低压控制-(英文)课件

LowVoltageElectricalControlAgendaMotorStartControlLowVoltageElectricalControlComponentsRefrigerantControlPartsElectricalDiagrams

MotorStartControlMotor/CompressorComponentsMotorBasicsMotorSynchronousSpeed=60*f/p(rpm) MotorAsynchronousSpeed=(1-S)*60*f/p(rpm)s:slipofmotorf:frequency(Hz)p:pairsofpoles2.Pin=√3*U*I*cosφ(kw)Pout=√3*U*I*cosφ*η(kw)CenTraVacMotorsThreePhaseTwoPoleSquirrelCageInductionMotorBasicsMotorBasicsStartingCurrent LockedRotorAmps(LRA)RunningCurrent FullLoadAmps(FLA),MotorAmps RatedLoadAmps(RLA),a.k.a.SelectionAmps MaximalContinuousCurrent(MCC) OverloadShortcircuitShortCircuitCurrent,a.k.a.FaultCurrent

MotorPhasetoPhase,orPhasetoGroundShortFaultCurrentsOftenOver100,000Amps!OverloadsProtectionDoNotProvideShortCircuitProtection!FaultCurrentisInterruptedbyFusesorCircuitBreakerMotorStartingStarting(fullvoltage)RLAisaboutSixTimestheFLA!MayExceedPowerTransformerKVAVoltageDropsLightsDimStarting(reducevoltage)ReduceInrushCurrent,(Current∝Voltage)MayResultinDeficientStartingTorque,(Torque∝SquareVoltage)StartinginLightLoadMotorStartingStartingType(reducevoltage)StarDelta(OpenorClose)Part-windingPrimaryReactorAuto-transformerSolidStateVFDMotorStartingMotorStartingMotorStartingStar-DeltaStartingStar-DeltaStartingTraneStar-DeltaStartingSolidStateStarterS.S.S

controlsthevoltagetothemotorthroughtheuseofSCRs(SiliconControlledRectifier)andabypasscontactorforpowercontrolAfullsix-SCRconfigurationisusedforthreephrasecompressorload.SolidStateStarterDuringstarting,controlofcurrentoraccelerationtimeisachievedbygatingtheSCRonatdifferenttimeswithinthehalf-cycle.WhentheSCRsarefully“phasedon”,thebypasscontactorisenergized,andturntheSCRsoff.ThiswillreducestheefficiencylossesduetoheatbeinggeneratedintheSCRsOtherStartingPrimaryReactorAuto-transformerMotorStarting<=600voltsLowVoltageUnitMountedRemoteMountedStarDeltaSolidStateStarDeltaSolidStateVFDAutotransformerStarterChoicesX-Line

50/60Hz

601-10000voltsMediumVoltageUnitMountedRemoteMountedXLinePrimaryReactorXLinePrimaryReactorAutotransformerAutotransformerXLineSolidStateStarDelta

LowVoltage

ElectricalcontrolcomponentsElectricComponentsPowersupplyIsolationShortcircuitProtectOverloadMotorrun/offControl

ElectricComponentsPrimaryFunctionTomechanicallybreakconnectionofincomingpowertothemotorcircuit.SecondaryFunction(circuitbreaker)Toprovideshortcircuitandthermaloverloadprotectiontothesystemcontrollingthemotor.Disconnects(Non-FusedDisconnectSwitch,FusedDisconnectSwitch,CircuitBreaker)ElectricComponentsShortCircuitProtection(Fuse,CircuitBreaker,MMS)PrimaryFunctionInterruptfaultcurrentinshortcircuitSecondaryFunctionTodisconnectpowertothemotor(suchasCB)ElectricComponentsContactors(Electro-Mechanical,Vacuum,SolidStateStarter)PrimaryFunctionTomagneticallybreakpowertothemotorCapableofremote&automaticoperationAbletoswitchinrushmotorcurrentsSecondaryFunctionTodisconnectpowertothemotorintheeventofanoverload(beforebreaker)ElectricComponentsOverload(Thermalrelay,Tranestartermodule&CTs)PrimaryFunctionToprotectthemotorfromadamagingthermalconditionToprotectthemotorfromshortcircuitsSecondaryFunctionToclosealarmcontactsTosensecurrentdrawofmotorElectricComponentsContactorCoil(1M,2M,etc.)ControlPowerTransformers(CPT)AuxiliaryContacts(1M,2S,etc.)Pushbuttons,SelectorSwitches(Start/Stop)ControlRelay(CR)Thermostats,AlarmContacts,PressureSwitchesetc.

