(A)( l ) through (6): t'xception: AFC/ protection shrill not be required for an individual (l ) (2) (3) A listed combination-type arc-fault circuit interrupter installed to provide protection of tlie entire branch circuit A listed branch/ feeder-type AFCJ installed at the origin of the branch-circuit in combination with a Listed outlet branch-circuit-ty pe arc-fault circuit interrupter installed a.t the first outlet box on the branch c ircuit. The first outlet box in the brand1 c ircuit shall be marked to indicate tliat it is tl1e first outlet of the circuit. A listed supplemental arc protection cirntit breaker installed at tlie origin of the branch circuit in com bination with a listed outlet branch-circuit-type arc-fault ci rcui t interrupter installed at the first outlet box on tlie branch circuit where a ll of the following conditions are met: a . The branch-cirntit wiring shall b e contit1uotL5 from che branch-circuit overcurrent device to the outlet branch-circuit arc-fault c ircu it i.n ten-upler. 70-64 branch circ1.1.it, sufJfJlying a fim aln,m1 system installed in nccmdanre wilh 760.4J(B) or 760.121(B). The branch cirr:1.1.itshall bp installn! in a metal mCPW(~Y, me/al att:>,,'ilia-t)' gutter, sleel-a-nnored cablP, 7)'p,i MC or TypP AC, meeting the applit;able ·mquirernent1 of 250.118, with metal boxP.s, conduit bodies, and enclosures. Informational Note No. 1: For information on c;ombination-type and branch/ feeder-type arc-fault circuit in1.errupters, see UL 1699--2011, Standrmi ,far An°Fault Circuit hllenupt11rs. For information on 0LL1l et branch-circui1 type arc-fault circuit inrerruplers, see UL Subjecc 1699A, 01./lhlle of lm111s1;gnlim1 f or 011/lt;l Bmnc/1 Cim11il J\r,;,Faull Cfrc11il-h,terrup1ers. For information on system combinaLio n AFCl s, see UL Subjeer J699C, Outline of lnve11igalionj'ot Sysl,tm Combi 11ali011 An:-Fault Circuit hlil'rruf>/.ers. Informational Nore No. 2: See 29.6.3(5) of NFPA 72-201'1. . Nalional hr; Alonn rind Sig;nali-l1K Codt, for information relater! LO secondary power-supply requiremems for smoke alarms installer! in dwelling uniLS. Informational Note Nn. 3: See 760.41 (B) and 760.121 ( B) for powe1°supply requirements for fire alarm systems. NATIONAL ELECTRICAL CODE 2020Edition ARTIC LE 2J O- BRANCH ClRCUITS (B) Dormitory Units. All J 20-volt, single-phase, 15- and 20ampere branch circuit5 supplying outlet~ and devices installed in dormitory unit bedrooms, living rooms, hallways, closers, bathrooms, and similar rooms shall be protected by any of the means described in 2 LO. J2(A) ( I ) through (6) . (C) Guest Rooms, Guest Suite s, and Patient Sleeping Rooms in Nursing Homes and Limited-Care Facilities. A ll 120-volt, sing le-phase, l .'i- and 20-ampere b ranc h circuit~ supplying o utlets and devices installed in guest rno1n5 a nd guest sui tes of hotels and motel5 and patient sleepi11g rooms in nursing homes and limited-care facilities shall be protected b y any of tl1e means desc1·ibed in 2 10. L2(A) ( I ) through (6) . (D) Branch Circuit Extensions or Modifications - Dwelling Units, Dormitory Units, and Guest Rooms and Guest Suites. Whe1·e branch circuit wiring for any of the areas specifi ed i.n 2L0. 12(A), (B}, or (C) is modified, replaced, or extended , the b ranch circuit shaJI be protected by o ne of the fo llowi ng: ( 1) (2) By an)' o f the means described in 210.12(A)( l) through (A) (6) A listed outlet branch -circuit-type AFC! located at me fi rst receptacle outlet of tl1e existing branch circuit Exce/Jlion: AFC/ pmtection shalt not be requirecl where thP extension of the r:;.irling /Jmnd, 1:i,rru.it tond'l,1ttors ir not more than 1.8 m (6 fl) llnd does not ·include any additional outlPt,~ or devices, other than spliring devices. This mtasim.rment shllfl not include the conductors insidP an endosure, cabinet, orjunction box. 210.1 3 GroUild-Fault Protection of Equipment. Each b ranchcircuit d isconnect rated l000 A or more and installed on solic!Jy grotmded wye electrical systems of more than 150 vol t5 to grnund, but not exceeding 600 volts phase-to-pha~e. shall be provided with ground-faul t protection of equipment in accordance with 230.95. Informational Note: For buildings that contain health care occupancies. see the reqLLirememsof5 17.17. l!.x1;eption No. 1: This section shall not apt>ly to ,1 clisronnecting means for a rontinuo'l/S indu.st·ri.al process wlwre 11 nonorrler!y shutdown will intmdua additional or incmmd ha:umLt Exmption No. 2: 771iJ se,;tion shall no/ af1/Jly if gmundf@lt fnvtection of equifrmenl is f1rovided on the suf1p!:y side of the branch cin:uil and on thr load sidr ofany lran.ifcmner supplying thr branr.h ri:rrnit. 210.15 Reconditioned Equipment. The follmving shall n ot be recondition ed: ( 1) (2) (3) Equi pment tliat provides ground-fault circuit-interrupte1protection for personnel Equipme nt that provides arc-fault circuit-inten-upter p rotection Equ·iprnent tlrnt provides gTound-fault protection of equipment 210.17 Guest Rooms and Guest Suites. G uest rooms and g uest suites tl1at a.re pr0\7 ided wim permanent provisio ns for cooking shal l have branch circuits instaJled to meet the rules for dwelling unit~. Part IL Branch-Circuit Ratings 210.18 Rating. Branch circ uit~ recognized by this article sha.U be rated in accordance with tl1e maximum permitted ampere rating or .~etting of tl1e overcurren t device. The rati ng for other 2020 E(lition NATIONAL ELECTRICAL CODE 210. 19 tlian individual branc h circu its sha ll be 15, 20, 30. 40, and 50 amperes. Whe1·e conductors of higher a mpacity are used for any reason, the ampere rating or ~etting of tl1e specified overcurrent device sha ll determine tl1e circuit rating. Excepti<m: Multiou//,el brr.cnrh cirr.uits grmter than 50 mnfJl'res slwlf be /Jermitted to stt/1p!:y nonligh.ting outl,et loads 011 industrial premise, whem amditions of mainlenant:f' cmd stLperuision rmsw,, that only qnalified persons senlicl' th.r eq aipmmt. 210.19 Conductors-MinimumAmpacity and Size. (A} Branch Circuits Not More Than 600 Volts. Informationa l Note No. 1: See 310.14 for ampacicy and temperature limimtions of conductors. Ln.formational NoLe No. 2: See Part U of ArticJe 430 for rninirating of motor branch-circuit conduc1ors. mw)) Informational Note No. 3: Conducmrs for branch circu.irs as defined in Article 1()0, sized LO prevent a voltage drop exceeding 3 percent at the farr.hesr outlet of power. heating, and lighting loads, or combinations of such loads, and where the maximum total mil.age drop on both Jee<;lers and branch circuits to 1he farthest ot11let does nm exceed !i percent, provide reasonable efficiency of operation. See I nfonnational Note No. 2 of ~15.2(A) ( I) for voltage drop on feeder conduc1ors. (1) General Branch-circuit conductors ~hall have a n ampacity not les tkm tl1e larger of 2I0. 19(A)( l )(a) or (A)( l )(b ) and comply with ll 0.14(G) fo r equipme nt term inations. (a) Where a branch circuit supplies continuo us loads or an y combination of contim.1otL5 and noncontinuous loads, the minimum bra nch-ci1·c uit conductor size shall have an ampacity not less man the noncon tin uous load plus 125 percent of d1e conti.n uous load i.n atcorc;lan ce with 3 I0.1 4. (b) The minimum bnmch-cfrcuit conductor size shall have an ampaci1y not less tha n the maxi mum load Lo be served after me a pplication of any adjtt~tmen t or correction factors in accordance with 310.15. Exception No. 1 to /1 J(a): If the a.ssernbl)\ in.duding lh.f ove.rcu.rrenl de1.1ii;e~ jJrolecting lht branch d ,rnit(s), i1 listed for operation at JOO J>ercnit of its rriling, th.e mn.jJar.it.y of the l1rand1.-r,i.1ruit cond'l.tctors shall b~ f1ermittfd to be not less- than the nirn of Ifie C<mlinumis load fJlits the noncontinuou.t load in accordance utith 110.14(C). faception No. 2 lo ( l )(a) and ( l )(b): Where a portion of a branch circu.il. is tonnecled at both its supply and load ends lo sefmrntrfy imtalled pre.mire tonnections (LI i:overed in 110. 14(C)(2), it sh.all bt> perrn-itlerL to have an allowable 11mj>11city, in accordance uritlt 310.15, not less than tht> sum of the continuous load jJlus the noncont.imwus load. No fwrtion of a bmnrh circuit installed im.der this Pxnption shall extend into an enclosurt> containing liither the l1r(mrh-drruil su.f1ply or the branrh..;;irmit /o!l(l terminations. (2) Branch Circuits with More than One Receptacle. Conductors of b ranch circuiL~ suppl)~ng mo re than one receptacle for cord-and-plug-connected portable loads sha ll have a n ampacity of not less than tl1e rating of the branch ci1·cuit. (3) Household Ranges and Cooking Appliances. Bra n chcircuit conductors supplying househo ld ranges, wall-mounted ovens, counte 1°mounted cooking units, and o the r ho useh o ld cooking appliances shall have a.n ampacity not less tha n the rating of the branch ei rcuiL anrl not less than the maximum load to be served. For ranges of 8¼ kW or more rating, tl1e minimum branch-circuit rating shall be 40 a m peres. 70-65 210.19 ARTICLE 210 - Exc&{ltion No. 1: Conrlur:tors tapped from. a &ranch circuit not exceeding 5 0 amjm·es s upj1lying elPCtric ran1,ms, wall--mmmt,erl elect1ir ovenr, and cQimter-moiml ed electrir cooking un·ity shall have an am.pacity of not less than 20 rlilnperes rmrl shall be sufficient for the loar.l to be served. These tap r;ondur:tors include any conditctnn that are a /mrt of the li•ads .1'1.1ppliecl with lhe appliancr, thr.tt arP smaller than the {1ranchrircuil condurtors. The ttlf>s shall not be longer than nec.essary Jar snvidng /ftp 11ppliance. BRANCH CIRCUITS (A) Continuous and Noncontinuous Loads. Where a branch circuit supplies continuou~ loads o r a n y combina tion of continuo us and noncontinuou.~ load~, tJ1e rating of the overcun·e n t device shall not be less rhan the noncontinuo us load p lu s 125 p ercent of tl1e continuous load. l 'xteption: Whn-e. the a.~~fmbl)', induding the overcurrenl devices protecting tlu: branrli d rcuit(s), is listrd fin· oprration at 100 fJl'ri:ent of it,~ rating, the arn.j>Prf rating of thP over,:urrmt device .1hafl l!t j)('l'mitted lo f1e not less than llu1 surn. of the amtirw.<Jus lorul fll'!IS tlu1 noncontinu- Exception No. 2: Tiu: neutral condurt,or of a 3-wire branch l'iiruit supplying a ho·Use!J.old elect·ric range. a tvafl.-mm1ntrd oven, nr a cou:nteic1no·unt~d rnoking ii.nit shalt bf pn711i/ted to br smalln than the 11.ngmu:ndul condw:/ors where the r11.axi.rm1.rn de11utnd of a mnge of 8 31, kW or morn rating has been calculated according to Column C of Tab[,, 220.55, but such mnductor shall have an amjJarit:y of not lf'Ss th.an 70 f>err,Pnl of the branc/1-circuit rating and shall not bP sma!lrl' than 10AWG. {B) Conduclor Protection. Conductors shaJI b e protected in accordance with 240.4. .E'lexible cords and fixtu re wi.res shall be protected in accordance with 240.5 . (4) Other Loads. Branch-circuit conductors that suppl)' loads o ther than those specified in 210.3 and otJ1ei- th an cooking appliances as covered in 2l0.19 (A) (3) shall have an ampaci ty sufficient for tJ1e loads served and shall not be smalle r than 14AWC. (D) Outlet Devices. The rating o r setting shall n o t exceed that specified in 210.21 for outle t devices. Exception No. 1 : Tap cond11rtors shall !tavR an ampacity sufficient for the loctd served. l n addition, lluy shaft havr rm mnj>acity of not fess lhan 15 firr i;i,muilf mled lrss than 40 amprres and not lf.tf llwn 20 for rircuits rated al 40 or 50 am,/11'1-e.s and on~ wherf these la/1 conduct(n;f supply £171)' of t!tt following loads: ( 1) (2) (3) (4) (5) Individual lamplwlden or lmnin.aires with laps i<Xlending not longer than 450 mm ( 18 in.) bfyond r.my portion of the la.rnjr holder or lamina.ire A lmninairr having tap rnndttctor.1· as j11rroit.fPd in 4 IO. 11 7 individual o-utlets, othrr than rece/Jlad.e oul{fJS, with taps 1wt over +50 rnrn (18 in.) long i nfrared larnp industrial heating appliances N!mlu:ati 11g lec1ds njr{,eii;ing and ~-nml!-tn.elting rnbles and mals E.xr:eption No. 2; Fixt1.1re wires and jlP>,,'ib/f rn-rds shall be t>Rrmitted to b~ smaller than 14 A.WG tts /JPrmitted by 240.5. (B) Branch Cin:uit,; Over 600 Volts. TI1e ampac ity of conductors shall be in accordance with 3 10.14 and 311.60, as applicable. Brauch-cir·cuit conducto rs over 600 volts shall b e sized in accordance wit11 210.l 9(B) ( 1) or (B) (2) . (1) General. The a mpac ity of branch-circuit conductors sha U not be less than I 25 pe rcent of the d esign ed pote ntial load of utilization equipme nt t11at will be operated simult.."lneou sly. (2) Supervised Installations. For supervised installa tions, branch-circuit conductor sizing shall be p e rn1itted to be determined by qualified persons under e n g ineering supe1v ision. Supervised installatio n.~ are defined as th ose portions o f a facility where b o th of the fo llowing conditio ns are met: (1) (2) Conditio ns of design a nd imtallation are provided nnder engineering supervision. Q ua lified persor1.5 witJ1 documemed training a nd experie n ce in ove1· 600.volt systems provide mainte nance, monitoi-i.ng, and servicing of the system. 210.20 Overcurrent Protection. Branch -circuit conductors a nd equipment sh a ll be protected by overcurre nt protective devices t11at h ave a ra ting or settin g that complies with 210.20(A) through (D ) . 70-6fi O'Lts lortd. (C) Equipment. TI1 e rating o r setting of the overcurrent protective device sha ll not exceed th at specified in the applicable articles refe renced in Ta ble 240.3 for equipm e nt. 210.21 Outlet Devices. Outlet devices shall have an a mpere rating that is n o t less tha n tJ1e k1ad to be served a n d sha ll comply with 210.21 (A) and (B). (A) Lampholders. Where connected to a branch c ircuit h aving a ratin g in excess of 20 amperes, la mpholders shall be of the h eavy-duty type. A h eavy-duty la mpholde r shall have a rating of n or less than 660 watt~ if of t11e admedium type, or not less t11a n 750 watts if of any other type. (B) Receptacles. (1) Single Receptacle on an Individual Branch Circuit. A sing le receptacle installed on a n ind ividual branc h c ircuit shall have an ampere rating not less t11an that oftJ1e branch circuit. Exce/>lion No. I: A 1-pcrp!adt instt.illed in accorr.lancr• wilh 430.81(8). 1 .Exce/1lion No. 2: A receptcu;/f instal/frl rxclusi.rnry for lhr 'USP of a. rorrlr awl-pl?ig-connerted an: welder shall bP fJP1-rnit1ed to have an arnf,erf rating not less than the minim wn bmnclt-fircuil cmulw'/or 1u114xuity det,mniner.l by 630. l l (A) for arr welders. 1 l nformaLion~I No1e: See rhe definido n of rectj1lr,ct,, in Anicle 100. (2) Total Cm·d,and-Plug-Connected Load. Where connected to a branch circuiL supplyin g two or mo re r ecepta cles or outJets, a receptacle sh aU not suppl)' a total cord-and-plugconnected load in excess of the maximum specified in Ta ble 210.21 (B) (2) . (3) Receptacle Ratings. Whe re connecte d to a bra n ch circui t supplying two o r mo re receptacles m· outlet5, receptacle ratings shall conform to the values listed in Tobie 210.2 l (B )(:3 ), or-, whe1-e rated high er t11an 50 amperes, t11e receptacle rating sh all not be less than tJ1e branch-circuit rating. Table 210.21 (B)(2) Maximum Cord-and-Plug-Connected Load to Receptacle Receptacle Rating (Amperes) Maxim.um Load (Amperes) 15 or 20 15 12 20 30 20 30 24 Circuit Rating (Amperes) NATIONAL ELECTRICAL CODE 16 2020 Edition 210. 25 ARTIC LE 210 - BRANCH CJRCUlTS Exception No. J.- Receptacles installed exclu..1ively for the we of one or rnore rmd-and-plug-connectPd an: welders shall lie permitted lo have ampere ratings not less llw:n ihf rninim:u.m branch.-ci:rcuit conduCLor arnpacity detrrmined by 630. 1l (A) or (B) for arc welders. (1) Cord-and-Plug-Connected Equipment Not Fastened in Place. The rating of a ny one cord-and-plug-connected utilization equipment not fa5tened in place sha ll not exceed 80 percent of rl1e bran ch-circuit a mpere rating. Exception No. 2: The arnpen: rating of ti receptacle instal/Pd for elertric ,tisch.mge lighting ~hall be permitted to be based on 410.62(C). (2) Utilization Equipment Fastened in Place. TI1e tota l rating of utilization equipment faste ned in p lace, o ther than luminaires, shall not exceed 50 perce nt of 1.he brancJ1-circuit ampere ,-al:ing where lighting units, cord-and-pl ug-connected utilizati on equipment not fastened in p lace, or both, a re a l50 su pp lied. (4) Range Receptacle Rating. T he ampere rating o f a range receptacle shall be permitted to be based on a sing le range demand load as specified in Table 220..'55. 210.22 Pern:ussible Loads, Individual Branch Circuits. An individual branch circuit shall be permitted to supply any· load for which it is rated. but in no ca~e sha ll 1.he load excee d the branch-circuit ampere rating. 210.23 Pern:ussibJe Loads, Multiple-Outlet Branch Circuits. In no ca5e shall the load exceed tJ1e bmnch-circ uit ampere rating. A branch circuit supplying two or m ore o utle ts or receptacles shall supply only the loads specified according to iL5 size as specified in 210.23(A) th.roug h (D ) and as summarized in 210.24 and Ta ble 2 I0.24. (A) 15- and 20-Ampere Branch Circuits. A 15- or 20-a mpere b ranch circuit shall be permitted to supply lighting units or other utilization equipment, or a combination of both, and shall compl)' with 2 l0.23(A) ( 1) and (A) (2) . Exception: The sm(![l,.af;pli,ance bm-ni;lt cin:uits, lmmdry /Jmnl'h cirwils, and bathroom branch circuits requirl!ll in a dwelling unit(s) by 210.11 (CJ( 1), (C)( 2), and (C)(3) shall .mf>ply only thl' rneptade oi1,tlets specified in that sPclion. Table 210.21 (B)(3) Receptacle Ratings for Various Size Circuits Circuit Rating (Amperes) 15 Not over 15 15 or 20 30 40 or 50 50 50 (C) 40- and 50-Ampere Branch Circuits. A 4(}. o r 50-ampere branch circ uit s hall be permitted to su pply cooking a ppliances that are fastened in place in a n y occupancy. In other than dwelling units, suc h circuits shall be permitted to s upply fixed lighti ng wliL5 with heavy-du ty lampholders, infrared hea ting u n.its, or other utilization equipme nt. (D) Branch Circuits Larger Than 50 Amperes. Bn1.11ch c ircuit5 larger U1an 50 amperes sha ll su pply only nonlighting o utlet loads. 210.24 Branch-Circuit Requirements Summary. The requi rements for circuiLS th a t have two or m ore o utlets o r receptacles, other than the receptacle circuit5 of 210.11 (C) (1), (C) (2) , a nd (C)(3), are summarized in Tab le 210.24. This table provides o nly a s ummary of m inimum requirem e nts. See 210.19, 210.20, and 210.21 for th e specific requ.irement5 a pplying to br,rnch circuit5. 210.25 Branch Circuits in Buildings with More Than One Occupancy. (A) Dwelling Unit Branch Circuits. Bra nch cirCLtits in each dwelling uni t sha ll supply o nl y load5 within that dwelling unit or loads a5sociated o nly with that dwelling unit. Receptacle Rating (Amperes) 20 30 40 (B) 30-Ampere Branch Circuits. A 30-ampere branch c ircuit shall be permitted to supply fixed lighting units with heavy-duty lampholders in o the1' than a dwel ling unit(s) or utilization equipme nt in any occupancy. A rating of any one cord-andplug-connected utiliza tion equipment shall 11ot exceed 80 percent of the hra nch-circ uiLa mpen" rating. (B) Common Area Branch Circuits. Brnnch circuits insta ll ed for lig h ting, central alarm, signal, communications, or other purposes for public or common ,1.reas of a two-family dwelling, a multi fa mily dwelli ng, o r a multi-occupancy build ing shall not Table 2 10.24 Summary of Branch-Circuit Requirements Circuit Rating 15A 20A 30A 40A 50A 14 l~ 14 10 J4 14 8 12 n Overcurrent Protection 15A 20A 30A 40A 50A Outlet d evices: Lampho lders permi1.ted Rcccp1.aclc rating~ Any type 15 max. A Any type 15 or 20 A I-lcavy duty 30A Heavy duty 40 or 50 A H eavy d uty 50A Maximum Load 15A 20A 30A 40 A 50A See 2I0.23(C) Sec 210.23(C) Conductors (m i11. size) : Circuit wires 1 Taps Fixl.llre \\~res and corcl5 - see 240.5 Sec 2J0.23(A) See 210.23(A) Perm issible load Sec 2J0.23(B) 'These gaug-es are for copper co nduno rs. 2 For receprncle rating of' cord-connecred electric-di.Kharge luminai res, see 4 I 0.6\!(C). 2020 Edition NATIONAL E LECTRICAL CODE 6 70-67 210.50 ARTICLE 210- BRANCH CIRCUITS be supplied from equipment that supplies an individual dwelling unit or tenant space. (3) Informational Note: E.xarnples of public or common a.reas include, but are not limited LO, .lobbies, corridors, stairways, laundry rooms, roofs, elevmors. washrooms, store rooms, driveways (parking), and mechanical rooms. sha ll be lnformar.ion::tl Note: See In.formative Annex .I for informafion regarding ADA accessibrncy design. (A) Cord Pendants. A cord connector tl1at is supplied b y a permanently connected cord pendant sha ll be considered a receptacle outJet. (B) Cord Connections. A receptacle outlet shall be .installed wherever fl exible cords witl1 attachment p.lugs are used. Where flexible cord~ are permitted to be permanently connected, r eceptacles shall be permitted to be o nutted for such corcL~. (C) Appliance Receptacle Oullers. Appliance receptacle outlets installed in a dwelling w1it for specific appliances, such as laundry equipment, shall be installed with in 1.8 m (6 ft) of the intended location of the appliance. 210.52 Dwelling Unit Receptacle OutlelS. This section provides require ments for 125-volt, 15- and 20-ampere receptacle o utlets. The receptacles 1·equi1-erl by this section shal.l be in addition to an.y receptacle tl1ati.s as fo llows: (1) (2) (3) (4) Part of a luminaire or appliance, or Controlled by a listed wall-moun ted control device in accordance witJ1 2 I0.70(A) ( J ), Exception No. 1, or Located within cabinets o r c upboard~, or Located more than 1.7 m (5½ ft) above the floor Permanently installed elecn-ic baseboard heaters equipped witJ1 factory-installed receptacle oullets or omlet~ provided as a separate assembly hy the manufacturer shall be permitted as tl1e requ ired outlet or outlets for the wall space utilized b y su ch pem1anenlJy installed heaters. Such receptacle outlets shall not be connected to the h eater circuiL~. lnformar.ional Note: Listed baseboard heaters include instruccions thar may not permit their installaifon below recepracle o utlets. (A) Genera.I Provisions. In every kitche n, family room, din ing room, living room, parlor, library, den, sw1room, bed.room, recreation room, or similar r oom o r area of clwelJing unit~. receptacle o utleL5 shall be installed in accordance with the general provisions specified in2L0.52(A)( L) through (A)(4) . ( l ) Spacing. Receptacles shall be installed such tl1at no point measured horizomall)' along the floor li11 e of any wall space is more man L.8 m (6 Ii.) from a recep tacle outlet. (2) Wall Space. As used i.n this section, a wall space s hall include the following: (1) Any space 600 mm (2 ft) or more in width (including space measured around corners) a nd unbroken along the floor line by doorways and similar openings, fireplaces, and fixed cabinets that do not have coLmtertops o r similar work surfaces 70-68 The space occupied by fixed panels i11 walls, excluding sliding panels The space afforded by fixed room clividers, such as freestanding baH:ype counters or railings (3) Floor Receptacles. Receptacle outlets in or o n floors shal l not be coLL11ted as part of the required number of receptacle out.l et5 unless located within 450 mm ( 18 in. ) of Lhe wall. Part III. Required Outlers 210.50 Receptacle Outlets. Receptacle ouLlets installed ,t~ ~peci.fied in 210.52 through 210.65. (2) (4) Countertop and Similar Work Surface Receptacle Outlets. Receptacles installed for colu1te:rtop and similar work smfaces a5 specified in 210.52(C) shall not be considered as tl1e receptacle ouLlets required by 2 I0.52(A). (B) Small Appliances. (l) Receptacle Outlets Se1·ved. In l11e kitch en, pantry, breaklast room, dining room, or similar area of a dwelling unit, the two or more 20-ampere small-appliance branch circuit5 required by 210.ll (C)(l ) shall serve a ll wall and floor receptacle o utlet.