Upload
doduong
View
226
Download
1
Embed Size (px)
Citation preview
Guide for the Design and Production of LV Power Factor Correction Cubicles
Power Factor Correction
Panel Builder Guide2011
Panel Builder Guide 2011
Contents
CHAPTER 1: General design rules 3 - 11 Applicablestandardsanddefinitions Reactive Energy Guidelines EffectsofHarmonics
CHAPTER 2: Component Selection Guide 12 - 42 Capacitor 12 - 21 RatedVoltageandCurrentofCapacitor Capacitorsselectionbasedonoperatingconditions Offeroverview–VarplusCan/VarplusBox
Detuned Reactors 22 - 27 Detunedreactorsoverview CapacitorRatedVoltagewithDetunedReactors ChoiceofDetunedReactorTuningFrequency Offeroverview-Detunedreactors
Contactors 28 - 30 Offeroverview–TeSysDContactors ParallelOperationofCapacitorsandInrushCurrentLimiting
Switching and Protection Devices 31 - 32 Power Factor Controller 33 - 37 VarlogicNPowerFactorController PhysicalandElectricalcontrolofPFCrelay
CT and Protection Devices 38 - 42 CurrentTransformer ProtectionDevicesinAPFCPanels Switchgearandfuseselection
CHAPTER 3: Installation Rules 43 - 55 Capacitor 43 - 45 GeneralInstallationrules Installationrules-VarplusCanandVarplusBox Installationrules-VarplusBoxCompact
Detuned Reactors 46 APFC Panels 47 - 55 MaximumkvarperstepinAPFCPanel Installationrules-APFCPanels Ventilationforcapacitorbanks Protectionofpanels Cableselection
CHAPTER 4: Assembly, Inspection and Testing 56 - 61 AssemblyandInspection Themeans Thetests
CHAPTER 5: Handling 62 - 64 Packagingandtransport Storageandhandling
CHAPTER 6: Installation, Commissioning and Maintenance 65 - 67 Pre-Commissioningchecklists InstallationguidelinesforAPFCPanels CommissioningofAPFCPanel
ANNEXURE 68 - 70 Annexure1:Troubleshootingincapacitor Annexure2:Importantanalysisformulas
Design of LV compensation cubicle
Inadditiontotherulesandstandards,productionofelectricalswitchboardsfortheLVcompensationrequiresconsiderationofspecificconstraints.
1- The compensation modules The VarplusCan and VarplusBox capacitors Theirpositioningmustensureproperventilation.Theirsizingmusttakeintoaccountambientconditions(harmonics,temperature,etc…)
The contactorsTheymustbesuitedtocapacitorcontrol.SchneiderElectrichasdesignedandtestedspecificcontactorsforthisapplication.Theircontrolvoltagemustbemonitoredinordertopreventrapidreclosing.
2- The detuned reactors (DR) Theymustbechosenaccordingtoharmonicstressesandinstalledinordertoavoid,asfaraspossible,capacitortemperaturerise.
The DR temperature sensor must be connected so that the step can be disconnected if the temperature is too high
Key points discussed in the document
3- VentilationItmustbeefficientinordertokeepoperatingtemperaturelowerthanmaximumpermissibletemperatureofcomponents.
4- The power factor controller Itsfunctionsmustbeadaptedtothecapacitorbankcharacteristics:numberandpowerofsteps,sequence,etc.Thetimedelaymustbeadaptedtocapacitordischargetime.
5- Low voltage network Networkcharacteristics,andinparticularnetworkharmonicdistortion,mustabsolutelybetakenintoaccountwhenchoosingcapacitorsanddetunedreactors(ifany).
6- Tests to be done after production of the bank Attheendofthemanufacturingprocess,aLVswitchboardmustundergovariousroutineinspectionsandtestsinthefactory,followinganestablishedprogramme.
Theswitchboardmustcomplywith: theappropriatestandards thedesignfile(drawings,diagramsand
specificrequirements) manufacturermountinginstructions in-houseinstructions.
7- Maintenance must be done every yearOnemonthafterenergising,checkallcontactorterminaltighteningtorques.Annualchecks
Generalcleanlinessoftheequipment Filtersandventilationsystem Terminaltighteningtorques Properworkingorderofswitchingand
protectivedevices Temperatureinthepremises:
-5°Cto+40°cmax-fornormaldesigns Capacitorcapacitance:Consultusifthe
capacitancevaluehaschangedbymorethan10%.
General DesignRules
3
Applicable Standards IEC:61921(PowerCapacitors-Lowvoltagepowerfactorcorrectionbanks)istheinternationalstandardapplicableforLowVoltagePowerFactorCorrectionBanksandAutomaticPowerFactorCorrection(APFC)equipmentsintendedtobeusedforpowerfactorcorrectionpurposes,equippedwithbuiltinswitchgearsandcontrolgears.Theguidelinesfordesign,installation,operationandsafetyofAPFCpanelsarefollowedbasedonthisinternationalstandard.
ThedesignoftheLowVoltagePowerFactorCorrectionbanksandaccessoriesshallcomplywiththefollowingstandards
IEC60831:Part1&2-Shuntpowercapacitorsoftheselfhealingtypefora.csystemshavingratedvoltageuptoandincluding1kV.
IEC 60439-3:Lowvoltageswitchgearandcontrolgearassemblies.Particularrequirementsforlow-voltageswitchgearandcontrolgearassembliesintendedtobeinstalledinplaceswhereunskilledpersonshaveaccessfortheiruse-Distributionboards.
IEC 60947:LowVoltageSwitchgear Part2:MoldedCaseCircuitBreakers&AircircuitBreakers Part4:PowerContactors Part4-3:ThyristorSwitch
IEC 60269:LVFuses IEC 60076-6:Reactors IEC 60529:Degreeofprotectionprovidedbyenclosure(IP
code) IEC 60044-1:Currenttransformers. IEC 60664-1 / IEC 61326:PowerFactorController.
Definitions ThedesignoftheAPFCequipmentinvolvesthefollowingmajorpartsandtheselectionofthesedependsverymuchontheabovesystemconditions.
Enclosure:protectstheAPFCsystemcomponentsagainsttheexternalsolidorliquidparticlesandalsoprovideprotectionforhumanbeings.
PFC Controller:IsthebrainoftheAPFCsystem,whichswitchesON/OFFthestepsdependingonthekvarrequiredinordertomaintainthePFclosetounity.
Bus bars:Busbaristheelectricalconductingpath,towhichallthecomponentsintheAPFCsystemareconnected.
Switchgears:Switchgearsarethedeviceswhichcontrolthecircuitunderfaultyandnormalconditions.SwitchgearsprotecttheAPFCsystemagainstfaultyconditions.
Cables:Cablesareusedtoconnectvariouscomponentsinthesteps.Propercablesizinghastobeconsideredforaparticularstepdependingontheratedcurrentandtheoperatingtemperatureinordertolinkthevariouscomponentsofthesystem.Cablesloopthepowercircuit&controlcircuitinthesystem.
Applicable standards and definitions
General DesignRules
4
Protection devices:Protectionhastobeprovidedtosafeguardthecapacitorsandothercomponentsduetoabnormalitiesinthesystem.TheincomingswitchgearoftheAPFCsystemshouldbetrippedbyprotectivedevices.
Reactors:Reactorsareusedinstepsasdetunedfiltersandareconnectedinserieswithcapacitors.Itmustbedesignedtowithstandfundamentalandharmoniccurrents.
Capacitors:CapacitorsformsthecorecomponentinAPFCequipmentandplaysavitalroleinpowerfactorcorrection.Properselectionofcapacitorsisverymuchnecessarytocomplywiththeapplications.
Note: The above components are explained further in details
GlossarySFU : SwitchFuseUnitSDF : SwitchDisconnectorandFuseUnitACB : AirCircuitBreakerMCCB : MoldedCaseCircuitBreakerHRC : HighRuptureCapacityFuseSMC : SheetMoldingCompoundDMC :DoughMoldingCompound
General DesignRules
5
Principle of reactive energy management AllACelectricalnetworksconsumetwotypesofpower:activepower(kW)andreactivepower(kvar):
The active power P(inkW)isthe real powertransmittedtoloadssuchasmotors,lamps,heaters,computers…Theelectricalactivepoweristransformedintomechanicalpower,heatorlight.
The reactive power Q (inkvar)isusedonlytosupplythemagneticcircuitsofmachines,motorsandtransformers.
The apparent power S(inkVA)isthevectorcombinationofactiveandreactivepower.
Inthisrepresentation,thePower Factor (P/S)isequaltocosφ.
Thecirculationofreactivepowerintheelectricalnetworkhasmajortechnicalandeconomicconsequences.ForthesameactivepowerP,ahigherreactivepowermeansahigherapparentpowerandthus,ahighercurrentmustbesupplied.
-Thecirculationofactivepowerovertimeisresulting in active energy(inkWh).
-Thecirculationofreactivepowerovertimeisresultinginreactiveenergy(kvarh).
-Inanelectricalcircuit,thereactiveenergyissuppliedinadditiontotheactiveenergy.
Duetothishigher supplied current,circulationofreactiveenergyondistributionnetworksresultsin:
Overloadoftransformers, Highertemperatureriseofthesupplycables, Additionallosses, Largevoltagedrops, Higherenergyconsumptionandcost, Lessdistributedactivepower.
Forthesereasons,thereisagreatadvantagetogeneratereactiveenergyattheloadlevelinordertopreventtheunnecessarycirculationofcurrentinthenetwork.Thisiswhatisknownas“PowerFactorCorrection”.
Thisisobtainedbytheconnectionofcapacitors,whichproducereactiveenergyinoppositiontotheenergyabsorbedbyloadssuchasmotors.
Theresultisareducedapparentpower,andanimprovedpowerfactorP/S’asillustratedonthediagramontheleft.
Thepowergenerationandtransmissionnetworksarepartiallyrelieved,reducingpowerlossesandmakingadditionaltransmissioncapabilityavailable.
Thereactivepowerissuppliedbycapacitors.
Nobillingofreactivepowerbytheenergysupplier.
Reactive Energy Guidelines
Reactiveenergysuppliedandbilledbytheenergysupplier
Power generation
Transmission network Motor
Active energyActive energy
Reactive energy Reactive energy
Power generation
Transmission network Motor
Capacitors
Active energyActive energy
Reactive energy
DE
9007
1_r.e
ps
Power generation
Transmission network Motor
Active energyActive energy
Reactive energy Reactive energy
Power generation
Transmission network Motor
Capacitors
Active energyActive energy
Reactive energy
DE
9007
1_r.e
psD
E90
087.
eps
DE
9008
8.ep
s
QcQ
General DesignRules
6
Optimizedmanagementofreactiveenergybringseconomicandtechnicaladvantages.
Savings on the electricity bill: EliminatingpenaltiesonreactiveenergyanddecreasingkVA
demand, Reducingpowerlossesgeneratedinthetransformersand
conductorsoftheinstallation.Example:Lossreductionina630kVAtransformerPW=6,500WwithaninitialPowerFactor=0.7.Withpowerfactorcorrection,weobtainafinalPowerFactor=0.98Thelossesbecome:3,316W,i.e.areductionof49%.
Increasing available power:Ahighpowerfactoroptimizesanelectricalinstallationbyallowingabetterusageofthecomponents.
ThepoweravailableatthesecondaryofanMV/LVtransformercanthereforebeincreasedbyfittingpowerfactorcorrectionequipmentatthelowvoltageside.
ThetableshowstheincreasedavailablepoweratthetransformeroutputbyimprovementofPowerFactorfrom0.7to1.
Reducing the installation sizeInstallingpowerfactorcorrectionequipmentallowstheconductorscross-sectiontobereduced,sincelesscurrentisabsorbedbythecompensatedinstallationforthesameactivepower.
Thetableintheleftshowsthemultiplyingfactorfortheconductorcross-sectionaccordingtothedifferentvaluesofpowerfactor.
Reducing the voltage drops on installationInstallingcapacitorsallowsthevoltagedropstobereducedupstreamofthepointwherethepowerfactorcorrectiondeviceisconnected.Itavoidstheoverloadofthenetworkandallowsthediminutionofharmonicssothatnooverratingoftheinstallationisnecessary.
Benefits of reactive energy management
Power factor Increased available power
0.7 0%
0.8 +14%
0.85 +21%
0.90 +28%
0.95 +36%
1 +43%
Reduction in kvar Demand
Reduction in Transformer RatingReduction in Transformer RatingReduced Loading on TransformerReduction in Line Current
Reduction in electricity bill
Reduction in kVA Demand
Reduction in Switchgear rating
Reduction in Line losses / Cable losses
Improvement in voltage regulations
Power factor Cable cross-section multiplying factor
1 1
0.80 1.25
0.60 1.67
0.40 2.50
General DesignRules
7
TheselectionofthePowerFactorCorrectionequipmentcanfollowa4-stepprocess:
1. Calculation of the requested reactive energy,
2. Selection of the compensation mode: Global,forthecompleteinstallation, Bysectors, Forindividualloads,suchaslargemotors.
3. Selection of the compensation type: Fixed,byconnectionofafixed-valuecapacitorbank, Automatic,byconnectionofdifferentnumberofsteps,allowing
theadjustmentofthereactiveenergytotherequestedvalue, Dynamic,forcompensationofhighlyfluctuatingloads.
4. Taking account of operating conditions and harmonics
Power Factor Correction guidelines
8
Power Factor Correction guidelines
8
Power Factor Correction for Transformer no-load compensationThetransformerworksontheprincipleofMutualInduction.Thetransformerwillconsumereactivepowerformagnetizingpurpose.
