Workingprinciple
Thecircuitbreakerisgenerallycomposedofacontactsystem,anarcextinguishingsystem,anoperatingmechanism,atripunit,andahousing.
Whenashortcircuitoccurs,themagneticfieldgeneratedbyalargecurrent(generally10to12times)overcomesthereactionspring,thereleasepullstheoperatingmechanism,andtheswitchinstantaneouslytrips.Whenoverloaded,thecurrentbecomeslarger,theheatgenerationincreases,andthebimetaldeformstoacertainextenttopushthemechanismtomove(thelargerthecurrent,theshortertheactiontime).
Thereisanelectronictype,whichusesatransformertocollectthecurrentofeachphaseandcomparesitwiththesetvalue.Whenthecurrentisabnormal,themicroprocessorsendsasignaltomaketheelectronictripunitdrivetheoperatingmechanism.
Thefunctionofthecircuitbreakeristocutoffandconnecttheloadcircuit,aswellascutoffthefaultcircuit,topreventtheexpansionofaccidentsandensuresafeoperation.Thehigh-voltagecircuitbreakerneedstobreakthe1500V,current1500-2000Aarc,thesearcscanbestretchedto2mandstillcontinuetoburnwithoutbeingextinguished.Therefore,arcextinguishingisaproblemthatmustbesolvedbyhigh-voltagecircuitbreakers.
Theprincipleofarcblowingandarcextinguishingismainlytocoolthearctoweakenthethermaldissociation.Ontheotherhand,tolengthenthearcbyblowingthearctostrengthentherecombinationanddiffusionofchargedparticles,andatthesametime,thechargedparticlesinthearcgapareblownawayquickly.Restorethedielectricstrengthofthemedium.
Low-voltagecircuitbreakersarealsocalledautomaticairswitches,whichcanbeusedtoconnectandbreakloadcircuits,andcanalsobeusedtocontrolmotorsthatstartinfrequently.Itsfunctionisequivalenttothesumofpartorallofelectricalappliancessuchasknifeswitch,over-currentrelay,voltagelossrelay,thermalrelayandleakageprotector,andisanimportantprotectiveelectricalapplianceinlow-voltagepowerdistributionnetwork.
Low-voltagecircuitbreakershaveavarietyofprotectionfunctions(overload,shortcircuit,undervoltageprotection,etc.),adjustableactionvalue,highbreakingcapacity,convenientoperation,safety,etc.,sotheyarewidelyused.StructureandworkingprincipleThelow-voltagecircuitbreakeriscomposedofoperatingmechanism,contacts,protectiondevices(variousreleases),arcextinguishingsystem,etc.
Themaincontactofthelow-voltagecircuitbreakerismanuallyoperatedorelectricallyclosed.Afterthemaincontactisclosed,thefreetripmechanismlocksthemaincontactintheclosingposition.Thecoiloftheovercurrentreleaseandthethermalelementofthethermalreleaseareconnectedinserieswiththemaincircuit,andthecoiloftheundervoltagereleaseisconnectedinparallelwiththepowersupply.Whenthecircuitisshort-circuitedorseverelyoverloaded,thearmatureoftheovercurrentreleasepullsintomakethefreetripmechanismact,andthemaincontactdisconnectsthemaincircuit.Whenthecircuitisoverloaded,theheatingelementofthethermaltripunitwillbendthebimetalandpushthefreetripmechanismtomove.Whenthecircuitisunder-voltage,thearmatureoftheunder-voltagereleaseisreleased.Italsomakesthefreetripmechanismact.Theshuntreleaseisusedforremotecontrol.Duringnormaloperation,itscoiliscutoff.Whendistancecontrolisrequired,pressthestartbuttontoenergizethecoil.
Maincharacteristics
Thecharacteristicsofcircuitbreakersmainlyinclude:ratedvoltageUe;ratedcurrentIn;overloadprotection(IrorIrth)andshort-circuitprotection(Im)tripcurrentsettingrange;Ratedshort-circuitbreakingcurrent(industrialcircuitbreakerIcu;householdcircuitbreakerIcn),etc.
Ratedworkingvoltage(Ue):Thisisthevoltageatwhichthecircuitbreakerworksundernormal(uninterrupted)conditions.