~ covered by 210.n2(A), all countertop o utlets covered b)' 210.52(C), and receptacle outlet5 for refrigeration equipment. E:tce/1Lion No. 1: Tn addition to thP required receptacles specified by 210. 52, switrherl rwptaclPs supf1lied frorn a general-pmpo.w' 15- or 20-ampere branch circuit as require,t in 210. 70(/\)(1), Exreption No. 1, shall be /1ermi1ted. Exuption No. 2: l n addition lo lhP required rn:eptncles s/)111:ified by 210.52, a receplacle outlet to St'rve a sper:ific apt1liance s!tc1ll be /Jermilted to be .mfrpli"d from an individual branch circuit ratfd 15 amperes or grea/e,: (2) No Other OutlelS. The two or more small-applia nce brnnch circuits specified in 210.52(B) ( I ) shall have n o otl1er outJ ets. Excej1tion No. 1: A ·rec.eptadt inslolled solf(V for the flP(trical swptl!:y lo and support of an e!n:tric dol'k in any of tfu, rooms specified in 2!().52(B)( I ). E..,;cl'{Jtion No. 2: Receptacle:, insutl!.ed to pmvirle potvP>· jlJI" .wipplemenlal equifmient and lighting rm gos-fired ranges, mwns, or /'Ountei~ mounted cooking wnits. (3) Kitchen Receptacle Requirements. Receptacles in.5talled in a kitchen to serve countertop surfaces shall b e supplied by not fewer than two small-appliance brnnch ci.t·cuits, e itl1er o r bo tl1 ofw luch shall also be permitted to supply 1·eceptacle outlet5 in l11e same kitchen and in other rooms specified in 210.52(B) ( 1). Additional small-appliance branch circuits shall be permit: ted to supply receptacle o utle ts i.t1 ilie kitchen and o!J1e1- rooms specified in 2 L0.52(B) (l ) . No small-appliance branch circui t sha.11 serve more than o ne kitchen. (C) Countertops and ·work Surfaces. In kitchens, pantries, breakfasl rooms, dining rooms, and similar areas o f dwelling units. receptacle outlet~ for countertop and work surfaces tJ1at are 300 mm (12 in.) or wider shall be installed in accordance witJ1. 210.52(C)(l)tl1rough (C)(3) and sh;:\11 not be considered a~ the receptacle outlet~ required by 210.52(A). For the purposes of this section, whe1·e ming multioutlet a.~semblies, each 300 mm ( 12 in. ) of multioutl et assembly con taining two or more receptacles installed in individual or continuous lengths sha ll be considered co be one receptacle outlet. NATIONAL ELECTRICAL CODE 2020Edition ARTICLE 2J O- BRANCH CIRCUITS (1) Wall Spaces. Receptacle outlets shall be installed so that no point along tl1e wall line is more tllan 600 mm (24 in.) measured horizontally from a receptacle outlet in t hat space. 1:.':,.cception: Receptacle oullets sludl not bf' required directly behind a range, coimter..,mnunted conking unit, or sink in lhe installation described in figure 210.52(C)( 1 ). (2) Island and Peninsular Counlertops and Work Surfaces. Recepr.acle o utlet5 shal l be in.stalled in accordance witl1 210.52(C)(2) (a) and (C)(2) (h). (a) At least one receptacle outlet sha ll be provided for tl1e first 0.84 ni (9 fti), or fraction thereof, of the countertop or work surface. A 1·eceptacle outlet shall be provided for every additional J .7 111 2 (18 Ft2 ), or fraction tJ1ereof, of the countertop m- wrn-k surface. (b) At least one receptacle o utlet shall be located witl1in 600 mm (2 ft) of the outer end of a peninsular countertop or work surface. Additional required receptac.le outlet~ shall be permitted to be located as determined by the installer, designer, or buikling owner. The location of the receptac le outlets shall be in accordance witl1 210.52(C) (3). space exempt from wa ti t "th· ti •th' - . 0 u e WI in ;-+ r 1"f X 300 (12 . ) - - Ou et WI 111 .600 mm (24 in-) ine < mm in. 600 mm (24 in.) 210.52 A peninsular coLm tertop shalJ be measured from th e connected perpendicular wall. (3) Receptacle Outlet Location. Receptacle outlet5 shall be localed i11 one or more of the following: (I) (2) (3) On or above countenop or work surfaces: On or a bove, but nol more tJian .500 mm (20 in.) a bove , tl1e countertop or work surface. In countertop or work su rfaces: Receptacle o utle t assemblies listed for LL.5e in countertops or work surfaces shall be permitted to be installed in coumertops or work surfaces. Below co1mtertop o r works sm-faces: Nol more d1an 300 111111 ( 12 in. ) below tl1e countertop o r work surface. Receptacles i11st,illed below a countenop or work surface shall not be located where the countenop o r work surface extends more than 150 mm (6 in.) beyond its support base. Receptacle outlets rendered not readily access.ible b y applia nces fa5tened in place, appliance garages, sinks, or rangetops as covered in 210.52(C) ( I ), Exception , or appliances occupying a5signed spaces sha ll not be considered a.5 tl1ese required outlet5 . i Informational Note No. I: See 406.5(E) and 406.5(G) for installal.ion of receptacles in co1.ui1enops and 406.S(F) and 406.5(G) for insLallalion of recepcacles in work rnrfaces. See 380. 10 fo,· ios1al lal.ion nfnrnltio1.,tlec a.ssemblies. t Informational Nme No. 2: See Annex J and ANSI/ ICC Al 17.1-2009, Slm1d1ttd on Acr:11s,ibk at!tl Usablt B11ildfr1gs and Fatili- X lil!.s. .Range, counter-mounted cooking unit, or si nk extending from face of counter Space exempt from wall line if X < 450 mm (18 in.) Outlet within 600 mm (24 in.) (D) Bathrooms. At least one receptacle outlet sha ll be installed in bathrooms within 900 mm (3 ft) of the out5ide edge of each basiH. The receptacle outlet sha ll be localed o n a wall or partition that is adjacent to tl1e basin or basin cou11 tertop, located o n the countertop. or installed on the side 0 1- face of tl1e basin cabinet. ln no case shall tJ1e receptacle be located more tJ1a11 300 mm (12 in.) bek1w tJ1e top of tJ1e basin or basin counte rtop. Receptacle outlet assem bli es ILsted for use in countertops shall be permitted to be iJ1sta lled in the countertop. Informationa l Note: See 406 ..~(E) and 4()6.!i(GJ for requireme nc~ for installatio n of recepmdes in countertops. (E) Outdoor Outlets. Outdoor receptacle o utJelS shall h e installed in accordance wiLh 2l0.52(E) (1) through (E)(3). X lnformal.ional Note: See 210.S(A) (:~). (1) One-Family and Too-Family Dwellings. for a one-family dwelling and each unit of a two-family dwelling tJiat is at g rade level, at leas t one receptacle o utlet readily accessible from grade and not more than 2.0 m (6½ ft) above grade leve l shal l be i.nsr.alled at the front and back of tlie dwelling. Outlet within 600mm (24in.) (2) Multifamily Dwellings. For each dwelling unit of a multifamily dwelling where tl1e dwelling unil is located at grade leve l a nd provided with incJjvidual exterior entrance/ egress, at lea5t one receptacle outlet readily accessible from grade and not more than 2.0 m (6½ ft) above g,ade level shall be installed. Range, counter-mounted cooking unit, or sink mounted in corner FIGURE 210.52(C) (1) Determination of Area Behind a Range, Counter-Mounted Cooking Unit, or Sink. 2020 Ei;lition NATLONAL ELECTRLCAL CODE (3) Balconies, Decks, and Porches. Balconies, decks, and porch es tl1at are witJ1 in 102 mm (4 in.) horizontally of tJ1e dwelling unit shal l have at least one receptacle omJet accessible from the balcony, deck. OI- poi-ch. The rece ptacle outle t shall not be located more than 2.0 m (6½ fr) above U1e balcony, deck, or porch walking su rface. 70-69 210.52 ARTICLE 210- BRANCH CIRCUITS (F) L·mndry Areas. In dwelling units, at least one receptacle outlet shall be installed in areas designated for the installation oflaundry equipment. Excef1ti11n No. 1: A receplacle Jar la·1.mrby eq11ipmml sh.all nol be required in a dwelling unit of a multifi.imil:y building wlwre laundry facilities are p1miided on the f>re·misesJor !L5e by all building ocrupan/,J. Excef1lion No. 2: A reuplaclP /!Jr lmmthy equipment sludl not be requirPd in other than onefamil~ dwellings whmJ laitnd1)' fariliti~s are not, to be installed or permitted. (G) Basements, Garages, and Accessory Buildings. for oneand two-famil y dwellings, and multifamily dwelling-s, at least o n e receptacle outlet shall be installed in the area~ specified in 210.52(G) ( l ) tl1rough (G) (3). T hese receptacles shall be i.n addition to receptacles required for specific equipment. ( 1) Garages. l n each attached garage and in each detached garage with electric power, at least one receptacle outlet shall be i.nstalled in each veh icle bay and not. mo1·e tl1an 1.7 m (5½ ft) a bove tl1e noor. Exception: Garage spar.es not altarh.l!lt lo an individual dtvelling unit of a multifarnily ilwelling shall not require a receptacle otitlel in each vehiclt bay. (2) Accessory Buildings. In each accessory building wilh electric power. (3) Basements. In each separate unfinished portion of a basement. (H) Hallways. In dwelling uni.ts, hallways of 3 .0 m (10 [t) or more in length shall have at least one receptacle outlet. As used in tl1is subsection, the h a llway length sh all b e considered the length along lhe centerline of the hallway without' passing through a doo1way. (I) Foyers. f oyers ~hat are not part of a hall way in accordance witJ1 210.52( H ) and tJ1at have an area that is greater than 5.6 nl (60 ft') sh,1ll h ave a receptacle(s) located in each wall space 900 mm (3 ft) or more in widtJ1. Doorways, doo1~side windmvs that extend to the noor~ and similar openings shall nol be considered wall space. 3.7 Ii.near .m ( 12 linear ft) or major fracti.on thereof of show window area meas1.u·ed horizontally at it~ maximum width. 210.63 Equipment Requiring Servicing. A 125-volt, singlephase, 15- or 20-am pere-raled receptacle outle t sh all be installed at an acce.'isible location w ithin 7.5 m (25 ft) of the equipment as specified in 210.fi3(A) and ( B) . (A) H eating, Air-Conditioning, and Refrigeration Equipment. The required receptacle outlet shall be located on the same level a~ the heating, au'--cond.itioning, and refrigeration equipment. The receptacle outlet sha ll not be conn ected to the load side of the equipment's branch-circuit d isconnecting means. E:,;ception: A rect>ptade o-utlet shall not. bt required at one- and IW<>Ja,mily dwellingsfor the seivim ofevaporativPciwlers. (B) Other Electrical Equipment. Tn o tl1e1· than one- and twofamily dwellings, a receptacle outlet sh all be located as specified in 210.63(B) ( 1) and (B) (2) . (J) Indoor Service E<iuipmenL The required receptacle outlet shall be located within the same room or area as t.l1e service equipment. (2) Indoor Equipment Requiring Dedicated Equipmen t Spaces. Where equipment, other tJ1ai1 service equipment, requires dedicated equipment space as specified in 1 l0.26(E ), the required receptacle outlet shall be located within the sam e room or area as tl1e elecu·ical equipment and shal l not be connected to the load side of the equipment's branch-circuit disconnecting means. 210.65 Meeting Rooms. not more than 93 m 2 ( 1000 fl~) in otJ1er than dwell ing unit~ sh a ll have o utlern fo1· non.lockin g-Lype, 125-volt, 15- or 20-ampere receptacles. The outlet. sh all be installed in accord<Ulce with 210.6.~(B). \.\There a room or space is provided with movable partition(s), each room size shal l be determined witl1 tl1e partition in tl1e position tl1at result5 in the smalles t size meeting room. (A) General. Each meeting room lnfom1ationa.l Note No. 1: For d1e purposes of r.h'is section, meeting rooms are ty pically rlesigned or intended for the gathering of seated occupants for such purposes as conferences, deliberations, or similar purposes, where portable e lectronic ec1u.ipme m such as computers, projectors, or simjbr equipment is likely lo be used. 210.60 Guest Rooms, Guest Suites, Dormitory Units, and Similar O ccupancies. (A) General. Guesl rooms or guesl suites in hotels or motels. sleeping rooms in dormitory w1itS, and sim.ilar occupancie~ shall have receptacle out.lets installed in accordance with 2 l0.52(A) and (D) . Guest rooms 01· guest suites provided wilh permane nt provisions for cooking shall have receptacle outlet5 installed in accordance witJ1 all of t.l1e applicable rules in 210.52. (B) Receptacle Placement. 111e total numbe r of receptacle outlets shall not be less than required in 210.52(A). These receptacle outlets shall be permitted to be located conveniently for permanent ftm1i tm·e la)•out. At least two receptacle outlets shall be readily accessible. Where receptacles are installed behind tJ1e bed. the receptacle shall be located to prevent the bed from contacting any attachment plug that may be installed or the receptacle shal l be provided witJ1 a sujtable guard. 210.62 Show Windows. At least one 125-volc, sing le-phase, 15or 20-ampere-rated receptacle outlet shall be irL~talled within 450 mm (18 in .) of tl1e top of a show window for each 70--70 o[ Informational Note No. 2: Examples of rooms chat are not meeting rooms include auditoriums, schoolrooms, and coffee shops. (B) Receptacle Outlets Required. The total number of receptacle outlet~. inclucl.iJ1g floor outlets and receptacle outlets in fixed furniture, sh all not be less lhan as determined in ( 1) and (2) . (J) Receptacle Out.leis in Fixed Walls. The 1·equired number receptacle o utlets sh all be determined in accordan ce witJ1 210.52(A)(1) through (A)(4) . These receptacle o utlets shall be permittecl. to be located as determined l)y the installer, designet~ or building owner. o[ (2) Floor Outlets. A meeting room with a ny Ooor dimension that is 3.7 m ( .I 2 fl) or greate r in any direction and that has a floor area of at least 20 m ~ (215 ft2 ) shall have at leasl one floor receptacle outl.e t, 01· al lea~L one floor o u1Jet to serve receptacle(s), located at a di.stance not Jess than 1.8 m (6 f-t) from any NATIONAL ELECTRICAL CODE 2020Edition ARTTCLE 215 - fixed wall for each 20 m 2 ( 215 ft2) or major portion of floor space . Informa tional Nore No. l : See 314.27(8) for tloor boxes used fo r receptacle~ locared in the floor. ln fonmJcional Nole No. 2: See Article 5 18 for a~se,ubly occupancies designed for LOO o r more persons. 210.70 Lighting Outlets Required. Lig ht ing outlets shall be installed where specified in 2 10.70(A), ( B), and (C) . (A) Dwelling Units. In dwelling unit5, lighting outlet~ sha ll be installe d in accordance w ith 21 0.70(A)( l ). (A)(2), a nd (A)(3) . (1) Habitable Rooms. At least one lighting outlet con trolled by a listed wall-mmmted conu·ol device shq]I be installed in eveiy h abita ble room, kitche n , and bathroom. The wallmounted conu·ol device shall be localed nea1· an e n u,1nce to the room on a wall. 215.2 FEEDERS Exception No. 2: Lighting outlets shall br pnwtitled lo /)e controlled by occnj)mwy sensors Llwl are ( 1) £n addition lo listed Wllllr11wtmled wnlrol devicts or (2) located at a cuslomtl1)' wall swilrh In cation and rquip,ped with r1 mamwl ov1'1Tide that allotus 1hr semor to funrtion as a wrdl switch_ (C) All Occupancies. For attics and w1.de1floo r spaces , utility rooms, and ba5ements, a t lea5t o n e lig hting o utle t conta ining a switch or conu·olle d by a wall switc h or listed wall-mounted conn·ol device sha ll be instal led where these spaces are used for storage Ol- contain equipment requit-ing servicing. A point of control shall be at each enu-y that permit~ access to tl1e attic a nd underfl oor space, utili ty room , or baseme nL. \'\1h e re a lig h ting outlet is installed for equipment req uir ing service, the lig·hti ng outlet sh a ll be installed at or near tl1e equipme nt. Ex«,ptinn No. 1: In other than lritrlums and balhromns, onr. or morf rec&ptac/,es controlled by a lifted wall-11wunted con/ml device slwLl be pcnniltfd in lifu of lighting outle/.s. ARTICLE 215 Feeders Ext:fption No. 2: Lighting outlets shall br prrrnitted to be contmllfd by ocmpancy sensors that a re ( 1) in nddition to listed wall-moimled i:ontrot d;,vii:es or (2) lomtrd al ri customary w111/ switdt loc£1tion and equij1ped with. (I mam1al override thal toill allot.ii thf sensor to function as a wall switrh. 215.l Scope. This article co vers the insta lla tion require ment~, overcurre nt protectio n require men ts, minimLUn size , and ampacity of conducto rs fo r feeders. (2) Additional Locations. Additiona l lig hting outlets shall be i1uralled in accordance w ith the following: Exception: Feedn~ for electrolytic cells as covered in 668.J(C)( l ) and (l ) 215.2 Minimum Rating and Size. (2) (3) At lea5t one lig hLing outlet controlled by a listed wal lmounted conu·ol device shall be installed in ha llways, stairways, attac hed garages, and detached garages with e lecu·ic power. for dwelling uni ts, attached garages, and detached garages with elecu·ic powet~ at l.ea5t one lighting outlet controlled by a listed wall-mounted con trol device sha ll be installed to provide illumination on the exterior side of outdoor entrances or exits with grade-level access. A vehicle door i.n a garage sha ll not be conside red a.5 an outdoor enu-ance o r exit. \i\7here one or more ligh ting outlet(s) are installed for interior stairways, tl1ere shall be a listed wall-moun ted control device a t each floor level a.nd landing level tha t in cludes an e nu-yway to control the lig h ting outle t (s) where the stairway between floor levels ha5 six riser o r more. l!):crption to (A)(2)(1), (f\)(2)(2), 11n1t (f\)(2)(3): In hallways, in stairways, and al ouldoor entrancPs, mmote, central, or autmnatic i:ontrol of fighting shall /Jr, pmnitlrd. ( 4) Lig h ting outlet5 controlled in accordance witl1 2 10.70(A) (2)(3) shall not be conu·olled by ll5e of listed wallmow1.ted cono·ol devices unless they provide the full range of dimming conn·ol at e ach location. (B) Guest Rooms or Guest Suites. In hoteL5. mote ls, o r similar occupa ncies, guest rooms or g uest suites sh all have a t least o ne lighting ouLlet conn·olled by a listed wall-mo unted conu-ol d evice iru,talled in every ha bitable room a nd bathroom. l!.xception No. 1: in other tluin bathrooms and kitclu·ns where prrJt!ided, onf or nUJre receptacles controlled by a listed wall-mounted con/ml device shall be permitted in liru of lighting IJtLilets. 2020 ll\lirjon NATIONAL E LECTRICAL CODE (C)(4). (A) Feeders Not More Than 1000 VoJts. (l) General. f eed er conductors shall have an ampacity not less than the larger of 21.'>.2(A) (]} (a) or (A)(]) (b ) and shall comply with ll 0.14(C) . (a) '"'h ere a feeder su pplies continuous loads or a ny combination of con tinu oLL5 and noncon tinuous loarfa, tl1e minimLtm feeder conductor size ~hall have a n ampacity not less than the no ncontinuotL5 load plus 125 pe rcen.c of the con tinuous load. txception No. 1: 1cf the assembly, inrtuding thP ovetrnrrent rleoires prote,;ting tlw feeder(.~), is listrd for oj1emlion at I 00 percent of ils ra:ling, the am.padty of th,,feeder conductors shall be pennil/ed ta be not fi,ss than the sum ofthe rontinuous load plus the nonr:ontinuous load. Excepti<m No. 2: \iWiere a /Jortion of a feedflr is c<mnected at both its .mp/J/:j and load ends lo sPfi4ratef:v installed pressure connections CL, rnvemd in 110.l 4(C)(2), it shall be pennittnL to hav,1an ampr.1cil~ no/ less than lhe smn of the continuou.r lnad f1/u:; the nonconti:n·iwiL5 load. No po1tio11 of a feeder insll1lftd wuwr tfiL5 exar/1tion J/ut!f extend into a:n enclosure containing eithn the feeder su/>ply or the f eedfr [o(ld lPrminations, as 1;ov111r,d in 110.14(C)( 1 ). Exupti1Jn No. 3: Grmmded mnduclors tlwt are no/ mnnl'CtPd to an overrnrrent devim sh(lll he penn£1ted lo bP sized al 100 perrml of lit/' c<mtin uom and noncontinuous load. (b) The minimum feeder conducto r size sha ll have an ampacit1, not less than th e maximum load to be 8erved after the a pplication of any adjustment or correc tio n factors in accordance with 310.1 4. lnformaf.iona l Note No. l : See Examples DJ d1rough D 11 in lnfr,rmative Annex D. 70-71 215.2 ARTICLE 2 15 - lnformat.ional Nme No. 2: Conductors for feeders, as c;iefined in Article LOO. sized ro prevent a voltage drop exceed ing 3 percenL at the farthest outlet of' power, heating, and light.ing loads, or cornbinat.ions of such loads. and where d1e maxi.mum total voltage drop on both feeders and b ranch circuits m the far1 hes1 outlet does not exceed 5 percent, will provide reasonable effi. ciency of operat.ion. Informational Note No. 3: See 2IO.l 9(A) , Info rmational Note No. 4, fot voltage drop for bran ch circuits. (2) Grounded Conductor. The size of the feeder circuil grounded condu ctor sha ll not be smal ler than that required by 250.1 22, except that 250.1 22(F) shall no t apply whe re grolmded conductor5 a re run in paral lel. Additiona l mi nimum sizes shall be as specified in 215.2(A) (3) u nder th e cond itio ns sti pula ted. (3) Ampacity Relative to Service Conductors. The feeder co ndu ctor ampacity sha ll not be less than that of th e service conductors where the feeder conductor s can-y the tota l load supplied by service condu ctors with an ampacity of 55 am peres or less. (B) Feeders over 1000 Volts. The a mpacicy of conduCLors s hall be in accordance with 310.14 and 311.60 as applicable. Where installed, th e size of the feeder-circuit grow1ded con d uctor sh all not be sma lle r than that requi red by 250.1 22, except rh at 250. J 22 (F) sha ll not apply where grounded conductors are rw1 in parall el. Feeder conductors over I 000 volts sha ll be sized in accordance with 2 15.2(B)( I ), (B) (2), or (B) (3) . ( 1) Feeders Supplying Transformers. The a mpacity of feeder conductors shall not be less than the sum of the na me plate ratings of Lhe tra nsforme rs sup p.lie d when o nly transformers are suppli ed. (2) Feeders Supplying Transformers and Utilization Equipment. T he am pacity of feeders su pplying a combination of transforme rs a nd u tilization equipmen t sha ll not be less tha n the swn of the namepla te ratings of the transforme1·s a nd 125 percen t of the designed potential load of the utilizatio n equipmem that,vi ll be o pe rated sim ultanenu~ly. (3) Supervised Installations. Fo t· su pe1·vised installa tio ns, feeder conductor sizing sha ll be permitted to b e determined by qualified persons unde r engineering su pervision in accord ance with 3 10.l 4( B) or 3 l l.60( B) . Supervised installations are defined as Lhose portions of a facility where all of the following conditions are met: (1) (2) Conditions of desig n a nd ir1~talla tio.n a1·e provided under engi neering supe1-vision. Qualified persons with documen ted tn.in ing a nd expe1ie nce in over 1000-volt systems provide maintenan ce, monitoring, a nd serviciJ1g of the system. 215 .3 Overcurrent Protection. Feeders shall be prorected against overcu rren t in accordan ce with Part 1 or Ar ticle 240. Whe1·e a feeder sup plies continuo us loads o r a ny combination of continuo us and noncontin uou~ loads, the ra ting of th e overcurre nt d evice shall no t be less Lha n the no ncontin uous load plus 125 pe1-cel1l of the contin uous lo<1d. Excej>tion: Wherr thr as.mmbly, including the (J(Je1nmrml devites prot n:ting the jPeder(s ), is listed for o/Jeration al LOO j,e,r;en.t of ifs rating, the am/Jere mting rif the overrnmmt devicr slwfl be pP.nniUed to be nnl less than t.l,e sum of!.hr rnntin't tmls load plus the nonconliniww load. 70-72 FEEDE RS 215.4 Feede1-s wilh Common Neutral Conductor. (A) Feeders with Common Neutral. Up to tlu·ee set5 of 3-wire feeders or Lwo set~ of 4-wire or 5-wfre feeders sha ll b e permitted to utilize a com mo n neutral. (B) In Me tal Raceway or .Enclosure. ,i\,'here Lnstalled in a me tal raceway o r o th er metal enclosu re , a ll conductors of a ll feed ers using a commo n ne utral conductor sha ll be e nclosed within the same raceway or 0 Lhe1· e nclosure a~ requi red in 300.20. 