Followingequivalentcircuitoftransformerprovidesthedetailsofreactivepowerdemandinsidethetransformer:
Power Factor Correction where Load and present Power Factor is KnownTheobjectiveistodeterminetherequestedreactivepowerQC (kvar)tobeinstalled,inordertoimprovethepowerfactorcosφandreducetheapparentpowerS.
Forφ’<φ,we’llget:cosφ’>cosφandtanφ’<tanφ.
Thisisillustratedonthediagramintheleft.
QCcanbedeterminedfromtheformula:QC=P.(tanφ-tanφ‘),whichisdeducedfromthediagram.QC: powerofthecapacitorbank,inkvarP: activepower,inkWtanφ: tangentofthephaseangle-beforecompensation,tanφ‘: tangentofthephaseangle-aftercompensation
Theparametersφandtanφcanbeobtainedfromthebillingdata,orfromdirectmeasurementintheinstallation.
Thefollowingtablecanbeusedfordirectdetermination.
Example:Considerone1000kWmotorwithcosφ0.8(tanφ=0.75).Inordertogetcosφ’=0.95,itisnecessarytoinstallacapacitorbankwithareactivepowerequaltokxP,i.e.:Qc=0.42x1000=420kvar
Calculation of Reactive Energy Based on the Application
Transformer
No Load reactivePower = 2% ofTransformer rating
Xo Ro
Leakage reactancereactive power= Z % x Transformer rating
Load
Xo1 Ro1
kVA rating of Transformer kvar required for No-Load compensation
Uptoandincluding2000kVA 2%ofkVArating
Before Reactivepower(kvar)tobeinstalledperkWofload,compensation inordertogettherequestedtanφ’orcosφ’ tanφ’ 0.75 0.62 0.48 0.41 0.33 0.23 0.00 cosφ’ 0.8 0.85 0.9 0.925 0.95 0.975 1.00
1.73 0.5 0.98 1.11 1.25 1.32 1.40 1.50 1.73
1.02 0.7 0.27 0.40 0.54 0.61 0.69 0.79 1.02
0.96 0.72 0.21 0.34 0.48 0.55 0.64 0.74 0.96
0.91 0.74 0.16 0.29 0.42 0.50 0.58 0.68 0.91
0.86 0.76 0.11 0.24 0.37 0.44 0.53 0.63 0.86
0.80 0.78 0.05 0.18 0.32 0.39 0.47 0.57 0.80
0.75 0.8 0.13 0.27 0.34 0.42 0.52 0.75
0.70 0.82 0.08 0.21 0.29 0.37 0.47 0.70
0.65 0.84 0.03 0.16 0.24 0.32 0.42 0.65
0.59 0.86 0.11 0.18 0.26 0.37 0.59
0.54 0.88 0.06 0.13 0.21 0.31 0.54
0.48 0.9 0.07 0.16 0.26 0.48
tanφ cosφ
DE
9008
8.ep
s
QcQ
Note: It is widely accepted to use a thumb rule that Motor compensation required in kvar is equal to 33% of the Motor Rating in HP.
But it is always suggested to check the name plate of a motor and find out the kvar required using the above mentioned method (using the above table) for accurate compensation.
9
Power Factor Correction guidelines
9
Thelocationoflow-voltagecapacitorsinaninstallationconstitutesthemodeofcompensation,whichmaybeglobal(onelocationfortheentireinstallation),bysectors(section-by-section),atloadlevel,orsomecombinationofthelattertwo.Inprinciple,theidealcompensationisappliedatapointofconsumptionandatthelevelrequiredatanyinstant.
Inpractice,technicalandeconomicfactorsgovernthechoice.
Theplaceforconnectionofcapacitorbanksintheelectricalnetworkisdeterminedby:
Globalobjective(avoidpenaltiesonreactiveenergy,relieveoftransformerorcables,avoidvoltagedropsandsags),
Operatingmode(stableorfluctuatingloads), Foreseeableinfluenceofcapacitorsonthenetwork
characteristics, Installationcost.
Global compensation Thecapacitorbankisconnectedattheheadoftheinstallationtobecompensatedinordertoprovidereactiveenergyforthewholeinstallation.Thisconfigurationisconvenientforstableandcontinuousloadfactor.
Compensation by sectorsThecapacitorbankisconnectedattheheadofthefeederssupplyingoneparticularsectortobecompensated.Thisconfigurationisconvenientforawideinstallation,withworkshopshavingdifferentloadfactors.
Compensation of individual loadsThecapacitorbankisconnectedrightattheinductiveloadterminals(especiallylargemotors).Thisconfigurationiswelladaptedwhentheloadpowerissignificantcomparedtothesubscribedpower.Thisisthetechnicalidealconfiguration,asthereactiveenergyisproducedexactlywhereitisneeded,andadjustedtothedemand.
Selection of the compensation mode
Supply Bus
Transformer
Circuit breaker
CC
GC GC
IC IC
M M M M
IC IC
CC : Central CompensationGC : Group CompensationIC : Individual CompensationM : Motor Load
10
Power Factor Correction guidelines
10
Differenttypesofcompensationshallbeadopteddependingontheperformancerequirementsandcomplexityofcontrol:
Fixed,byconnectionofafixed-valuecapacitorbank, Automatic,byconnectionofdifferentnumberofsteps,allowing
theadjustmentofthereactiveenergytotherequestedvalue, Dynamic,forcompensationofhighlyfluctuatingloads.
Fixed compensationThisarrangementusesoneormorecapacitor(s)toprovideaconstantlevelofcompensation.Controlmaybe:
Manual:bycircuit-breakerorload-breakswitch, Semi-automatic:bycontactor, Directconnectiontoanapplianceandswitchedwithit.
Thesecapacitorsareapplied:
Attheterminalsofinductiveloads(mainlymotors), Atbusbarssupplyingnumeroussmallmotorsandinductive
appliancesforwhichindividualcompensationwouldbetoocostly, Incaseswheretheloadfactorisreasonablyconstant.
Automatic compensationThiskindofcompensationprovidesautomaticcontrolandadaptsthequantityofreactivepowertothevariationsoftheinstallationinordertomaintainthetargetedcosφ.Theequipmentisappliedatpointsinaninstallationwheretheactive-powerand/orreactive-powervariationsarerelativelylarge,forexample:
Atthebusbarsofamaindistributionswitch-board, Attheterminalsofaheavily-loadedfeedercable.
Wherethekvarratingofthecapacitorsislessthan,orequalto15%ofthesupplytransformerrating,afixedvalueofcompensationisappropriate.Abovethe15%level,itisadvisabletoinstallanautomatically-controlledbankofcapacitors.
Controlisusuallyprovidedbycontactors.Forcompensationofhighlyfluctuatingloads,fastandhighlyrepetitiveconnectionofcapacitorsisnecessary,andstaticswitchesmustbeused.
Dynamic compensationThiskindofcompensationisrequestedwhenfluctuatingloadsarepresent,andvoltagefluctuationsshouldbeavoided.Theprincipleofdynamiccompensationistoassociateafixedcapacitorbankandanelectronicvarcompensator,providingeitherleadingorlaggingreactivecurrents.
Theresultisacontinuouslyvaryingandfastcompensation,perfectlysuitableforloadssuchaslifts,crushers,spotwelding…
Selection of the compensation type
11
Power Factor Correction guidelines
11
Equipment
MotorTransformerSwitchgearandcables CapacitorsProtectiveRelaysPowerelectronicequipmentControl&instrumentationElectronicequipmentCommunicationequipment/PC’sNeutralcable Telecommunicationequipment
Effect of Harmonics
Overheating,productionofnon-uniformtorque,increasedvibrationOverheatingandinsulationfailure,noiseNeutrallinkfailure,increasedlossesduetoskineffectandoverheatingofcablesLifereducesdrasticallyduetoharmonicoverloadingMalfunctionandnuisancetrippingMisfiringofThyristorsandfailureofsemiconductordevicesErraticoperationfollowedbynuisancetrippingandbreakdowns Interference HigherNeutralcurrentwith3rdharmonicfrequency,NeutraloverheatingandoropenneutralconditionTelephonicinterference,malfunctionofsensitiveelectronicsused,failureoftelecomhardware
Effects of Harmonics
Harmonics in electrical installationsThepresenceofharmonicsinelectricalsystemsmeansthatcurrentandvoltagearedistortedanddeviatefromsinusoidalwaveforms.
Harmoniccurrentsarecurrentscirculatinginthenetworksandwhichfrequencyisanintegermultipleofthesupplyfrequency.
Harmoniccurrentsarecausedbynon-linearloadsconnectedtothedistributionsystem.Aloadissaidtobenon-linearwhenthecurrentitdrawsdoesnothavethesamewaveformasthesupplyvoltage.Theflowofharmoniccurrentsthroughsystemimpedancesinturncreatesvoltageharmonics,whichdistortthesupplyvoltage.
Themostcommonnon-linearloadsgeneratingharmoniccurrentsareusingpowerelectronics,suchasvariablespeeddrives,rectifiers,inverters,etc….Loadssuchassaturablereactors,weldingequipment,arcfurnaces,alsogenerateharmonics.
Otherloadssuchasinductors,resistorsandcapacitorsarelinearloadsanddonotgenerateharmonics.
Influence of Harmonics in CapacitorsCapacitorsare particularly sensitivetoharmoniccurrentssincetheirimpedancedecreasesproportionallytotheorderoftheharmonicspresent.Thiscanresultinacapacitoroverload,shorteningsteadilyitsoperatinglife.Insomeextremesituations,resonancecanoccur,resultinginanamplificationofharmoniccurrentsandaveryhighvoltagedistortion.
AmplificationofHarmoniccurrentsisveryhighwhenthenaturalresonancefrequencyofthecapacitorandthenetworkcombinedhappenstobeclosetoanyoftheharmonicfrequenciespresent.
Thissituationcouldresultinsevereovervoltagesandoverloadswhichwillleadtoprematurefailureofcapacitors
Toensureagoodandproperoperationoftheelectricalinstallation,theharmoniclevelmustbetakenintoaccountintheselectionofthepowerfactorcorrectionequipment.Asignificantparameteristhecumulatedpowerofthenon-linearloadsgeneratingharmoniccurrents.
12
General DesignRules
12
Component Selection guideCapacitors
12
AccordingtoIEC60831-1standard,theratedvoltage(UN)ofacapacitorisdefinedasthecontinuouslyadmissibleoperatingvoltage.
Theratedcurrent(IN)ofacapacitoristhecurrentflowingthroughthecapacitorwhentheratedvoltage(UN)isappliedatitsterminals,supposingapurelysinusoidalvoltageandtheexactvalueofreactivepower(kvar)generated.
Capacitorunitsshallbesuitableforcontinuousoperationatanr.m.s.currentof(1.3xIN).
Inordertoacceptsystemvoltagefluctuations,capacitorsaredesignedtosustainover-voltagesoflimitedduration.Forcompliancetothestandard,capacitorsareforexamplerequestedtosustainover-voltagesequalto1.1timesUN,8hper24h.
VarplusCanandVarplusBoxcapacitorshavebeendesignedandtestedextensivelytooperatesafelyonindustrialnetworks.Thedesignmarginallowsoperationonnetworksincludingvoltagefluctuationsandcommondisturbances.Capacitorscanbeselectedwiththeirratedvoltagecorrespondingtothenetworkvoltage.Fordifferentlevelsofexpecteddisturbances,differenttechnologiesareproposed,withlargerdesignmarginforcapacitorsadaptedtothemoststringentworkingconditions(HDuty&Energy)
CAUTION: the life expectancy will be reduced if capacitors are used at the maximum level of the working conditions.
Rated voltage and current of Capacitor
13
General DesignRules
13
Component Selection guideCapacitors
13
Capacitor Selection Based on operating conditions
Theoperatingconditionshaveagreatinfluenceonthelifeexpectancyofcapacitors.Forthisreason,differentcategoriesofcapacitors,withdifferentwithstandlevels,mustbeselectedaccordingtooperatingconditions.
Capacitorsmustbeselectedinfunctionofthefollowingparameters:
AmbientTemperature(°C), Expectedover-current,relatedtovoltagedisturbances,including
maximumsustainedovervoltage, Maximumnumberofswitchingoperations/year, Requestedlifeexpectancy.
Capacitorsareparticularlysensitivetoharmonics.Dependingonthemagnitudeofharmonicsinthenetwork,differentconfigurationsshallbeadopted.
Differentrangeswithdifferentlevelsofruggednessareproposed:
SDuty:Standarddutycapacitorsforstandardoperatingconditions,andwhennosignificantnon-linearloadsarepresent.
HDuty:Heavydutycapacitorsfordifficultoperatingconditions,particularlyvoltagedisturbances,orwhenafewnon-linearloadsarepresent.Theratedcurrentofcapacitorsmustbeincreasedinordertocopewiththecirculationofharmoniccurrents.
Energy:Speciallydesignedcapacitors,forharshoperatingconditions,particularlyhightemperature.
Capacitors with detuned reactors:applicablewhenasignificantnumberofnon-linearloadsarepresent.
Tuned filters:whennon-linearloadsarepredominant,requestingharmonicmitigation.Aspecialdesignisgenerallynecessary,basedonon-sitemeasurementsandcomputersimulationsofthenetwork.
Sincetheharmonicsarecausedbynon-linearloads,anindicatorforthemagnitudeofharmonicsistheratioofthetotalpowerofnon-linearloadstothesupplytransformerrating.