Ratedcurrent(In):Thisisthemaximumcurrentvaluethatacircuitbreakerequippedwithaspecialover-currenttriprelaycanwithstandindefinitelyundertheambienttemperaturespecifiedbythemanufacturer,andwillnotexceedthecurrent-bearingcomponentThespecifiedtemperaturelimit.
Short-circuitrelaytripcurrentsettingvalue(Im):Theshort-circuittriprelay(instantaneousorshortdelay)isusedtoquicklytripthecircuitbreakerwhenahighfaultcurrentvalueappears,anditstriplimitIm.
Ratedshort-circuitbreakingcapacity(IcuorIcn):Theratedshort-circuitbreakingcurrentofacircuitbreakeristhehighest(expected)currentvaluethatthecircuitbreakercanbreakwithoutbeingdamaged.ThecurrentvalueprovidedinthestandardistherootmeansquarevalueoftheACcomponentofthefaultcurrent.Whencalculatingthestandardvalue,theDCtransientcomponent(alwaysappearingintheworstcaseshortcircuit)isassumedtobezero.Industrialcircuitbreakerratings(Icu)andhouseholdcircuitbreakerratings(Icn)areusuallygivenintheformofkArms.
Short-circuitbreakingcapacity(Ics):Theratedbreakingcapacityofcircuitbreakersisdividedintoratedultimateshort-circuitbreakingcapacityandratedoperatingshort-circuitbreakingcapacity.Thenationalstandard"Low-VoltageSwitchgearandControlEquipmentLow-VoltageCircuitBreaker"(GB14048.2—94)explainstheratedultimateshort-circuitbreakingcapacityandratedoperatingshort-circuitbreakingcapacityofcircuitbreakersasfollows:
1.CircuitbreakerTheratedultimateshort-circuitbreakingcapacityofthecircuitbreaker:Accordingtotheconditionsspecifiedintheprescribedexperimentalprocedures,excludingthebreakingcapacityofthecircuitbreakertocontinuetocarryitsratedcurrentcapacity;
2,theratedoperatingshort-circuitbreakingcapacityofthecircuitbreaker:Theconditionsspecifiedintheprescribedexperimentalproceduresincludethebreakingcapacityofthecircuitbreakertocontinuetocarryitsratedcurrentcapacity;
3.Thetestprocedurefortheratedultimateshort-circuitbreakingcapacityisO-t-CO.
Thespecifictestis:adjustthecurrentofthelinetotheexpectedshort-circuitcurrentvalue(forexample,380V,50kA),butthetestbuttonisnotclosed,thetestedcircuitbreakerisintheclosedposition,pressthetestbutton,Whenthecircuitbreakerpassesa50kAshort-circuitcurrent,thecircuitbreakerisopenedimmediately(open,referredtoasO),andthecircuitbreakershouldbeintactandcanbeclosedagain.tistheintermittenttime,generally3min.Atthistime,thelineisstillinhotstandbystate.Electricalandthermalstabilityundercurrent).ThisprocedureiscalledCO.Ifthecircuitbreakercanbecompletelybroken,itsultimateshort-circuitbreakingcapacityisqualified.
4.Thetestprocedurefortheratedoperatingshort-circuitbreakingcapacity(Icn)ofthecircuitbreakerisO—t—CO—t—CO.IthasonemoreCOthanIcn'stestprocedure.Afterthetest,thecircuitbreakercancompletelybreakandextinguishthearc,anditisdeterminedthatitsratedoperatingshort-circuitbreakingcapacityisqualified.
Therefore,itcanbeseenthattheratedlimitshort-circuitbreakingcapacityIcnmeansthatthelow-voltagecircuitbreakercanoperatenormallyafterbreakingthemaximumthree-phaseshort-circuitcurrentattheoutletendofthecircuitbreakerandthenbreakthisshort-circuitcurrent.Once,astowhetherthecircuitbreakercanbeturnedonandoffnormallyinthefuture,thecircuitbreakerisnotguaranteed;andtheratedoperatingshort-circuitbreakingcapacityIcsmeansthatthecircuitbreakercanbreaknormallyformanytimeswhenthemaximumthree-phaseshort-circuitcurrentoccursatitsoutletend.