215.5 Diagrams of Feeders. If required by the a utho rit)' havi ng jurisdictio n, a d iagra m s howin g feeder details shall be p rnvided prior to t he installa tion of th e feeders. Such a diagrnm sh a ll show the a rea in square feet of the building or other su·ucture supplied by each feeder, the total calcul ated load before applyi ng demand fact.ors, the demand factors used, the calculated load after applying dema nd factors, and tl1e size and typ e of cond ucto rs to be m ed . 215.6 Feeder Equipment Grounding Conductor. \<\fhere a feeder supplies branch circuit~ in whicl1 equipment grounding con d uctors are required, the feeder sh a ll in clude or provide an equipment ground ing cond uctor, to whic h th e e quipme n t g rounding cond uc tors of the bra nch circuits shall be connected. Wher e the feeder supplies a separate building or su·ucture, the re quirement~ of 250.32 shall apply. 215.7 Ungrounded Conductors Tapped from Grounded Systems. Two-wire de c ircuits and ac c ircui ts of two 0 1· more u ngro tmded con d uctors sh a ll be pe rmitte d to be tapped from the tu1grounded conductors of circu its having a grou nded n euu·al conductor. SwiLching de vices in each ta pped circui l shall h ave a pole in each u ngrounded conductor. 215.9 Ground-Faull Circuit-Interrupter Protection for Personnel. Feeders shall be per m.itted to h e protected by a grow1dfaulLc ircuit.interrupter installed iJ1 a readily accessible locatio n in lie u of the pro visio ns for such interrupte rs as specified in 210.8 and 590.6(A). 215.10 Ground-Fault Protection of Equipmenl. Each feeder d isconnect rated IO00 a mperes or m ore an d installed o n solid ly grounded wye electr ical systems of mo re tha.n 150 volts to grow1d, but no t exceeding 600 volt5 phase-to-phase, ~hall be provided witl1 ground-fault protection of equipme m in accordan ce with 230.95. l nfo rma t.io na l Nme: For bu.il(lings 1.h at cont,,fo health care occupancies, see 517. 17. 1.-'.xr:ep!.inn Nn. 1: This section shall not aj1ply lo a disconnr.cting nieans for n continuous industrial proffSS whmr a nrmorderly shnl.down will introduc,, additional or in.creased haz.mrls. l!.'xct/1Lion No. 2: This section shall not app{y ifgrrmndfa·1tlt f1rntection ofequifnnrmt is fYrovi4ed on thr .mf1ply side of lhl' f Pfder rind 1m the load si.de of any lransfonner S'!Lf>plying the fefde1: Excl'j1lion No. 3 : If temporary feeder cond1uto1~· are used to wnnect a (I farility for repair, nwinlenance, or emngencies, grm.vndc fau/J. /Jmtection ~f equi/nnent shall not be required. Temporaly feedn:i with.out ground-fault pmtection shall he perniilted for /he time pnind necemiry b~il :;hall not. exceed 90 daJw. genflmlor lo 215.11 Circuits Derived from Autotransformers. Feeders shal l n ot be derived from au totransformers un less the system supplied has a grounded conduc trn· tl1qt is elecffically connected to a grounded conducto r of the system supplying th e a utotransformer. NATIONAL ELECTRICAL CODE 2020Edition ARTICLE 220- BRANCH-CIRCUIT, FEEDER, AND SERVICE LOAD CALCULATIONS Excepi·ion No. 1: An autotransformer shall be pemlitted without lhe connection to a gmunded rnndw:tor whm! tmnsforming from n nominal 208 vol!s lo a nmni·nal 240-voll supp{v or similar~ Jmm 240 volls to 208 volts. l.xcfption No. 2: in indwlri.nl occupancies, whrre rnndilions of maintenance and si1/1eroisinn ensitrf that only quolifi.ed person.t servicr the imtallation, autotmnsformen shall br permittrd to .rnf>/1/y nornini1l 600-volt lor;ds from nominal 48()..volt systnns, and 480.voll loads from nominal 600-volt ~ysterns, witlwut lite connertion to a similar gm unded conductm: (4) An approved permanent marking means such as sleeving or shrink-tubing tliat is suitable for the conductor size, at all ternlinatiou, connection, and splice poinL5, witl1. imprinted plus signs (+) or tl1e word POSITIVE or POS durably marked on insulation of a color other tl1an g1·een, wh ite, gray, or black (b) Nr.gativP Po(arity, Sizes 6 A WG or Smalle1: \\There the negative polarity of a de system does not serve as tl1e connection for the g ro unded conductor, each negative LU1grouncled conducto1· shal l be identified b)' one of the following means: 215. 12 Identification for Feeders. (1) (2) (A) Grounded Conductor. The g1·ounded conducto1· of a feede1; if insulated, shall be identified i.t1 accordance with 200.fi. (3) (B) Equipment Grounding Conductor. The equipment grounding conductor shall be identified in accordance with 250.1 19. (4) (C) Identification of Ungrounded Conductors. Ungrow1ded conductors shal l be identified in accordance with 2 I5.12(C) ( l ) or (C)(2), as ,1pplicable. (1) Feeders Supplied from More Than One Nominal Voltage System. \!\There tl1e prem.ises wiring system has feeders supplied frbm more than one nominal voltage system, each ungrounded conductor of a fee der shall be identified by phase or line and system ar all termination, connection, and splice points in compliance with 2 15.12(G) (1) (a) and (b). (a) Means of ldentijiration. The means of ide ntification shal l be permitted to be by separate color coding, marking tape, tagging, or other approved means. (b) Posting ofldrmtification Means. The method utilized for conductors 01·iginating wi thin each feeder panelboard or similar feeder distribution equipment shall be documented in a marn1er that is readily available or shall be permanently posted at each feeder panelboard or simila1· feeder disu-ibution equipment. (2) Feeders Supplied from Direct-Current Systems. Where a feeder is supplied from a de system operati11g at more than 6() volts, each ungrnunded conductor of 4 AWG or larger shall be identified by polarity al all termination, connection, and splice point~ by marking tape, tagging. or other approved means; each ungrounded conductor of 6 AWG or smal.le1- shall be identified by polarity al all termination, connection, and splice points in compliance with 215.12(C) (2) (a) and (b) . The identification methods utilized for conductors originating within each feeder pwelboard o r _simila1· feeder distribution equipm em shall be documentect in a manner tha,t is readily available or shall be permanently posted at each feeder panelboard or similar feeder disu·ibution equipment. (a) Positivf Polw·ily, Sizes 6 A WG or Srnalle1: 'Where the positive polarity of a de system does not serve as tl1e connection for the grounded conductor, each positive ungrounded conductor shall be identified by one of the following means: (1) (2) (3) A continuous red outer finish A continuous reel stdpe durably marked a long the conductor's entire lengtl1 011 insulation of a color other than green, white, gray, or black Imprinted plus signs (+) or the word POSITIVE o r POS dw-ably marked on insulation of a colrn· otl1er than green, wh ite , gray, 01· black, and repeated at intervals not exceeding 610 mm (24 in.) in accot·dance with 310.S(B) 2020 ll\lirjon NATIONAL ELECTRICAL GODE 220.5 A con ti.nuou.5 black o uter finish A continuous black stri pe dw·ably ma1-ked along the conductor's entire le ngth on insuJati.on of a color otlu;r than green, white, gray, or red lmpri.t1ted minus signs (-) or tl1e word NEGATIVE or NEC durably marked on insulation of a color other than gi·een, white, gray, or red, and repeated at intervals not exceeding 610 mm (24 in.) in accordance witl1 3 10.S(B) An approved permanent ma1·king means such a5 sleeving or shrink-tubing that is suitable for the conductor size, at all termination, connection, a nd splice point~, witl1 imprinted mimrn signs (-) or the word NEGATIVE o r NEG durably marked 011 insulation of a color other thw green, white, gray, or red ARTICLE 220 Branch-Circuit, Feeder, and Service Load Calculations Part I. General 220.1 Scope. This article provides requirement5 for calcnlating branch-c ircuit, feede1; and service k,ad5. Part 1 pi-ovides general requirements for calculation meth()d5. Part II provides calculation metl10cL5 for branch-circuit loads. Part5 ID and IV provide calculation methods for reeder and service loads. Part V provides calculation methods for farm loads . Informal.iona l Note No. Annex D. I, See examples in Informative [nformal.ional Note No. 2: See Figure 220.1 for informal.ion on che organi1.alion of Anide 220. 220.3 Other Articles for Specific-Purpose Calculations. Table 220.3 shall provide references for specific-pLU·pose calculaLion requirements not located in Chapters 5, 6, or 7 that amend or supplement the requirement5 of tl1is a,rticle. 220.5 Calculations. (A) Voltages. Unless Other voltages are specified, for purposes of calculating branch-circuit and reeder loads, nominal system voltages of J 20, 120/ 240, 208Y/ J20, 240, 347, 480¥/277, 480, 600¥/ 34-7, and 600 volt~ shall be used. (B) Fractions of an Ampere. Calculations shall be permitted to be rOLmded ro the nearest whole ampe1°e, witl1 decimal fractions smaller tl1an 0.5 dropped. 70-73 220.10 ARTICLE 220- BRANC H-CillC UIT, FEEDER, AND SERVICE LOAD CALCUIATIONS Part I General Part II Branch-circuit load calculations (B) Energy Code. Where the building i~ designed and constructed to comply with an energy code adopted by th e local authority, the lighting load shall be permitted to be calculated using the un it values specified in the energy code where the following conditio ns are met: ( I) Part Ill Feeder and service load calculations 220.61 Neutral Loads Part IV Optional feeder and service load calculations (2) (3) Farm dwellings only Farm dwellings only (4) A power moniw1-ing system is installed tllat will provide contiJrnou s in formation regarding the total general lig hting load of th e build ing . The power mon itoring system 1vi.ll b e set with alarm values to alert the building own er or m anager if tl1e lighting load exceecl~ t he values set by the en e rgy code. Automatic mean s lo take action to 1-educe the connected load shall h e permitted . The demand facto rs specified in 220.42 are noLapplied to the gen eral lighting load. The continuous lm1d multiplier of l 2!'i percen t sh a ll be applied. FIGURE 220.J Branch-Circuit, Feeder, and Service Load Calculation Methods. 220.1 4 Other Loads - AH O cc·u pancies. In alJ occupa ncies, the minimum load for each outlet for genera.I-use receptacles and outleL~ not u sed for general illumination shall not be less tl1a11 that calculated in 220.l 4(A) through (M), tl1e loads s hown being hased on nominal br;m ch-circ;uit voltages. Part II. Branch-Circuit Load Calculations 1'..'xctj1Linn: The loads of nullets serving switchbolvrds and switching Jmmes in t,eleplwne fxclumges shall b~ waived from the mlc1.dalions. Part V Farm load calculations 220.10 General. Branch-circuit loads shall be calculated as sh own in 220.12, 220.1 4 , and 220.16. 220.11 Floor Area. The floor area fo r each floor sha ll be calculated from the o u t5ide dimensions of the building, dwelli.ng unit, or other area involved. F or dwelling units, the calculated fl oor area shall not include open porch es, garages, or unused or nnfini.shed spac;:es not adaptable for furu,re use . 220.12 Lighting Load for Non-Dwelling Occupancies. (A) General. A unit load of not les, than tJ1at specified in Table 220.12 fo r non-dwelling occupancies and the floor are a determined in 220.11 shall be used to calcLLlate the miJ1imum lighting load. Motors rated less tl1an 1/g HP and con nected to a lighting circuit s hall be con sidered general lighting load. Informa tional Note: The 11ni1 values of Tohle 220.12 are based on minimum load condirjons and 100 percem power facwr an<l may 1101 provide sufticiem capacity for the i nsLallai.lon cnmemp laterl. (A) Specific Appliances or Loads. A J1 outlet for· a specifi c appliance or otl1er load not covered in 220. J4(B) tl1rough (M) shall be caln1lated based on the ampere rating of tl1e appliance or load served . (B) Electric Dryers and Electric Cooking Appliances in Dwellings and Household Cooking Appliances U sed in Instructional Programs. Load calcula tio n s sh a ll be permitted as specified in 220.54 for electric dryers and in 220.55 for electric ranges ,md other cookiJ1g applian ces. (C) Motor Outlets. Loads for motor outlet~ ~hall be calc11lated in accordan ce wi.t h the require ments in 430.22, 430.24, an d 440.6. (D) Luminaires. An o utle t supplying luminaire(s) shall b e calculated based on tl1e max.imum volt-ampere rating of tl1e equip m ent and lamps for whic h ilie luminaire(s) is i-ated. (E) Heavy-Duty Lampholders. Outlets for h eavy-du ty lam pholde1·s shall be calcu lated at a minimum o1' 600 volt-amperes. Table 220.3 Specific-Purpose Calculation References Calculation Air-conditioning and n ::h;gerating equipme nt, br,mchc-ircuit conductor sizing Fixed clccui c heating equipmer\t for pipelines and vc~scls. branch-circuit sizing .Fixed e lt'Cl.ric s pace-hearing equipment, br,lnch-circuil sizing .Fixed o utdoor electric deicing and snow-melting equipment, branch-circuit ,izing Motors, feeder dem and faCLor :\fotors, m ulti.motor and combin<ltion-Joad cq uipmcm Mo tors, several mo tors or a motor(s) and otbcr load(s) Over 600-voli. branch-circuit calCLLla1iom Over 600-volt feeder calcula tions Pha.~c c<rnveners, conducto rs Storage-type wate1- hc.1ters 70--74 Article Section ( or Part) 44.0 Part N 427 4.27.4 424 42(j 424.3 426.4 430 430 430 2]() 4.30.26 430.25 4nf> 430.24. 2J0.19(B) 2l 5.2(B) 455.6 422 422. ll (E) 215 NATIONAL ELECTRICAL CODE 2020 Edition ARTICLE 220- BRANCH -CIRCUIT, FEEDER, AND SERVICE LOAD C'.ALCULATIONS Table 220.12 General Lighting Loads by Non-Dwelling Occupancy Unit Load Volt-amperes/ Volt-amperes/ Type of Occupancy m- ft2 Automotive fac ility Convc11tion ccnte ,Counh.ous(· Dormitory Exercise center Fin: station Gymnasium" Healtl1 care clin ic Hospital Ho tels ,\nd 111o tels, includ ing ap:u·tmcnt houses without p rovisions for cooking by tenants" Library ManufaCtLuing facility" Motion picture theater Museum Officerl Parking garage" Pe nitentiary Performing arts theater Po lice statio n Post office Re Ligious facility Restauran{ , Rctail8·" School/ universil)' SporL~ arena Townh<1U Transp ortation Warehouse Workshop 16 1.5 , l !j 1.4 15 1.4 16 1.5 15 14 l .4 18 1.3 J.7 17 17 1.6 1.6 18 1.7 16 1.5 24 2.2 17 17 14 1.6 l.6 3 0.3 13 16 14 17 1.2 1.5 24 2.2 l6 1-5 l.Y 20 33 33 15 1.3 1.3 1.6 3 3 13 1.4 1.2 13 U2 18 1.7 No Le: 171e 125 percenL m ulciplier for a concinuous load as specified in 210.20(A) is included when using the unit loads in Lhis table for calculating the rninimLLm lighcing load for a specit-ied occupancy. "Armories and auditoriums a re considered gymnasiunHyPe occupancies. bLodge rooms are similar to hote ls and motels. ' lndusrrial cornmercial loft bufldings are considered manufacruringtype occupancies. dBanks are office-type occupan cies. cGarages - commercial (storage) are considered parking garage occupancies. 1 C lubs a re considered reswuranc occupancies. •'Barber .shop~ and beauty parlo rs are considered retail nccupancies. hStores a re considered retail occupanc ies. (F) Sign and Outline Lighting. Sign and outline Lighting outlets shall be calculated at a nunimum or 1200 volte-amperes for each required bra n ch circuiL speci fied in 600.5(A) . (G) Show Windows. Show windows shall h e calcula te d in accordance with either of the fo llowing : ( L) (2) The unit load per outlet a~ req11i1-ed in other provis'ions of th is section At 200 volt-amperes per linear 300 mm ( 1 ft) of s how wi ndow 2020 ll(lirjon NATIONAL £LllCTRIC.AL CODE 220. 14 (H) Fixed Multioutlet Assemblies. Fixed 111ultiouLle1. assemblies used in other th<lll dwelling units or the g u est rooms or guest suites of h otel.s or m otels sh a ll be calculated in accorda n ce with (H ) ( 1) or (H ) (2) . For the purposes of this section, the calculation shall b e permitted to b e based o n th e portion that contains receptacle outlet~. (l) (2) ·w here applian ces are w1likely to be lL~ecl simultaneously, each 1.5 m (5 ft) or fraction thereof of each separate and conti11uous length shall b e con sidered as o ne o utlet of n ot less than 180 volt-amperes. Where appliances are like ly to be used simultan eou sly, each 300 mm ( I fL) o r fraction tl1ereof shall be conside red as an outlet of not less than 180 volt-am peres. (l) Receptacle Outlet.$. Except a5 covered in 220. 14(1) and (K), receptacle outlets s hall be calcula ted a,t not less than 180 volt-ampe res fo r each single oi- for each multi ple receptacle o n one yoke. A single piece of equipment consL~ting of a multi p le receptacle comprised of four or more receptacles shall be calculated at n o t less tl1an 90 volt-amperes per receptacle. This provision sh all not be applicable to th e receptacle outlet5 sp ecified i.J1 210.l L(C) (l ) and (C)(2) . Q) Dwelling Units. In one-fmnily, two-family, and multifamily dwelli.J1.gs, the minimum LLnit load sh a ll be not less tJ1an '.~3 voltamperes/ m~ (3 volt-amperes/ fc2) . The ligh ti.J1g and recep tacle o utlet~ s pecified in 220. l 4(J)( l ) , Q)(2), and (1)(3) are included in the minimum unit load. No addi tional load calculations shall be required for such outlets. The minimum lighting load s hall be d etermined using tl1e minimum unit load and tl1e floor a rea as dete rmined in 220.11 for dwelling occupancies. Motors rated less than Ys hp and connected to a Lig hting c ircuit s hall b e cons idered part of the minimum lig hting load. ( 1) (2) (3) All general-use receptacle outleL~ of 20-ampere rating or less, includ i.J1g receptacles connected to tl1.e circuits in 210.ll (G)(3) and210.ll (C)(4) 1l1e receptacle outlets specified in 210.52(E) and (G) TI1e lighting o utlets specified in 2 10.70 (K) Office Buildings. In office b11.ild i11gs, the receptacle loads shall b e calculated to be the larger of (l ) or (2) : (l ) (2) TI1e calculaterl load from 220. 14(I) after a ll demand factors h ave b ee n a_pplied 11 yolt-amperes/m~ o r l vol t-am pe re/ ff (L) Other Outlets. OtJ1er outlet~ not covered in 220.1 4(A) through (K) shall b e calculated based on 180 volt-amper es per outlet. (M) Hotel and Motel Occupancies. In g uest rooms or guest suites of h otels a nd m otels, tl1e lighting mi.cl receptacle outlet~ s pecified i.J1 220.1 4(M) (1 ), (M) (2), and (M) (3) a re included in 1J1e minimum unit load in Table 220. l 2. No additional load calculations shal l be requi red for such o u tle ts. The 111.i.J1i.mum lig hting load shall be determined using the m ini.Ju um unit load and the floor area as determined in 220.11 fo.r hotel a n d m otel occupanc ies. (I ) (2) (3) All generah1se receptacle outlet~ of 20-ampere rating or less, including receptacles connec ted to the circuits in 210 .11 (C) (~) and 21 O.ll (C) (4) T h e receptacle outlets specified i.J1 210 .52(E) (3) The lighting outlets specified in 210.70 70-75 220.16 ARTICLE 220-BRANCH-CillCUJT, FEEDER, AND SERVICE LOAD CALCUI.ATTONS 220.16 Loads for Additions to Existing Installations. Table 220.42 Lighting Load Demand Factors (A) Dwelling Units. Loads added r.o an existing dwelling un it(s) shall comply with the following as applicable: (1) (2) Load~ for structural additions to an existing dwelling unit or for a previously unwired portion of an existing dwelling unit shall be calculated in accordance with 220. 14. Loacl5 for new circ uit5 or extended circuits in p reviously wi1·ed dwelling units shall be calculated in accordance wilh 220.14. (B) Other Than Dwelling Units. Loads for new circu.it5 or extended circuits in other than dwelli ng unit5 sh all be calculated in acconlance with eid1er .2 20.12 or 220.14, as applicable. 220.18 Maximum Loads. The total load shall not exceed the rating of the br,1nch circuit, and it shall not exceed the maximum loads specified in 220. 18(A) through (C) under the conditions specified therein. (A) Motor-Operated and Combination Loads. Where a circuit supplies on ly motor-operated loads, Article 430 shall apply. Where a circLLit s upplies only air-conditioning equi pment, refrigerating equ ipment, or both, Article 440 shall apply. for circuits supplying loads consisting of motor-operated utiliza tion equipment that is fastened in place and has a motor larger than ½ hp in combination with oLher loads, th,e total calculated load shall be based on L25 percent of the largest motor load plus the sum of the other loads, (B) Inductive and LED Lighting Loads. For circuits supplying lighting units Lhat have ballast~, transformers, autotransforme rs, or LED d rivers, the calculated load shall be based on the total ampere ratings of such LmiL~ and not o n the mtal watts of die lamps. (C) Range Loads. ft sha ll be permissib le to apply demand factors ror range loads in accordruice widi Table 220.55, including Note 4. Part ill. Feeder and Service Load Calculations 220.40 General. T he calculated load of a feeder or se1vice shall not be less than the sum of the loads on the brru1ch circuits supplied, as determined by Part Ir of thi~ article, after any applicable demand factors pem1itted by Pan III or N or required by Pan V have been applied. Informational Nme: See Examples D l(a) through D10 in Informative Annex D. See 220.18(8) for the maximum load in amperes permitted for lighting ,.lllil~ operating at less than 100 pe rce m power facio r. 220.42 General Lighting. The demand factors specified in Table 220.42 sha ll apply to dial portion of die total bra nchcircuit load calculated for general illumination. They shall not be applied i11 deLennining the numbe 1- of branch cirn 1its for general illumination. 220.43 Show-Window and Track Lighting. (A) Show Windows. For show-window l.ighting, ,1 load o f not less than 660 volt-amperes/ linear meter or 200 volt-amperes/ linear fool shall be included for a show window, measured horizontally a long its ba.5e. Type of Occupancy Dwelling uniL5 HoLc:ls and motels, including apartment houses wi Lhou t pro~i.sion for cooking by tenants* Warehouses (st0rage) All others Portion of Lighting Load to Which Demand Factor Applies (Volt-Amperes) Demand Factor(%) ]00 35 2.l'i First 3000 at From 3001 to 120.000 at Remainder over 120,000 at First 20,000 o r less a1. From 20,0UJ to l 00,000 at Remainder over 1OU ,000 at 60 50 35 First l 2,500 or less at Remainder over J2,500 a t JOO 50 Total volt-amperes JOO *The demand fanors of this Lab le shal I not apply to the calculaLed load of feeders or services s upplying ar eas in hotels and rnmels where cbe entire lighting is likely r.o be l.Lsecl aL one Lime. as in ballrooms or dining rooms, (B) Track Lighting. Fo1· track lighting in other than dwelling units or guest rooms or guest suites of hotels o r mote ls, an additional load of l !'iO volt-am peres sh all be included for every tiOO mm (2 ft) o f lighting u-ack or fraction thereof. \!\There multicircuit u-ack is in s talled , d1e load shal l be considered robe divirled equally between the track circuiL5. J,):aption: if the track lighting is rnppli.ed tlmmgh a device tlwt limits thP current to the track, the load shall be jm'milled lo be calculated ba.~nt on the rating of thi' d~vire med lo limit the 1.11:nrmt. 220.44 Re ceptacle Loads - Othe1· Than DweIJing Units. Receptacle loads calculated in accordance wid1 220.l 4(H) and ([) shall be permitted to be made subject to d1e demand facto rs gi1>en i.n Table 220.42 or Table 220.44. 