ControlComponents

RefrigerantcontrolpartsCompressormotorcontrolApplication:refrigerantcompressfromlowpressurevaportohighpressurevaporSinglephasemotor:capacitorstartforsmallscrollcompressorThreephasemotor:Acrossthelinestarter,forscrollandscrewcompressorY/Dclosedtransitionstarter,forscrewandcentrifugalcompressorSolidstatestarter,forscroll,screwandcentrifugalcompressorVariablespeeddriver,forcentrifugalcompressorMediumvoltage(2300~10000V)acrossthelinestarter,forcentrifugalcompressorMediumvoltage(2300~10000V)primaryreactorstarter,forcentrifugalcompressorMediumvoltage(2300~10000V)auto-transformerstarter,forcentrifugalcompressorFanmotorcontrolApplication:Indoorfancoil,condenserfancontrolSinglephasemotor:capacitorstart,high/medium/low3speedscontrolforindoorfancoilThreephasemotor:Acrossthelinestart,stagingonandoffbasedoncondenserpressurewithmultiplecondenserfansTwospeedfancontrol,fornightnoisesetbackrequirement.Wyeconnectionforlowspeed,DeltaconnectionforhighspeedVFDfancontrol,forlowambientcoolingrunningrequirement.Usedonfirstrunningcondenserfanoftherefrigerantcircuit,speedvaryasafunctionofcondensingpressurecontrolTemperaturesensorApplication:WatertemperaturecontrolDischargehightemperatureprotectionCoiltemperaturedefrostcontrolAmbienttemperatureOiltemperaturecontrolUseNTC(negativetemperaturecoefficient)Temperature-ResistancecharacteristicforcontrolNTCbasicparameterNominalresistanceat25℃(R25)Materialconstant(B)R25=10Kforgeneralusage,R25=50Kforhightemperaturecontrol(Dischargetemp.control)PressuretransducerApplication:SuctionpressureforsuperheatcontrolandlowpressureprotectionDischargepressureforhighpressureprotectionOilpressureforoildifferentialpressureprotectionType:VariablecapacitiveSemiconductorpiezoresistive

Selectbypressurerangeandoutputtype(0~5Vor4~20ma)CH530pressuretransducerWorkingPressureRange:0to475PsigPower:24+/-10%VDC,20mAmax.Communications,RS485PhysicalLayer,19.2Kbit

CT/PTonCH530ApplicationCT(currenttransformer)detects3phasecurrentsofcompressormotor,formotoroverload,phasereverse,phaseloss,currentimbalanceprotectionPT(potentialtransformer)detectslinevoltageofpowersupply,forover/undervoltageprotection3CTsand3PTsconnecttostartermodulecanprovidepowermeterfunctiononCH530controlplatformCTandPTcanconverthighcurrentandvoltagevaluetosmallvalueforcontrol.WeusuallyuseCTwith50:0.1,100:0.1,150:0.1,200:0.1….,PTwith600:30WiringmustpayattentiontopolaritymarkontheCTsandPTsHighpressureCutoutSwitchApplication:refrigerantsystemhighpressureprotectionFunction:CutoutmotorrunningcontrolcircuitSendalarmsignaltocontrolcenterSPDTcontact,autoreset,pre-settrippointbasedonrefrigerantWaterflowswitchApplication:EvaporatorandcondensernoflowprotectionPaddleswitch:通过靶片去感应管道中水流量的变化，进而带动控制开关，输出信号

SPDT,presettrippoint,tripflowratecanbeadjustedNEMA1orNEMA4enclosureThermaldispersiontypeflowsensor:Houses2PTCsandaheaterelementDetecttemperaturedifferenceofPTCsforfluidvelocitypastthesensorprobeDC/AC24Vpower,

presetflowrate(10~60cm/s),drycontactoutputMotorthermostatApplication:protectmotorfromoverheatingunderoverloadconditionMotorthermostatinGP2compressorKlixon7895thermostatHermeticallysealedinthreephasemotorwindings,3pieces120°apartOpenonriseat115℃±5℃andcloseonfallat93℃±11℃forclassBinsulationconstructionMotorprotectorinScrollcompressor6PTCsmountinginthreephasemotorwindingsWiringinseriestoprotectormoduleOutputdrycontacttocontrolcenterCrankcaseHeaterApplication:compressorheaterFunction:keeptherefrigerantfromcondensingintheoilwhenthecompressorisnotrunningControl:heaterisconnectedtonormalclosecontactofcompressorrunningcontactor.Compressorruns,heaterisoff;compressorshutsdown,heaterisonHeateronGP2compressorCrankcaseheaterforscrollcompressor

ElectricalDiagramsDiagramsSchematicDiagramPanelConnectionDiagramUnitConnectionDiagramJobsiteConnectionDiagram(FieldConnectionDiagram)PanelLayoutDiagramUnitComponentsLocationDiagram

SchematicDiagramExpandedViewShowscompleteelectricalcircuit,legend,andoptionalsequenceofoperation

TraneDraftingStandardIECSymbolsPanelConnectionDiagramExpandedViewShowsapproximatelocationofcomponents,wirenumbersandcorrespondingterminationpointsconnectingtothemValidforconnectionswithinthepanelonlyUnitConnectionDiagramExpandedViewShowsapproximatelocationofcomponents,wirenumbersandcorrespondingterminationpointsconnectingtothemValidforfactory-madeconnectionsbetweenthepanelandunitdevicesonlyJobsiteConnectionDiagramExpanded