IEC947-2"Low-VoltageSwitchgearandControlEquipmentLow-VoltageCircuitBreaker"standardstipulates:ClassAcircuitbreaker(referringtoonlyoverloadlongdelay,shortcircuittransientcircuitbreaker)Icscanbe25%,50%,75%and100%.TheIcsofclassBcircuitbreakers(breakerswiththree-stageprotectionofoverloadlongdelay,shortshortdelayandshortcircuittransient)canbe50%,75%and100%ofIcs.Therefore,itcanbeseenthattheratedoperatingshort-circuitbreakingcapacityisabreakingcurrentvaluesmallerthantheratedlimitshort-circuitbreakingcurrent.
Generallyspeaking,acircuitbreakerwithathree-stageprotectionfunctionofoverloadlongtimedelay,shortcircuitshorttimedelayandshortcircuitinstantaneousactioncanachieveselectiveprotection,andmosttrunklines(includingtheoutletendofthetransformer)Alluseitasthemainprotectionswitch.Circuitbreakersthatdonothaveshort-circuitshort-timedelayfunction(onlyoverloadlong-timedelayandshort-circuitinstantaneoustwo-stageprotection)cannotbeusedforselectiveprotection.Theycanonlybeusedinbranchcircuits.IEC92"ShipElectrical"pointsoutthat:acircuitbreakerwiththree-stageprotectionemphasizesitsshort-circuitbreakingcapacityvalue,whileacircuitbreakerusedinbranchcircuitsshouldensurethatithassufficientlimitshort-circuitbreakingcapacityvalue.
Nomatterwhatkindofcircuitbreaker,althoughithastwoimportanttechnicalindicatorsofIcuandIcs.However,asacircuitbreakerusedonabranchline,itcanonlymeettheratedlimitshort-circuitbreakingcapacity.Themorecommonbiasisthatitisbettertotakethebig,nottotaketheright,andthinkthatthebiginsuranceistaken.However,ifitistoolarge,itwillcauseunnecessarywaste(thesametypeofcircuitbreaker,theHtype-highbreakingtype,is1.3to1.8timesmoreexpensivethantheStype-ordinarytype).Therefore,thecircuitbreakeronthebranchlinedoesnotneedtoblindlypursueitsoperationshort-circuitbreakingcapacityindex.Forthecircuitbreakerusedonthemainline,notonlymustmeettherequirementsoftheratedultimateshort-circuitbreakingcapacity,butalsoshouldmeettherequirementsoftheratedoperatingshort-circuitbreakingcapacity.Ifonlytheratedultimateshort-circuitbreakingcapacityIcuisusedtomeasureitsbreakingcapacity,Willbringhiddendangersofinsecuritytousers.
Thecircuitbreakerisabasiclow-voltageelectricalappliance.Thecircuitbreakerhasoverload,shortcircuitandundervoltageprotectionfunctions,andhastheabilitytoprotectcircuitsandpowersupplies.
Themaintechnicalindicatorsareratedvoltageandratedcurrent.Circuitbreakershavedifferentfunctionsaccordingtodifferentapplications,withmanyvarietiesandspecifications,aswellasmanyspecifictechnicalindicators.
Thecircuitbreakertripsfreely:atanytimeduringtheclosingprocessofthecircuitbreaker,iftheprotectionactionturnsonthetrippingcircuit,thecircuitbreakercanbedisconnectedreliably,whichiscalledfreetrip.Thecircuitbreakerwithfreetripcanensurethatthecircuitbreakercanbequicklydisconnectedwhenthecircuitbreakerisclosedandshort-circuited,whichcanavoidexpandingthescopeoftheaccident.
Mainclassification
Accordingtothenumberofpoles:singlepole,twopole,threepoleandfourpole,etc.;
Accordingtotheinstallationmethod:thereisplug-in,Fixedtypeanddrawertype,etc.
ProductintroductionA9/EC65miniaturecircuitbreaker:lightingdistributioncircuit,shortcircuitandoverloadprotection.
A9LE/EPNLEleakagecircuitbreaker:Inthegroundingsystem,shortcircuitoverloadandleakageprotection.Thenormaloperationfaultprotectionofthecircuitbreakermakesthephaselineandneutrallineofthecircuitbreakerinthebreakingpositionareinthedisconnectedstate,soastopreventtheneutrallinefrombeingelectrifiedwhentheneutrallinefails.Whenmakingandbreakingoperations,theneutrallinehasprioritytomake,andthebreakinghysteresis.Withshort-circuitcurrentlimitingfunction,highratedshort-circuitbreakingcapacity.Withoverloadprotection,short-circuitleakageandvoltageprotectiondevices,completeprotectionfunctions,convenientandreliablewiring.