ThisratioisnotedNLL,andisalsoknownasGh/Sn:
Example:Supplytransformerrating:Sn=630kVATotalpowerofnon-linearloads:Gh=150kVANLL=(150/630)x100=24%
NLL=Totalpowerofnon-linearloads(Gh)Installedtransformerrating(Sn)
DB
1214
13.e
ps
14
General DesignRules
14
Component Selection guideCapacitors
14
Capacitor selection taking account of harmonics
Thepercentageofnon-linearloadsNLLisafirstindicatorforthemagnitudeofharmonics.TheproposedselectionofcapacitorsdependingonthevalueofNLLisgiveninthediagrambelow.
Amoredetailedestimationofthemagnitudeofharmonicscanbemadewithmeasurements.SignificantindicatorsarecurrentharmonicdistortionTHDiandvoltageharmonicdistortionTHDu,measuredatthetransformersecondary,withnocapacitorsconnected.Accordingtothemeasureddistortion,differenttechnologiesofcapacitorsshallbeselected:
Note:The capacitor technology has to be selected according to the most restrictive measurement. Example, a measurement is giving the following results :- THDi = 15 % Harmonic solution.- THDu = 3.5 % HDuty / Energy solution.HDuty or Energy with Detuned Reactor has to be selected.
Measure THDi, THDu
Supplytransformer
Linear loads Non-linear loads
DE
9018
2.ep
s
NLL (%) 10 20 25 50
SDuty
HDuty
Energy
HDuty Energy (with detuned reactor)
THDi (%) 5 8 10 20
SDuty
HDuty
Energy
HDuty Energy (with detuned reactor)
THDu (%) 3 5 6 8
SDuty
HDuty
Energy
HDuty Energy (with detuned reactor)
15
General DesignRules
15
Component Selection guideCapacitors
15
SolutionSDuty
HDuty
Energy
HDuty + Detuned Reactor
Energy + Detuned Reactor
DescriptionStandardcapacitor
Heavy-duty capacitor
Capacitorforspecialconditions
Heavy-duty,harmonicratedcapacitor+detunedreactor
Energy,harmonicratedcapacitor+detunedreactor
Recommended use for
Networkswithnonsignificantnon-linearloads Standardover-current Standardoperatingtemperature Normalswitchingfrequency Standardlifeexpectancy
Fewnon-linear loads Significantover-current Standardoperatingtemperature Significantswitchingfrequency Longlifeexpectancy
Significantnumber ofnon-linearloads(upto25%) Significantover-current Extremetemperatureconditions Veryfrequentswitching Extralonglifeexpectancy
High levelofnon-linearloads(upto30%) Significantover-current Standardoperatingtemperature Significantswitchingfrequency Longlifeexpectancy
Highlevel ofnon-linearloads(upto30%) Significantover-current Extremetemperatureconditions Veryfrequentswitching Extralonglifeexpectancy
Max. conditionNLL≤10%1.5IN 55°C(classD)5,000/yearUpto100,000h*
NLL≤20% 1.8IN 55°C(classD)7,000/yearUpto130,000h*
NLL≤25%1.5IN 70°C10,000/yearUpto160,000h*
NLL≤30% 1.8IN 55°C(classD)7,000/yearUpto130,000h*
NLL≤30% 2.5IN 70°C(classD)10,000/yearUpto160,000h*
*The maximum life expectancy is given considering standard operating conditions: service voltage(UN), service current(IN), 35°C ambient temperature.WARNING: The life expectancy will be reduced if capacitors are used in maximum working conditions.
16
General DesignRules
16
Component Selection guideCapacitors
16
Offer OverviewVarplusCan
Aluminumcancapacitorsspeciallydesignedandengineeredtodeliveralongworkinglifewithlowlossesinstandard,heavy-dutyandsevereoperatingconditions.SuitableforFixedandAutomaticPFC,realtimecompensation,detunedandtunedfilters..
VarplusCan
PE90131
Robustness Easyinstallation&maintenance Optimizeddesignforlowweight,compactnessandreliability
toensureeasyinstallation. Uniqueterminationsystemthatallowsmaintainedtightening. 1pointformountingandearthing. VerticalandhorizontalpositionincaseofHeavyDuty.
Safety Self-healing. Pressure-sensitivedisconnectoronallthreephases. Dischargeresistorsfitted. Finger-proofCLAMPTITEterminalstoreduceriskofaccidental
contactandtoensurefirmtermination(10to30kvar). Specialfilmresistivityandmetallizationprofileforhigherthermal
efficiency,lowertemperatureriseandenhancedlifeexpectancy.
Compacity Optimizedgeometricdesign(smalldimensionsandlowweight).
Features Highlifeexpectancyupto160,000hours. Veryhighoverloadcapabilitiesandgoodthermaland
mechanicalproperties. Economicbenefitsduetoitscompactsize. Easymaintenance. Uniquefingerproofterminationtoensuretightening.
PE90132
PE90131
PE90130
SDuty HDuty Energy
Construction Extrudedaluminiumcan
Voltage range 230 V -525 V 230 V -830 V 400 V - 525 V Power range 1-30kvar 5-50kvar 5-15kvar(three-phase) Peak inrush Upto200xIN Upto250xIN Upto350xIN current Over voltage 1.1xUN 8hevery24hOver current 1.5xIN 1.8xIN 2.5xINMean life Upto100,000h Upto130,000h Upto160,000hexpectancySafety Self-healing+pressure-sensitivedisconnector +dischargedevice(50V/1min)Dielectric Metallized Metallized Doublemetallized Polypropylenefilm Polypropylenefilm paper+ withZn/Alalloy withZn/Alalloy Polypropylenefilm withspecialprofile metallizationand wavecutImpregnation Non-PCB, Non-PCB,sticky Non-PCB,oil Biodegradable (dry)Biodegradable resin resin Ambient min-25°Cto min-25°Ctotemperature max55°C max70°CProtection IP20,indoorMounting Upright Upright,Horizontal UprightTerminals •Doublefast-on+cable(<10kvar) •CLAMPTITE-Three-phaseterminalwithelectricshock protection(fingerproof) •STUDTYPEformorethan30kvar
17
General DesignRules
17
Component Selection guideCapacitors
17
VarplusCanTechnical Specifications
General characteristics
Standards IEC60831-1/-2Frequency 50/60HzLosses (dielectric) <0.2W/kvarLosses (total) <0.5W/kvarCapacitance tolerance -5%,+10%Voltage Betweenterminals 2.15xUN(AC),10stest Betweenterminal < 660V-3kV(AC),10s &Container >660V-6kV(AC).10sDischarge resistor Fitted,standarddischargetime60s Dischargetime180sonrequest
Working Conditions Humidity 95% Altitude 2.000mabovesealevel Over voltage 1.1xUN8hinevery24hSwitching SDuty Upto5,000switchingoperationsperyearOperations HDuty Upto7,000switchingoperationsperyear Energy Upto10,000switchingoperationsperyearMean Life expectancy Upto1,60,000hrsHarmonic SDuty NLL <10% Content HDuty NLL <20% Energy NLL <25%
Installation characteristics
Mounting SDuty Indoor,Upright position HDuty Indoor,Upright&horizontal Energy Indoor,UprightFastening & Earthing ThreadedM12studatthebottom
Safety Features
Safety Self-healing+Pressure-sensitive disconnectorforeachphase+Discharge device
18
General DesignRules
18
Component Selection guideCapacitors
18
Offer Overview VarplusBox
VarplusBoxcapacitorsdeliverreliableperformanceinthemostsevereapplicationconditions,inFixed&AutomaticPFCsystems,innetworkswithfrequentlyswitchedloadsandharmonicdisturbances.
Robustness Doublemetallicprotection. Mechanicallywellsuitedfor“stand-alone”installations.
Safety Itsuniquesafetyfeatureelectricallydisconnectsthecapacitors
safelyattheendoftheirusefullife. Thedisconnectorsareinstalledoneachphase,whichmakes
thecapacitorsverysafe,inadditiontotheprotectivesteelenclosure.
Flexibility Thesecapacitorscanbeeasilymountedinsidepanelsorina
standaloneconfiguration. Suitableforflexiblebankconfiguration.
Features Metalboxenclosure. Highpowerratingsupto100kvar. Easyrepairandmaintenance. Upto70°Ctemperature. Highinrushcurrentwithstandupto400xIN. Stand-alonePFCequipment. Directconnectiontoamachine,inharshenvironmental
conditions.VarplusBox
PE90135
PE90164
PE90137
PE90135
SDuty HDuty Energy
Construction Steelsheetenclosure
Voltage range 380 V - 480 V 230 V - 830 V 380 V - 525 VPower range 7.5-100kvar 2.5-100kvar 7.5-100kvar(three-phase) Peak inrush Upto200xIN Upto250xIN Upto350xIN current Over voltage 1.1xUN 8hevery24hOver current 1.5xIN 1.8xIN 2.5xINMean life Upto100,000h Upto130,000h Upto160,000hexpectancySafety Self-healing+pressure-sensitivedisconnector +dischargedevice(50V/1min)Dielectric Metallized Metallized Doublemetallized Polypropylenefilm Polypropylenefilm paper+ withZn/Alalloy withZn/Alalloy Polypropylenefilm withspecialprofile metallizationand wavecutImpregnation Non-PCB, Non-PCB,sticky Non-PCB,oil Biodegradable (dry)Biodegradable resin resin Ambient min-25°Cto min-25°Ctotemperature max55°C max70°CProtection IP20IndoorMounting Upright Upright,Horizontal UprightTerminals Terminalsdesignedforlargecableterminationand directbusbarmountingforbanking
19
General DesignRules
19
Component Selection guideCapacitors
19
VarplusBoxTechnical Specifications
General characteristics
Standards IEC60831-1/-2Frequency 50/60HzLosses (dielectric) <0.2W/kvarLosses (total) <0.5W/kvarCapacitance tolerance -5%,+10%Voltage Betweenterminals 2.15xUN(AC),10stest Betweenterminal < 660V-3kV(AC),10s &Container >660V-6kV(AC).10sDischarge resistor Fitted,standarddischargetime60s Dischargetime180sonrequest
Working Conditions Humidity 95% Altitude 2.000mabovesealevel Over voltage 1.1xUN8hinevery24hSwitching SDuty Upto5,000switchingoperationsperyearOperations HDuty Upto7,000switchingoperationsperyear Energy Upto10,000switchingoperationsperyearMean Life expectancy Upto1,60,000hrsHarmonic SDuty NLL <10% Content HDuty NLL <20% Energy NLL <25%
Installation characteristics
Mounting SDuty Indoor,Upright position HDuty Indoor,Upright&horizontal Energy Indoor,UprightFastening & Earthing ThreadedM6mountingscrewsatthe bottom
Safety Features
Safety Self-healing+Pressure-sensitive disconnectorforeachphase+Discharge device
20
General DesignRules
20
Component Selection guideCapacitors
20
Customer needsBelowtabledescribestypicalsolutionsusedinseveraltypesofactivities.
Notadapted Usually(70%) Possibly(20%) Rarely(10%)
Inanycase,itisrecommendedtomakemeasurementsatsiteinordertovalidatethefinalsolution.
SDuty HDuty (upto20%) Hduty/Energy Energy (upto25%) + Detuned ReactorGh/Sn ≤ 15 % 15% < Gh/Sn ≤ 25% 25% < Gh/Sn ≤ 50%Pollution rate
IndustryFood&BeverageTextileWoodPaper - PrintingChemical-PharmacyPlasticGlass-CeramicSteel-MetallurgyAutomotiveCement-MinesRefineryMicro-electronics
TertiarySupermarketsHospitalsStadium-AmusementparkHotels-Offices-Bank-Insurance
Energy & InfrastructuresWaterInternetfarmWindmillsRailways-SubwaysAirportsHarboursTunnels
Choice of compensation
21
General DesignRules
21
Component Selection guideCapacitors
21
Pressure Sensitive Disconnector (PSD)
PressureSensitiveDisconnector(alsocalled‘tear-offfuse’):thisisprovidedineachphaseofthecapacitorandenablessafedisconnectionandelectricalisolationattheendofthelifeofthecapacitor.
Malfunctionwillcauserisingpressureinsidethecan.Pressurecanonlyleadtoverticalexpansionbybendinglidoutwards.Connectingwiresbreakatintendedspots.Capacitorisdisconnectedirreversibly.
Self HealingAnelectricbreakdownispossibleinthecapacitorfilmsduetoelectricormechanicaloverstress.Duetothisasmallareaofmetallizationwillgetevaporatedandthecapacitorwillcontinuetobeinservice.Continuationofthesephenomenawillreducethecapacitancevalueaswellaslifeofthecapacitoroveraperiodoftime.
Self-healingisaprocessbywhichthecapacitorrestoresitselfintheeventofafaultinthedielectricwhichcanhappenduringhighoverloads,voltagetransientsetc.
Wheninsulationbreaksdown,ashortdurationarcisformed(figure1).
Theintenseheatgeneratedbythisarccausesthemetallizationinthevicinityofthearctovaporise(figure2).
Simultaneouslyitre-insulatestheelectrodesandmaintainstheoperationandintegrityofthecapacitor(figure3).
Discharge ResistorsAchargedCapacitormustbedischargedbeforere-switching,topreventprematurefailure.Built-indischargeresistorsareusedfordischargingthecapacitorwithadelayofoneminuteasdischargetime.
Caution! Do not touch the Capacitor Terminals before Discharging.
Safety Features in VarplusCan and VarplusBox
DB
4032
84
TD
B40
3285
T+12
+2
Figure 3
Figure 2
Figure 1 - (a) Metal layer - (b) Polypropylene film
(a) (b)
22
General DesignRules
22
General DesignRules
22
Component Selection guideDetuned Reactors
22
ReactorshavetobeassociatedtocapacitorbanksforPowerFactorCorrectioninsystemswithsignificantnon-linearloads,generatingharmonics.