220.50 Motors. Motor loads shall be calculate d in accordance widi 430.24, 430.25, a nd 430.26 llild with 440.6 for hermetic refrigerant motor-compressors. Table 220.44 Demand Factors for Non-Dwelling Receptacle Loads Portion of Receptacle Load to Which Demand Factor Applies (Volt-Amperes) First JO kVA or less al Remainder over JO kVA at Demand Factor (%) 100 E>O lnfomrntional Note: See 220.l4(G) for branch circuits supplying show windows. 70-76 NATIONAL ELECTRICAL CODE 2020Edition 220.60 ARTICLE 220- BRANCH -CIRCUIT, FEEDER, AND SERVICE LOAD C'..ALCULATIONS 220.51 Fixed Electric Space Heating. Fixed elecu-ic sp aceh eating load s shall b e calculated at I 00 percent o f the total crnrnected load. H owever, in no case s haJl a feed er or se1-vice lo ad cu rre n t rating b e l ess tha n the rating of t h e la rgest bra n ch circuit supplied. 1-.xcP/Jlion: \i\11,,er,, reduced loading of the conductors resulls fmm units operating on du/;y-{,ydP, intf>nnitten.tl;y, orfmm all ·1,miti not opmiting al the same limP, the aur,hority having jurisdiction mny gmnt. /Jt1·111issum for jfedl!I" and service amductors to have an ampacity less than 100 fiucent, pmvided the condw:tors havP an am.pacify for !he lond so dl'tenninerl. Dwelling Unit. (A) Small-Appliance Circuit Load. In each d welling l Ulit, the lo ad s ha ll be calculated at lEi00 volt-ampe 1·es for each 2-wire sma ll-a ppliance branc h circui t as covered by 210 .ll (C)(l ) . Whe re the load is subdivided th rough two o r m o re feeders , the calculated load for each sh all include n ot Le.~s than 1500 volta mperes fo r each 2-wire small-ap p lia n ce b ranch circuit. These loads sha ll b e pe rmitted to be included with th e gen eral ligh ting load a nd subjected ro t he d e m and factors p rovid e d i11 Ta ble 220.42. Exception: nw individuol branrh circuit t1wmitted by 210.52(B)(l), .t'xception No. 2, shall be permitted lo be excluded jh,rn Lhe calrnlation. required by 220.52. (B) Laundry Circuil Load.. A load of n ot less tha n 1500 volta mperes s h all be incl uded for each 2-wire laund ry bra n ch circuil install ed as cove red by 210. l J (C)(2) . This load s hall be pe nnitte d to be included witJ1 th e general lig hti11g load a nd sh all be s ul~ected to t he demand factors p rovided in Ta ble 220.42. 220.53 Appliance Load - DweJling Unit(s) . lt s hall be permissible to a pply a d em an d factor o f 75 percent to the na m e p late rating load of four o r m01·e applia n ces rnted 1/i hp or g reater, or 500 watt.~ o r gre ater, th a L a re fasten ed i n place, a nd th at are served b y the same fe eder o r service in a o ne-family, two-family, o r m ultifa mily dwelling . This d e m and facto r s hall n o t a p ply to: (2) (3) (4) H o useh o ld electric cooking equip me n t th at is fasten ed in p lace Cloth ei; d ryers Space h eatin g eq uipme n t: Aii~cond itioning equipme n t 220.54 Electric Oolhes Dryers - Dwelling Unit(s) . The lo ad for h o useh old elecu·ic clotJ1es d rye rs in a d welling uJlit(s) shall b e e ither 5000 watts (volt-am peres) or the n a meplate ratin g , whichever is large r, for each ch·yer served. Th e use of the demand factors in Table 220.54 shall b e permitted. Where two or more sing le-phase dryers are supplied by a 3-pha~e, 4-wi.re feed er or service, the total load shall be calculated o n the b asis o f tw ice the m axim um number connected b e tween a ny two phases. Kilovolt-ampe res (kVA) s hall be considered equivale nt to ki lowatt5 (kW) for Load s ca lculated in th is section. 2020 ll\lirjon Number of Demand Factor Dryers (%) 1-4 !) 6 7 NATLONAL Et.llCTRLC'.AL CODE lOO 85 75 65 IO 60 55 r,o 11 47 8 9 220.52 Small-Appliance and Laundry Loads - (l ) Table 220.54 Demand Factors for Household Electric CJothes Dryers 12- 23 47% minus 1 % for each dryer exceeding 11 24-42 3.5% minus 05% for each dryer exceeding 23 43 and over 25% 220.55 Electric Cooking Appliances in Dwelling Units and Household Cooking Appliances Used in Instructional Programs. The load for househo ld e lectric 1-anges, wallmo un ted ovens, coLmte r-mo Lmted cooking mtits, an d o ther househ o ld cooking a ppliances individua lly rated in excess of 11/t kW sha ll be p e rmitted to be calculated in accordan ce with Table 220.55. Kilovol t-amperes (k\lA) sh all be conside red equivale n t to kilowatts (kW) for loarl5 calculated l mde r this sectio n. Wh ere two o r more singl e-phase ra n ges are supplied by a 3-phase, 4-wi re feed er 01· ser vice, the total load sh a ll b e calculated o n th e basis o f twice 1J1e maxim um number connected b etween any two p h ases. Informa tio na l Nole No. I: See Lh e examples in Informative A nnex D . Informational Nme No. 2: See Table 220 ..56 lor commercial cooking equipme n L 220.56 Kitchen Equipme nt - Other Than Dwelling Unit(s). It s hall h e pe rmissible to calcula te the load for comme rcia l e lectric cookir1g equipmem , d ishwashe r booster heaters, wate1· heaters, a nd o th er kitchen equipment in accorda n ce with Ta ble 220.56. These d e ma nd factors sh all b e a ppli ed to a ll e quipme n t t h at h as e ither th ermosta tic con trol or i.nternlitte nt use a5 kitch en e quipmen t. The.~e d em a nd fac tors shal l not apply to s pace-h eating, ventilati ng, o r a ir-conclitioning equipm ent. H owever, in n o case s ha ll Lh e feeder or service cakuh1ted load be less than t he s um of tJ1e la rgest two kitch e n eqLtip ment load s. 220.60 Noncoincident Loads. Whe re it is u nlike ly that two o r mo re noncoincident loads will be in LL5e simulta n eously, it shall be pe rmissible to use o nly th e la rgest load (s) that will b e used at o ne Lime for calcula ting the total l oad of a feede1· o r service. \!\Th e re a moto r is pan o f t h e no ncoin cident load a nd is n ot t h e largest of th e n oncoincident loads, 125 pe rcen t of the moto r load sh all b e u sed in th e calculation if it is th e la rgest mo to1·. 70-77 220.60 ARTICLE 220- BRANCH-CIRCUIT, FEEDER, AND SERVICE LOAD CALCULATIONS Table 220.55 Demand Factors and Loads for Household Electric Ranges, Wall-Mounted Ovens, Counter-Mounted Cooking Units, and Other Household Cooking Appliances over 1% kW Rating (Column C to be used in all cases except as otherwise permitted in Note 3.) Demand Factor (%) (See Notes) Column A (Less than 3½ kW Rating) ColumnB (3½ kW through 8¾ kW Rating) l 2 80 3 70 66 62 80 65 55 50 45 Number of Appliances 4 5 75 ColumnC Maximum Demand (kV.') (See Notes) (Not over 12 kW Rating) 8 11 14 17 20 6 59 43 21 7 56 53 51 49 40 36 3.~ 22 23 34 25 47 45 43 41 40 32 32 32 32 32 26 27 28 29 30 39 28 28 28 28 28 31 32 8 9 10 11 12 13 14 lf> 16 17 18 19 20 38 37 36 35 24 33 34 35 22 23 24 25 34 33 32 31 30 26 26 37 26 38 26 26 39 26-30 31-40 30 30 24. 22 15 kW+ l kW for each range 41 -50 30 30 30 20 25 kW + ·1/, kW for each rn.11gc 21 51-60 61 and over 3fi 40 18 16 Nmes: I. Over 12 kW lhrough 27 kW ranges a ll of same racing. For ranges individually rated more lhan 12 kW but not more than 27 kW; the maximum demand in Column C sh;ul he increased .5 percent for each additional kilowan of rating or major fract.ion thereof by which che rating of in,;lividLtal ranges exceeds .12 kW. 2. Over 83/, kW 1.hrougl1 27 kW ranges of unequal rat.ing~. For ranges indivirlua.l ly rated more than 8 ¾ kW and of different ratings. hue none exceerling 27 kW, an average value of racing shall be calcularecl by adding togeLher the raLings ofaU ranges ro obrain the total connected load (using 12 kW for any range rated less Lhan 12 kW) and dividing by the total number of ranges. Then the maximtu11 rlemand in Column C shall be increased r, perce nt for each kilowan 01· major fraction thereof by which 1his average value exceeds 12 kW. ~- Over 13/, kW through 81/, kW. In lieu of the meLhod provided in Column C, iLShall be perm issible m add 1he nameplate ratings or all household cooki ng appliances rated more than 1-¼ kW but not more chan 8'¼ kW and multiply the sum by the demano facLOrs specifie,;I in Column A or Column B for the given number or appliances. Where che rating of cooking appliances falls ,mcler ho1h Column A and Column B, che deman(I fuccors for each column shall be applied to the appliances for that column, and the result~ added together. 4. Br,rnch-CircuiL Load. II shall -be permissible LO calnJace the branch-circuir .load for one range in accordance with Tab le 220.55. TI1e branch-circuit load for one wall-mounted oven or one counrer-mow1Led cooking unit shal l be the nameplate rating of the appliance. The branch-circ uit load fora counte r-mounted cooking unit and nor more th,111 cwr,, wall-mounted ovens, all supplied from a single branch circuit and located in the same room. shall be calculaLed by adrling the nameplate rating of the individual appliances and treating this total ,L< equivale111 LO one range. 5. TI1is rable shall a lso apply co household cooking appliances raced over I ¾ kW and used in instructional prog1-ams. 70-78 NATIONAL ELECTRICAL CODE 2020Edition ARTICLE 220- BRANCH -CIRCUIT, FEEDER, AND SERVICE LOAD CALCULATIONS Table 220.56 Demand Factors for Kitchen Equipme nt Other Thao Dwelling Unit(s) Demand Factor Number of Units of Equipment 2 3 4 5 6and over (%) 100 100 90 80 70 65 220.61 Feeder or Service Neutral Load. (A) Basic CalcuJation. The feeder or service n e urral load shall be 1be maximnm unbalance of the load determined by this article. The maximum unba lanced load sh all be the maximum net calculated load between the neutral conductor an.cl any one ungrounde d conductor. 220.82 Dwelling Unit. (A) Feeder and Service Load. This sectio n applies to a dweUing unit having the total connected load served by a single L20/ 240-volt or 208Y/ 120-volt sec of 3-wire service or feeder conductor-s with a11 ampacity of 100 or greate,·. It shall be permissible to calculate the feeder and service loads in accorda11ce with this section instead of the method specified in Part ITT of this artic le. The calculated load shall be the result of adding the loads from 220.82(8 ) a nd (C). Feede,- a nd se rviceenu·ance conductors whose calculated load is <letenninecl by this optional calculation shall be permitted to have the neutral load detem1ined by 2W.61. (B) General Loads. The general calculated load shall be nor less than 100 percent of the first 10 kVA plus 40 percent of the remainder of the fol.lowing loads: (J ) Exception: For 3-win, 2-phaM or 5-wirP, 2-phasP systn11s, the rnaxi-mum ·unbalanad load shall be the rnaximmn nPt calcitlaWJ load bettuPen llu• nmtt:ra.l 1:ond11ttor rind any onP 1tr1.grol/,n{.led rnn1factor rnultipli./?d by (2) 140 percent. (B) Permitted Reductions. A service or feeder supplyi11g the fo llowing loads shall be permitted to have an additional dema11d factor of 70 percent applied to the amount in 220.61 (B) (I ) or portion of the amount in 220.6 1 (B) (2) dete rmined by the foBowing basic calculations: (1) A feeder or service supplying household e lectric ranges, wall-mounted ovens, coumer-mowited cooking units, and electric dryers, where the maximum unbalanced load has been determined in accordance witJ1 Table 220.5.1'\ for ranges and Table 220.54 for dryers That portion of the unbalanced load in excess of 200 amperes where the feeder o r service is supplied Ei·om a 3-wire de or sing le-phase ac system ; or a 4-wire, 3-phase system; or a 3-wire, 2-phase system; or a 5-wire, 2-phase system (2) (3) (4) (l ) (2) (C) Prohibited Reductions. There shall be no reduction of the neuu·al or grounded conductor capacity appl ied to the amount in 220 .6 L(C)(l), or portion of tJ1e amoum in (C)(2), from that cletem1i.ned b y the basic calculation: (3) (2) Any portion of a 3-wire circuit consisting of 2 Lmgrounded conductors and the neutral conductor of a 4-wire, 3phase, ,vye-connected system That portion consisting of nonlinear loads supplied Ei· om a 4-wire, 1vye-co1mected, 3-phase system Informational Note: A 3-phase. 4-wire, wye--co nnected power system llSed ro supply power tO nonlinear loads may necessitate ll1a1 the po wer system design allow for the possibilit) of high harmon'ic n eutral conductor curre nLi, Part IV. Optional Feeder and Service Load Calculations 33 volt-amperes/m'.!. or 3 volt-amperes/ ft~ for general lighting and general-u se receptacles. The floor ai-ea for each floor shall be calculated from the o ut5ide dimensio ns of th e dwelling unit. The calculated floor area shall not in clude open porches, garages, or unused or unfinished spaces n o t adaptable for future use. 1500 volt-amperes for each 2-wire, 20-a111.pere smal.1applia nce bra11ch circuit and each laun<li-y branch c ircuit covered in 210. ll (C)( l ) and (C)(2) . The n ameplate rating of the following: a. All appliances that are fastened in place, pe1·manently connected, o r located to be on a specific circuit b. Range s, wall-mounted ovens, counteHnounted cooking uniL5 c. Clothes dryers that are not connected to the laundry b ranch circuit specified in item (2) cl. Water heatei-s The nameplate ampere or kVA rating of all permanently connected motors not included in item (3). (C) Heating and Air-Conditioning Load. The la1·gesc of the following six selections (load in kVA) shill be included: lnforni;1Lional Note: See Ex,1mples Dl (a) , Dl (b), D 2(b), D4(a), and D.~(a) in In fo rmative Annex D . (l) 220.82 (4) (5) (6) 100 percent of the nameplate rating(s) of the air concliLioning and cooling. 100 percent of the nameplate rating(s) of the h eat plrnlp when die heat pump L5 used without any suppleme ntal e lectric h eating. 100 percent of the nameplate rating(s) of the heat pump compressor and 65 percent o f the supple mental electric heating for central e lectric space-h eati ng systems. If tJ1e heat pump compressor is prevented fro m operating at the same time as the supple mentary heat, it does not n eed to be added to Lhe supplementa1·y h eal for tJ1e tolal centra l space h eatin g load. 65 percent of the nameplate rating(s) of electric ~pace h eating if less tJ1a11 four sepai·ately conu·ol led lllliL5. 40 percent of the nameplate ratin g(s) of electric space h eating if four or more sepai·ately controlled units. 100 percent of the nameplate ratings of e lectric chennal storage and other h eating systems where the LLmal load is expected to be con tinuous at the full nameplate val ue. Systems q uali fying under this selection sh all not be calculated under an y other· selectio n in 220.82(C). 220.80 General. Optional feeder and service load calculatio ns shall be permitted in accordance with Part TV. 2020 ll\lirjon NATIONAL E LECTRICAL CODE 70-79 220.83 ARTICLE 220- BRANC H-CIRCUIT, FEEDER, AND SERVICE LOAD CALCUIATTONS 220.83 Existing Dwelling Unit. This section shall be permitted to be used to determine if the existing senrice or feeder is of sufficie nt capacil-y to serve additional loads. Where the dwelling unit is served by a 120/ 240-volt or 208Y/ 120-volt, 3-wire service, it shall be permissible to calculate the tolal load in accordance with 220.83(A) or (B ) . (A) Where Additional Air-Conditioning Equipment or Electric Space-Heating Equipment Is Not to Be Installed. The following percentages sh all be LL,ed for existing a nd additional new loads. Load (kVA) Percent of Load First 8 kVAof load a t 100 Remainder of load at 40 220.84 Multifamily Dwe lling. (A) Feeder or Service Load. It shall b e permissible to calculate the load of a reeder- or service thaL supplies three or more dwelling units of a multifamily dwelling in accordance with Table 220.84 instead of Part ill of this a rticle if all the following conditions are met: ( 1) (2) Excrption: When tlw mlrulated loadfor mnltifhrnily dwellings without elecl.rit- coo/ling in Par/, ill of lhis article exceeds l.h.al calcula!.erl undr.r Part IV for the identical load /1/us eledric cooking (based on 8 kW per unit), 1hr lesser ofthe li.vo loads sh.nil br permit!Pd to bP used. (3) Load calculations shall include the following: (1) (2) (3) General lighting and general-use receptacles at 33 volramperes/ m2 or 3 volt-amperes/ft2 as determined by 220.12 1500 volt-amperes for each 2-wire, 20-ampere smallappliance branc h circuit and each laund1·y bran.ch circuit covered in 2 10.l l (C) (1) and (C) (2) The n ameplate rating of the following·: a . All appliances that are fastened in place, permanently connected, or located to be on a specific circuit b. Ranges, wall-mounted ovens, counter-mounted cooking un its c. Clot.hes drye1·s that a re not connected to the latuiclt-y branch circuit s pecified in item (2) d. Waler heaters (B) Where Additional Air-Conditioning Equipment or Electric Space-Heating Equipment l'> to Be Installed. The following percentages shall be used for existing ,md ;Jdditicmal new loads. The larger connected load o.f a ir conditioning or space heating, but not both, shall be used. Load Percent of Load Air-c()nditioning equipment Ccntrd.l electric space ht'ating Less than four separdtc ly co111ro lled space-heating units First 8 kVA of all other loads Remainde r of all o ther load;; 100 JOO 100 (2) (3) (B) House Loads. H ou se loads s hall be calculated in accord ance with Par t III o f this article and s hall be in addition to the dwelling unit loads calcu.lated in accordance with Table 220.84. (C) Calculated Loads. The calculated load to which the demand factors of Table 220.84 apply shalt include the following: (l) (2) 33 volt-amperes/m2 or 3 volt~mperes/fti for general lig hting and general-use receptacles 1500 volt-amperes for each 2-wire, 20-ampere smallappliance branch circ uit and each latmdry branch circuit covered in 210.11 (C) ( l ) and (C) (2) Table 220.84 Optional Calculations - Demand Factors for Three or More Multifamily Dwelling Units N umber of Dwelling Units Demand Factor (%) 3-.5 6-7 45 44 8-10 43 ll 42 12-13 41 14-15 40 ,:1-0 16-17 18-20 39 21 22-23 24-25 2f>-27 28-30 37 36 35 34 33 31 32-33 34-36 37-38 32 31 30 29 39-42 28 43-45 27 26 25 General lighting and gen e ra.I-u se receptacles at 33 voltamperes/ m2 or 3 volt-amperes/ ft~ a~ determined by 220.1 2 1500 volt-amperes for each 2-wire, 20-ampere smallapplia n ce branch circuit and each laundr)' brancl1 circuit covered in 210 .11 (C)( l ) and (C)(2) T he nameplate rating of the following: a . AU appliances that are fastened in place, permanently connected, or located to be on a specific c ircui t b. Ranges, wall-mounted oven.~, cou11te 1'-mou11ted cooking units c. Clothes dryers that are nor connected to the la undry branch circ uit specified in item (2) cl. Water h eaters 70--80 Each dwelling unit is equipped wi th e ithe r electric space heating or air conditioning, or boLh. Feedern ;md service conductors whose calculated load is determined by this optional calculation shall be permitted to have the neuu·al load determined by 220.fil. 100 Other loads shall include the following: (l) No dwe lli ng unit is s upplied by more than one feeder. Each dwelling tmit is equipped with elecu-ic cooking eqLtipmen t. 4()-.50 .51-.55 56-61 61 and ove r 38 24 23 NATIONAL ELECTRICAL CODE 2020Edition ARTICLE 220- BRANCH -CIRCUIT, FEEDER, AND SERVICE LOAD C'.ALCULATIONS (3) (4) (5) T he nameplate ratin g of the following: a . All a p p liances that are fastened in p lace, permanen tly connected, o r located to be on a specific circui t b. Ranges, wall-moLmted ovens, cou nter-mou nted cooking u n its c. Clothes dryers that are not conn ected to the l,1undry branch circuit specified in item (2) d . Wate,· heaters T he n ameplate ampere or kVA rating of al l permanently conn ected motors not included in item (3) T he larger of the air-con ditionin g load o r th e fixed electr-ic space-heating load 220.85 Two Dwelling Units. ' "'h ere two dwelling ut1.iL5 are su ppl ied by a sin gle feeder and the calculated load under Part ll[ of this article exceeds d1at for three identical un its calculated under 220.84, 1.he Lesser of 1.he two l oads s hall be perm itted to b e used. 220.86 Schools. The calculation of a feeder or service load fo1· scl1ools shall be permi tted in accordance with Ta ble 220 .86 in lie u of Parr III of this ar ticle wh e re equipped ,vith electric space h eating, air conditio ning, or b oth . T he connected load to w hich the demand factors of Table 220.86 apply shal l include a ll of t he inte1·ior and exterior ligh ting, powe1~ water heatin g, cooking, other loads, and the lar ger of t he air-con d itioning Load or space-heating load ,vithin the build ing or structure . Feeders a nd se1vice con ductors whose calculated load is determined by this o ptional calculation shall be pern"l.i tted to h ave the neutral load deten 11.ined by 220.6 1. Where IJ1e building or structure load is calculated by this optional metl,od, feeders \vitl1.in the b uild ing or structure shall have ampacity as permitted in Part m of this artid e; h oweve r, tl1e ampacity of an ind iv idual feeder shall not be required to h e larger th an the a m paci ty for t he en tire b uild ing. This section shall not apply to portable classroom build ings. 220.87 Determining Existing Loads. The calculation of a feeder or service load for existin g i11stallations shall be pe,-mitted to use actual ma.xi.mum demand Lo determ.in e IJ1e existing load under a ll of th e following conditions: ( 1) T he m aximum deman d data .is available fo r a 1-yea.r period. Exmption: If the maxim·um demand data for a I-year period i.s not available, the calculated lortd shall bl' jJm'11titted lo be based on {hH maximum. demrm1l ( the highest nveragl' kilowatts reached and maintrtined for ri 15-nrinute interval) rnntirmo!Lsl.y wcorded ov,w n mini- Table 220.86 Optional Method - Demand Factors for Feeders and Se rvice Conductors for Schools Connected Load First 33 VA/ m" Plu s, Over 33 through Demand Factor (Percent) 100 (3 through 20 VA/ fl~) a l 75 220VA/ m 1 Plus, Remainder ove1· 220 VA/ m~ 2020 E,;lition NATl ONAL ELECTRlC-AL CODE 220.103 mmn 30-day ptriod using a recording mmneter or potvl'r meter connecled lo the highe.1t loaded fihose of the jPeder or srrvire, based on !he initial loading al lhl' sta·rt of the rl'cording. The recording shall rejlel't llu! ma:dmwn demand of 1h11 jfeder or serviCI' by bf'ing taken when the building or s/Jare is ocr.11f!ied and shall inrlude by mea.mrement ar mlc-ulalion the largn- of thr. heating or cooling equipment load, and othl'r loads that -may be fmiodic in nalurf du.e lo SPasonal or similar conditions. (2) (3) T h e m aximum demand at 125 percent. p lus the new loa.d does not exceed tJ1e a m pacity o f the feeder or ratin g of the se1vice. ll1e feeder has overcLu-t·en t protectio n in accordance \'/ith 240.4, a n d d, e service has overload protection in accordan ce with 230. 90. l!.xception: If the feeder ar servi.tl' hos any renewable energy system (i.e., .1olar p!wtovolli1ic .1yslenu or wind e/Pctrii- systems) or employs any form of peak. load shaving~ thi1 calrnlation ·method sholl not bl' /)f'rmitted. 220.88 N ew Restaurants. Calculation of a service o r feeder load, wher e the feede r se,ves the total load, for a new restaurant sh all b e permitterl in accordan ce with Table 220.88 in lieu o f Part Ill of this article. The overload protecti on of the service con ducLOrs s hal l be in accordance with 2~0.90 a nd 240.4. Feeder condu ctors sh all n ot b e req u ired to be of greater arn pacit)' th an t h e service con ductors. Ser vice or feeder conductors wh ose calcula ted load is determ ined by this optiona l calculation sha ll be pen n ilted to h ave tJ1e neutral l oad determined by 220.61. Part V. Farm Load Calculations 220.100 General. Farm loads sha ll be calculated i n accordance \vid1 Pan V. 220.102 Farm Loads- Buildings and Other Loads. (A) Dwelling Unit. The feeder or se1v ice load of a Jann dwelling u n it s hall be calculated in accordan ce with the provisions for dwellings i n Part III 01· IV of this article . \/11h e re the dwelli ng has e lectric heat and 1.he farm has e lecu·ic grain-d1ying systems, Part IV of tl1is article s hall not be used to cal culate the dwelling load where tJ1e dwelling and farm loads a1·e su pplie(l by a com mon service. (B) Other Than Dwelling Unit. Wh ere a feeder o r sen~ce supplies a fann b u ilding 0 1· oth e r load having LWO or more separate branch circuits, t h e load for feeders, service conductors, a nd service equi p ment shall be calculated in accordance with demand factors not less tJ1an indicated in Table 220.102. 