Picturesofcircuitbreakers(2photos)
Over-voltageandunder-voltagereleases:automaticover-andunder-voltagedelayprotectorsareanewgenerationofproductsdevelopedaccordingtomarketneeds.Theprotectorisreasonablydesignedandassembledwithimportedcomponentsanddomesticfamous-brandcomponents.Theproductcanquicklyandreliablyswitchthepowersupplyunderhigh-voltageshockandunder-voltageconditionstoprotecthouseholdappliances.Whenthevoltagereturnstothenormalvalue,thecircuitcanbeautomaticallyconnectedandthepowersupplyisrestoredafteradelay,whichcaneffectivelyprotecttheelectricalappliancesfromtheimpactoftheinstantaneouspowersupply.Allfunctionsarefullyautomated,nospecialpersonisrequiredtooperate,andtwo-colorlight-emittingdiodesareusedforinstructions,whichissafeandfast.
EC100miniaturecircuitbreaker:industrialpowerdistributionsystem,shortcircuitandoverloadprotection.Theratedcurrentis63A-125A,theratedshort-circuitbreakingcapacityishigh,andithasashort-circuitcurrentlimitingstructure.Theprotectionfunctioniscomplete,withoverloadandshortcircuitprotectiondevices,thewiringissafeandreliable,andthe"frame-type"wiringstructureisadopted,whichiseasytoexpandandsafeandreliable.Itcanbeequippedwithavarietyofaccessories:leakagetrip,auxiliarycontact,alarmcontact,shunttrip,undervoltagetrip,busbar.
EPDsurgeprotector:EPDplug-intypeadoptsthesameworkingprincipleandselectioncriteriaasfixedsurgeprotection.Protectsagainstindirectlightninganddirectlightningeffectsorothertransientovervoltagesurges.
EIC1ACcontactor:MainlyusedforAC50Hzor60Hzratedvoltageto660Vandbelow,forremoteconnectionanddisconnectionofcircuits,andcanbecombinedwithcorrespondingspecificationsofthermalrelaysorelectronicprotectorsIntoanelectromagneticormechatronicsmotorstarter.
ENSplasticcasecircuitbreaker:Plasticcasecircuitbreakerisoneofthenewcircuitbreakersdesignedanddevelopedcomprehensivelyusinginternationaladvancedtechnology.Itisusedtodividethecircuitbreakerwithratedinsulationvoltageof800V,suitableforAC50Hzand60Hz,ratedworkingvoltageto690V,andratedworkingcurrentfrom6Ato1250A.ItisusedtodistributeelectricalenergyandprotectlinesandpowerequipmentfromOverload,short-circuit,under-voltageandotherfaultsaredamaged,anditcanalsobeusedasinfrequentstartingofthemotorandoverloadshort-circuitandunder-voltageprotection.Thecircuitbreakerhasthecharacteristicsofsmallsize,highbreaking,shortarcing(ornoarcing),etc.,whichisanidealproductforusers.Thecircuitbreakerisinstalledvertically(ieverticalinstallation)orhorizontally(horizontalinstallation).
ENSLEplasticcaseleakagecircuitbreaker:usedtoprovideindirectcontactprotectionforpeople,andcanalsopreventfirehazardscausedbyequipmentinsulationdamageandgroundfaultcurrentgeneration,andcanbeusedtodistributeelectricalenergyandprotectlinesandpowersuppliesTheoverloadshortcircuitoftheequipmentcanalsobeusedfortheinfrequentconversionofthecircuitandtheinfrequentstartingofthemotor.Theworkingpowersamplingoftheconventionalleakageprotectionmodulewithresidualcurrentprotectioncircuitbreakeristwo-phase,andthisseriesofcircuitbreakersarethree-phase.Ifanyphaseismissing,thecircuitbreakerleakageprotectionmodulecanstillworknormally,andtheratedresidualoperatingcurrentandmaximumdisconnectiontimecanbeadjustedonsiteaccordingtotheactualsituation.