Capacitorsandreactorsareconfiguredinaseriesresonantcircuit,tunedsothattheseriesresonantfrequencyisbelowthelowestharmonicfrequencypresentinthesystem.Forthisreason,thisconfigurationisusuallycalled“DetunedCapacitorBank”,andthereactorsreferredas“DetunedReactors”.
Theuseofdetunedreactorsthuspreventsharmonicresonanceproblems,avoidstheriskofoverloadingthecapacitorsandcontributestoreducingvoltageharmonicdistortioninthenetwork.
Thetuningfrequencycanbeexpressedbytherelativeimpedanceofthereactor(in%),orbythetuningorder,ordirectlyinHz.
Themostcommonvaluesofrelativeimpedanceare5.7,7and14%.(14%isusedwithhighlevelof3rdharmonicvoltages).
Theselectionofthetuningfrequencyofthereactorcapacitordependsonmultiplefactors:
Presenceofzero-sequenceharmonics(3,9,…), Needforreductionoftheharmonicdistortionlevel, Optimizationofthecapacitorandreactorcomponents. Frequencyofripplecontrolsystemifany.
Topreventdisturbancesoftheremotecontrolinstallation,thetuningfrequencyistobeselectedatalowervaluethantheripplecontrolfrequency.
Inadetunedfilterapplication,thevoltageacrossthecapacitorsishigherthanthenominalsystemvoltage.Then,capacitorsmustbedesignedtowithstandhighervoltages.
Dependingontheselectedtuningfrequency,partoftheharmoniccurrentsisabsorbedbythedetunedcapacitorbank.Then,capacitorsmustbedesignedtowithstandhighercurrents,combiningfundamentalandharmoniccurrents.
Detuned Reactors Overview
Relative Tuning order Tuning frequency Tuning frequency impedance (%) @50Hz (Hz) @60Hz (Hz)
5.7 4.2 210 250
7 3.8 190 230
14 2.7 135 160
23
General DesignRules
23
General DesignRules
23
Component Selection guideDetuned Reactors
23
Working limits Inordertoavoidanyoverloadofdetunedreactorsandcapacitors,maximumvaluesofvoltagedistortionhavetoberespected.HarmonicvoltagesandTHDuhavetobemeasuredatthetransformersecondary,withthecapacitorsconnected.Thecurrentthroughthecapacitorshastobecomparedtotheratedvalue.
Imp/INistheratioofthemaximumpermissiblecurrenttotheratedcurrentofthecapacitor.
Theproposedlimitsareonlyindicative.Inanycase,ifyouhaveadoubtorifvaluesarehigherthantheabovelimits,contactus.
Working THDu Harmonic Voltage Imp / IN limits max. % of the order max
3 5 7 11 13SDuty 5 1.5Hduty 7 1.8Harmonic 10 3 8 7 3.5 3 1.12(14%relativeimpedance)Harmonic 8 0.5 6 5 3.5 3 1.19(7%relativeimpedance)Harmonic 6 0.5 5 4 3.5 3 1.31(5.7%relativeimpedance)
24
General DesignRules
24
General DesignRules
24
Component Selection guideDetuned Reactors
24
480 830 480 575 690
CapacitorRatedVoltage(UN)V NetworkServiceVoltage(US)V
50Hz 60Hz
400 690 400 480 600RelativeImpedance(%) 5.7% 7% 14% 480 480
VarplusCanandVarplusBoxcapacitorswhenusedalongwithDetunedReactorshavetobeselectedwitharatedvoltagehigherthannetworkservicevoltage(US).
Therecommendedratedvoltageofcapacitorstobeusedindetunedfilterapplicationswithrespecttodifferentnetworkservicevoltage(US)andrelativeimpedanceisgiveninthetablebelow.Thesevaluesensureasafeoperationinthemoststringentoperatingconditions.
Lessconservativevaluesmaybeadopted,butacasebycaseanalysisisnecessary.
Example of Capacitor Selection with a Detuned Reactor Case:Fora400V50Hzsystem,ItisrequiredtoconnectaVarplusCanHDutyof25kvarreactivepowerwithadetunedreactorwith7%relativeimpedanceP(Tuningfactor=3.8).QS=25kvar,US=400V,P=0.07
Step 1: calculationofthecapacitorratedvoltageThevoltageappliedtothecapacitorisgivenbytheformula:UC=US/(1–P)UC=400/(1-0.07)=430.1V
TheCapacitorwillbechoosenwithUN=480V.(LessStringentvaluescanbeadoptedbasedonthenetworkconditions)
Step 2: calculationofthecapacitorreactivepowerThereactivepowerQCofthecapacitor(withUCapplied)isgivenbytheformula:
QC=QS/(1-P)@UC
QC=25/(1-0.07)=26.88kvar@UC
ThecapacitorkvarratingatUNwillbe:QN=QC*(UN/UC)
2
QN=26.88*(480/430)2=33.5kvar
TheCapacitorwillbechoosenfor33.5kvarat480Vfordelivering25kvarwitha7%reactorina400V50Hzsystem.UseReferencenumberBLRCH339A407B48
CombinationofCapacitorwithPartnumberBLRCH339A407B48 andDetunedReactorwithpartnumber52405willgive25kvaratPointB(ReferPictureabove)
Refertothepictureaboveandconsiderthefollowing:Us: systemvoltage(V),QS: requestedreactivepower(kvar)UN: capacitorratedvoltage(V)QN: capacitorratedpower(kvar)
Load
Supply network
US, QS
A
UN, QN
B
C
Capacitors rated voltage with Detuned Reactor
25
General DesignRules
25
General DesignRules
25
Component Selection guideDetuned Reactors
25
Technical dataChoiceoftuning:ThetuningfrequencyfrcorrespondstotheresonancefrequencyoftheL-Cassembly.
Wealsospeakoftuningordern.Fora50Hznetwork:
Thetuningfrequencychosenmustensurethattheharmoniccurrentspectrumrangeisoutsidetheresonancefrequency.Itisessentialtoensurethatnoremotecontrolfrequenciesaredisturbed.
Themostcommontuningordersare3.8or4.3(2.7isusedfor3rd orderharmonics).
fr=1
———2 π √LC
n=fr
———50Hz
Curve:impedancemoduleatpointA
DB
1214
12D
B12
1411
D
B12
1408
GeneralThedetunedreactors(DR)aredesignedtoprotectthecapacitorsbypreventingamplificationoftheharmonicspresentonthenetwork.Theymustbeconnectedinserieswiththecapacitors.Thedetunedreactorsgenerateanovervoltageatthecapacitorterminals.Theratedvoltageofcapacitorshastobeincreasedaccordingly.
The tuning factor (P) Thetuningfactor(P)istheratioofInductorImpedancetothecapacitorImpedance
Choice of detuned reactor tuning frequency
XLfr=——=(2πf)2 LC=(2π√LC)2 f 2
XC
f
2
P=—— fr
2
ffr=—— √P
26
General DesignRules
26
General DesignRules
26
Component Selection guideDetuned Reactors
26
Offer OverviewDetuned reactors
Thedetunedreactors(DR)aredesignedtoprotectthecapacitorsbypreventingamplificationoftheharmonicspresentonthenetwork.
PE90154
Operating conditions Use:indoor Storagetemperature:-40°C,+60°C Relativehumidityinoperation:20-80% Saltspraywithstand:250hours(for400V-50Hzrange). Operatingtemperature
Technical specifications
Maximum Permanent Current (IMP) Let’sdefinetheservicecurrent(IS)asthecurrentabsorbedbythecapacitoranddetunedreactorassembly,whenapurelysinusoidalvoltageisapplied,equaltothenetworkservicevoltage(US).IS=Q(kvar)/(√3xUS)
Inordertooperatesafelyinrealconditions,adetunedreactormustbedesignedtoacceptamaximumpermanentcurrent(IMP)takingaccountofharmoniccurrentsandvoltagefluctuations.
Thefollowingtablegivesthetypicalpercentageofharmoniccurrentsconsideredforthedifferenttuningorders.
General characteristicsDescription Three-phase,dry,magneticcircuit, impregnatedDegreeofprotection IP00Insulationclass HRatedvoltage 400to690V-50Hz 400to600V-60Hz OthervoltagesonrequestInductancetoleranceperphase -5,+5%Insulationlevel 1.1kVDielectrictest50/60Hzbetween 4kV,1minwindingsandwindings/earthThermalprotection Restoredonterminalblock250VAC,2A
Altitude Minimum Maximum Highest average over any period of:(m) (°C) (°C) 1year 24hours
1000 0 55 40 50
>1000, 0 50 35 45 ≤ 2000
(%) Harmonic currentsTuningorder i3 i5 i7 i11
2.7 5 15 5 23.8 3 40 12 54.2 2 63 17 5
Tuning order IMP (times IS)
2.7 1.123.8 1.24.2 1.3
A1.1factorisappliedinordertoallowlong-termoperationatasupplyvoltageupto(1.1xUS).Theresultingmaximumpermanentcurrent(IMP)isgiveninthefollowingtable:
27
General DesignRules
27
General DesignRules
27
Component Selection guideDetuned Reactors
27
Installation Forcedventilationrequired Verticaldetunedreactorwindingforbetterheatdissipation Electricalconnection:> toascrewterminalblockfor6.25and12.5kvardetuned
reactors> toadrilledpadfor25,50and100kvardetunedreactors
Note:As the detuned reactor is fitted with thermal protection, it is imperative that the normally closed dry contact be used to disconnect the step in the event of overheating (see drawing at left).
Normallycloseddrycontact
DB
1141
56
Component Selection guideContactors
2828282828
Offer OverviewTeSys D Contactors
GeneralCapacitorcontrolisaccompaniedbytransientoperatingconditionsresultingfromthecapacitorloadwhich,amongstotherthings,generatesaveryhighovercurrentequivalenttoashort-circuitofshortduration.
Theuseofstandardcontactorsmaycompromisethesafetyofpersonsandinstallations.
TeSys D contactors for capacitor controlTheLC1-D•Kcontactorsarespeciallydesignedforcapacitorcontrol.Theyarefittedwithacontactblockallowingthecurrenttopassonclosingandwithdampingresistorslimitingthecurrentonenergisation.(Seepageno.30)
Personal safety Thecontactorscannotbeoperatedmanually. Thecontactorsarefittedwithcoversforprotectionagainstdirect
contact.
Safety of installationsThedampingresistorsaredisconnectedafterthecapacitorcurrentenergisingpeak.Afaultycontactorpolethereforedoesnotallowthepermanentcurrenttoflowthroughtheresistorandpreventsitfromburning.
Simplicity and durabilityLC1-D•Kcontactorsareaready-to-usesolutionthatdoesnotrequiretheinstallationofshockcoils.Theirdurabilityisfargreaterthanthatofconventionalsolutions(300,000operatingcyclesat400V).
CautionIfspecificcontactorscannotbeusedtocontrolthecapacitors,thenenergisingcurrentlimitingreactorsmustbeused.Pleaseconsultthecontactormanufacturer.
Note: LC1D contactors not incorporating damping resistor can be used with detuned reactors. The inductance of the detuned reactor limits the energising current to a value that can be accepted by the contactor.
DB109701
EffectinNetworkvoltage,CapacitorcurrentandCapacitorvoltagewithoutusinginrushcurrentlimiters
Component Selection guideContactors
2929292929
The power values in the above table are valid for the following conditions: Prospectivepeakenergisingcurrent LC1-D•K 200IN Maximumoperatingrate LC1-DFK/DGK/DLK/DMK/DPK 240operatingcycles/hour LC1-DTK/DWK 100operatingcycles/hour 400V 3,00,000operatingcycles 690V 2,00,000operatingcycles
Power ratings Instantaneous auxiliary Tightening torque Basic reference no. to which Weighttemp. ≤ 55 °C contacts on end-piece the control voltage reference no. (Kg) should be added (2)
220 V 400 V 660 V240V 440V 690Vkvar kvar kvar «F» «O» Nm6.5 12.5 18 1 1 1.2 LC1-DFK11•• 0.43 2 1.2 LC1-DFK02•• 0.436.5 15 24 1 1 1.7 LC1-DGK11•• 0.45 2 1.7 LC1-DGK02•• 0.4510 20 30 1 1 1.9 LC1-DLK11•• 0.6 2 1.9 LC1-DLK02•• 0.615 25 36 1 1 2.5 LC1-DMK11•• 0.63 2 2.5 LC1-DMK02•• 0.6320 30 48 1 2 5 LC1-DPK12•• 1.325 40 58 1 2 5 LC1-DTK12•• 1.340 60 92 1 2 9 LC1-DWK12•• 1.65
References and maximum power ratings
Tension (V) 110 220 230 240 380 400 415
50/60Hz F7 M7 P7 U7 Q7 V7 N7
Othervoltages:Contactus.
Electricaldurabilityatnominalload Allcontactorratings
(2) Control circuit voltage (••):
3030303030
Component Selection guideSwitching and protection devices
30
Atcapacitorswitchingwhileoneormorecapacitorsareconnectedtothesystem,theswitchingcapacitorwillseeahighinrushcurrent.Thisisduetothecurrentflowfromthealreadyconnectedcapacitor(s)(whichwillactasasource)throughtheleastimpedancepathsetbytheswitchedcapacitoralongwiththecurrentfromthemainsource.Thismeansthatwhenthenumberofcapacitorsinparallelincreases,theamountofinrushcurrentalsoincreases.Inrushcurrentwilldamagethecapacitoraswellastheswitchingdevice.