220.103 Farm Loads - Total. Where s u pplied by a common service, th e total load of the fa.rm for se,v ice conductors and service eq uipment sh all be calculated in accordance with the farm dwelling u nit load a nd deman d factors specified in Tabl e 220.103. Where there is equipmen t in two or more farm equipme n t b uildings or fo r loads havin g the sam e function, s u ch loads sh all be calcu lated in acco1·dance with Table 220.1 02 and s hall be permitted to he combined a5 a single load in Tabl e 220.103 for calculating the total load. 25 70-81 225.l ARTICLE 225- OUTSIDE BRANCH ClRCUITS AND FEEDERS Table 220.88 Optional Method-Per.mitted Load CalcuJations for Service and Feeder Conductors for New Restaurants Total Connected Load (kVA) 0-'.WO '.!OJ-325 '.-126---800 O ver 800 All Electric Restaurant Not All Electric Restaurant Calculated Loads (kVA) Calculated Loads (kVA) 80% 10% (amow1t over 200) + 160.0 50% (amount over 325) + 172.5 50% (amountover800) +410.0 50% (amoum over 200) + 200.0 45% (amount over 325) + 262.5 20% (amount over 800) + 476.3 JOO% Note: Add al l elec u·ical loads, including both heating and cooling loads, 10 calculate th e to ral connecred load. Selecr d1e one dem and factor that applies from the r.able, rhen m,,1Liply the toral connected load by d1is single demand factor. ARTICLE 225 Outside Branch Circuits and Feeders Table 220.102 Method for Calculating Farm Loads fQr Other Than Dwelling Unit Demand Factor Ampere Load at 240 Volts Maximum 225.1 Scope. This a rticle covers requirements for ouL~ide branch circuits and feede1·s run on or between buildings, 5tructUt·es. or poles o n the premises; and electrical equipment and wiring for the .~upply of utilization equ ipmenl that is located on or attached to the outside of buildings, su·,1ctLU·es, or po les. Informatio nal Note: Fo r additiona l into rmaUo n o n wiring over 1000 volts, see ANSI/IE,EE C2-2017, National Elecl1i.:al Safi1ly Code. 225.3 Other Articles. Application of other articles, including additional requirements to specific cases of e quipment a nd conductors, is shown in Table 225.3. Part I. General 225.4 Conductor Covering. Where wi thin 3.0 m ( 10 ft) of any building o r strnc ture oll1er than supporting poles or towers, open individual (ae1·ial) overhead conductors shall be insulated for the nominal voltage. The insulatio n of conductors in cables o r raceways, except Type MI cable, shall be of thermoset or the1·mo plas tic type and, in wet locations, shall comply with 310.lO(C) . The ins ulation of conductors fo1· festoon lighting shall be of l11e thermoset or thermoplastic type, Exceptiou: J:,qui/1117,pnf grmmding conducton and grou,,uJPd rirruil conduclo1:f shall be jJermittell lo be br1re or covered as sjm-rfirally permit- /Pd elsetvheir in this Code. 225.5 Size of Conductors 1000 Volts, Nominal, or Less. The ampacity of o utdoor branch-ciJ·cuit a nd feeder conductors shall he in accordance with 3 10.14 ba~ecl on loads 3$ determined under· 220.10 and Part III of Article 220. 225.6 Conductor Size and Support. (A) Overhead Spans. Open individua l conductors shall noL be sma lle r than the following: (1) (2) For 1000 volts, nominal, or less, JO AV\TG copper or 8 AWG aluminum for spans up to 15 rn (50 ft) in le ngl11 , and 8 AWG coppe r o r 6 AWG aluminum fo r a longer span LU1le.~s supported by a messenger wiJ·e For over 1000 volL~, nominal, 6 AV-,!G copper or 4 ,'-\';,VG aluminum where open individua.1 conductors, and 8 AWG copper or 6 AWG a luminum where iJ1 cable (B) Festoon Lighting. Overhead conductors fo r fesloo n ligh ting shall not be smaller than 12 AWG unless l11e conductors are supported by messenger wires. In all spans e.xc,eeding 12 m 70--82 (%) The greater of the following: Al.I ·1oads Lhat arc expected LO opernte siniulurneornly, QI' 125 percent or the fu ll load current of the largest moto1; or First 60 amperes of the load Next 60 a mpe res ofalJ o the r· lo ads Remainder of c)ther loads ]()() 50 25 Table 220.103 Method for Calculating Total Farm Load InclividuaJ Loads Calculated in Accordance with Table 220. l 02 Demand Factor (%) HJO Largest load Second largest load Third largest load Remaining loads 75 65 50 Nme: Tor.his total load, add the load of the fa rm dwelling unit calculared in accordance with Pan Ill or IV of this a rticle. Where the dwelling has electric heat and die fa,·m has electric g rain-dryi ng systems, PartN of this article sha ll not be used LO calculate d1e dwelUn~ load. (40 ft), the conductors sha ll be suppo rted by messenger wire. The messenger wire shall be supported by su·ain insulators. Conductors m· messenger wires shall not be attached to a ny fire escape. downspout, or plumbing equipme n t. 225.7 Lighting Equipment Installed Outdoors. (A) General. For the supply of lig hting equipme nt installed ouLdoors, the br,mch c ircuiL~ sha ll comply with Article 210 and 225 .7 (B) through (D) . (B) Common Neutral. The ampacity of the ne1m-al conductor shall not be less tha n the ma.,-ximm11 net calcula ted load cm-rent between tl1 e neuu-al conductor and a ll ungrounded conductors ton netted to a ny o ne p hase of the circuit. (C) 277 Volts to Ground. Circuits exceedi ng 120 volt~, nomin a l, between conductors and not exceeding 277 volt~. nomina l, to ground shall he permitted to supply l.u.mina ires for illumi11ation of outdoor ,u·eas of industrial establishm ents, office buildings, .~chools, stores, a nd other commercial or public buildings. NATIONAL ELECTRICAL CODE 2020falition 225.17 ARTICLE 225- OUTSIDE BRANC H CfRCUfTS AND FEEDERS Table 225.3 Other Articles Equ.ipment/ Condt1ctors Branch circuiL~ CJass 1 , Class 2, and Class 3 remmecontrol, signaling, and power-limited circuits Communications circuiL~ CommLmity an tenna television and radio distribution systems Conductors for geneml wiring Electrically diiven or con t,·olled irrigation machines Electric signs and o utJinc light.ing Feeders Fire alarm systems Fixed o utdonr e lectric d eicing and snowruelti.ng equipment Floating buildings GrOLmding and bonding Hazardous (classified) locations Hazardous (classified ) locatio ns specific Marinas a11d bmuyanls Medium-voltage conducwrs and cab le Messenger-su pported wiring Mobile hon1cs, manufactured homes, and mobile home parks Open wit;ng on insulators Over 1000 volts, general Ove rcu1Tent p1·otcctio11 Radio and telc,isio n equipment Services Solar pho tovoltaic ")'Stems Swimming pools, fotmtains, and similar installations Use and ide ntification of grounded conductors Article 210 725 805 820 310 675 600 2Jrj 760 4.26 553 250 500 510 555 3 11 396 550 (15) ( 16) ( l 7) Type MC cable Type MI cable Type SE cabl e ( I 8) Type T C-ER cable ( 19) TypeUF cable (20) Wireways C ircuit~ of over LOOO volt5, nom.inal, shall be installed as provided in :100.37. 225.11 Feeder and Branch-Circuit Conductors Entering, E.xiting, or Attached to Buildings or Structures. Feede r and branc h-circ uit conductors e n tering 01· exiting buildings 01· structures shall be installed in accordance with the re9uirements of 230..152. Overhead b ranch cit-cuit~ and feeders attached to buildings or structures sha ll be installed in accordance with the requirements of 230.54. 225.12 Open-Conductor Supports. Open conductors sha ll be supported on knobs, racks, bracket5 , or strai n insulators, that are made of glass, porcelain, 01· o the r approved materials. 225.14 Open-Conductor Spacings. (A) 1000 Volts, Nominal, or Less. Cond uctors of I 000 voltS, nomjna l, or less, shall com ply w ith d1e spac ings prnvided in Table 230.Sl(C). (B) Over 1000 Volts, Nominal. Conductors of over 1000 volt5, nominal, shall comply with die spacings p rovided in 11 0.36 and 490.24 . 398 490 240 810 230 690 680 200 (C) Separation from Othei· Circuits. Open conductors shall he separated from open conductors of od1e r circuits or systems by not less than 100 mm (4 in.) . (D) Conductors on Poles. Conducto rs on poles shall h ave a separation of not less tl1an 300 mm (1 ft) w here not placed on rack5 or hracket5. Conductors supported on poles sha ll prnvicle a hori zo ntal climbing space not less d1an the fo llowing: (J) (2) (D) 1000 Volts Between Conductors. Ci1-cuits exceeding 277 vollS, nomi11al, LO ground and not exceeding 1000 volt~, nomjnal, between conductors sha ll b e permitted to supply the al.Lx.iliary e quipmenl of e lectric-discharge lamps in accorda nce with 210.fi(D)( l ) . 225.10 Wiring on Buildings (or Other Structures). The installatio n of o u tside wiring on smfaces of buildings (or other stn.1ctures) shall be permitted for circuits not exceeding l000 volt5, nominal, as Lhe following: ( I) Auxilia1·y gi.m e rs Busways Cable trays Cablehus Electrical metallic tubing (EMT) Flexible metal conduit (FMC) Intermediate metal condui t (IMC) Liquidtight flexible metal conduit (LFMC) Liq uidtigh t fl exible nonmetallic conduit (LFNC) Messenger-supported wiring Open wiring o n insulators Reinforced thermosetting resin conduit (RTRC) Rig id metal conduit (RMC) Rig id polyvmyl c hlo ride conduit (PVC) (2) (3) (4) (5) (ti) (7) (8) (9) (10) ( 11 ) (12) (1:1) ( 14) 2020 ll\lirjon NATlONAL E LECTRIC-AL CODE (3) (4) Power conductors below com munications conductors 750 mm (30 in.) Power conducto rs alo ne or above com mun icaLions conductors: a. 300 volts o r less-600mm (24 in. ) b. o,,er 300 volts - 750 mm (30 i.n. ) Communicati ons conductors below power conductors sam e as powe1- conductoL~ Com mw1icati ons cond uc tors a lo ne - no requirem e nt 225.15 Supports over Buildings. OuL~ide branch-circuit and feeder conductors passing over a building shall be secure ly supported. 225. 16 Attachment to Buildings. (A) Point of Attachment. The point of attachment ing shall be in accordance with 230.26. LO a build- (B) Means of Attachment. Th e means of attachm ent to a building shall be iu accordan ce with 230.27. 225. 17 Masts as Suppo1·ts. Only .feeder or bra nch-circuit conductors specified within th is section shall be permitted to be attached to the feed e r a nd/ or branch-circuit mast. MasL~ used for the support o f final spa ns of feeders o r b ranch c ircuits shall b e installed in accordauce with 225.17 (A) a nd (B) . 70-83 225.17 ARTICLE 225 - OUTSIDE BRANCH CIRCUITS AND FEEDERS (A) Strength. The mast shall have adequate strength or be supported by b races or gu y wires to safely withstand the strain imposed by tJ1e overhead feeder or bran ch-circuit conductors. Hubs intended for use with a conduit serving as a masL for support of feeder or branch-circuiL conductors shall be identified for use with a mast. nonbui.lcling or nonbridge s1Tuctures, clearances - vertical, d iagonal, and horizontal - shall not be less thm1 900 mm (3 ft) . (B) Attachment. Feeder and/or branch-circuit conductors shall not be auachecl to a ma.st where me connection is between a weatherhead or the end of the condui t and a coupling where me coupliHg is located a bove the la5t point of securement to the building or other su·ucture, or where the coupling i.~ located above the building or other structure. (D ) Fmal Spans. Final spans of feeders or branch ci1 n1iL~ shall comply witJ1 225 .J 9(D) ( 1), (D) (2), a11d (D ) (3). 225.18 Clearance for Overhead Conductors and Cables. Overhead spans of open conductors and open multiconductor cables of not over LOOO volts, nom.inal, shall have a cleara11ce of not less than the following: (1) (2) (3) (4) (5) 3.0 J11 (JO ft) - above fmished grade, sidewalks, or from any platform or projection that will permit personal contact where the voltage does not exceed l.i'iO volts to ground and accessible to pedestrians only 3 .7 111 ( 12 ft) - over residential property and driveways, and those commercial areas not sul:iect to truck traffic when" tJ1e voltage d-0es not exceed 300 volts m ground 4.5 111 (15 Ft) - for those areas listed in the 3.7 m ( 12 Ft) classification where the voltage exceeds 300 volt5 ro ground 5.5 m ( 18 ft) - over public streets, alleys, roads, parking areas subject to truck traffic, driveways on other th an residential prnperty, and other land traversed by vehicles, such as cultivated , grazing, forest, and 01-chard 7.5 m (24½ ft) - over u·ack rail5 of railroads 225.19 Clearances from Buildings for Conductors of Not o ver 1000 Volts, Nominal. Oved1ead spans of open conductors a nd open multiconcluctot· cables shall comply with 225.Hl(A), (B), (C), and (D) . (A) Above Roofs. Overhead spans of open conductors and open muJticonductor cables shall have a vertical clearance of not less tl1an 2.7 m (8 ft 6 in .) above t he roof surface. The vertical clearance above the roof level shall be maintained for a di.stance not less tha11 900 mm (3 Ft) in all directions from the edge of tl1e roof. Exception No. I: The arPa above a roof surjr1ee subject lo fJedPslrinn or vehimlar trafjit slwll have a vertical clem-ance from !he mof smfare in accordanre urith thi> clettrante requirements <if 225. 18. Exception No. 2: WhP.m the vollage bettoem cond.uctors does not txceed 300, and the mof luir n slope of 100 mm in 300 mm ( 4 in. in 12 in.) ar greate1; a reditclion in clearance lo 900 rnrn (3 fl) shall be /Jermilled. Exception No. 3: Wl,.em /he vollagP bftween conduCIO'IS does no/ exceed 300, a reduction in clfanmce above <m~ the overhanging portion of the roof to not ll/S$ than 450 mm, ( 18 in.) shall be permitted if (1) not more than 1.8 rn (6 fl) 1>[ lhr wnd'l1ct11rs, 1.2 m (4 fl) horizonta,llJ, j1ass above the roof overhang, mu:l (2) they fl.re lfnninriled at a thro·ugh-them1>[ raceway or 11j1provrrl .mpf1ort. l!.'xcej1tion No. 4: Tfu, 1r,qidremml for maintaining the vertical clertrante 900 mm (3 fl).frorn /he edge ofthr roof shall not apply to the final rnnduclor span wlum1 the l'<mdw:tors mr· attarhed to the side rif n bu-ilding. (C) Horizontal Clearances. Clearances shall nor he less lha11 900 111111 (3 ft). (l ) Clearance from Windows. Final spa11s to the build.iJ1g they supply, or from which they are fed, shall be permitted to be attached to the building, bur they sh all be kept not less man 900 mm (3 ft) from windows tl1at are designed to b e opened, a11d from doors, porches, balconi es, Ladders, stairs, fire escapes. or similar locations. Excej1tion: Condw:tors run abnvl! the top Imel of a window shall /;e permitled to be less than //,p 900 mm (3 Ji) requirement. (2) Vertical Clearance. The vertical clearance of final spa11s above or witl1in 900 mm (3 ft) measured horizo n tally of platforms, prqjecti.ons, or surfaces that will permit personal contact shall be maintained in accor dance with 225.18. (3) Building Openings. The over·head branch-circuit a11d feeder conduclors shall not h e inst<\,llecl beneath. openings through which materials may be moved, such as open ing-s in fann and com mercial build ings, and shall not be installed whet·e they obstruct enu·ance to tJ1ese o pe nings. (E) Zone for Fire Ladders. ,l\lhe re buildi11gs exceed tlu·ee stories or l 5 m (50 ft ) in height, overhead lines shall be aJTanged, where practicable, so that a clear space (or zone) at least 1.8 m (6 ft) wide will be left eitJ1er adjace nt m tl1e buildings or beginrting not over 2.5 m (8 fL) frorn them to facil itate the raising of ladders when necessary for fire l'ig hti11g. 225.20 Pr<>tection Against Physical Damage. Conductors installed on buildings, structures, or poles shall be protected against physical damage as provided for services in 230.50. 225.21 Multiconductor C.ables on Exterior Surfaces of Buildings (or Other Structures). Supports for multi conductor cables on exterior surfaces of buildings (or other str:uctures) shall be a~ provided in 230.51. 225.22 Raceways on Exterior Surfaces of Buildings or Other Structures. Raceways on exteriors of buildings o r other structures s hall be arranged to d ra in and shall be lis ted or approved for use in wet locations. 225.24 Outdoor I..ampbolders. Wh ere outdoor lampholders are attached as pendants, the connections to tl1e circuit wires shall be staggered. v\lhere such lampholders have terminal~ of a type tl1at puncture the insulation and make contact with tl1e conduclors, they shall bl;! attached only to conductm·s of the stranded type. 225.25 Location of Outdoor Lamps. Locations of lamps fo r outdoor ligh ting shall be below a ll e n e,-gized conductors, transformers, or o ther electric utilization equipment, m1less e ither of me fo llowi ng apply: (J ) (2) ClearaJ1ces or other safeguards aJ·e provided for 1-elamping operations. Equipment is conu·o llecl by a disconnecting means that is lockable open in accordance with .I 10.25. (B) From Nonbuilding or Nonbridge Structures. From signs, chimneys, radio and television antennas, tanks, and other 70-84 NATIONAL ELECTRICAL CODE 2020Edition ARTICLE 225- OUT SIDE BRANC H CIRCUITS AND FEEDERS 225.26 Vegetation as Support. Vegetatio n suc h as trees sha ll not be used for support of overhead co nd uctor spans. 225.27 Raceway Seal. \,\There a raceway enters a build ing or su-uctw·e from out5ide, it shall be sealed. Spa re or wrnsed raceways shall a lso be seale d. Sealan ts sh a ll be ide ntified for use wi U1 cable insulatio n, conductor insula tio n, ba re conductor, shie ld, o r othe r componen t5. Part JI. Buildings or Other Structures Supplied by a Feeder(s) or Branch Circuit(s) 225.30 Number of Supplies. A build ing o r othe r structure d,al is served by a b ranch circuit or feed e r o n d1e load side of a service disconnecting means sha ll be supplied b)' o nly one feede1· o r bra nc h circuit unless permitted in 225.30(A) d1ro ugh (E) . For the p urpose of this section, a multiwire b ranch circuit shall be con sidered a single cir cuit. Wh ere a b ranch ci.1-cuit or fee d e r o riginates in U1ese additio nal build ings or o m er su·uctures, o nly one feeder o r b ranch circuit sha ll be pe rm itted co supply power back lo the o.rigina l buildi ng or structure, unless pe rmitted in 225.30(A) th roug h (E) . (A) Special Conditions. Ad d iti onal feeders o r branch ci.rcuit5 shall be permitted to supply th e following: ( 1) Fire p umps (2) Emergen cy systems (3) Legally required standby system.5 ( 4) (5) (6) (7) (8) O p tio na l stand by systems Pa ra llel power p1·oductio n systems Syste ms design ed fo r connection to multip le sources of supply for the purpose of e nha nced reliability Electric vehicle cha rg ing systems liste d , la be led, a nd ide ntified fo r more U1an a sing le b ranc h circuit o r feede 1· Docking faci lities and pie rs (B) Common Supply Equipmenl. Wh ere feed e1- cond uctors 0 1iginate in the same -pan e lboard, switchboard, o r 0 U,e 1· d istributio n equipme n t, and each feeder termin ates in a sing le disconnecting mean s, not mo re than six feede rs shall be permitted. Whe re more tha n o ne feeder is installed in accorda nce wiU, this section, a ll feeder disconnects supplying the building or structure sha ll be grouped in the same locatio n , a nd U1e require me n t~ of 225.33 shall not appl)'. Each disconnect sh a ll be ma rked to ind icate the load served. (C) Special Occupancies. By sp ecia l permission, additional feeders o r bra nc h circuits s ha ll be permitted for e ither of the fo llowing: (1 ) (2) Multiple-occupa ncy build ings whe re the re i~ no space available [or su p ply equipment accessi hie lo all occu pant5 A sing le building or od1er structure sufficiendy large to make two or more supplies necessary (D) Capacity Requirements. Additional feede rs o r b ranch ci rcuits sha U be pennitted whe re the capacity require ments a re in excess of 2000 amp eres at a su ppl)' voltage of 1000 volt5 or less. (E) Different Characteristics. Ad d itio na l feeders or b ranch circuits sha ll b e permitted for different voltages, freque ncies, or phases, or for d iffe re nL uses such as con trol of out5ide lighting from multiple locations. 2020 ll\lirjon NATLONAL ELECTRLC-.AL CODE 225.34 (F) Documented Switching Prncedures . Additio nal feeders or br a nch circui t~ shall be permi tted to supply installations under sing le man ageme nt where d ocLLmented safe switching p roced ures a re esta blished and maintained for disconnection. 225.31 Disconnecting Means. Means shal l be provided for disconnecting a ll ungro w1ded conductors d,at supply o r pass th rou g h th e build ing or strl1cture. 225.32 Location. The disconnecting m eans sh all be insta ll ed eiUu:r inside o r OLLt5ide of d1e build ing or structme served or wh ere the conductors pass d1rough m e building or su·uc ture. TI1e di5co1111ecting means sha U be al a readily accessible locatio n nearest d1e point of e nu·ance of the conductors. For th e purposes of this sectio n , the requirem ents in 230.6 shall be u tilized. Excepti<m No_ 1: For installations under single managmien t, where doc1Jrnented .wife stuitrhing procedurrs me esiabfahed and 111aintained j<1r discDnnettion, and where the installa/,i1m is monilorl'II by qualified inrliviriualr, the d iscnnnecting m.eans shall be f1trm.iued to bP lor,ater,f, elsf111hen' on the frremi.ses. Exc1,pt:i<m No. 2: For buildings or other stnu:tnre$ qualifying under Artirle 685, lhe disconnecting w.eans shall be firnnillal to be located PLw,.vluwe on 1,/w fmm1ises. Exu,plion No. 3: For lowers or poles u.sed as lighting slamlards, the o-rl. !hi' premises. disconnecting means shall bt' j)en nilled lo be localed elsewh.tre &cepti<m No. 4: For jJoles or similar structures used only for mpjim·t of signs installed in accordanc/i iuith A rticll' 600,. !he disconnecting means shall bl' permitted to br lomtn/. PLwwhew on thl' premises. 225.33 Maximum Number of Disconnec ts. (A) General. The d isconnecting means for each supply permitted h )' 225.30 shall con sist of no t more man six switch es o r si.x ci rcuit breakers mo unted in a sing le enclosure, in a grou p o f separate e nclosures, or in o r o n a switchboard or swiLchgear. The re shall be no mo re d1an six d isco nn ect~ per supply grouped in an y o ne locatio n. Exception: For the /m1j1oses of this secli.rm, disconnei;ling means med solely for lhf control ci'lmil of the gruund-frmlt protection system, or the control circuit of the power-operatPd supply disronnecting means, install/id as jiart of the li.rtrd equipment, shall not be considmnl tt s 1.tpj)ly. discowwcting 111mns. (B) Single -Pole Units. Two or Uiree sing le-po le switches or breake1-s capa ble of individu a l o pe ratio n sh all be pennitted on multi.wire circ uit~, o ne pole for each ung ro unded cond uctor, as o ne mu.ltipole d iscon nect, provided d1ey a re equi p ped wim iden tified hand le ties or a master ha ndle LO d.isconnect all ung rounded con.d uct01·s wid1 no mo1·e th an six o peratio ns of the h a nd. 225.34 Grouping of Disconnects. (A) General. T he two to si.x disconnects as pen11ittecl in 22.5.33 shall be g rouped. Ea.ch disconnect sha ll be m arked to indicate Lhe load served. 1.xti!jJri:on: One of thP /rvo Lo six disrnnnecting means /:iermitted in 225.33, 111/u,r!' imd only for a writerpurnp also intended to fnvvidi' jirr /Jroti'ction, shall be permitted to bP located remote fr/Jrn the other disr.on11.erting means. 