EGL-125isolatingswitch:Theisolatingswitchisoneofthemostusedelectricalappliancesinthehigh-voltageswitchgear,whichactsasanisolationinthecircuit.Itsworkingprincipleandstructurearerelativelysimple,butduetoitslargeusageandhighreliabilityrequirements,ithasagreaterimpactonthedesign,establishmentandsafeoperationofsubstationsandpowerplants.Themainfeatureoftheswitchisthatithasnoarcextinguishingcapabilityandcanonlyopenandclosethecircuitwhenthereisnoloadcurrent.EGL-125-4000Aissuitablefortwolow-voltagecircuitswitchingortwoloadequipmentconversionorsafetyisolation,etc.
EATS3dualpowertransferswitch:Twopowersourcesareusedtoensurethereliabilityofpowersupply.Oneproductcanreliablyswitchbetweenthetwopowersources.Theproducthastwoswitchingfunctions:automaticswitchingandautomaticrecoveryandautomaticswitchingwithoutautomaticrecovery.Thissectionisamanualtransferswitch.Noveldesign,safeandreliable,highdegreeofautomation,widerangeofuse.
EW45universalintelligentcircuitbreaker:mainlyusedtodistributeelectricenergyandprotectcircuitsandpowerequipmentfromoverload,shortcircuit,undervoltage,single-phasegroundingandotherfaults.ThiscircuitbreakerhasavarietyofintelligentprotectionsFunction,selectiveprotectioncanbedone,andtheactionisaccurate,avoidunnecessarypoweroutages,andimprovethereliabilityandsafetyofpowersupply.
Components
Internalaccessories
Auxiliarycontacts:MechanicallylinkedwiththemaincircuitopeningandclosingmechanismofthecircuitbreakerThecontactsaremainlyusedtodisplaytheopeningandclosingstatusofthecircuitbreaker,andareconnectedtothecontrolcircuitofthecircuitbreakertocontrolorinterlocktherelatedelectricalappliancesthroughtheopeningandclosingofthecircuitbreaker.Forexample,outputsignalstosignallights,relays,etc.Moldedcasecircuitbreakerframeratedcurrent100Aisasinglebreakpointswitchingcontact,225Aandaboveisabridgecontactstructure,andtheagreedheatingcurrentis3A;frameratedcurrent400AandabovecanbeequippedwithtwonormallyopenandtwonormalClosed,theagreedheatingcurrentis6A.Thenumberofoperatingperformanceisthesameasthetotalnumberofoperatingperformanceofthecircuitbreaker.
Alarmcontact:Thealarmcontactusedforcircuitbreakeraccidents,andthiscontactwillonlyactwhenthecircuitbreakertripsandbreaks,mainlyusedfortheloadofthecircuitbreakerIttripsfreelyfromtimetotimewhenthereisanoverloadshortcircuitorundervoltagefault,thealarmcontactisconvertedfromtheoriginalnormallyopenpositiontotheclosedposition,andtheindicatorlamp,electricbell,buzzer,etc.intheauxiliarycircuitareconnectedtodisplayorremindthecircuitbreakerfaultTrippedstate.Sincetheprobabilityofthecircuitbreakertrippingfreelyduetoloadfailureisnottoomuch,thelifeofthealarmcontactis1/10ofthelifeofthecircuitbreaker.Theworkingcurrentofthealarmcontactgenerallydoesnotexceed1A.
Shuntrelease:Theshuntreleaseisareleasethatisexcitedbyavoltagesource,anditsvoltagehasnothingtodowiththemaincircuitvoltage.Shuntreleaseisanaccessoryforremotecontrolofopening.Whenthepowersupplyvoltageisequaltoanyvoltagebetween70%and110%oftheratedcontrolpowersupplyvoltage,thecircuitbreakercanbedisconnectedreliably.Theshuntreleaseisashort-timeoperatingsystem,andthecoilenergizationtimegenerallycannotexceed1S,otherwisethelinewillbeburned.Inordertopreventthecoilfromburningout,amicroswitchisconnectedinserieswiththeshunttripcoilinthemoldedcasecircuitbreaker.Whentheshuntreleaseispulledinbythearmature,themicroswitchisconvertedfromnormallyclosedtonormallyopen,duetothepowersupplyoftheshuntrelease.Thecontrolcircuitiscutoff,evenifthebuttonispressedartificially,theshuntcoilwillneverbeenergizedagain,whichpreventsthecoilfromburning.Whenthecircuitbreakerisclosedagain,themicroswitchisinthenormallyclosedpositionagain.