Inordertopreventinrushcurrent,itisrequiredtousecurrentlimitingdevicessuchasCapacitorDutyContactorsorInductorCoil.Pictorialillustrationoftheconventionalswitchingandswitchingusingaspecialcapacitordutycontactorisshownintheleft.
Conventionalsinglestagecapacitorswitching
Conventional SwitchingContactor
Power supply
Capacitors
Before Switching
Conventional SwitchingContactor
Power supply
Capacitor
After Switching
Inrush
Conventionalmultistagecapacitorswitchingwithnormalpowercontactor
Conventional SwitchingContactor
Power supply
Capacitors already on
Capacitors to be switched
on
Conventional SwitchingContactor
Power supply
Capacitors already on
Capacitors switched on
Before Switching After Switching
Inrush
MultiStageCapacitorSwitchingwithCapacitorDutyContactorStage1-Capacitorisswitchedthroughainrushcurrentlimiter
CapacitorSwitchingContactor
Power supply
Capacitors already on
Capacitors to be switched
on
Before Switching After Switching Stage 1
CapacitorSwitchingContactor
Power supply
Capacitors already on
Capacitor switched on
Limited Inrush
Stage2-CapacitorisswitchedthroughContactorandinrushcurrentlimiterStage3-inrushcurrentlimiterisremovedfromthecircuitandCapacitoriscompletelyswitchedon
After Switching Stage 2 After Switching Stage 3
CapacitorSwitchingContactor
Power supply
Capacitors already on
Capacitors switched on
CapacitorSwitchingContactor
Power supply
Capacitors already on
Capacitors switched on
Limited Inrush Normal Current
Parallel operation of capacitor and inrush current limiting capacitors in APFC panels
313131
Component Selection guideSwitching and protection devices
313131
Useswitchingandprotectiondevicesdesignedforcapacitorswitchingduty.
Afterswitchingoffacapacitor,adelayofatleast1minutemustbeallowedbeforeswitchingonagaintoensurethedischargeofindividualcapacitorstep/unitbeforereconnection.SolidStateswitching(ThyristorSwitches)canbeusedwhenfastswitchinginAPFCPanelsisneeded.
Short Circuit Protection Device MCCBorHRCfusesareusedwiththecapacitorforShortCircuitProtection.Thishastoberatedfor1.5timestheratedcurrentofthecapacitor.ItisrecommendedtoUseCompactNSX/CVSrangeofMCCBs.
ContactorsContactorsshallbeusedtoswitchcapacitorsinoroutofserviceofeachindividualstep.Thecontactorsshallpreventinrushcurrenttoasafelevelwhenthecapacitorstepsareswitchedon.
Therearetwotypesofcontactorsusedforswitchingeachstep:
CapacitorDutyContactor PowerContactor
CapacitordutycontactorsarerecommendedinAPFCequipmenttominimizeinrushcurrentsexperiencedduringtheswitchingofcapacitors.Thesecontactorshavespecialearlymakecontactswithseriesresistanceswhichdampenstheinrushcurrents.However,whennormalPowercontactorsareused,andwhentherearenoreactorsinseries,asuitableinductorcoilhastobeconnectedinserieswiththecontactorforlimitingtheinrushcurrents.
Contactorswillhavetobechosenwithcare,keepinginmindthefollowingfactorswhichcaninfluencetheirperformance:
Contactorshallbere-strikefreeandadaptedforcapacitors Theratedvoltageofthecontactorshallbeequaltoorhigher
thanthemaximumnetworkvoltagewiththepowerfactorcorrectioninstallation.
Thecontactorshallbedesignedforcontinuouscurrent(includingharmonics)whichcanpassthepowerfactorcorrectioninstallationand/orfilteratmaximumsourcevoltage,maximumfrequencyandextremetolerancesofthecomponents,especiallycapacitorsandreactors.
CapacitordutycontactorsareratedbasedonnominalreactivepowerandPowercontactorsareratedbasedontheratedoperationalcurrent.
ItisrecommendedtouseSpecialContactorsLC1D.Kwhicharedesignedforswitching3phaseSingleorMultiplestepCapacitorBanks.
Capacitordutycontactorsarenormallyratedupto60kvar.Whenhigherratedstepsexistsuchas75kvar,100kvarandabove,thefollowingmethodscanbeadopted.
Selection of Capacitor Switching and Protection Devices
3232323232
Component Selection guideSwitching and protection devices
32
Method 1:forstepsupto120kvar
CapacitorDutyContactorscanbeusedinparalleltoswitchtheSteps.
Example:
Toswitch100kvarstep,usingcapacitordutycontactor,therearetwoalternatives.
Providetwostepsof50kvareach,(having50kvarswitch,and50kvarreactorand50kvarcapacitors)andtheconnectionofrelayinsuchawaytooperatebothtogether.(referFigA)
Providesinglestepusingtwocapacitordutycontactorsinparallelwithone100kvarreactorandone100kvarcapacitor(4x25kvar/2x50kvar)(referFigB)
InoptionB,ifonecontactormalfunctions,theothercontactorgetsoverloadedandthereispossibilityfordamageinsecondcontactoralso.Howeverifbothcontactorsareingoodconditionsandoperateexactlyatthesamemoment,theoreticallytherewillbenoproblem.Butthecontactorswitchingmaynotoccurexactlyatthesametime,andaverysmalltimedifferencemaycauseoverloadingofcontactors.
Method 2:forstepsmorethan120kvar
ContactorsofAC3Dutycanbeusedinthiscasebutcapacitorsneedtobeputinserieswithinductorcoil.
Example:Toswitch120kvarstep,usingAC3Dutycontactor,providefourstepsof30kvarVarplusCancapacitorconnectedtoainductorcoilinseries.(seeFigC).
K1 KN
S/P
Capacitors
APFCRelay
FigA
K1 KN
S/P
Capacitors
APFCRelay
FigB
K1
IC
S/P
Capacitors
APFCRelay
FigC
Component Selection guidePF Controller
33
PFcontrollersaremicroprocessorbased,whichtakesrealtimeinputsfromthenetwork,calculatethekvarrequiredandswitchon/offcapacitors.ThemicroprocessoranalyzesthecurrentinputsignalfromtheloadcurrenttransformerandtheVoltagetappedfromtheBustoproduceswitchingcommandstocontrolthecontactorON/OFFofthecapacitorsteps.IntelligentcontrolbyPFCcontrollersensuresanevenutilizationofcapacitorsteps,minimizednumberofswitchingoperationsandoptimizedlifecycle.
FeasibilityforFourquadrantoperationforsensingtheenergyflowdirectionbecomesnecessaryforcertainapplicationsbasedonsystemconditions.
Thecontrollerplacedinsidethepanelshallhavethereliabilitytowithstandtheoperatingtemperatureofatleast50°Cormore.
C/k setting:C/kvalueisusedinthesettingofoldgenerationPowerFactorControllers,howeveritisfoundrarelytobeusedinpanelsnow.
C/kvalueisathresholdvalueforswitchingOn/Offthecapacitorstepsbythecontroller.C/kisthevalueobtainedbydividingfirststepcapacitorpower“Q”tothecurrenttransformerratio”K”.Thissettingshallbeautomaticorcanbesetmanually.
ThemainfeaturesofthePFcontrollermustincludethefollowing:
AutomaticC/k-valuesetting,Connectionofdifferentcapacitorsteps.
Automaticdetectionandusageofoptimumcapacitorsteps. Currentmeasuring10mA-5A,suitableforconnectingCTx/1A
andx/5A. Programmablecapacitorswitchingdelay Indicationforovercurrent Indicationforlowpowerfactor Fancontact
ModerndayAPFCcontrollersprovidevariousadditionalfunctionslikeelectricaldatalogging,selfdiagnosticsandsystemhealthfeaturesandarecapableofcommunicationusingstandardprotocols.Additionalfeaturescanbechosenbasedonspecificrequirementsofenduserwhichareasfollows:
FourQuadrantoperation Automaticphasereversalcorrection Variousautomatictripconditionscanbeprogrammed–over
current,overvoltage Singlephasemeasurement VariousmeteringparameterslikeV,I,THD-V,Hz,kvar,temp,
PFetc.,
Power Factor Controller
Component Selection guidePF Controller
34
General data operatingtemperature:0…60°C storagetemperature:-20°C…60°C colour:RAL7016 standard: EMC:IEC61326 electrical:IEC/EN61010-1.
panelmounting mountingon35mmDINrail(EN50022) protectionclassinpanelmounting: frontface:IP41 rearface:IP20.
display NR6,NR12type:backlightedscreen65x21mm NRC12type:backlightedgraphicscreen55x28mm. languages:English,French,German,Portuguese,Spanish
alarmcontact temperatureinternalprobe separatecontacttocontrolfaninsidethepowerfactorcorrectionbank accesstothehistoryofalarm.
Inputs phasetophaseorphasetoneutralconnection insensitivetoCTpolarity insensitivetophaserotationpolarity currentinput: NR6,NR12type:CT…X/5A NRC12type:CT…X/5AetX/1A.
Outputs potentialfreeoutputcontacts: AC:1A/400V,2A/250V,5A/120V DC:0,3A/110V,0,6A/60V,2A/24V.
Settings and parameters targetcosφsetting:0.85ind…0.9cap possibilityofadualcosφtarget(typeNRC12) manualorautomaticparametersettingofthepowerfactorcontroller choiceofdifferentsteppingprograms: linear normal circular optimal.
mainstepsequences: 1.1.1.1.1.1 1.2.3.3.3.3 1.2.2.2.2.2 1.2.4.4.4.4 1.2.3.4.4.4 1.1.2.3.3.3 1.1.2.2.2.2 1.2.4.8.8.8
personalizedsequencesforNRC12type delaybetween2successiveswitchonofasamestep: NR6,NR12type:10…600s NRC12type:10…900s stepconfigurationprogramming(fixed/auto/disconnected)(NRC12type) 4quadrantoperationforgeneratorapplication(NRC12type) manualcontrolforoperatingtest.
Offer overview - Varlogic N power factor controller
Varlogic NR6/NR12
Varlogic NRC12
PE90161
PE90156
Technical data
Type Number of step output contacts Part numberNR6 6 52448NR12 12 52449NRC12 12 52450RT6 6 51207RT8 8 OnrequestRT12 12 OnrequestAccessoriesCommunicationRS485ModbussetforNRC12 52451TemperatureexternalprobeforNRC12typeinaddition 52452tointernalprobeallowsmeasurementatthehottestpointinsidethecapacitork52
Range
PE
9015
5.ep
s
Component Selection guidePF Controller
35
Varlogic - Technical characteristics
General characteristics
Output relays AC 5A/120V 2A/250V 1A/400V DC 0.3A/110V 0.6A/60V 2A/24VProtection Index Frontpanel IP41 Rear IP20Measuringcurrent 0to5ASpecific features RT6 NR-6/12 NRC12Numberofsteps 6 6/12 12Supplyvoltage(VAC) 88to130 88to13050/60Hz 185to265 185to265 185to265 320to460 320to460 320to460Display4digit7segmentLEDs 65x21mmbacklitscreen 55x28mmbacklitscreen Dimensions 143x143x67 155x158x70 155x158x80Flushpanelmounting 35mmDINrailmounting (EN50022)Operatingtemperature 0°C-55°C 0°C-60°C 0°C-60°CAlarmcontactInternaltemperatureprobeSeparatefanrelaycontactAlarmhistory Last5alarms Last5alarmsType of connectionPhase-to-neutral Phase-to-phase Current inputCT…10000/5A CT25/5A…6000/5A CT25/1A…6000/5A Target cosφ setting0.85ind.…1 0.85ind.…0.9cap. Possibilityofadualcosφ target Accuracy ±2% ±5% ±2%Responsedelaytime 10to1800s 10to120s 10to180sReconnection delay time 10to1800s 10to600s 10to900s 4-quadrantoperationforgeneratorapplication Communicationprotocol Modbus
Component Selection guidePF Controller
36
TheVarlogicpowerfactorcontrollerscontinuallymeasurethereactivepowerofthesystemandswitchthecapacitorstepsONandOFFtoobtaintherequiredpowerfactor.Theirtenstepcombinationsenablethemtocontrolcapacitorsofdifferentpowers.
Step combinations1.1.1.1.1.11.2.3.3.3.31.1.2.2.2.21.2.3.4.4.41.1.2.3.3.31.2.3.6.6.61.1.2.4.4.41.2.4.4.4.41.2.2.2.2.21.2.4.8.8.8
Thesecombinationsensureaccuratecontrolbyreducing
thenumberofpowerfactorcorrectionmodules reduceworkmanshipforpanelassembly
Optimisingthecontrolinthiswaygeneratesconsiderablefinancialbenefits.
ExplanationsQ1=PowerofthefirststepQ2=Powerofthesecondstep- - - - - - - - - - - - - - - - - - - - Qn=Powerofthenthstep(maximum12)
Examples:
1.1.1.1.1.1: Q2=Q1,Q3=Q1,…,Qn=Q11.1.2.2.2.2: Q2=Q1,Q3=2Q1,Q4=2Q1,…,Qn=2Q11.2.3.4.4.4: Q2=2Q1,Q3=3Q1,Q4=4Q1,…,Qn=4Q11.2.4.8.8.8: Q2=2Q1,Q3=4Q1,Q4=8Q1,…,Qn=8Q1
Calculatingthenumberofelectricalstepsdependson:
thenumberofcontrolleroutputsused(e.g.7) thechosencombination,accordingtothepowerofthevarioussteps(e.g.1.2.2.2).
