ANSI IEEE C37.20.1-2002 Standard for Metal-Enclose

IEEEStdC37.20.1™-2002(RevisionofIEEEStdC37.20.1-1993)IEEEStandardsC37.20.1TMIEEEStandardforMetal-EnclosedLow-VoltagePowerCircuitBreakerSwitchgearPublishedbyTheInstituteofElectricalandElectronicsEngineers,Inc.3ParkAvenue,NewYork,NY10016-5997,USA10October2002IEEEPowerEngineeringSocietySponsoredbytheSwitchgearCommitteeIEEEStandardsPrint:SH95004PDF:SS95004IEEEStdC37.20.1TM-2002(RevisionofIEEEStdC37.20.1-1993)IEEEStandardforMetal-EnclosedLow-VoltagePowerCircuitBreakerSwitchgearSponsorSwitchgearCommitteeoftheIEEEPowerEngineeringSocietyApproved13June2002IEEE-SAStandardsBoardAbstract:Low-voltagemetal-enclosedswitchgear—whichcontainseitherstationaryordrawout,manuallyorelectricallyoperatedlow-voltageacordcpowercircuitbreakersinindividualgroundedmetalcompartments,inthree-pole,two-pole,orsingle-poleconstruction—iscovered.Ratedmaximumvoltagelevelsare254V,508V,or635V(ac)and300/325V,800V,1000V,1200V,1600V,or3200V(dc).Thepreferredcontinuouscurrentratingsofthemainbusinacdesignsare1600A,2000A,3000A,3200A,4000A,or5000A.Fordcdesigns,thepreferredratingsare1600A,2000A,2500A,3000A,4000A,5000A,6000A,8000A,10000A,or12000A.Theswitchgearmayalsocontainassociatedcontrol,instruments,metering,protective,andregulatingdevicesasnecessary.Thestandarddealswithserviceconditions,ratings,temperaturelimitations,andclassificationofinsulatingmaterials,insulation(dielectric)withstandvoltagerequirements,testprocedures,andapplication.Keywords:circuitbreaker,control,cumulativeloading,currenttransformers,drawout,indoor,instrumentation,loadcurrent-carrying,metering,outdoor,protection,stationaryTheInstituteofElectricalandElectronicsEngineers,Inc.3ParkAvenue,NewYork,NY10016-5997,USACopyright
2002bytheInstituteofElectricalandElectronicsEngineers,Inc.Allrightsreserved.Published10October2002.PrintedintheUnitedStatesofAmerica.Print:ISBN0-7381-3303-5SH95004PDF:ISBN0-7381-3304-3SS95004Nopartofthispublicationmaybereproducedinanyform,inanelectronicretrievalsystemorotherwise,withoutthepriorwrittenpermissionofthepublisher.IEEEStandardsdocumentsaredevelopedwithintheIEEESocietiesandtheStandardsCoordinatingCommitteesoftheIEEEStandardsAssociation(IEEE-SA)StandardsBoard.TheIEEEdevelopsitsstandardsthroughaconsensusdevelopmentprocess,approvedbytheAmericanNationalStandardsInstitute,whichbringstogethervolunteersrepresentingvariedviewpointsandintereststoachievethefinalproduct.VolunteersarenotnecessarilymembersoftheInstituteandservewithoutcompensation.WhiletheIEEEadministerstheprocessandestablishesrulestopromotefairnessintheconsensusdevelopmentprocess,theIEEEdoesnotindependentlyevaluate,test,orverifytheaccuracyofanyoftheinformationcontainedinitsstandards.UseofanIEEEStandardiswhollyvoluntary.TheIEEEdisclaimsliabilityforanypersonalinjury,property,orotherdamage,ofanynaturewhatsoever,whetherspecial,indirect,consequential,orcompensatory,directlyorindirectlyresultingfromthepublication,useof,orrelianceuponthisoranyotherIEEEStandarddocument.TheIEEEdoesnotwarrantorrepresenttheaccuracyorcontentofthematerialcontainedherein,andexpresslydisclaimsanyexpressorimpliedwarranty,includinganyimpliedwarrantyofmerchantabilityorfitnessforaspecificpurpose,orthattheuseofthematerialcontainedhereinisfreefrompatentinfringement.IEEEStandardsdocumentsaresupplied‘‘ASIS.’’TheexistenceofanIEEEStandarddoesnotimplythattherearenootherwaystoproduce,test,measure,purchase,market,orprovideothergoodsandservicesrelatedtothescopeoftheIEEEStandard.Furthermore,theviewpointexpressedatthetimeastandardisapprovedandissuedissubjecttochangebroughtaboutthroughdevelopmentsinthestateoftheartandcommentsreceivedfromusersofthestandard.EveryIEEEStandardissubjectedtoreviewatleasteveryfiveyearsforrevisionorreaffirmation.Whenadocumentismorethanfiveyearsoldandhasnotbeenreaffirmed,itisreasonabletoconcludethatitscontents,althoughstillofsomevalue,donotwhollyreflectthepresentstateoftheart.UsersarecautionedtochecktodeterminethattheyhavethelatesteditionofanyIEEEStandard.Inpublishingandmakingthisdocumentavailable,theIEEEisnotsuggestingorrenderingprofessionalorotherservicesfor,oronbehalfof,anypersonorentity.NoristheIEEEundertakingtoperformanydutyowedbyanyotherpersonorentitytoanother.AnypersonutilizingthisandanyotherIEEEStandardsdocument,shouldrelyupontheadviceofacompetentprofessionalindeterminingtheexerciseofreasonablecareinanygivencircumstances.Interpretations:Occasionallyquestionsmayariseregardingthemeaningofportionsofstandardsastheyrelatetospecificapplications.WhentheneedforinterpretationsisbroughttotheattentionofIEEE,theInstitutewillinitiateactiontoprepareappropriateresponses.SinceIEEEStandardsrepresentaconsensusofconcernedinterests,itisimportanttoensurethatanyinterpretationhasalsoreceivedtheconcurrenceofabalanceofinterests.Forthisreason,IEEEandthemembersofitssocietiesandStandardsCoordinatingCommitteesarenotabletoprovideaninstantresponsetointerpretationrequestsexceptinthosecaseswherethematterhaspreviouslyreceivedformalconsideration.CommentsforrevisionofIEEEStandardsarewelcomefromanyinterestedparty,regardlessofmembershipaffiliationwithIEEE.Suggestionsforch