Under-voltagerelease:Under-voltagereleaseistomakethecircuitbreakerhaveadelayornodelaywhenitsterminalvoltagedropstoacertainrange.Whenthepowersupplyvoltagedrops(evenslowly)totherangeof70%to35%oftheratedworkingvoltage,theunder-voltagereleaseshouldoperate.Theunder-voltagereleaseshouldbeoperatedwhenthepowersupplyvoltageisequaltotherelease.Whentheratedworkingvoltageis35%,theunder-voltagereleaseshouldbeabletopreventthecircuitbreakerfromclosing;whenthepowersupplyvoltageisequaltoorgreaterthan85%oftheratedworkingvoltageoftheunder-voltagerelease,itshouldbeabletoensurethereliabilityofthecircuitbreakerunderthermalconditionsclosure.Therefore,whenacertainvoltagedropoccursinthepowersupplyvoltageintheprotectedcircuit,thecircuitbreakercanbeautomaticallydisconnectedtocutoffthepowersupply,sothattheloadappliancesorelectricalequipmentbelowthecircuitbreakerareprotectedfromundervoltagedamage.Wheninuse,theundervoltagereleasecoilisconnectedtothepowersupplysideofthecircuitbreaker,andthecircuitbreakercanbeclosedaftertheundervoltagereleaseisenergized.
Externalaccessories
Electricoperatingmechanism:Thisisanaccessoryusedforremoteautomaticopeningandclosingofcircuitbreakers,electricallyoperatedTherearetwotypesofmechanisms:amotoroperatingmechanismandanelectromagnetoperatingmechanism.Themotoroperatingmechanismisamoldedcasecircuitbreakerwitharatedcurrentof400Aandabove.Theelectromagnetoperatingmechanismissuitableforamoldedcasecircuitbreakerwitharatedcurrentof225AandThefollowingcircuitbreakers,nomatteritisanelectromagnetoramotor,theirpull-inandrotationdirectionsarethesame.Theclosingandopeningareachievedonlybythepositionofthecaminsidetheelectricoperatingmechanism.Whenthecircuitbreakerisoperatedbytheelectricmechanism,theratedcontrolAtanyvoltagebetween85%and110%ofthevoltage,thecircuitbreakershouldbeabletoreliablyclose.
Rotationaloperatinghandle:Suitableformoldedcasecircuitbreakers,amechanismforrotatingtheoperatinghandleisinstalledonthecoverofthecircuitbreaker,theshaftofthehandleisinstalledinitsmechanismmatchinghole,andtheshaftTheotherendofthehandlepassesthroughthedoorholeofthedrawercabinet,thehandleoftherotatinghandleisinstalledontheshaftheadexposedonthedoorofthecompleteset,andtheroundorsquareseatofthehandleisfixedonthedoorwithscrews.ThisinstallationcanenabletheoperatortoOutsidethedoor,turnthehandleofthehandleclockwiseorcounterclockwisetoensuretheclosingoropeningofthecircuitbreaker.Rotatingthehandleatthesametimecanensurethatthecabinetdoorcannotbeopenedwhenthecircuitbreakerisclosed;thedooroftheswitchpanelcanonlybeopenedwhenthehandleisopenedorre-buckled.Inanemergency,whenthecircuitbreakeris"closed"andthedoorneedstobeopened,presstheredreleasebuttononthesideoftherotatinghandleseat.
Extendedhandle:isanexternalextendedhandle,directlymountedonthehandleofthecircuitbreaker,generallyusedonlarge-capacitycircuitbreakersof600Aandabove,formanualopeningandclosingGateoperation.
Handlelockingdevice:istoinstallacardonthehandleframe,punchaholeonthehandleandlockitwithapadlock.Mainlyusedwhenthecircuitbreakerisclosed.
Intheworkingstate,donotallowotherpeopletoopentheswitchandcauseapoweroutage,orwhenthecircuitontheloadsideofthecircuitbreakerneedstoberepairedorisnotallowedtobeenergized,topreventthecircuitbreakerfrombeingclosedbymistake.
Wiringmethod
Thewiringmethodofcircuitbreakerincludesfrontboard,backboard,plug-intype,andwithdrawabletype.Ifusershavenospecialrequirements,theyaresuppliedaccordingtothefrontboard.Thefrontboardwiringiscommon.Wiring.
