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1、电气英语证书考试(PEC)-GlossaryofElectricalEngineeringTerms3oAmpereThemeasurementofintensityofrateofflowofelectronsinanelectriccircuit.AnampereistheamountofcurrentthatwillflowthrougharesistanceofoneohmunderapressureofonevoltoAmpereRatingThecurrent-carryingcapacit
2、yofafuse.Whenafuseissubjectedtoacurrentaboveitsampererating,itwillopenthecircuitafterapredeterminedperiodoftimeoAmpereSquaredSeconds,l2tThemeasureofheatenergydevelopedwithinacircuitduringthefuse’sclearing.Itcanbeexpressedas“Meltingl2t”,“Arcingl2t”orthesu
3、mofthemas“Clearingl2t”.“l”standsforeffectivelet-throughcurrent(RMS),whichissquared,and“t”standsfortimeofopening,inseconds.oArcingTimeTheamountoftimefromtheinstantthefuselinkhasmelteduntiltheovercurrentisinterrupted,orclearedoCartridgeFuseAfuseconsistingo
4、facurrentresponsiveelementinsideafusetubewithterminalsonbothendsoClassCC Fuses600V,200,000ampereinterruptingrating,branchcircuitfuseswithoveralldimensions.Theirdesignincorporatesarejectionfeaturethatallowsthemtobeinsertedintorejectionfuseholdersandfusebl
5、ocksthatrejectalllowervoltage,lowerinterruptingrating fuses.oClassGFuses20A@600VAC,25-604@480VAC,100,000ampereinterruptingratingbranchcircuitfusesthataresizerejectingtoeliminateoverfusing.Theseareavailableinratingsfrom1ampthrough60amps.ClassHFuses250Vand
6、600V,10,000ampereinterruptingratingbranchcircuitfusesthatmayberenewableornon-renewable.Theseareavailableinampereratingsof1ampthrough600amps.oClassJFusesThesefusesareratedtointerruptaminimumof200,000amperesAC.Theyarelabelledas“Current-Limiting”,areratedfo
7、r600voltsAC,andarenotinterchangeablewithotherclasses.oClassKFusesThesearefuseslistedasK-1,K-5,orK-9fuses.EachsubclasshasdesignatedI2tandlpmaximums.ThesearedimensionallythesameasClassHfuses,andtheycanhaveinterruptingratingsof50,000,100,000,or200,000amps.T
8、hesefusesarecurrent-limiting.However,theyarenotmarked“current-limiting”ontheirlabelsincetheydonothavearejectionfeature.oClassLFusesThesefusesareratedfor601through6000amperes,andareratedtointerruptaminimumof200,000amperesAC