Physical and Electrical Control of PFC Relay
Combinations Number of controller outputs used 1 2 3 4 5 6 7 8 9 10 11 121.1.1.1.1.1… 1 2 3 4 5 6 7 8 9 10 11 121.1.2.2.2.2… 1 2 4 6 8 10 12 14 16 18 20 221.2.2.2.2.2… 1 3 5 7 9 11 13 15 17 19 21 231.1.2.3.3.3… 1 2 4 7 10 13 16 19 22 25 28 311.2.3.3.3.3… 1 3 6 9 12 15 18 21 24 27 30 331.1.2.4.4.4… 1 2 4 8 12 16 20 24 28 32 36 401.2.3.4.4.4… 1 3 6 10 14 18 22 26 30 34 38 421.2.4.4.4.4… 1 3 7 11 15 19 23 27 31 35 39 431.2.3.6.6.6… 1 3 6 12 18 24 30 36 42 48 54 601.2.4.8.8.8… 1 3 7 15 23 31 39 47 55 63 71 79
Component Selection guidePF Controller
37
PracticalExample:
ConsideranAPFCSystemof250kvar
Solution 1: Electrical control 10 x 25 kvar25+25+25+25+25+25+25+25+25+25;sequence:1.1.1.1.1.110physicalsteps10contactors–ReferContactorSelection12-stepcontroller–(Varlogic–NR12)ReferPFCrelays-VarlogicSelectionCapacitors-VarplusCan–10x25kvar
ConclusionHighLabor,highcost:non-optimisedsolution.PossiblePowerlevels(kvar):25,50,75,100,125,150,175,200, 225,250
Solution 2: Electrical control 10 x 25 kvar25+50+75+100=10x25kvarelectrical;sequence:1.2.3.4:44physicalstepsallowingfor10differentpowerlevels4contactors(refercontactorselection)6-stepcontroller(VarlogicNR6-referPFCrelays-Varlogicselection)Capacitors-VarplusCan-2x25kvar+2x50kvar+1x100kvar
ConclusionOptimisedSolution.Optimisationofcompensationcubicle-Possiblepowerlevels(kvar)Thesymbol“”showsthephysicalstepisOnforobtainingthePossiblepowerlevels.
Possible power levels (kvar) Physical Steps 25 50 75 10025
50
75
100
125
150
175
200
225
250
Component Selection guideCT and Protection Devices
38
Current Transformer
Currenttransformer(CT)isusedinAPFCpanelsformeasurementpurposes.Itstepsdownloadcurrenttoalowvalue(5A)output.TheVAratingofCTshallbe5VAor10VAasthemaximum.
The following aspects shall be considered while selecting CTs:
ResinCastCTsorMouldedcaseCTsaresealedunitsandhavebetterlifethantheordinarytapeinsulatedCTs.MouldedcaseCTsareusuallypreferredforlowercurrentratingsandresincastforhigherratings.
PrimarycurrentoftheCThastobeselectedbasedonthetotalkvarofthepanel.
SinceCTsandrelaysareprovidedinthesamepanel,theleadwirelengthwillbeveryshortandhenceuseof5Asecondaryispreferred.
Ammeteristheonlyloadandconsideringshortdistanceofwires,5to10VAisselectedasamaximumburden.
ItisrecommendedtouseClass1CTsforCommercialmeasurements
Current Transformer- Installation recommendations currenttransformermustbeinstalledupstreamoftheinstallation
tobecompensated thecontrollervoltageshouldbesetbetweenL2andL3andthe
CTtophaseL1 thecapacitorbankwiringdiagramshouldbedesignedtoensure
thatthetimerequiredtodischargethecapacitorsisobserved(minimum1minute),forexampleintheeventofalossofcontactorauxiliaryvoltage
iftheinstallationcomprisestwoormoresupplytransformers,asummingCTthatwilltakealltheenergyconsumedbytheinstallationintoaccountmustbeprovided.TheratiotobeusedtocalculatetheC/kisthesumoftheratiosofthevariousmeasuringCTs
iftheinstallationincludesageneratorset,acontactwilldisconnectthecapacitorbankintheeventofgeneratorsetoperation.Thebestmethodinthiscaseistouseittocutoffthesupplytothecontroller
DB
1214
45D
B12
1443
DB
1214
46D
B12
1444
CTA
CTC CTD
CTB
CTFCTE
Where to connect CT
How to connect Controller
Connecting controller when summing CT is used
Connecting CTs when more than one supply Transformer is used
Component Selection guideCT and Protection Devices
39
ThefollowingaretheprotectionschemesprovidedforAPFCpanels:
Over voltageIntheeventofanovervoltage,electricalstressonthecapacitordielectricandthecurrentdrawnbythecapacitorswillincrease.TheAPFCequipmentmustbeswitchedoffintheeventofovervoltagewithsuitableovervoltagerelay.
Under voltageIntheeventofundervoltage,electricalstressonthecapacitordielectricandthecurrentdrawnbythecapacitorswilldecrease.Thisconditionisnotharmful.Butprotectionisprovidedbasedoncustomerrequesttoprotectsystemfromundervoltage.
Over Current Overcurrentconditionisveryharmfultoallcurrentcarryingcomponents.Alltheswitchgearsareselectedonahighermaximumcurrentcarryingcapacity.Howeversuitableovercurrentrelayswithalarmcanbeusedforovercurrentprotection.
Short circuit protectionAttheincomerlevelshortcircuitprotectionisprovidedbydevicessuchasMCCB,ACBandSFUsuitably.Atthestepprotectionlevel,suitablefuses,MCB,MCCBcanbeused.
Thermal OverloadItistakencarebythermaloverloadrelay.TheAPFCcontrollermustbetrippedincaseswhereinternalambienttemperatureexceedsthelimits.Reactorsarealsoprovidedwiththermalswitches,totripinthecaseoftemperatureincrease.
EarthingTwoearthingpointsareprovidedintheAPFCpanelforconnectingtotheearthbus.Thiswillensuretheoverallsafetyofoperatingpersonnelandequipmentprotectionincaseofearthfaults.
Earth Leakage RelayIthastobeconnectedatpowerincomingsideofthepanel,Earthleakagerelayisprovidedtosafeguardtheoperatorbytrippingtheincomer.
TimersCapacitorsrequireaminimumdischargetimeofapproximately60secondsaftertheyareswitchedoffbeforetheycanbeswitchedonagain.ThisistobesetintheAPFCcontroller.Capacitorsareprovidedwithdischargeresistors.
Protection Devices inAPFC Panel
Component Selection guideCT and Protection Devices
40
MainincomerisusedtodisconnecttheAPFCsystemincaseofshortcircuit,overloadandearthfault.TheratingoftheincomerswitchgearwillvarydependingonratingoftheAPFCequipmentandtherequiredfaultcurrenthandlingcapacity.SDF,MCCBorACBcanbeusedasincomerswitchgeardependingonthecurrentratingoftheAPFCequipmentandtherequiredfaultlevel.
OutgoingprotectionisprovidedtoprotecttheindividualcapacitorstepintheAPFCequipment.Theoutgoingprotectionmaybefuses,MCB,MCCB&SDFdependingontheratingoftheindividualcapacitorsteps,requiredfaultlevel&customerrequirementtoo.
Factorof1.5foroverloads
Thefactorof1.5hasarrivedbytakingintoaccountthecombinedeffectsofharmonics,OverVoltageandcapacitancetoleranceasperstandardIEC60831.
1.5=(1.3x1.15=1.495)~1.5where
1.3-Factorofmaximumpermissiblecurrentofcapacitorsatratedsinusoidalvoltageandratedfrequencyexcludingtransients.
1.15-Capacitancetolerance.
AsperIEC61921,capacitorcurrentshouldnotbeallowedtoexceedtheabovevalueof1.5timeshencethereisnopossibilityofincreasingthefactor.Thereisnoneedforreducingthefactorsincethefactors1.3and1.15areapplicabletoalltypesofcapacitors.
Thereforethesafetyfactorof(1.5xIn)isusedforselectingallswitchgear.
Other than selecting the rating of the circuit breaker or SDF ,it is essential to protect the capacitor bank by selecting- proper thermal magnetic release setting in case of a circuit breaker- proper fuse rating selection in case of a SDF
Switchgear and Fuse Selection
Component Selection guideCT and Protection Devices
41
Thermal and Magnetic setting of a Circuit breakerTheratingmustbechosentoallowthethermalprotectiontobesetto:
1.5InforSDuty/HDuty/EnergyCapacitors 1.31×InforHDuty/Energywith5.6%DetunedReactor
(TuningFactor4.3) 1.19×InforHDuty/Energywith7%DetunedReactor
(TuningFactor3.8) 1.12×InforHDuty/Energywith14%DetunedReactor
(TuningFactor2.7)
Note: Restrictions in Thermal settings of system with Detuned reactors are due to limitation of IMP (Maximum Permissible current ) of the Detuned reactor.
Example1:150kvar/400v–50HzCapacitor
Us=400V;Qs=150kvar
Un=400V;Qn=150kvar
In=150000/400√3=216A
CircuitBreakerRating=216x1.5=324A Selecta400ACircuitBreaker.
CircuitBreakerthermalsetting=216x1.5=324
Conclusion:-SelectaCircuitBreakerof400Awith
ThermalSettingat324Aand
MagneticSetting(ShortCircuit)at3240A
Example2:
20kvar/400v–50HzHarmonicRangewith7%DetunedReactor
Us=400V;Qs=20kvar
Un=440V;Qn=22.51kvar Refer:Selectionofcapacitorwithdetunedreactor
In=22510/440√3=29.9A
CircuitBreakerRating=29.9*1.5=45A
CircuitBreakerthermalsetting=29.9x1.19=35.6A
Conclusion:-SelectaCircuitBreakerof45A(ornextavailableappropriaterange)with
ThermalSettingat35.6Aand
MagneticSetting(ShortCircuit)at356A
Capacitorbankprotectionbymeansofacircuitbreaker
Example 1: Capacitor alone
Example 2: Capacitor with detuned reactors
Individualcapacitorprotectionbyfuses
Individualcapacitorprotectionbycircuitbreaker
Individualcapacitorprotectionbycircuitbreaker
Individualcapacitorprotectionbyfuses
Component Selection guideCT and Protection Devices
42
Fuse SelectionTheratingmustbechosentoallowthethermalprotectiontobesetto:
1.5InforSDuty/HDuty/EnergyCapacitors 1.35×InforHDuty/Energywith5.7%DetunedReactor
(TuningFactor4.3) 1.2×InforHDuty/Energywith7%DetunedReactor
(TuningFactor3.8) 1.15×InforHDuty/Energywith14%DetunedReactor
(TuningFactor2.7)
Note: Restrictions in Thermal settings of system with Detuned reactors are due to limitation of IMP (Maximum Permissible current ) of the Detuned reactor.
Example1:
150kvar/400v–50HzCapacitor
Us=400V;Qs=150kvar
Un=400V;Qn=150kvar
In=150000/400√3=216A
SDFRating=216*1.5=324ASelectaSDFof324A (ornextavailableappropriaterange)with
HRCFuseRating=216*1.5=324A (ornextavailablelowerrating)
Example2:
20kvar/400v–50HzHarmonicRangewith7%DetunedReactor
Us=400V;Qs=20kvar
Un=440V;Qn=22.51kvar Refer:Selectionofcapacitorwithdetunedreactor
In=22510/440√3=29.9A
SDFRating=29.9*1.5=45A
HRCFuseRating=29.9*1.2=36A
Conclusion:-SelectaSDFof45A (ornextavailableappropriaterange)with
HRCFuseRating36A (ornextavailablelowerrating)
DB
1141
62 Example 1: Capacitor alone
Example 2: Capacitor with detuned reactors
Individualcapacitorprotectionbycircuitbreaker
Individualcapacitorprotectionbycircuitbraker
Individualcapacitorprotectionbyfuses
Individualcapacitorprotectionbyfuses
Capacitor bank protection by means of fuses
Installation rulesCapacitors
43
General Indoorinstallationonfirmsupportinacorrectlyventilated
localorenvelope.
Ambienttemperaturearoundcapacitorsmustnotexceed35°Coveroneyear,45°Cover24hoursand55°Cmax(accordingtoIEC60831for-25/Dtemperaturecategory)(ExceptforEnergyrange(55°Cover24hoursand70°Max).
Maintainagapofmin.30mmbetweencapacitorunitsandmin.30mmbetweencapacitorsandpanelenclosureforbetteraircirculation
Electricalclearancebetweenphasesshallbe30mm.
For3phcapacitorskeepmin.30mmgapabovethetopofthecapacitor
Usecapacitordutycontactororinductorcoilinserieswithtwophasesinordertolimittheinrushcurrentwhencapacitorsareswitchedinparallelwithotherenergizedcapacitorunits.
PleaseensurethatthereisnoforcebyanymeansonthePressureSensitiveDisconnector(PSD)insuchawaytoaffecttheoperationofPSDwhenitisrequiredtooperate.
PE90132
PE90131
PE90130
General Installation RulesPE90164
PE90137
PE90135
Installation rulesCapacitors
44
Terminals
Double Fast-On + CableForlowerratingsDoublefast-onterminalswithcablesareprovided(forrating<=10kvar)
CLAMPTITE terminalsTheuniquefinger-proofCLAMPTITEterminationisfullyintegratedwithdischargeresistorsandallowssuitableaccesstotighteningandensurescableterminationwithoutanylooseconnections.Oncetightened,thedesignguaranteesthatthetighteningtorqueisalwaysmaintained.(forrating>10kvar,upto30kvar)
STUD type terminals Thistypeofterminalsareusedforpropercurrenthandlingcapabilitiesincapacitorsof40&50kvar
Electrical connection Selectthecablecrosssectiondependingonthekvar&voltage
rating–seecableSelection Userisrecommendedtouseacableofminimumtemperature
withstandcapacityof90°C.(recommendedis105°C) Removeconductorinsulationofthecableonly10mmfor
connection. Suitablesizelugshavetobeusedwithconnectingcableto
capacitorterminalsinordertoavoidheatgenerationduetoimpropercontacts,incaseofVarplusBoxorStudtypeVarplusCan.