1.Wiringmodebehindtheboard:Thebiggestfeatureofthewiringbehindtheboardisthatthecircuitbreakercanbereplacedorrepairedwithoutrewiring,justdisconnectthefront-levelpowersupply.Duetothespecialstructure,theproducthasbeenequippedwithspecialmountingplatesandmountingscrewsandwiringscrewsaccordingtothedesignrequirementswhenleavingthefactory.Specialattentionshouldbepaidtothefactthatthereliabilityofthelarge-capacitycircuitbreakerwilldirectlyaffectthenormaluseofthecircuitbreaker,soduringinstallationItmustbetakenseriouslyandinstalledstrictlyaccordingtotherequirementsofthemanufacturer.
2.Plug-inwiring:firstinstallacircuitbreakermountingseatonthemountingplateofthecompletesetofequipment,with6plugsonthemountingseat,and6socketsonthecircuitbreakerconnectingplate.Thereareconnectingplatesonthesurfaceofthemountingbaseorboltsbehindthemountingbase,andthemountingbaseispre-connectedwithpowercordsandloadlines.Wheninuse,insertthecircuitbreakerdirectlyintothemountingbase.Ifthecircuitbreakerisbroken,justpulloutthebrokenoneandreplaceitwithagoodone.Itsreplacementtimeisshorterthanthefrontandbackwiringoftheboard,anditisconvenient.Acertainamountofmanpowerisrequiredforpluggingandunplugging.Therefore,forChina'splug-inproducts,theframecurrentislimitedtoamaximumof400A.Thissavesmaintenanceandreplacementtime.Wheninstallingtheplug-incircuitbreaker,checkwhethertheplugofthecircuitbreakeristightlypressed,andsecurelyfastenthecircuitbreakertoreducecontactresistanceandimprovereliability.
3.Drawertypewiring:Theinandoutdrawerofthecircuitbreakerisrotatedclockwiseorcounterclockwisebytherocker,andtheplug-intypeisusedinthemaincircuitandthesecondarycircuit.
Thestructureomitstheisolatornecessaryforthefixedtype,andachievesonemachinefortwopurposes,whichimprovestheeconomicefficiencyofuse,andatthesametimebringsgreatconveniencetooperationandmaintenance,andincreasessafetyandreliability.Inparticular,themaincircuitcontactholderofthedrawerseatcanbeusedincommonwiththeNTtypefusecircuitbreakercontactholder.
Workingconditions
Ambientairtemperature:Theupperlimitofambientairtemperature+40℃;○Thelowerlimitofambientairtemperatureis-5℃;theaverageofambientairtemperaturefor24hoursThevaluedoesnotexceed+35°C.
Altitude:Thealtitudeoftheinstallationsitedoesnotexceed2000m.
Atmosphericconditions:Therelativehumidityoftheatmospheredoesnotexceed50%whentheambientairtemperatureis+40℃;itcanhaveahigherrelativehumidityatalowertemperature;thewettestmonthThemonthlyaveragemaximumrelativehumidityis90%,andthemonthlyaverageminimumtemperatureofthemonthis+25℃,takingintoaccountthecondensationonthesurfaceoftheproductduetotemperaturechanges.
Pollutionlevel:Thepollutionlevelislevel3.
Controlcircuit:
1.ItshouldbeabletomonitortheintegrityofthecontrolcircuitprotectiondeviceanditstripandclosingcircuitstoensurethenormalityofthecircuitbreakerWork;
2,itshouldbeabletoindicatethenormalclosingandopeningpositionstatusofthecircuitbreaker,andthereshouldbeobviousindicationsignalsduringautomaticclosingandautomatictripping;
3,Afterclosingandtrippingiscompleted,thecommandpulseshouldbereleased,thatis,thepowersupplyforclosingortrippingcanbecutoff;
4.Whenthereisnomechanicalanti-tripdevice,anelectricalanti-tripdeviceshouldbeinstalled;
5.Theaccidenttripsignalcircuitofthecircuitbreakershouldbewiredaccordingtothe"non-correspondenceprinciple";
6.Forequipmentthatmayhaveabnormalworkingconditionsormalfunctions,itshouldbeinstalledPre-announcementsignal;
7.ThepowersupplyofspringoperatingmechanismandmanualoperatingmechanismcanbeDCorAC,andthepowersupplyofelectromagneticoperatingmechanismrequiresDC.