70-85 225.34 ARTTCLE 225- OUTSIDE BRANCH CIRCUITS AND FEEDERS (B) Additional Disconnecting Means. The one or more additional disconnecti11g means for fire pumps o r for e m er ge11cy, legally required standby or optional standby system permitted b y 225 .30 shall be installed sufficiencly remote from the o ne to six disconnecting me ans for normal supply to nli.ni.rnize Lhe possibili ty of sim ultaneotL~ interruption o f supply. switchgear section is ma.r'ked to indicate a g rounded conductor disconnect is contained within th e equipment. 225.35 Access to Occupants. In a multiple-occupancy building, each occupant shall h.we access to the occupant's supply disconnecting means. 225.39 Rating of Disconnect. The feeder o r branch-circuit disconnecting means shall have a rating of n ot less 1.han the calcul<1ted load to be supplied, determined in accordance witl1 Parts l and TI of Article 220 for b ra.ri ch c ircuits, P,irt III or JV of Article 220 for feeders, o r Part V of Article 220 for fa.rm load5. vVhere the branch circuit o r feede r disconnect.i.n g me ans consist5 of m o re than one switch 01· circuit breaker, a5 permit,. ted by 225.33, combining Lhe ratings of a ll the switc hes or circuit breakers for determining th e rating of the disconnecting m eans shall be permitted. Tn no case shall the rating be lower than specified in 225.39(A), (B), (C), or (D) . 1!.'.-cref1tion: ln a miiltiple-occitfxtniy building where eln:tril' supply and electri.cal mainlPnance ,11-e provided by the building mrm.agernenl and whel"I' these are 11-nrkr contfou.ous building num.agemmt sup«rv(,wn, the s·tt/J/1~\I disconnt>cting rn.e1ms supplying more tlian one offtt,Pancy shall be penniUed to bP accessible to authorized managnnent pt>rsonnel on ly. 225.36 Type of Disconnecting Means. The disconnec ting means specifie d in 225 .3 1 shaJI be comprised of a circuit breaker, molded case switch, general-use switch, snap switch , or other approved means. \.\'he re applied i11 accordan ce with 2 50.3 2 (B) . Exception No. l. 1.he disconnecting means shall be suitable for u se as service equipm e nt. 225.37 Identification. Where a building or stnicture ha5 any combination of feeders, branch circuits, or services pa5sing tl1rough it or supplying it, a permanent plaque o r directory shall be installed al each feeder and branch-circ uit disconnect location denoting all other services, feeders , or branch circ uits supplying that building or su·ucture or pa5sing through that bui.lding or strucnire a nd the area served b y each. Excef1tion No. I: A f1laquf or dire,;tmy shall not be 1,'1f!li111d for largecaf1acity rnultibwlrting industrial installations under single management, where it is ens-m-ei.l that di.sconr1ection can be a,;cmnfJlished by esta(Jlishing anll maintrtining .wife switdl.ing procedures. Excef1tion No. 2: This irlentijication shall not be required for branch circuits installed /min a dwdling 11-nit to a second building or st1·ttdm-e. 225.38 Disconnect Construction. D isconnecti ng means shall meet the requirements of225.38(A) through (D ) . (A) Manually or Power Operable. The disconnecting means sh all consi.~t of either ( 1) a manuaJly operable switch or a i;irnrit breake r equipped with a ha ndle or o t11er suitable o pe rating m eans or (2) a power-operable switc h or circuit. breaker, provide d Lhe switch or circuit breaker can be opened by hand in the event ofa power failure. (B) SimuJLaneous Opening of Poles. Each building o r structure disconnecting means shall simultaneously disconnect all ungrow1ded supply conductors that it controls from the building or st.nicture wiring system. (C) Disconnection of Grounded Conductor. Where Lh e building or stsuctw ·e disconnecting means does not disconnect the grc,unded cc,n ductor from the grounded conduc wrs in the building or strncnu-e wiring, othe r means shall be provided for th L5 pw,pc,se a t 1.he location of Lhe di5connecting means. A terminal or bus to which all grounded conductors can be attached h y means of pressure connectors shall be permitted for this purpose . 1n a mulLisection switchboard or switc hgear, d isconnects for the groLmded conductor shall be permitted to be in any sec tion oft.he switchboard or switchgear, if the switchbmu·d section or 70--86 (D) Indicating. The building or structure disconnecting means sh all plainly indicate wh e the r iLis u1 the o pen or closed position. (A) One-Circuit Installation. For installations to supply only Limited loads of a single b ra.nch circuit, Lhe bra nch circuit disconnecting means sh a ll ha,1 e a rnti.i1g of not less than 15 a mperes. (B) 1\vo-Circuit Installations. For installations consisting of not more than Lwo 2-wire branch cirnlits, tl1e feede1· or branchcircuit disconnecting means shaJI h ave a rating of not. less than 30 amperes. (C) One-Family Dwelling. For a one-fami ly dwelling, the feeder disconnecting means sha ll have a rating of n o t less than 100 ampe1-es, 3-wire . (D) All Otl1ers. For all o ther installations, tl1e feeder or branch-circuit disconnecting means shall have a rating of not less tlian 60 amperes. 225.40 Access to Overcurrent Protective Devices. \,\The1·e a feeder overcurre nt device is nc,t readi ly accessible, branchcircuit overcurrent devices shall be installed on the lo ad side, shall be l110Lu1Led in a readily accessible location , and shall be of a lower ampe re rnting Lha n the feeder overcnrrent device. Part Ill. Over I 000 Vol ls. 225.50 Sizing of Conductors. The sizing of conduct0rs over 1000 volts shall. be in accordan ce with 210.19(B ) for branch circu it~ and 215.2(B) for feeders . 225.51 Isolating Switches. Where oil swi tch es or ai.t\ oi l. vacuum , or s ulfur hexafluoride ci rcuit b reakers constintte a building disconnecting m ea.r1s, an i~olating swi tch witl1 visible break con tact.~ and meeting the requi rement5 o f 230.204(B), (C), a nd (D ) shall be installed on the supply side of the d isconnecting means and all associated eq uipmenL .Excej1tion: The i~olating switch shall not be rrquiml whem lhe disrnnnecting means is mounted on remo11ablP trud1. pantls or swilchgPm' •units that cannot be opened unless the circuit i.s disconnected and that, tohen removed fivm the nonnal ojierating position, aulomalically disamnecl the circuit brmk.er or switch from all energized fJarts. 225.52 Disconnecting Means. (A) Location. A building or struc ti.u·e d isconnecting mean s s hall be localed in accordance with 22.''i.32, o r, if not readily accessible., iL shall be operable b y mecha nical linkage from a readily accessible po int. For multibuikling indusu·ia l installa- NATIONAL ELECTRICAL CODE 2020Edition 225.60 ARTICLE 225- OUTSIDE BRANCH CIRCUITS AND FEEDERS tions tmder single management, it shall be permitted ro be electrically operated b y a readily accessible, re mote-contrnl device in a separate building or su·ucture . (B) Type. Each lmilcling or su·ucture disconnect s hall simultaneously disconnect all ungrounded supply conductors it contro ls and s hall have a fault-closing rating not less than t he available fault current al it5 supply terminals. Exception: Whem llw individ'ltal discon·nerting rnerm,5 CIJ'Tlsisi5 of/1.t,W!ll C'l-tlouls, the sinmlla11t1011,,,· disconnertion of all ungmwnded supj1ly conductors shall n o/ be reqiiireil if there -is a rne,ms to diiconnect thP load before opPn ing the cillou/s. A /wnnrment [fgible sign shall be installed arljorml lo the fused m_itonlr r.md shall read DJSCONNJ::cr LOAD BEFORE OPJ,,,'NJNG CUTOUTS. Where fused switches or separately m ounted f uses are installed, the fuse characteristics s hall be permitted to contribute to the fault-closing rating of the disco1rnecting means . (C) Locking. Disconnecti.ng means shall be lockable open in accordance with 11 0.25. Exception: Mlhe1l' cm individual llisa;n1111rting rnerms 1xmsists offusecl Clll outs, n suitable mdo.wr~ tapable of being lor.k.ed and siud to contain all cutout Jnsr holder.; shall bl' ,instnlletl at a crmveni;mf !oration to the fuserl ciaouts. (D) Indicating. Disconnecting means shall clearly imlicate wheLher they are in the open "off' or close d "on:' position. (E) Uniform Position. Where disconnecting means handles are operated vertically, the "up" position of the handle shall be the "on" position. l.xception: A switching devir;e having rnore than one "on" position, such (l,S a do11ble lhrotv switch, shall not OP '11'/Jllirrd lo cmnt1z~ wilh lhis rrquirimuml. (F) Identification. Where a building or ~tructure has any combination of feeders, branch c ircui ts, or services passing through or supplying it, a pe rman ent p laque or directory s hall b e installed at each feeder and branch-circtdt di5connect location that denotes ail other services, feeders, or brancl1 circuit~ supplytng that build ing or structure 0 1· pass ing through that building or structure and the area served by ead1. 225.56 Inspections and Tests. (A) Pre-Energization and Operating Tests. The complete elecu·ical system design, including setdngs for protective, switc hing, and control circuits, sh all be prepared in advance and made available on request to UH" authority having jmisdiclion and shall b e performance tested when first installed on-site. Each protective, switching, and control circuit s hall be a(ljusted in accordance with the system de5ign and tested by actual operation using q.1rrent i1tjec tion or equivalent meth od s as n ecessary to ens ure that each and every s uc h circuit operates cotTectly to the satisfaction of the authority h aving jurisdiction . (1) Instrument Thansformers. All insu·ume nt tra.nsforme ns shall be tested to verify correct polarity and burden. (2) Protective Relays. Eac h protective relay shall be demonstrated to operate by i1tjecting c urrent or voltage, or hoth, a t d1 e associate d insu-ume nt tI'ansfonner output termina l and o bserving that d1e associated switching and signaLi11g function.~ o ccur correctly and in prnper Lime and sequence i:o accomplish tl1e protective li.111ction inte nded. 2020 ll\lirjon NATIONAL £ LllCTRICAL CODE (3) Switching Circuits. Each switching circuit shall be observed to o perate the associated equip ment being switcl1ed. (4) Control and Signal Circuits. Each conu·ol or·signaJ c ircui t shall be o bserved to perform its proper conu·ol function or produce a coITect signal output. (5) Metering Circuits. All metering c ircuits s hall b e verified to operate correclly from voltage and current sources in a simi lar man.net- to protective relay circuits. (6) Acceptance Tests . Complete acceptance tests shall b e performed., aft.er the substation installation is completed, on all assemblies, e quipment, conductors, and conn-ol a nd protective systems, as applica ble. to verify tJ1e integrity of ail the syste m s. (7) Relays an.cl Metering Utilizing Phase Differences. ALI rela ys and m e tering tl1at use phase differences for operation shall b e vel'ified by measuring phase angtes at the relay under actua l load conditions after operation commences. (B) Test Report. A test report covering tl1e 1·esults of the tests required in 225.56(A) shall be del ivered to the authority having jurisdiction prior to energization. Informatio nal Nore: For an example of acceptance s pecificacions, see ANSI/ NETA ATS-2013, rlcre/1tar,ce Te.,ling Specif,mtiom for Ete,:triraL Power DistlibUlion 1'.'guijmuml n11r/ Systems, pubLish ed b y lhe lnterNa1jonal Electrical Testing Association. 225.60 Clearances over Roadways, Walkways, Rail, Water, and Open Land . (A) 22 kV, Nominal, to Gro und or Less. The clea rances ovi:r roadways, walkways, rail, waler, and open lan(l for conductors and live part~ up to 22 kV, nominal, to grotmd or less sh all b e not less than d1e value s shown u1 Table 225.60. (B) Over 22 kV N ominal to Ground. Clearances for the categories shown in Table 225.60 shall be increased by 10 mm (0.4 .in.) per kV above 22,000 volts. (C) Special Cases. Fo r special cases, such as where crossings will be made over lakes, rivers, o r areas using large vehicl es such as mining operations, specific designs shall be engineered conside ring th e special circumstances and shall be approved by the authority having jurisdiction. l nformarional Nore: For adclirional info mrntion, ~ee ANSI/ IE£E C2-2017, Nr,tioi,al Etm,Oimt Safety Code. Table 225.60 Clearances over Roadways, Walkways, Rail, Waler, and Open Land Clearance Location Ope n land s ubject t◊ vehicles, cul Livation, or gra zing Roadways, d1iveways, parking lots. and a lleys Walkwa)'S Rails Spaces ,md ways for pedesuians and restricted traffic Wat.er areas no t s uitable frn' boating m ft !),6 18 ..5 5.6 18.5 4.l 13.5 8.1 4.4 2fi.5 14.5 ri.2 17.0 70-87 225.61 ARTICLE 230 - SERVICES 225.61 CJearances over Buildings and Other Structures. General Overhead Service Conductors Underground Service Conductors Service-Entrance Conductors Service Equipment- General Service Equipment- Disconnecting Means Service Equipment- Overcurrent Protectlon Services Exceeding 1000 Volts. Nominal (A) 22 kV Nominal to Ground or Less. The clearances over buildings and other structures for conductors and live part5 up to 22 kV, nominal , to ground or less shall he not less than the values shown in Table 225.61. (B) Over 22 kV Nominal to Ground. Clearances for the categories shown in Ta ble 225.61 shall be increased by 10 mm (0.4 in. ) p e r kV above 22,000 volt~. Serving Utility In forma tio nal Note: Fo r add itio nal informat.io n, $ee ANSl/ lEEE C2-W I7. N,11io11at EIHctrirnt Safely Coc/P. Table 225.61 Clearances over Buildings and Other Structures Part 11 230.24 Clearance from Conductors or Live Parts from: Building walls, prnjections, a nc.l windows Balconic~, catwalk~, and similar areas accessib le to people Over or wider roots o r projectio ns no t readil y accessible to people Over rool:s accessible to· veh icles but not trucks Over roofs accessible to IJ'Ucks 0 th er struc.t,1res Horizontal m ft 2.3 7.5 2.3 7.5 Overhead Last pole Underground Street main Overhead service conductors Clearances Underground Part 111 service conductors Depth of burial 230.32 and protection Service head Terminal box, meter, or other enclosure Vertical m ft 4.1 13.5 :\.8 12.5 4.1 13.5 Grounding and bonding 5.6 l l:l.5 Service equipmentdisconnectlng means Part VI Service equipmentovercurrent protection Part VII Service-entrance conductors Part IV Service equipment-general 2.11 7.5 Part V Article 250 Articles 21 o, 225 Articles 215, 225 Branch circuits Feeders ARTICLE 230 Services 230. l Scope . This article covers service conductors and equipment for control an.rt protection of services and th e ir installatio n re qui remen t~. lnf'orma uo nal Note: See Fig ure 230 ,1. FIGURE 230.1 (fi) (1 ) 230.2 Number of Services. A b~Li ldi11g o r other stru cture served s hall b e supplied b y on ly one service LU1less permitted in 2 30 .2 (A) through (D) . Fo r the purpose of 230.40, Exception No. 2 only, unde rgro u nd sets of conductors, l / 0 AWG and lar ger, running to the s,une locatio n and con11ected together at th eir supply end but not connected t0getl1er at their l oad e nd shall be considered to b e supplying o n e se1·vice. (A) Special Conditions. Additional se1-vices shall be permitted to supply the fo llowing: Fire pumps Eme rge ncy syste ms Legally requixed sta ndby syste ms Optional standb y systems Pa1·allel powe r productio n system s 70-88 Services. System s d esigne d fo1· conne ction to muJtipl e sources of s upply for th e pmpose of enJian ced reliability (B) Special Occupancies. By sp ecial p e rm ission, additio nal services s hall be permitted for e ither of the following: Parl I. General (l ) (2) (3) (4 ) (5) Part I Part 11 Part Ill Part IV Part V Part VI Part VII Part VIII (2) Multiple-occupan cy buildings wh e re the re is no available s pace for service equ ipmen t accessible to a ll occupan ts A singl e build ing o r t1th e r struc ture sufficie ntly la1·ge to m a ke two o r more services necessary (C) Capacity Re quirements. Additional permitted under any of rl1e fo llowin g: (1) (2) (3) services sh all be \!\The re the capacity re[Juirement~ are in ex cess of 2000 amperes at a supply vo ltage of J000 volt~ or le ss W he re the load requiremen ts of a single-phase installatio n a re g reater rl1an the serving agency no rmally supplies thx·ough one service By special permission (D) Different Characteristics. Adrlitional services shall be p ermitted for diffe re nt vpltages, freque ncies, or phases, or fo r di.fferent mes, s uch as for differe m rate schedules . NATIONAL ELECTRICAL CODE 2020falition ARTIC'..LE 230 - SERVICES (E) Identification. v\'he re a building or structure is suppli.erl b y more tha n o n e ser vice , or any combinatio n o f branch ci rcuits, feed e rs, and services, a permane nt plaque o r directory shall be installed at e ach service disconnect locatio n d e noting a ll othe 1· se rvices, fe ed e rs, and bra nch c ircuit~ supplying tha t building o r str uc ture and the aJ·ea served by each. See 225.37. 230.3 One Building or Other Structure Not to Be Supplied Through Another. Se rvice cond uctors supplying a building or othe r structLU·e shall no t pass through the inte 1·ior of another building or o thersu-ucrure . 230.6 Conductors Considered O utside the Building. Conductors sha ll be considered out~ide o f a building o r oth er su·ucture Lmder an y o f th e fo llowing conditio ns: (l ) (2) ('.1) (4) (!'i) Where insta lled unde r not less than 50 mm (2 in.) o f conc re te be neath a building o r other sLn1ct1.tre Where installed within a building o r o the r structure in a r aceway tha t is e ncased in conc rete or brick no t less tha n 50 mm (2 in.) thick Where installed in a ny vault that meets tJ1e construc tio n requirem ents of Article 450, Pa rr ill \!\'here installed in conduit and under no t less tha n 450 rnm (1 8 in.) o f earth be neatJ1 a buildi11g or other strucuire \'\'here installed within rigid metal conduit (Type Rl\llC) o r inte rme diate m eta l cond uit (Type IMC) used lo accomm odate th e clearan ce reqult·eme nt~ in 230.24 and routed d i rectl y through a n eave hut no t a wall a f a building 230.7 Other Conductors in Raceway or Cable. Cond ucto rs o ther tha n service conductors sha ll no t be insta lled in tJ1e same service raceway or service cable in whic h the service cond uctors a 1·e installed. Exmption No. 1: Oroimdin[I el,1ctrode wnductors or s1.1j)f1ly side bonding.furnrpers or conductors shall be permitted ttJith-in service raceways. Exception No. 2: l oad management control rondiu:lors having ovrrc1.1rrent protection. shall be f1Prmitted tuithin semice raceways. 230.8 Raceway Seal. ,'\There a ser vice raceway e nte rs a building o r su·uctw·e fro n, an u nd e1·g-r0 Lmd distributio n syste m, it sha ll be seale d in accord.rnce with 300.5(G) . Spa re or uJ1used raceways shall a lso be seale d. Sealan ts sh a ll be identified for tL~e witJ1 tJ1e cable insulati on , shie ld, o r o ther compo ne n t~. 230.9 Clearances on Buildings. Service conductors a nd fina l spa ns shall comply with 230.9(A) , (B), and (C) . (A) Clearances. Service conductors installed as ope n conducto rs o r multiconduc tor cable witho ut an o verall outer j acket shall have a clea rance o f not less than 900 mm (3 ft) fro m windows that are desig·ne d to be opened, d oors, po rches, ba lconies, Ladders, stairs, fire escapes, or similar locatio n s. Exwptian: Conductors run above the Lop level rrf a window shall be perrnill.ed l o he li>.ss than the 900 rnm (3 JI) requirnnenl. (B) Vertical Clearance. The vertical clearance of final spans a bove, o r wid1 in 900 mm (3 ft) measu red h o rizontally of platfo rms, p roj ectio ns, or surface s tJ1at will permit persona l con tact shall be ma intaine d in accord ance wi th 230.'i!'l(B) . (C) Building Openings. O verhead service condu ctors sha ll n ol be insmlled benea d1. op enings thr()ugh which materials may he moved, such as o pe nings in farm a nd commercial build ings, 2020 ll\lirjon NATIONAL £ LllCTRICAL CODE 230.24 and shall no t be installed where they o bstruct e n tran ce co th.ese building o pen ings. 230.10 Vegetation as Support. Vegetation such as trees shal l not be used fo r suppo rt o f overhead service cond ucrors o r service e quipme nt. Part II. Overhead Service Conductors 230.22 Insulation or Covering. Individual cond ucto rs shall be insn Ia ted or covered. Excepti<m: The grounded ronductor of a multirnnr.tuctor cable sluill be permiUed to be ha:re. 230.23 Size and Anlpacity. (A) General. Conducto1·s shall have sufficien t am pa city to carry the curre nt for the lo ad as calcula te d in acco rda nce with Article 220 an d shall have ad e gua te mechanical su·ength. (B) Minimum Size. The conductors shall no t be sm aUer U1an 8 AWC coppe r or 6 AWC a lurnimun or coppe r-clad aluminum. l:.'xce/1tion: Condtu:lors siipplying only lirnilNl loads rrf a sing!,e branrh ci1ruit - such as s111r1ll polyplwse f)()wer;_ con/rolled waler h.eatn:1, and similar load~ - shall not be srnalkr than 12 A WG hcml-rlrawn m/Jper o-r equivrdent. (C) Grounded Conductors. The grounded cond uctor shall no.t be less d1an the minim u m size as re quired hy 250.24(C). 230.24 Clearances. O verhead ser vice conductors shall not be readily accessible and sha ll comply with 230.24(A) throug h (E ) for services n ot over LOOO volt~, no min al . (A) Above Roofs. Conducto rs sha ll have a vertical clearnnce of nor less tJ1a n 2.5 m (8 ft) above the roo f sw·face. The vertical cleara nce a bove the roo f level shall be ma intaine d for a distance o f no t less tha n 900 mm (3 fl) in a ll direc tions fro m the e d ge of t11e roof. Exceptimi No. 1: ThP rnm above a. mofsniface s11b.fecl lo j)ridPstrian or veh.icidar traffic shall have a vertical dearanfl' from the roof s-i irfaa in accordanrr tvith the rlearance requiremm1ts of230.24(B). J,,xceptirm NQ. 2: Where the volt1.1gr' bett(•ren C<mductors does no! exCPed 300 and the roof has a slope of 100 mm in 300 mm (4 in. in 12 in.) m· gr1:aln; 11 rpdi1.rtion in d mrance Lo 900 mm (3 ft) slwll be /mwiiLtrd. ExCf'Plion No. 3: Where the voltagP. betwe1m umdm:tm·s dors not exawf 300, a mdi1cLion in cluirancf! above only the overhanging portiou of lit/' roof lo not less than 450 mm (18 in.) shall be />Brmitted if ( 1) not more than 1.8 1ll (6 fl) of overhead service condurtors, 1.2 in (4 fl) horizontally, J>a.ss abovr1 tlw roof overhang, and (2) they a.re terminated al o 1hm1.i.gh-1h.e-mof ratlfl.u(1y or (lj1fnv11Pt,l S?lflfJOrt. Informationa l Nme; See 230.28 for rna.sLsupporLS. J:.'xcept-i,m No. 4: The requirement for ma.irrtafning the ve,tical clearance 900 mm (3 fl) from the edge of the wof shall not apjJly lo thP final rnnductor span whern tlw service dmjJ or ovG'rhfad servicfl cm1.dv1"tor.; are a11adwl to the sidP of a liuilding. Bxreption No. 5: Where the vollag~ bt>ltur.en condurtors does not exceed 300 and tft1, roof area is guarded or isolated, a redtteli<m in cleamnre to 900 mm (3 ft) shall b~ permitted. 70-89 230.24 ARTICLE 230 - SERVICES (B) Vertical Clearance for O verhead Service Conductors. Overhead se1-vice conductors, where n ot in excess of 1000 volts, nominal, shall have the fo llowing minimum clearance from final g rade: (1) (2) (3) (4) (5) ,HJ m (] 0 ft) - at the electrical .