InsertconductorfullyinsidewithoutconnectinglugsintheCLAMPTITE,nosinglestrandtocomeoutfromtheslot,incaseofCLAMPTITEterminals.
UsepneumaticguntotightenthescrewfromtopoftheCLAMPTITEterminalcover.Ifnotpossible,pleaseensurepropertightnesswhenascrewdriverisusedtoavoidloosetermination.Applyatorqueof2.5Nmtotighten
ForStudtypeterminalsuseapressureof20NmtotightentheTerminalsafterconnectingcableusingpropersizedlugs.
FortighteningtheVarplusBoxterminalstudsapplyatorqueof forM6studs-4Nm forM8studs-8Nm forM10studs-12Nm
Mounting Varpluscapacitorscanbemountedaloneorinrow. Position: SDuty&Energy :upright HDuty : uprightorhorizontal Capacitorbodyshallbeearthedatbottom. Capacitorshallbeinstalledindryplaceawayfromheat
generatingsource&avoiddustyatmosphere Provedpropercrossventilationforheatconduction Applyatighteningtorqueof8NmtofixtheVarplusBoxcapacitor
onthemountingplates. Tighteningtorqueof10NmtobeappliedonHexagonal
mountingnutforVarplusCan(seepictureintheleft).
Installation rules VarplusCan and VarplusBox
10Nm
DoubleFast-On+Cable
Clamptite
StudType
VarplusBox
Cableentryhole
Slidingcover
Topcover
Removablescrews
RemovableTerminalNutsandWashers
FixedWasherand Plate
Installationstep1 Installationstep2
2.5NM
Installation rulesCapacitors
45
FollowingarethestepsforinstallationofVarplusBoxHDutyCompactCapacitors.
Step 1UnpacktheVarplusBoxHDutyCompact
Step 2MountingofCapacitor
Step 3CableConnectionandInstallation
SelecttheCablecrosssectiondependingonthekvar&Voltagerating–seeCableSelection
UserisrecommendedtouseacableofminimumTemperaturewithstandcapacityof90°C.(Recommendedis105°C)
Removeconductorinsulationofthecableonly10mmforconnection.
Suitablesizelugshastobeusedwithconnectingcabletocapacitorterminalsinordertoavoidheatgenerationduetoimpropercontacts.
ForthestepratingswhereVarplusBoxHDutyCompactisputinparellelensurethat“Maximumpowerperstep”Ruleisfollowed.-SeeMaximumpowerperstep-VarplusBoxHDutyCompact
Followtheinstructionsbelow.
VentilationCapacitors,contactors,fusesandelectricalconnectionsgenerateheatdissipation(about2,5W/kvartotalor8W/kvarwithseriesreactors).Specificprecautionsmustbetakeninordernottoexceedtemperaturevaluesof-25°C/Dcategoryaroundthecapacitorsinsidethecubicle(seeparagraph.Installation.).
Theairflowinsidethecubiclemustgofrombottomtotop.Thecrosssectionofthetopairoutletmustbeatleastequalto1.1timesthecross-sectionofthebottomairinlet.Forpowerhigherthan200kvarin2mhighcubicleforcedventilationisnecessary.Itisrecommendedtoinstallforcedventilationwithextractorfansonthecubicleroof.Incaseofdetunedreactorsuse,itisrecommendedtoinstalltheminacolumnseparatefromthecapacitors.PreferablyreactorsatthetopandCapacitorsatbottom.
Installation rules VarplusBox Compact
Capacitor and accessories
Installation instructions
Mounting instructions
Installation rulesDetuned Reactors
46
Temperature rise stressesThepreferredarchitectureofaPFCswitchboardwithdetunedreactorsiswithaseparatecolumn,specificallyreservedforthereactors.(Seepicture) Detunedreactorsrequireforcedventilation.
Note: under no circumstances may the detuned reactors be fitted beneath the capacitors.
Detuned reactors D
B12
1436
ExampleofcapacitorbankswithDetunedReactors
Location of the detuned reactorsToensureproperventilation,theDRwindingsmustbevertical.D
B12
1428
DB
1214
27
Installation distanceTheminimumdistancesillustratedoppositemustbeobservedforinsulationpurposesandtopreventoverheating.
DB
1214
37
Installation rulesAPFC Panels
4747
For VarplusCanTherearenorestrictionsinnumberofVarplusCancapacitorstobeputonparallel;thefollowingpointshavetobetakencarebeforedecidingthemaximumkvarperstepa) Contactorrating.b) VAburdenoftherelay.c) Ventilationd) Minimumclearances
a) Contactor RatingCapacitordutycontactorsarenormallyratedupto60kvar.Wheneverhigherratedstepsexistsuchas75kvar,100kvaror120kvar,thecontactorsareconnectedinsuchawaytobeoperateedbyasinglecontactoftherelay.
Howeverforrating120kvarandaboveAC3dutycontactorscanbeusedalongwiththesuitableinductorcoilsinserieswithcapacitorsintwophasesforsuppressingtheinrushcurrent.(refer to selection of capacitor switching and protection devices - Contactors )
b) VA burden of the relayThemaximumkvarperstepalsodependsontheVAburdenofeachoutputcontactofthepowerfactorrelay.ThecoilratingofallthecontactorsinthestepshouldnotexceedtheVAburdenoftherelaycontact.
c) VentilationThemaximumambienttemperatureonthecapacitorsis+55˚C.Thecapacitorshavetobeplacedintherackinsuchawaythattemperatureshouldnotexceedthislimit.So,properventilationisverymuchrequired.
d) Minimum clearancesForbetteraircirculation,aminimumclearenceof30mmbetweencapacitorunitsandpanelenclosureneedtobekept.Alsomaintaina30mmgapabovethetopofthecapacitor.Thesearethepointstobeconsideredwhiledecidingthenumberofcapacitorsinarack.
Maximum kvar per step in APFC Panel
Installation rulesAPFC Panels
4848
Restrictions for VarplusBox HDuty CompactTherearerestrictionsinnumberofVarplusBoxHDutyCompactcapacitorstobeputinparallelduetotherestrictioninthemountingofthesecapacitors.Allthe4pointsdiscussedabovearevalidforVarplusBoxHDutyCompactexceptthemountingrestrictions.
Maximumacceptablepoweroftheassemblyisshowninthebelowtable.
Applicablemaximumpowercanbeestimatedfromthefigurebelow.
Rated voltage Maximum quantity Maximum acceptable power of units mechanically of the assembly assembled 380/400/415V 4 65kvar(20kvaristhemaximum withsingleunit)440V 4 65kvar(20kvaristhemaximum withsingleunit)480/525V 4 50kvar(12.5kvaristhemaximum withsingleunit)690V 4 50kvar(12.5kvaristhemaximum withsingleunit)
* Mentioned is the effective Power at the network voltage with Detuned Reactor- Refer – Capacitor rated voltage with detuned reactor
50/60Hz UN<400V ≤40kvar >40kvar
50/60Hz UN≥400V ≤65kvar >65kvar
Installation rulesAPFC Panels
4949
EnclosureEnclosureprovidesprotectionforthecomponentsusedintheAPFCpanelagainstingressofexternalsolidorliquidparticles.EnclosuresaremadeupofCRCA(ColdRolledCloseAnnealed)highcarbonsteel.Theenclosuresshallbethoroughlydegreasedandcleanedandphosphatecoatedbeforeprimercoats&powdercoating.
EnclosuredesignshallcomplytoalloweasyaccessofcomponentsinsidetheAPFCPanel.Properelectricalclearancesmustbemaintainedinsidethepaneltoensuresafetyandeaseofmaintenance.Utmostcareshallbetakenforthedesignofenclosureandlayoutofallthepartsandcomponentsinsuchamannerthatitgiveseasyaccessformaintenance(Especiallythecomponentsonthefrontdoorforaestheticappearance).Enclosuremustbedesignedtoensureproperventilation;necessarylouversshallbemadeattherequiredareaforproperventilation.TheselouversshallbeclosedwithwiremeshorperforatedsheetsofrequiredsizefrominsidetoachievethespecifiedIPlevels.
Size of enclosureSelectingtheenclosuresizeisanimportantaspect,whichaccommodatesmostofthecomponentsinitandthesizeoftheenclosureshouldbeselectedproperlyafteraproperlayoutofcomponentsismade,inordertomaintaintheelectricalclearances,ventilationandsafety.Theheatgeneratingcomponentsshouldbelocatedinsuchamannerthattheheatgenerateddoesnotcomeincontactwithothercomponents,especiallywhicharesensitivetoheat.Aproperairflowhastobeplanned.Sizeoftheenclosuredependsonthefollowingpoints.
TotalkvarratingoftheAPFCsystem. TypeofAPFCPanel,normalorharmonicfilterpanel. Numberofphysicalsteps. Typeofincomerprotection(SDF,MCCBorACB). Typeofoutgoingprotection(HRCFuses,MCBorMCCB) Typeofcapacitors(application&constructionbased)and
numberofcapacitorsinthepanel. Cableentry-BottomorTop. Installationtype-OutdoororIndoor. Busbarsizingandpositioninginpanels
Installation rulesAPFC Panels
Installation rulesAPFC Panels
5050
Ventilation inside the APFC PanelProperventilationisessentialtoensuregoodperformanceoftheinstalledcomponentsintheAPFCpanel.Caremustbetakentoensurethatunimpededairflowismaintainedinsidethepanel.
Theaccumulationofheatinanenclosurewillpotentiallydamagetheelectricalequipments.Overheatingcanshortenthelifeexpectancyofcomponents,especiallythecapacitors,whicharehighlysensitivetotemperatureandleadstocatastrophicfailure.
Sinceadequateventilationisrequired,sufficientlouversshallbeprovidedatthebottomportionofthepanelasinletforair,andattopportionforexhaust.Thisgivesanaturalairflowfrombottomtotopinsidethepanel.Forhighkvarratedpanels,thisnaturalairflowhastobeassistedbyforcedventilationusingexhaustfansatthetoptohavequickerreplacementofhotairinsidewithcoolairfromoutsideandmaintaintheinternalambienttemperatureofthepanelatthedesiredlevel.
Note: Providing louvers throughout the height of the panel is not recommended since it doesn’t give the ducting effect for air flow.
Selection of FanItisbettertouseafanwiththermalswitches.Inthiscasethepositioningofthefansshouldbetakencaresoastonotplacethefan’sthermalswitchclosetoheatdissipatingdevicessoastoavoidanymalfunctioningofthermalswitch.
Theselectionoffansshallbebasedonseveralparameters:
Totalwattlossincludingallcomponentsinthepanel, IPlevelofthepanel. Totalvolumeoftheenclosure, Outsideambienttemperature, Desiredinternalambienttemperature.
Thecubicmeterperhourcapacityofthefanandtheambienttemperatureatwhichthefancancontinuouslyoperatearealsotobetakenintoaccountfordecidingthenumberoffans.
Thefollowingaretheconditionsconsideredforfancalculation,andapplicableonlyforthisdesign,
Thedesignconditionsaretakeninsuchawaytotakecareofevenextremetemperatureof50°Cinsidethepanel(Asthedesignisforhighertemperature,safetyfactorwillbeveryhigh)
ExternalTemperature-(Ambient)-40°C EnclosureDimension(seetable)
User can see the recommended practices for Ventilation in following pages with respect to the application
Installation rulesAPFC Panels
5151
Ventilation Practices NormaloperatingconditionsaccordingtoIEC61439-1
Maximumtemperatureintheelectricalroom:≤40˚C Averagetemperatureover24hrsintheelectricalroom:≤35˚C Averageannualtemperatureintheelectricalroom:≤25˚C Minimumtemperature:≥5˚C Maximumaltitude:≤2000m
Otherconditions,contactus
Ventilation rules: Sduty, HDuty & Energy RangeCapacitors,contactors,fusesandelectricalconnectionsdissipateheat.Theselossesareroughly2-3W/kvar.Calculatethelossesroughlyandusethetablementionedinthenextpage("Minimumnumberoffansrequiredinthepanel").
Thefollowingventilationrulesmustthereforebecompliedwith:
Theairwithinthecubiclemustflowupwards.
Itisrecommendedthatextractorfansbefittedontopofthecubicle.
Thebottomairinletmustbeaslowaspossibleforbetterventilation
Thecross-sectionofthetopairoutletmustbemorethanthecross-sectionofthebottomairinlet
Theopeningsmustbecompatiblewiththesafetyrating(IP)
Thereshouldbeatleast100mmbetweenthefanandthemodulesorcomponents
Theairinletatthebottomairintakegrillemustnotbeobstructedorrestrictedbyacomponentormodule
Alwaysletagapofminimum600mmbetweenthebackofthepanelandthewallforafrontopenpanelandaminimumgapof1000mmfortherearopenedpanel.Itallowstohaveagoodventilation
Takeintoaccountthepressuredropsoftheairinletandoutlet.
Asanindication,therealairflowis0.6to0.75timetheairflowannouncedbythefanmanufacturer
Thefollowingrulesapplytocapacitorbankswithoutreactor
Ventilation for capacitor banks
Installation rulesAPFC Panels
5252
Ventilation for capacitor banks with detuned reactors Capacitors,DetunedReactors,contactors,fusesandelectricalconnectionsdissipateheat:
TheseLossesareroughly8-9W/kvar.CalculatethelossesroughlyandusethetablebelowwithrespecttoWattlosses.