Developmentstatus
Theearliestcircuitbreakerintheworldwasproducedin1885.Itisacombinationofaknifeheadandanovercurrentrelease.In1905,anaircircuitbreakerwithafreetripdevicewasborn.Since1930,withtheadvancementofscienceandtechnology,thediscoveryoftheprincipleofarcandtheinventionofvariousarcextinguishingdeviceshavegraduallyformedamechanism.Attheendofthe1950s,duetotheriseofelectroniccomponents,electronictripswereproduced.Today,duetothepopularityofsingle-chipmicrocomputers,intelligentcircuitbreakershaveappeared.
Commonlow-voltagecircuitbreakersandvacuumcircuitbreakers:
Low-voltagecircuitbreakersareusedforswitching,controllingorprotectingcircuitswithACvoltageof1200VandDCvoltageof1500V.Electricalappliances.Low-voltagecircuitbreakersareanimportantpartoftheelectricalindustry.Itisabasicaccessoryinthemachineryindustry.Thelow-voltageswitchgearinthepowerdistributionsystemismainlycomposedofvariouslow-voltagecircuitbreakercomponents.Thefunctionandperformanceoflow-voltagecircuitbreakersareimportantforlow-voltageswitchgear.Equipmentplaysavitalrole.Morethan80%oftheelectricenergygeneratedbypowergenerationequipmentisdistributedandusedthroughlow-voltagecircuitbreakers.Foreveryadditional10,000kWpowergenerationequipment,about20,000piecesofvariouslow-voltagecircuitbreakersareneeded.Inindustrialautomationsystems,variouscontrolpanels,consoles,controllersandotherproductscomposedoflow-voltagecircuitbreakersarealsoneeded.Since1949,China'slow-voltagecircuitbreakerindustryhasgraduallydevelopedintoanindustrycapableofindependentdesignandproductionbasedonsomesimplerepairandassemblyfactories.By1979,thereweremorethan600manufacturers.After1985-1986and1990-Thereweretwodevelopmentpeaksin1991.In1995,therewereabout1,500manufacturersinthelow-voltagecircuitbreakerindustry.
China'slow-voltagecircuitbreakermanufacturersaremainlyconcentratedinBeijing,Tianjin,Liaoning,Shanghai,Jiangsu,Zhejiang,Guangdongandotherplaces.Whilepromotingthedevelopmentofthenationaleconomy,theyalsoexposedmanyproblems.Therearemainlythefollowingtwopoints:
1.Thescaleoftheenterpriseissmallandthenumberistoolarge.Amongthelow-voltagecircuitbreakermanufacturersinChina,thereareonly2to4large-scaleenterpriseswithannualsalesrevenueandtotalassetsofmorethan500millionyuan,mostofwhicharesmallandmedium-sizedenterprises,whichleadstothelackofeconomiesofscaleandcompetitivenessofenterprises;andChina'slow-voltagecircuitbreakerFromtheearlydaysofthefoundingofthePeople’sRepublicofChinatomorethan1,500companiestoday,thenumberofmanufacturershasresultedinexcessivedispersionofeconomicresourcesandlackofoverallinnovationpower,resultinginlowproductionefficiency,economicbenefitsandmarketcompetitiveness.
2.Theregionalstructureconverges,andrepeatedconstructionisserious.China'slow-voltageelectricalapplianceindustryhasblindlylaunchedprojectsandpavements,andthephenomenonofregionalindustryconvergenceisserious,andlow-levelrepeatedconstructionhasresultedinoverproductionofproducts,lowutilizationofenergyandrawmaterials,loweconomicefficiency,regionalprotection,andviciouscompetition.
Theprogressofvacuumcircuitbreakertechnology,theprogressofvacuumcircuitbreakertechnologyismanifestedinlargecapacity,lowovervoltage,intelligenceandminiaturization.Andthisprogressisduetothedevelopmentofvacuumtechnology,interruptertechnologyandtheadoptionofnewtechnology,newmaterialsandnewoperatingtechnology.Accordingtotheinventor,thistechnologywillnotonlyserveasasubstitutefortraditionalmotortechnology,butwillalsoexpandabroaderdevelopmentandapplicationspaceforDCmotors.Forexample,thedevelopmentoflarge-capacityDCmotorstoreplaceACsynchronousgeneratorsandconverterstationequipmentpoweredbyhigh-voltageDCtransmissiongridscannotonlysavealotofconverterstationconstructioncosts,butalsogreatlyreducepowertransformationlosses.