~ervice enmmce to buildingi,, al50 at the lowest point of the drip loop of the building e leca·ical entrance, and a bove a rea.5 or sidewalks accessible only to pedestrians, measured from final gnde 01· orher accessible surface o nly fo r overhead service conductors supported on and cabled together witJ1 a g rounded bare messenger where the voltage does not exceed 150 volt5 to g1·otmd 3.7 rn (12 ft) - over residential property and driveways, and those commercial areas not subject to truck traffic where the voltage does not exceed 300 volts to ground 4.!'i m (15 ft) -for those areas Listed in the 3.7 m (12 ft) classification where th e voltage exceeds 300 volL5 to ground 5.5 m ( LS ft) - over public streeL5, alleys, roads, parking areas subject co truck traffic, driveways on 01.he1· than residential property, and other land .5u ch as cultivated, grazing, forest, and orchard 7.5 m (24½ ft) over cracks of railroads 230 .29 Supports over Buildings. Service conducto rs passing ove1· a roof shaU be securely supported by substantial structures. For a grounded ~')'Stem, whe1·e the substantial su·uccure is metal, it shall be bonded by means of a bonding j umper and listed connector to the grounded overhead service conducto1·, 1,Vhere practicable, such supports shall be independent of the building. Part fil Underground Service Conductors 230.30 Installation. (A) Insulation. U nderg:row1d service conducto1·s shaU be insulated for the applied voltage. E>::ception: A grounded cond11.ctor shall be fJe-rmilled to b1• uninmlated as follows: ( 1) (2) (3) ( 4) (C) Clearance from Building Openings. See 230.9. (D) Clearance from Swimming Pools. See 680.9. (E) Clearance from Communication Wires and Cables. C lear- ance from communication wires and cables shaU be in accordance with 800.44(A) (4). 230.26 Point of Attachment. ll1e point of a ttachment of the overhead se1-vice conductors to a building o r oth er structure shall provide the m inimum clearances a5 specified in 230.9 and 230.24. In no case shall th is point of attachment be less than 3.0 m ( 10 ft) above finis heel grade. 230.27 Means of Attachment. Multiconductor cabl es used. for overhead service conductor·s shall be attached tO buildings or oth er strucrures by fittings identified for use with se rvice conductors. Open conduc tors shall be attached to fitting·s identified for use with service conduc tors or to noncombustible, nonabsorbent insulators securely attache d to w e building or other structure . 230.28 Service Masts as Supports. Only power se1-vice-drop or overhead service conductors shaU be permitted to be attached Lo a service masL Service ma~ts used for the support of servicedrop or overhead service conductors shall be installed in accordance with 230.28(A) and (B) . (A) Strength. The service ma.~t shall be of adequate su-ength or be supported by braces or gu)' wires t.o withstand safely the stra i.n imposed b y th e ser-vice-drop or overhead service conductorn. Hubs intended for U5e with a conduit tJrnt serves as a service mast shall be ide n tified for use witJ1 sen~ce-entrance equipment. (B) Attachment. Service-drop or overhead service conductors shall not be attached. to a service ma~t between a wead1erhead or the end of the conduit and a cotipling, where d1e coupling is Located a bove the last point ofsecureme.nt to the building or other structw·e or is located above the building o r od1er structLtre. 70-90 Bare cof)j}fr used in a ral'eway Barf coPfurrfor dimt lmrial wlumt bare. copf*r is af,prvved for the soil conditions Barr ,;opj1w for dirert bmial wilhout 1y,gard lo soil rm1dilions where part of a cable assem/J9, identified for undr,rground me A lwnimtrn or co/1/>eH;lad alurninwm witho1.tl indiuidua,l insulation or covering where /Jart of a cable assembly identified for wndergrmmcl usr in a raceway orfor dir('(;t bwictl (B) Wrring Methods. Underground service conducwrs shal l be in..5talled .u1 accordance with the applicable 1·equiremencs of this Corlr, covering the type of wiring method tL,ed a nd shall be Iimi ted to the follo\\in g methods: (1) (2) (3) (4) (5) (6) (7) (8) (9) Type RMC conduit Type IMC conduit Type NUCC conduit Type HDPE cond uit Type PVC conduit Type RT RC comlLtit T)'pe IGS cable Type USE conductors o r cables T)rpe MV or Type MC cable identified for d irect burial applications (Hl ) Type MI cable, w here suitably protected agains t physical damage and corrosive conditions 230.31 Size and Ampacity. (A) General. Underground service conductors shall have SLLfficien t ampacicy to carry 1:he ctu-ren t fo r the k1ad as calculated in accordance with Article 220 and sha ll have adequate mechanical strength. (B) Minimum Size . The conductors shall not be smaller tl1an 8 AWG copper or 6 AWG aluminum or copper-dad a lurn i1rnrn. J.-.xce/1tion: Conduc/ots supplying only limiled load~ of a singl.e branch rin:uit - sw:!t as small pol)1Jftase /1ower, controlled water heatn-s, and sirnilar loads - shall nol be smaller than 12 A \IVG copper or I OA WC alwnim.1,m, or coppeH:lad al'wminwn. (C) Grounded Conductors. T he grou nded conductor shal l not be less than tl1e mu1imum size required b y 250.24(C) . 230.32 Protec tion Against Damage. Undergro w1d servi.ce conductors shall be protected against damage in accordance with 300.5. Service conductors e ntering a buildu1g or other stru ctLtre shall be installed in accordance with 230.6 01· protected hy a racewaywiru1g me thod identified in 230.43. NATIONAL ELECTRICAL CODE 2020Edition 230.43 ARTIC'..LE 230 - SERVICES 230.33 Spliced Conductors. Service conductors shall be permitted to be spliced or tapped in accordance with 110.14, 300.5(E), 300.13, and 300.1 5. Part IV. Service-Entrance Conductors 230.40 Number of Service-Entrance Conductor Sets. Each service drop, set of overhead service ci;rnductors, set of underg round service conductors, or service lateral shall supply o nly one set of se1vice-en u·ance conductors. Exceplion No. 1: A building tni.th rnmt than one orcuprJnry shall be /Jwmitted lo have one set of sRrvice-entrancR ronductors for mdi service, a.r permil.led in 230.2, nm lo each occ'UJ/>ancy or gm-up of occw/1ancies. If tlu nurnb1tr of service disrnnned [orations for any givRn classification of service does nol exrPe,t si.x, lhe requirements of 230.2(£) shall af>ply at each lorn.tfon. if tlw number of service dfo:onru<,;/ {orations r,:,:,;e11ds six for any given S1.1.f1p!:y classijira1ion, all servicP disconnect loi·a1ions for all s·u/1pl:y clmracleri.stics, togrthtr with any branch 1-imiit or jfeder supply sources, if a/1plica/Jle, sh(J,ll be rlmr~ described using graphics or wxt, or both, on O'lle or 1110/"P plaques ln,;ated in rm fl,/J/Jmv11d, readily accessible location(s) on lhe building or s/ruct-u·w sn-ved and as near as j>rarticable to !he point(s) of 11ttachment or entry(ies) for earh service drof> or service lateral rm(l for each set of overhead or wnder6n-ound servir:(1 conr.litr.lon. Exception No. 2: Where two to six sl'rvi1,P dfo:onn11rting means in sepo,ratP mc!nsitrPJ a:re grouped at one location and supply sepam,tP loads from one servicP dro/1, set of overhead service conducto1:f, set of 'I.I nd11rgmwnrl service conduclor.1, m· servir.e latem,L one set of se1vice-entrance rnndi1,ttors slwll be fHfl'!llitled to sup/1ly mch or sroeml s·uch service equi/nnen t enrlosures. .Exception No. 3: A. onefamily dwelling uni.t and its accessmy sJ,mctures shall be p11rmilifd to luiv11 one s<ft of servire-eritrance conductors run lo each jr01n a single service drop, sPt of overhead service conductor.., sel of unde,gmund .w,rvi1:e mnd1,1don, or servite lateral. Exception No. 4: Twofr.tmily dwPllings, multifmnil:y rlwellingr, and mnl/iple occupancy buildings shall br /Je17n.i/f.ed to luwf onr srt of servi1:e-e•ntmnte condutlors installed to su.pply thr circuits covered in 210.25. Exception No. 5: One set of service-'i!ntra.nct' conductors connected to lhe .sit/>ply side <if the normal srrvit:e disconnecting 111rans shall b<i pennWed lo si.1ppl:y eacl, or several systems ravered by 230. 82(5) or 230.82(6). 230.41 Insulation of Service-Entrance Conductors. Serviceenmrnce conductors entering o r on the exterio r of buildings or other su·uctures shall be insulated. Excrption: A gnmndPd conditclor shall be /Jennilled to be iminsulaled ci1-Jol[ows: (1) (2) (3) (4) (5) Bare copper usnl in a mct.1.uay or part ofa service cable tJ,,5Sembly &trf copper for direcl bwial where barP i:optJer if o.pjm1ved for the soil conditiom Bare cof>jJer for direr/ burial wilhoul regrmt lo soil mnditi<ms where part ofa a1blr ass1m1bly identified Jqr 1.mdergmund ti.St' Aluminwn or ro/1/Jrr-dwi al'l.lmimJ•rrt iuilhoul individual insulation or covering where /Jar/ of a cabll' (lssembly or idmtified for undergtrn.vnd usr in a rw:nuay, orfor direct b·witd Bate conduct.ors used in an auxiliary [!yl ter 230.42 Mmimum Size and Ainpacity. (A) Geueral. Service-enmtn ce conductors sh a ll have a n ampacity of not less than the maximum. load to be served. 2020 ll\lirjon NATIONAL £LllCTRICAL CODE Conductors sh a ll be sized not less tha n the la rgest of 230.42(A) ( 1) or (A)(2) . Loads shall be determined in accor·dance with Part Ill, IV, or \I of Article 220, as applicable. Ampa.city shall be determ ined from 3 10. 14 and shall complyw:ith 11 0.14(C). The maximum current of busways shall be that value for which the hLL~way has been listed or labeled. l nlonnational No1e: For information on buswavs, see UL 8fi7, Slri-nrlard(or Safely for B11s-wr,ys. · (I) Vlfhere the service-entrance conductors supply conti.nuous loarfa or any combination of n o n continuous and continuous loads, the minimum service-enu·ance conductor size shall have an ampacity not less than the sum of the noncontinuous loads plus 125 percent of con tinuous load5. Excl'pli<Jn No. I: Omunded rnnductm;~ //tat arp not conneclnl lo an overcttrrenl devia shrill be pennilled t.o bi' sized at 100 perrml of lhP .57,mi of lite contimwus and noncontinuous load. Exception No. 2: The sum of the noncontinuous load and !he contirmous load if the service-entrancl' cond·11ctors J,errninale in an overcurre-nt droice whn·~ both Liu: cmerrnrmnl device and i fs a,1Scrnbly cirf! listPd for o/111ration at I />~rrenL of (heir rating shall be jJermitted. on (2) The minimum service-enu·ance condm;to1· size sh a ll have an a mpacity not less than d1e maximum load to b e served after d1e application of any adjustment or co1Tection factors. (B) Specific Installations. In addition to d1e req1.ti.remenl~ of 230.42(A), t11e m inimum ampacity for ungrounded conductors for specific installa tions sh all not be less than th e nlting of the service disconnecting mea11.~ specified in 230. 79(A) through (D) . (C) Grounded Conductors. 1l1e grnunded conduclor shal l not be smaller d1an d1e minimum size a~ required by 250.24(C). 230.43 Wiring Methods for 1000 Volts, Nominal, or Less. Service-enu·ance conductors sha ll be insta lled in accordance wil11 the applicable requiremeJ1t~ of d1is Code covering the type of wiring metJ1od used and shall be limi ted to d1e following method5: ( 1) (2) (3) (4) (5) (6) (7) (8) (9) (10) ( 11 ) ( 12) ( I '.~) ( 14) ( 15) Open wi1ing on i11.5u la tors Type IGS cable Rigid meta l conduit (RM.C) Intermediate tUetal conduit (Th1C) Electrical metallic tubing (EMT) Electrical nonmetallic tubing Service-enu·ance cables Wireways Busways Auxiliary gutters Rigid polyvinyl chloride conduit (PVC) Cablebus Type MC cable Mine ral-insulated, metal-sheathed cable, Type Ml Flex ible metal conduit (FMC) not over 1.8 m (fi ft) lo ng or liquidtight flexible metal conduit (LFMC) not ove1· 1.8 m (6 ft) long between a raceway, or b etween a raceway and service equipme nt, wid1 a supply-side bo nding jumper routed wil11 l11e flexible meta l conduit (FMC) or the liquidtight fl exible metal conduit (LFMC) according to 250.102(A), (B), (C), a nd (E) ( 16) Liquidtight flexible nonmetallic conduit (LFNC) 70-91 230.44 ( L7) (18) ARTICLE 230 - SERVICES High density polyeth ylene conduit ( H OPE) Nonmetallic underground conduit with condu ctors (NUCC) Re info rced thermosetting resin conduit (RTRC) Type TC:-ER cable ( 19) (20) 230.44 Cable Trays. Cable tray sys tems shaU be permitted to support service-en tran ce conductors. Cable tTays used to support service-en1:1:a11ce conductors sh all cont.iin only serviceentrance conductors a nd sh all be Limited to th e following methods: (I) (2) (3) (4) (5) (6) Type SE cable Type MC cable Type l'v11 cable Type lGS cable Single conductors l / 0 and la1-ger that are liste r! for use in cable u-ay Type TC-ER cable Such cable trays shaU be identified wil.h pe rmanently affixed label~ with the wording "Service-Entra n ce Conductors.'' The la bels sha ll be located so as to be visible after ins tallation with a spacing not to exceed 3 m ( IO ft) so that th e service-emrance conductors are able to be readily traced thro ug h the e ntire length of the cable tray. Exception: Con.rfoclors, oth11r than seivice-mtrance conductors, shall he fNrmitted lo he insl.a/led in a cabtr, tray with s1Jrvice-entranN condurtors, /1rovided a solid fixed barrier of a waterird annpatible with the cable tray is installed lo separate I.he servim-nitmnce condw:lors jfrnn other tondittlors installed in Litt cabl,e l·ray. 230.46 Spliced and Tapped Conductors. Service-en trance conductors sha ll be permitted to be spliced or tapped in accordance with 110.1 4, 300.5 (E) , 300. l 3. and 300. 15. Power clistributio n blocks, pressure connectors, and devices for splices and taps sha ll be listed. Power distributio n blocks irt~taJled on service conductors shall be m arked "suitable for LL~e on the line side of the service equipment" or equivalent. Effective J a nuar y l , '.:!023, press ure connectors a n d devices for splices a nd taps installed on se rvice conductors shall be marked "suitable for use on the line side o f the service equipme nt" 01- equivale n t. 230.50 Protection Against Physical Damage. (A) Underground Service.Entrance Conductors. Un dergrntmd service-entran ce conductors shall be protected again~t physical damage in accordance with 300. 5. conductors, shall be protected against physical damage as specified in 2 30.50 (B) ( l ) or (B) (2) . ( I ) Service-Entrance Cables. Service-entrance cabl es, where s ul?jec1. to physical damage, sh a U be protected by a ny of the follow ing: (l ) (2 ) (3) (4) (.5 ) (fi) Rigid metal conduit (RMC) Inte rmediate metal conduit (IMC) Sch edule 80 PVC conduit Elecu·ical metallic tubing (EMT) Re inforced the rmosetting resin conduit (RTRC) Other approved means (2) Other Than Service-Entrance Cables. Individua l open con d uctors and cables. other tl1an service-entrance cables, sh all not b e in~talled witl1in 3.0 rn ( I O ft) of grade level or w he re exposed to physical cla,.mage. Exclj1tion: ?3'/1e Ml and ?ypt MC cable .1lwll be f1ermiltn} within 3. 0 m (10 ft) of grade level where not exposed to physical damagr1 or where /1rot.tcted in acco·,danre with 300.5(D). 230.51 Mounting Supports. Sen~ce-emrance cables or individual open se1v ice-e nu·,mce conductors shall be suppo rted a~ specified in 230.51 (A), (B ), or (C) . (A) Service-Enttance Cables. Service-entra n ce cables shall be su pported by straps or o ther approved mea ns within 300 mm ( l 2 in .) of every service head , gooseneck, or connection to a raceway or en closure and a t interval~ not exceeding 750 mm (30 in.) . (B) Other Cables. Cables tl1at are n ot approve~! for mou11Ling in contact with a building o r other su-i.1cnire sh a U be mo unted on insula ting supports installed at inte1val5 n ot exceeding 4.5 m (15 ft) and in a manner tl1at maintains a clearance of n o t less than 50 mm (2 in .) from the smface over which they pass. (C) Individual Open Conductors. Individual open conductors shall be installed in accordance with Table 230.51 (C). Where exposed to the weatl1e r, tl1e conduc to rs shall be mounte d o n insulators o r on insulating supports attached to racks, b rackets, or other approved means. Where not exposed to ~he weatl1e1~ the conductors sh all be m ounted on g lass o r porcelain kn o bs. 230.52 Individual Conductors Entering Buildings or Other Structw·es. Vl'here individual open conductors enter a building o r otl1er structure, tl1ey shall en.ter throu gh roof bushings or tl1rough t11e wall in a n upward slant tl1roug h i11dividual , n oncombusti ble, nona bsorbent ins ulating rubes. Drip loops shall b e formed o n the conductors before t hey enter tl1e tubes. (B) All Other Service-Entrance Conductors. All other se1-vicee nu-ance conductors, othe r than w1derground service e ntrance Table 230.!>l(C) Supports Maximum Volts 1()()0 1000 300 1000* Minimum Clearance Maximum Distance Between Supports m ft 2.7 4.5 !) 15 1.4 4½ 1.4* 4½* Between Conductors From Surface in. nun in. 150 (j 300 75 fi5* 12 50 50 50 25* 2 2 mm 3 21/,* 2 I* *Wh ere n ot exposed to weath er. 70-92 NATIONAL ELECTRICAL CODE 2020Edition ARTTC'.J...E 230 - SERVICES 230.53 Raceways lo Drain. Where exposed co the weather, raceways enclosing service-entrance conductors shall be Listed or approved for use in wet locations and arranged to drain. Where embedded in masonry, raceways shall be arranged to drain. 230.54 Overhead Service Locations. (A) Service Head. Service raceways shall be equipped with a service head at the point of connection to service-drop or overhead service conductors. The service head shall be lt5ted fot· use in wet locations. (B) Service-Entrance Cables Equipped wilh Service Head or Gooseneck. Se rvice-entrance cables shal l be equipped with a service head. The service h ead shall be listed for use in wet locations. 1'.'xception: Type SE cablP shnll be permilled l.o be fc111ned in a goosenPck. and taf1Nl with a selfsmling wealheMesistant lhemt0/1lastic. (C) Service Heads and Goosenecks Above Service-Drop or Overhead Service Attachment. Service heads on raceways or service-entrance cables and goosenecks in service-ent.r~mce cables shall be located a b ove the poim of attachment of the service-drop or overhead sen1ice conductors to tl1e building o r otJ1er strucuu-e. Exception: Whe1e il is im/1rru;ticnble to locaLP. the service head or goosfnerk r1bo11e the. point. of attadwwnl, the Sl'l't1ice hrnd or goosem'd: lotr1r lion shall be f1enniiled not farther Lhan 600 m.m (24 in. )from the jJoinl of attaclirnent. (D) Secured. Se1·vice-e ntrnnce cables sh a ll be he ld securely in place. 230.70 (A) En.closed. Energized parrn sh a ll be enclosed so rJ1at they will not be exposed to accidental contact or sha ll be guarded as in 230.o2(B) . (B) Guarded. Energized pai·ts that are not enclosed shall be installed on a switchboard, panelboard, or control board and guarded in accordance with 110.18 and 110.27. Where energized parts are guarded as provided in 110.27(A)( l ) and (A)(2), a means for locking or seal ing doors providing access to energized parts shall be provided. (C) Barriers. Barriers shall be placed in service equipment such that 11.0 tminsulaled. ungrounded service bmbar or service tenninal is exposed to inadvertent contact by persons or maintenance equipme nt while servicing load terminations. 230.66 Marking. (A) General. Service equip1nent rared at 1000 volts or less shall be marked to identify it as b eing suitable for use a~ service equipment. All service equipment shall b e listed or field evaluated. (B) Meter Sockets. Meter socket5 sha ll not be considered service equipment but .~hall be listed and rated for the voltage and current rating of the service. Exceptim1: Meter socliet.s suf!'pli.ed hy and wnder the exclusive control of an electrir utility shall no/ be req'lliil'd lo be listed. 230.67 Surge Protection. (A) Surge-Protective Device. All services supplying dwelling units shall be provided with a surge-protective device (SPD). (B) Location. The SPD shall be an integral part of the service equipment or shall be located immediately adjacent there LO. (E) Separately Bushed Openings. Service heads shall have conductors o:f different potential brought out through separately bushed openings. Exception: 171.e SPD shall nol be required lo be localed in the servir.e equipment as required in (B) if located at ear:h next ll!tJel distribution t:xCPption: For jarketed mullimndnrtor servict-mtrrtncP w/)[e w-il/101.1.t eqnipment rlownstn:11111 toward the load. sf1lice. (C) Type. The SPD shall be a Type J or Type 2 SPD. (F) Drip Loops. D rip loops shall be formed on individ ual conductors. To prevent Lhe entrance of moisture, servi.ceenu·ance conduclors shal l be c(rnnected to tJ1e service-drop or overhead service conductors eitJ1er (l ) below the level of the service head or (2) below the level of the termination of the service-entrance cable sheatJ1. {D) Replacement. Where service equipment is replaced, a ll of the requirement5 oftJ1.is section shall apply. (G) Arranged That Water Will Nol Enter Service Raceway or Equipment. Service-entrance and overhead service conductors shall b e atTanged so that water will not e nter service rnceway or equipment. 230.56 Service Conductor with the Higher Voltage to Ground. On a 4-wire, delta-connected service where th e midpoint of one phase winding is grounded, the service conductor h aving the higher pha5e voltage to ground shall be dttrably and permanently marked by an outer fu1ish that is orange in colo1~ or by otJ1er effective means, at each termination or junction point. Part V. Service Equipment - General 230.62 Service Equipment - Enclosed or Guarded. Energized parrn of service equipmem sh a ll be enclosed as specified in 2S0.62 (A) or guai·cled a5 specified in 230.62 (B). Part VL Service Equipment- Disconnecting Means 230.70 Gen.era!. Means sh a ll be provided to disconnect all ungrounded conductors in a building o r other structure from the service conductors. (A} Location. The service disconnecting me ans shall he installed in accordance with 230. 70(A) ( 1), (A) (2), and (A) (3). (I) Readily Accessible Location. The service disconnecting means sh all be installed a t a readily accessible location either ou tside of a building or structtu·e or inside nearest the poiHL of entrance o f the service conductors. (2) Bal.brooms. Senice disc;:01rnect.ing means sh a ll not be installed in bathrooms . (3) Remote Control. Where a n :mote control device(s) is used to acmate rJ1e servic;e di~connecting m e;u1s, the senrice disconnecting means shall be located in accordance ·with 230.70(A)(l}. (B) Marking. Each service disconnect shall be permanently m arked to identily it as a service disconn ect. 2020 ll\lirjon NATIONAL ELECTRICAL. CODE 70-93 230.70 ARTICLE 230- SERVICES (C) Suitable for Use. Each service disconnecting means shall be suitable for the prevailin g conditio ns. Service equipment installed in hazardous (classified) locations shall comply with tJ1e require ments o f Articles 500 through 5 17. 230.71 Ma.xi.mum Nmnber of Disconnects. Each service shall h ave only one disconnecting means unless the requirements of 230. 7 1 (B) are m el. (A) General. F01- the (JLu-pose of this section, disconnectiJig means installed a5 part of listed equipment and tL5ed sole ly for the following shall not b e considered a service disconnectiJig 111.eans: ( 1) (2) (3) (4) Power monitoring equipme nt Surge-protective device(s) Control circuit of the ground-fault protection system Powe r-opera ble service disconnecting rnea11.5 (B) Two to Six Service Disconnecting Mean1,. Two to six service disconnects shall be permitted for each service permitted by 230.2 or for each set of se1vice-enu·an ce co nductors permitted by 2 30.40, Exception No. l , 3, 4, o r 5. The Lwo to six service d isconnecting mea11s sh all be permitted to consist of a co mbination of any of the following: (1) (2) (3) (4) Separate enclosures with a main se1v ice d isconnecting means in each e nclosure Panelboards with a main service disconnecting mea ns in each pa.ne lboard e nclosuxe Switchboanl(s) where the re is only o ne service disconn ect in each separate vertical seccion where there are barriers .~eparating each vertical section Sen?ice dhconnect~ jn switchgear o r metei-i..ng centers where each disconnect is located in a separate compartm e nt Lnfonnatinnal Note No. I : Metering centers are addressed in UL 67. Standmd(or Pane/boards. lnfornrn l.lnnal Note No. '.!: Examples of separate e nclosures wir.h a main service disconnecLing means in each e ncJns11re include b ut are nol limiterl to moLOr control cemers, fused disconnects, circu it breaker enclosu res, and U.J.nsfer swicches 1.hat a re suitable for lL~e as service equipmen c. 230.72 Grouping of Disconnects. E:xc,:ption: ln a m·u lliple-ocmpanL)' building tuhere electric servir,e and elel'tri,;al mainlenanre m·p f1mvided by thf b'uilding rnanag11numl. and tuhere LhPse are under Ctmli1w.om buildi.ng mana,gement supervision, the service disconnecting means supplying more than one oanjJanty .f/wll be permitted to be accessible to rw lharized 111anagemen/ fJersonnet on0'· 230.74 Simultaneous Opening of Poles. Each service d isconnec t shall simnltaneow;ly- disconnect <1ll ungrn1111ded service conductors diat it controls from the prem ises wiring syste m. 230.75 Disconnection of Grounded Conductor. Where die service disconnecting means does not di~co nnect the grounded conductor fro m tJie premises wii-i.ng, otJi er means shall be provided for dus purpose in Lhe service e quipment. A terminal or bus to which all g rounded conduc tors can be attached by means of pressure connectors shall be pern1itted for th is pLU'pose. ln a multisection switchboard or switchgear, disconn ect, for the growided conductor shall be permined to be in all)' section of the switchboard o r switchgear. Informational Note: In switchgear or multisection switchboards, che disconnecl.lng means prO\ided fo r th e grou nded conductor is typically identified as a neutral disconnect link and is typical ly loc,tted in the bus m which th e service gro w1ded conductor is connected. 230.76 Manually or Power Operable. The service disconn ecting means for ungro unded service conductors shall consist o f one of the following: (l) (2) A manually operable switch or c ircuit breaker equipped with a hand.le or od1e,- suitable o perating m eans A p ower-opera ted switch or circuit breake1~ provided die switch or circuit hreaker can be opened b y h a nd in d1e event of a power supply failure 230.77 Indicating. The setv ice disconnecting m eans sh all plainly indicate whed1er it is in the open (off) or closed (on ) p osition. 230.79 Rating of Service Djsconnecting Means. The service disconnecting meani; shall h ave a rating no t less than the calcula ted load to b e carried, dete rmined in acco,-dance with Part ]JI, IV. or V of Article 220, a~ applicable. In no ca~e sh all the ratiJig be lower dian specified in 230.79(A), (B), (C), or (D). (A) General. The lwo to six disconnect~, if pe.rm itted in 2 30.71 , shall be grouped. Each disconnect shall be marked to indicate the load served. 1.-.'xcefilion: One of lhr two to six urvia disconnecting rneans permitted in 230. 71, where twrl only for a water purnfJ alw1 intn11lerf lo pmvide Jfre protection, shall be pmnilled to be located rnnQlP jh)llt the ot!ter disconnecting means. If remotely instalkd in acl'ordancr tuilh this exception. a plaque shall be posted at lhe location of 1/11• remaining grouped dis,;onneds denoting its lorn/ion. (B) Additional Service Disconnecting Means. The one OT mo1·e addjtional service disconnecting mea1is for fire pumps, e m ergency systems, legal ly re quired standby, 01· optional standby services permitted by 230.2 sha U be installed remote from the one to six serv ice disconnecting means for normal service to minim ize the possibility ofsirnuJ tan eous interruptio n of supply. (C) Access to Occupants. In a multiple-occupa11ey building, each occupant shall have access to the occupant's service disconnecting mea1i s. 70-94 (A) One-Circuit Installations. Fo.r installations to supply only limited loads of a sing le bra nch circuit, the service disconnect~ ing m.ea11s shall have a rating of not Jess than 15 amperes. (B) Two-Circuit Installations. For insta llations consis ting of n ot m ore tJ1an two 2-wire bran ch circuits, the service d iscon necting mean., shall have a rati ng of not less than :~0 a111peres. (C) One-Family Dwellings. For a one-family dwelling, the sen1ice disconnecting means shall h ave a rating of not less d1an 1.00 amperes, 3-wire. (D) All Others. for all other installations, tJie service disconn ecting means sh all have a ra ting of not less than 60 amperes. 230.80 Combined Rating of Disconnects. Where d1e service disconn ecting mea ns consist5 o f more d1an o ne switc h or cirCLtit breake r, a5 pern1itted by 230.71 , die combined ratings of all the switch es or circuit breakers used shall n ot be less than the rating required b y 230.79. 230.81 Connection to Terminals. The serv ice conductors shall be connected to 1J1e se1-vice disconnecting m ean s by pressu re NATIONAL ELECTRICAL CODE 2020Edition 230.91 ARTTC'.J..E 230 - SERVICES connectors, clamps, or other approved means. Co nnections that depend on solder shall not be used. 230.82 Equipment Connected to the Supply Side of Service Disconnect. Only the following eguipmenl sha ll be permi.tted to b e connected to the supply side of the service disconnecting means: (l ) (2) Cable limiters. Meters and meter sockeL5 nominally rated not in excess of l 000 volts, if all metal housings and service enclosures are g rOLmded in accordance with Part VII a.nd bonded in accordance with Part V of Article 250. (3) Meter disconnect switches nominally rated not in excess of 1000 volt5 that have a short-circuit current r a ting equal to or greater than the available fault c urrent, if all metal hoi1sings and service enclosures are grounded in accordance with Pan VIT a nd bonded in accordance with Part V of Article 250. A meter disconnect switch shall b e capable of interrupting the load served. A m eter disconnect shall be legibly field marked o n it~ exte1-ior in a ma1me1· suitable for the enviro nment as follows: METER DISCONNECT NOTS8tVfCEEQUIPNffiNT (4) Instnunent transformers (current and voltage), irn pedance shw1t5, Load ma nageme nt devices, surge arresters, and Type ] surge-protective de,~ces. (5) Conductm·s LL~ed. to supply load management devices, cil'cuits for standby power systems, fire pump equipment, and fire a nd sprinkler alarms, if provided with service equipme nt and installed in accordance with requirements for se rvice-entrance conduc tors. (6) Solar photovoltaic systems, fue l cell systems, wind elecu·ic systems, e nergy storage systems, or interconnected electric power production sources, if provide d with a di~c01111ecting means Li.~ted as suitable for use as service equipment, and overcurre nt protection as s pecified. in Pa rt VII of Article 230. (7) Control circ uit5 for power-operable service disco nnecting means, if suitable overcutTent protection and disconnecting means are provided. (8) Ground-fault -protectio n systems or Type 2 su rgeprotective devices, where installe d as part of listed equjpme nt, if suitable overcmrent protection and disconnecting means are provided. (9) Connections used only to supply listed communications equipment unde r the exclusive control of the serving e lectric n tili ty, if suitable overcu rrent protection a11d disconnecting means a re provided. for installations of equipment by the sening elecu·ic utility, a cliKonnecti ng mean s is n ot required iJ the supply is installed. as part of a meter socket, suc h that access can on ly be gained with the meter removed. ( 10) En1e rgency disconnects in accordance with 230.85, if a ll metal l10usings and service enclosures aJ'e grounded in accorda nce with Part Vll and bonded i.n accordance with Pa rt V of Article 250. ( 11 ) Mete 1~mounted mmsfer Sl\~tches nominally rated not in excess o f 1000 volt5 that have a sh ort-circuit curre nt rnting egual to or greater tha11 the available fault curre nt. A meter-mo unted trans fer switch shall be listed a11d be capable of U<11Hferring the load serve d. A metermounted trat"L~fer switch shall be marked on it~ exterio r with both of the following: a. Meter-mounted transfer switch 2020 ll\lirjon NATIONAL E LECTRICAL CODE b. Not service e quipment 230.85 Emergency Disconnects. For one- and two-family dwelling units, all service conducto rs shall terminate in disconnecting mea ns having a short-circui1 current rating equal to or grea te r than the availa ble fau lt current, install ed in a readily accessible outdoor location. If more than one disconnect is provided, they sha ll be grouped. Each d isconnect shall be one of the fo llowing: ( 1) (2) (3) Sen~ce d isconnects marked a~ fo llows: EMERGENCY DISCONNECT, SERVICE DISCONNECT Meter disconnects installed. per 230.82(3) and m a rked as follows: EMERGENCY DISCONNECT. METER DfSCONNECT, NOT SERVICE EQU1PMENT Other listed disconnect switcl1es or circ uit breakers on the supply sid e of each service d isconnect that are suitable for use a..~ se1·vice equipme nt and marked as follows: EMERGENCY DISCONNECT, NOT SERVICE EQUIPMENT Markings shall comply with l L0.2 1 (B). Part VIl. Service Equipment - Overcurrent Protection 230.90 Where Required. Each UJ1grounded service conductor shall have overload protec tio n. (A) Ungrounded Conductor. Such protection shall be p rovided by an overcurrent device in series with each trngrorn1ded service conductor t11at has a rating or setting not higher than tJ1e am pac ity of the conductor. A set of fuses sha ll be considered all the fuses re quired to pro tecl all the ungrounded conductors ofa circuit. Sing le-pole circuit breakers, grouped in accordance wit11 230.7 1 ( B), sha ll be conside red as o ne pro tective de,ice. Exceprinn No. I: Fnr motar-strtrting currents, ratings th.al cmnply tvit h 430.52, 430. 62, and 430. 63 shall lie permitted. E.,ccr,plion No. 2: P1.1ses and tirciiit brenkel'.5 with 11 mting or sPt/ing thal rnm/1lirs tvith 240. 4(B) or (C) and 240. 6 shall be pmnilled. Exrn/llinn No. 3: 11110 lo six cirtuit breaker.. or sets of jil.ses .1hall bP permitler.t as the overcurrenl device to Jm1vide the overload /m1tection. T he sum of the ratings ofthe rircuit breakers orj1L5es shall be /Jerrnitted lo exi:n1d thri ampacity of lite servit:e wndw:tors, pmvided .the m lrul.ated load does not exreerl the 4rnfJacity of thf' sf'.rvirR conductors. .Exceptinn Nn. 4: Overlo«d protection for fire pump su.pjJly cnnduct,ors shall i:omp!:y with 695.4(B)(2)(a). Exc1:jJti1m No. 5: OverlJ.Jad protntionfor 120/24 0-volt, 3-wire, singlliphase dtvr!ling services shall be jiermiUerl in rttcordance tvilh the wquirements of310.12. (B) Nol in Grounded Conductor. No O\'ercurre n t d evice shal l be inser ted in a grounded service conductor except a c ircuit brea ker t11at simultaJ1eously opens a ll conductors of the c ircuit. 230.9 1 Location. The servi ce ove rcurrenL device sha ll be an integral part of the service disconnec ting means or sha ll be located immediately adj acent thereto. , vh ere fuses are u5ecl as the service overcurrenL device, the disconnecting means shall be located ah ead of the supply side of th e fuses. 70-95 230.92 ARTTCLE 230 - SERVICES 230.92 Locked Service Overcurrent Devices. V\lhere the ser"" ice overcun-ent d evices are locked or sealed o r are not readily acces•;ible to the occupant, branch-circuit or feeder overcw·rent devices shall be installed on the load side, shall be mounted in a readily accessible location, and shall be of lower ampere rating than the service overctuTent device. 230.93 Protection of Specific Circuits. Where necessary to prevent tampering, an automatic ove1-curren t device th<1t protects se1-vice conductor·s supplying onl)' a speciftc load, such a~ a water heater, shall be permitted to be locked or sealed where located so as co be accessible. 230.94 Relative Location of Overcurrent Devfoe and Other Service Equipment. The overcurrent device shall protect all circuits and devices. Excej1tion No. 1: TIU' service switch shall be permil.ted on the supj,ly side. l!.'xcef1tion No. 2: High-impPdance shunt circuilf, surge arresters, Typ,, I .mrgp-protertivl' dr,vir:es, snrge-protective wpa1;ilor.1~ and instmmnit transformers (current, and voltagp) shall be pn-nlilled lo be connerted and insta/lnl o-n tfu, supply sic/I' of the service disconnerting mams as permillerl by 230.82. l.xcef1tion No. 3: Cirwits for lorut management devires shall be permit/rd lo be con11erterl on the sttfJ/Jly side of tlw sn·vice overcurrent df'llil'I' wll11te se/J1Zralely /1rovid~d with overrurrenl /nvterlion. Excef1tion No. 4-: Cirrnils usrd nnly for the opera/ion offii'P alann, other protective sign11ling syslmns, or the su/tply to fire pump eq•tiifmienl shall be /1ennitted lo be mnnl!f;ted on the si1pply sidP of the srrvicR overcurrenl r/evfoe whem separately fJrovid11d with overcurwnt protertion. Exreption No. 5: Meters nominally ratNl not in exr;fss of 600 voltr sha.ll br fwrrnitu-d, provided all rnetal lumsin~ and servire enr:ln.mre.,s- arP grownrled. Excej,ti.Qn No. 6: Whem srr,1.,ife equ.ifJtn.rnt is power operable, the control circuit shali be /1rrmitted lo be connected ahead of lhe servicr equipm.enl if mitab/P OVfl"C!trrent pmt~rtirm rmd dimmnerting means Cl/'IJ {:l'rovi- mum time delay shall be one second for ground-faul t current5 equal to or greater than :IO00 amperes. (B) Fuses. If a switch and fuse combina tion is used, the fuses employed shall be capable of interrupting any current higher tha n the interrupting· capacity of th e switch during a time that the gi·ow1d-fault prntective system will not cause the switch to open. (C) Performance Testing. T he ground•fauJL protection system shall be performa nce tested when first installed on site. T h is testing shall be conducted by a qualified person(s) using a test process of primary current injection, in accordance with instructions th at shall be provided with the equipm enl. A wriL• ten record of th.is testing s hall be made and sha ll be availa ble to the a uthority havi11gjurisdiction . Jnfom1aLiona'I Note No. I: Ground-fuulc protection. lha1 ftLnctions Lo open the service disconnec1 affords no protection from fau! LS on che line side of che protective elemenL L1 serves o nly to limi1 d,1mage lO conducwrs and equipment on 1he load side in the even1 of an arcing ground fault on 1he load side of 1he protective element. [nfom1aLional Nore No. 2: This added prorective equipment a1 the service eqLtipmenL may make it necessa1y to review the overall wiring system for proper selective overcurrent protection coordina1inn. Addi1jonal ins1al.la1ions of ground-fault protective eqtripment may be needed on feeders and branch ci rcuits where maximum continuity of e lec rric service is necessary. Informational Nore No. 3: Where ground-fault protection is provided for the service disconnect and interconnection is made wich another supply system by a Lransfer device, mea11S or devices may be n eeded m ensure proper grnund,faull sensing hy the ground-fault protecLion equipmenL lnfomrnt.ional Note No. 4: See 517.l 7(A) for informa1fon on where an additional s1ep nf g1:ound-fauh protection i, required for hospitals and other buildings wir.h critical are,lS or life sup pore eriuiprnen L. cled. Part VIII. Services Exceeding 1000 Volts, Nominal 230.95 Ground-Fault Protection of Equipment. Ground-fault protection of equipment shall be provided for solid ly grounded wye electric services of more than 150 volts to ground but not exceeding 1000 volt5 pha5e•to-phase for each service d isconnect rated 1000 amperes or more . The grounded conductor for the solidly grounded wye system shall be connected directly to ground through a g ro unding electrode system. a5 specified in 250.50, without inserting any resistor or impedance device. 230.200 General. Service condu ctm-s and equipment ·used on cil"Cu it5 exceeding 1000 volts, nominal, shall comply with all the applicable preceding sections of this article and w ith the following sections that supplement or modify the preceding sect.ions. l.n no case shall the provisions of Pa n V1l1 apply to e quiprnent on the supply side of the service point. The rating of the service d isconnect sh all be considered to be the rating of the largest fuse that can be installed or the highest continuo us cun-ent trip setting fo1· which the acn.1al overcu1-rent device i.mtalled in a circuit breaker is rated or can be adjusted. ExreJ1tion: 171e gronndfr111tt j.rrolection jmroisions of lids srction sha.ll not rippty to a servirP di5connPct for a conlinttQllS in.rl'tLtl'lial process wherr' a nonorr.lr<rly shutdown will introduce additicmal or inaensed hazards. (A) Setting. The gmtmd-fau.lt protection system shall ope rate to cause the service d isconnect to open a ll u ngrounded conductors of the faulted circuit. The maximum setting of the ground-fault protection shall be 1200 amperes, and the maxi- 70-96 Informational Note: f or clearances of conductors of over l000 volL~. nominal, see ANSI/IEEE C2-2Ul7, Nalionetl t:uxtriml Safety G,dt!. 230.202 Service-Entrance Conduc tors. Set-vice-en trance conducto1·s to building-s 01- enclosures shall be installed to conform to 230.202(A) and (B). (A) Conductor Size. Service-entra nce conductors shall not be smalle r- than 6 AWG unless in mult iconductor cable. Multiconductor cable shall not be smaller than S AWG. (B) Wiring Methods. Service-enffance con ductors shall be installed by one: of d1e wiring methocL5 covered in 300.37 and 300.50. 230.204 Isolating Switches. (A) Where Required. V\'here o il switches or air, oil, vacuum, 0 1· sulfur hexafluoride circuit breakers constitute the service NATIONAL ELECTRICAL CODE 2020Edition ARTfCLE 240 - disconnecting mea.i1$, a.i1 isolaLing switch with visible break contact.~ shall be installed on the supply side of the disconnecting means and a ll associated service eqLtipmenl. Exception: A n isolating switch shall no/, be required where the circuit breaker or switch ·is mounted on removable tmd, />lmeLs or switchgew· units where both of !he following conditions appl~•: (1) (2) 240.1 OVERCURRENT PROTECTION Cannot be Cf{1ened unless the circwil is disronnel'ted Wh11re all energized /Jarts are automaticrilly disconnected whe11 the t in:uil bmohcr or switch is removed fmm the normal operr.tting position (B) Fuses as Isolating Switch. Where fuses a.re of the type that can be operated as a disco nnecting switch , a set of such fuses shall be permitted as the isolating switch. (C) Accessible to Qualified Persons Only. The isolating switch shal l be accessibl e to qualified persons o nly. (D) Connection to Ground. Isolating switch es sh all be provided wit h a m eans for 1·eadily connectin g the load side conductors to a grnunding e lectrode system, equipme nt ground btL~bar, or grounded steel s1Tucture when disconnected from the source of suppl)'. A means for grounding the lm1d side conductors to a grOLmdin g electrode system , equi.pment grow1ding bmbar, or grounded structural steel shall not be required fo1· any duplicate isolating switch instal.led and ma in tained by the e lectric supply company: 230.205 Disconnecting Means. (A) Location. The service disconnecting mean s shall b e located in accordance with 230.70. For either overhead or unde1·ground primary d.isa-ibut.io n systems on private property. the se rvice disconnect shall be permitted to be located in a location that is n o t readily accessible, if the discormecting m ean s can be operated by mech an ical linkage from a readil)' accessible point, or e lectronically in accordance with 230.205(C), where applicable. capable of detecti.ng an d imerrnpting all value s of c urren t, in excess of it5 trip setting or rnelting point, that can occur at it5 location. A fuse rated in continuous a mperes not to exceed three times the ampacity o f the condu ctor, or a circ uit breaker with a trip setting of not m ore than six times the a mpacity of the conductors, s hall b e con sidered as providing the re quired short-circuit protectio n. Informational Nole: See Table 31 l.6U(C)(67) through Table 3ll .60 (C) (86) for ampacities of conducwrs raLed '.!001 volLs LO 35,000 volts. Ove1·cunent d evices shaLl conform to 230.208(A) a nd ( B). (A) Equipment T}pe. Equipme nt used to protect servicee ntnmce condu ctors sh all meeL t he requi remenrn of Article 490, Part IL (B) Enclosed Overcurrent Devices. The resu-ic tto n to 80 percenc of ci1e rating for a n enclosed o ve rcurrent device for continuous loads shall not apply to ovet·cwTent devices installed in systems operating a t over LOO() volL5. 230.209 Surge Arresters. Surge arresters installed in accordan ce wit h the require ments of Article 242 shall be pe rmitted on each ungrounded overh ead service conductor. Informatio nal Note: Surge arresters may he referred Ill as lig htning arresters in older documents. 230.210 Service Equipment - General Provisions. Se1·vice equipment, including instrum ent tra nsformers, s h a ll conform to Atiicle 490, Part I. 230.211 Switchgear. Switchgear shall consist of a substantial metal su-ucture and a sh eet metal e nclosnre. Where insta lled over a combustible floor, suitabl e protection thereto sh a ll b e provided. 230.212 Over 35,000 Volts. "''here the voltage exceeds 35,000 volts b etween conductors t hat enter a build ing, t hey shall terminate in a switch gear compartment o r a vault con formi n g to ci1e requirem e n ts of 450.4 1 through 4.150 .48. (B) Type. Each service disconnect shall simultaneornly disconnect all ungmunded service conductors that it controls a.i1rl shall h ave a fau lt-closing rati ng that is .not less tha n th e available fault current at it~ s upply terminals. ARTICLE 240 Whe1-e fused switche.~ or separately m o unted fuses are installed, th e fuse charac teristics sh all be permitted to con u-ibute to the fault-closing rating of the disconnecting mea.i1s. (C) Remote Control. For multibuilding, indu~trial installations Lmder single manageme nt, th e service disconnecting means s ha.11 be permitted to be located at a sepa rate building or sa-uctw·e . ln su ch cases, ci1e se1·vice disconnecting m eans shall be pern.1 itted LO be electrically o perated by a readily accessible, remote-control d evice. 230.206 Overcurrent Devices as Disconnecting Means. ,.\There the circ uit b1·eaker or alternative for it, as specified in 230.208 for service overctu-rent devices, meets the requirements specified in 230.205, it sh all constitute the service di~connecting mean s. 230.208 .P rotection Requirements. A short-circuit protective device shall he p rovided on th.e l oad side of, or a5 an integral pa rt of, tJ1e service disco nnect, and s ha ll protect all ung round ed condu ctors that it supplies. The protective device sha ll be 2020 ll\lirjon NATIONAL £LllCTRIC-AL CODE Overcurrent Protection Part I. General 240.l Scope . Part5 I tluoug h VII of thi.~ article provide the gen eral require ments for overc w·rent pmtection and overcurr en t protective d evices n ot mo1·e tha n 1000 volt~, no minal. Part VIll covers overcun-ent protection for those portions of s upe rvised inclustt·ial installations operating at voltages of not more than 1000 volt5, n ominal. Part lX cove rs overcurrent protection o ver 1000 volts, nomina l. l nfi:,rmatio nal Note: Ove rcurre nt protectio n for conductors aod eq uipment is provided to open l he circuit if rhe curren1 reaches a value t hat will cause a n excessive or dangerous temperature in conductors or conducwr insulation. See a lso I 10.!-) for requireme n ts for inte rrupting rat.ings and 110. 10 fo r require me nts for prmect.ion against fmtlt curre n u;. 70-97

NFPA 70 2020-edited

Related documents

Products

Support

NFPA 70 2020-edited

Related documents

Add this document to collection(s)

Add this document to saved

Suggest us how to improve StudyLib