Thisequipmentmustalwaysinclude a forced ventilation system.
TheDRsmustbeinstalled:inaseparateenclosureorinthesameenclosureasthecapacitors,butinaseparatecompartment,orpossiblyabovethecapacitors.
Thepartoftheenclosurecontainingthecapacitorsmustbeventilatedaccordingtothestandardcapacitorbankrules.
ThepartoftheenclosurecontainingtheDRsmustbeventilatedaccordingtothedissipatedpower.
Theventilationrulesinthepreviouspageareapplicableherealso.VentilationfansarerequiredwithrespecttoWattlosses.(Thedesignsismadebasedontheassumptionofthesystemasdescribedabove.AnyspecialsystemconditionsneedconsultationofSchneiderElectric.Itisalwayspreferredtodothermalstudybeforefixingtheventilationinthepanel)
ThefollowingrulesapplytoCapacitorbankswithreactors
DB
1141
65
Recommended Enclosure sizes ThefollowingtablegivestheexamplesforthepaneldimensionsforbetterVentilation
Minimum number of fans required in the panel (1)
Total losses No. of fans required(2)
0-500W 0500-1500W 11500-2400W 22400-3000W 33000-3500W 43500-4500W 54500-5000W 6
kvar rating Total no. of steps Panel dimension (H x L x W)mm
Withreactor Withoutreactor
100 5 1800x800x800 1800x800x600150 6 1800x800x800 1800x800x600200 6 1800x800x800 1800x800x600250 7 2000x800x800 2000x800x600300 8 2000x800x800 2000x800x600350 8 2000x800x800 2000x800x600400 8 2000x800x800 2000x800x800
(2)Theairthroughputofthefansrecommendedaboveis160m3 /h
(1)Thenumberoffansrecommendedcanbefollowedonlyifproperventilationofallthecomponentsasperthedesignrulesofthecomponentsareimplementedwiththerecommendedenclosuresizesandalsoensuretherecommendedmountingdistancefromthewall.
Installation rulesAPFC Panels
5353
Protectionofpanelistoprotectboththeenclosureandtheequipmentinsidetheenclosure,againstexternalinfluencesorconditionssuchas
Mechanicalimpacts, Corrosion Corrosivesolvents Fungus Vermin Solarradiation Icing Moisture(forexample,producedbycondensation) Explosiveatmospheres Protectionagainstcontactwithhazardousmovingpartsexternal
totheenclosure(suchasfans)
Degree of protectionDegreeofprotection(IP)isrepresentedbytwonumeralsandtwooptionalcharacters
IP0-60-8A-DHMSW
SeestandardIEC60529
AcceptabledegreeofprotectionisIP4XformostoftheAPFCpanels.Fordustyenvironment,ahigherlevelofingressprotectionisrecommended.AhigherIPlevelgivesreductionincoolingandhencespecialcoolingsystemshouldbedesigned(i.e.airconditioning)andbetterventilation.Whensomedegreeofprotectionagainstingressofwaterisrequired,weusuallygotoIP42.TherecommendedIPis:IP42
EarthingEarthingorgroundingmeansliterallytomakeanelectricalconnectionbetweenthegroundandametallicbody.Themainreasonfordoingthisissafety.Thetermgroundisoftenusedtomeanapartofthecircuitwhichhaszerovoltsonit.
Themainobjectivesareasfollows
Provideanalternativepathforthefaultcurrenttoflowsothatitwillnotendangertheuser.
Ensurethatallexposedconductivepartsdonotreachadangerouspotential.
Earthingsafetypointstobeadheredforpanelsareasfollows: Interconnect all earthingpointsofdoormountedmetallic
componentsandallnon-currentcarryingpartsofcontrolwiring.Connectfinallytopanelearthbuswithsuitablecable.
Interconnectallearthingpointsofpowercircuitcomponents(capacitors,reactors,switchesetc).
Providecouplinglinksforconnectingtheearthbussectionsatsite.
Asperstandardstwoearthterminalsmustbeprovidedforpanels.
Theearthmustbedesignedbasedonthesystemfaultlevelatthelocation.
Protection of panels
Installation rulesAPFC Panels
5454
CablesareusedforpowercircuitandcontrolcircuitinAPFCsystem.Choosingaproperandadequatecableisofverymuchimportance.Theselectionofcabledependsonthefollowingpoints.
VoltageRating. AmpereCapacity. HeatingConditions.
Voltage RatingThetypeandthicknessofinsulationisdeterminedbythevoltagegrade.Italsohelpsindeterminingtheminimumsizeofconductorthatissuitableforloads.
Ampere CapacityCurrentcarryingcapacityofthecableisselectedbasedonthemaximumcurrentratingofeachstep.
Heating conditionsIncludetheexternalthermalconditionswhichareresponsiblefordeterminingthetemperatureincrementofacable.
Someimportantfactorstobeconsideredduringselectionofcables are
Ambienttemperature Presenceofartificialcooling Proximitytoheatingelements.
Step Power cable selectionFlexible,rigidorsemirigidcoppercablesaregenerallyusedinsidethePanel.
Itshallhaveavoltageclassof1100Vgrade.Foraworkingvoltagethatislessthanhalftheinsulationvoltageofthecable,i.e<550V,thesecablesareconsideredtobeclass2.
Thereforetheycanbeflangeddirectlytometalsupportswithoutuseofanyadditionalinsulatingmaterial.
TheCablecrosssectionmustbecompatiblewith:
Thecurrenttobecarried Theambienttemperaturearoundtheconductors.
Dimensional Rules: Theambienttemperatureintheelectricalroommustnotexceed
40˚C TheCablesmustbeappropriateforacurrentofatleast1.5
timesthecapacitorcurrentatatemperatureof50˚C Theambienttemperatureoftheelectricalroommustnotexceed
50˚C
Cable Selection
Installation rulesAPFC Panels
5555
Auxiliary Circuit cable selectionUnlessotherwisestatedinspecifications,thefollowingcablecrosssectionsarerecommendedforauxiliarywirings.
1.5mm²copperwiresfortheauxiliaryvoltagecircuits 2.5mm²copperwiresforcurrentcircuits-CTsecondary
connectionandforearthing Itshouldhaveavoltageclassof1100/660Vgradeormore. Thecablesmustbemultistrand,singlecoreandPVCinsulated.
Note: For CT connection the lug used should be ring type.
Capacitor Bank connection Cable Selection Powerconductorsandchosentocarrycontinuouscurrentof1.5
timestheratedcurrent Powercablesareusedforinterconnectionbetweenbusbar,
stepprotection,switches,reactorsandcapacitors. Themaximumpermissibleconductortemperatureis90˚C. Thecablesshallbemultistrand,singlecoreandPVCinsulated. Minimumof4mm²powercableisconsideredforconnection
capacitorstepupto10kvar Maximumof35mm²cableisconsideredfor50kvarstep. Andforhigherratedstepsof75or100kvar,2numbersof35
mm²cablearegenerallyusedinparallel.
Variousmanufacturersofcablesdistinguishcablesbasedoncablediameter,currentcarryingcapacityandtype.HenceitisnecessarytoselectcablessuitablytomeettheneedsinAPFCpanels
Note: selection of suitable lugs is very much important in order to achieve a proper joint. Proper crimping of these lugs to the cables should also be ensured. Only 2 lugs are permitted in one hole for termination (i.e. at either sides of the hole and not one above the other).
Recommended size of cables and lugs kvar rating Cable Size in mm2 Lug Size 230V/240V 400 to 480V >600V Al Cu Al Cu Al Cu
2.5 1.5 1 1.5 1 1.5 1
5 4 2.5 1.5 1 1.5 1
7.5 10 6 4 2.5 1.5 1
10 16 10 6 4 2.5 1.5
12.5 10 6 4 2.5
15 10 6 6 4
20 16 10 10 6
25 25 16 16 10
30 35 25 16 10
40 50 35 25 16
50 50 35 35 25
75 2×50 2×35 2×25 2×16
100 2×50 2×50 2×35 2×25
M5/M6/M8Pintype,forktypeorring type basedontheterminalofthecomponents
M5/M6/M8forktypeorRing based
**The above details/specifications will vary from manufacture to manufacture. Calculations are based on standard operating conditions.
Assembly, Inspectionand Testing
5656
Assembly and Inspection
Layout of various components in APFC panelsComponentslayoutispreparedbasedonthearrangementsofswitchgears,capacitors,reactorsandothercomponentstobeinstalledintheAPFCpanel.TheothersalsoincludeBusbars,incomercableentrywhetheratbottomortop,fans,etc.
Usuallycapacitors,switchgearsandreactorsareprovidedatseparatelocations,howeverbetweencapacitorsandreactorsacompletepartitionshouldbeprovided.Capacitorsaremountedverticallyonaseparatemetalchannel,tightenedbythemountingscrewtoavoiddislocation.Capacitorsaretransposedandplacedwhenarrangedonebelowtheotherinracks.Thisarrangementgivesbettercoolingtoallcapacitorsequally.Capacitorsaresensitivetohightemperatureandhencepropercarewillhavetobetakenwhilelocatingthem.
Reactorsoperateatmuchhighertemperaturethancapacitors.Placingreactorsadjacenttocapacitorsorbelowthemwillharmcapacitors.Capacitorswillbesubjectedtoreactorsheatandtheoperatingperformancewillbeaffected.Hencecapacitorsandrectorsarenotassembledtogetherandacompletepartitionisrequiredbetweenthem.
Thecablesconnectingthecomponentsrunincablealleys,properlynumberedforrespectivesteps.
Inspection- Applicable tests and procedure for conducting in APFC panelsTestsaccordingtoIEC61921tovalidatetheAPFCdesignisconductedA.TypeTestsB.RoutineTest
A. Verificaton of type tests Temperaturerisetest Dielectricproperties Shortcircuitwithstandstrength Effectivenessoftheprotectioncircuit Clearanceandcreepagedistances Mechanicaloperation Degreeofprotection
B. Routine Test Inspectionofassemblyincludinginspectionofwiringandif
necessaryelectricaloperationtest Dielectric test Checkingofprotectivemeasuresandoftheelectricalcontinuity
ofprotectivecircuit Verificationofinsulationresistance
Assembly, Inspectionand Testing
5757
The means
Principle Practical rulesAttheendofthemanufacturingprocess,aLVswitchboardmustundergovariousroutineinspectionsandtestsinthefactory,followinganestablishedprogramme.
Theswitchboardmustcomplywith:theappropriatestandardsthedesignfile(drawings,diagramsandspecificrequirements)manufacturermountinginstructionsin-houseinstructions.
Test conditionsTestsmustbecarriedoutinaclearlydefinedarea,incompliancewithapplicablelegislationorregulations,byqualifiedpersonnel.
Inspectioniscarriedoutinaspecialareareferedtoasthetestplatformwhichissetasideforfinaltesting.Allinspectorsmustfirstattendaspecialtrainingcourseandmustbequalifiedforworkingintheproximityofliveparts.
Inspection meansThenecessarypartsshouldbesuitableforthepurpose,correctlycalibratedandingoodworkingorder:
dielectricteststation megohmmeter multimeter capacitancemeter torquewrench controllertestbench…
The reference documentsThemaininternationalstandardsare:IEC60439-1,IEC60529,IEC60831-1&2andIEC61921.
Inadditiontothoseitemswhicharespecifictotheswitchboard:drawings,diagramsandspecificspecifications,qualityinspectorsshouldrefertoup-to-datedocuments,integratingrevisionsandupdates:
totechnicalfiles toin-houserules,etc keepingtrackofchangesinstandardsinordertohavethemost
recentversionatalltimes
DD
3823
59-6
5
Megohmmeter.
Assembly, Inspectionand Testing
5858
The tests
Practical rulesCarryoutallthecompulsoryinspectionsandtestsandinparticularthethreeroutinetestsspecifiedbytheIEC60439-1standards.
Theycomplementanytypetestswhichmayhavebeencarriedoutpreviouslybythemanufacturer.
StandardIEC60439-1defines10teststobecarriedoutonelectricalswitchboards:
7 type tests 3routinetests.
The7typetestsmustbecarriedoutinlaboratoriesandtestplatformsoncubicles,usingrealworkingconfigurations:completecubiclesfittedwithstandardcomponentsandequippedwithVarplusCanandVarplusBoxcapacitors.
Theassemblyinstructionsandthe3routinetests(describedbelow)providethenecessaryproofthattheswitchboardisoftheTypeTestedAssembly(TTA)orPartiallyTestedAssembly(PTA)type,andincompliancewithstandards.
1st routine testInspectionoftheassembly,includinginspectionofwiringand,ifnecessary,anelectricaloperationtest.
Conformity conformityofthefinishedswitchboardtothedrawings,partlists
anddiagrams: number,typeandratingofdevices conformityofcabling:auxiliaryandpowercircuitconnections qualityofcables:conductorcross-section,crimpingand
tightness markingofconductorsanddevices.
Visual inspection checkclearances and creepagedistancesatconnectionsorpart
ofbusbars checkthedegreeofprotection.Presenceofprotectiveelements,
accordingtorequirements(canopy,gasket,frontplate,etc.).Noenclosureinfractions(cut-outs,holes,etc.)thatmightcompromisetheoriginaldegreeofprotection
checkthepresenceofanameplateortechnicaldocumentationshowingthemanufacturer’sname,theprojectidentitynumberandallthetechnicalspecificationsrelevanttotheLVcorrectionswitchboard(kvar,voltage,frequency,etc.)
Electrical operation InspectthecablesandchecktheproperoperationoftheLV
correctionswitchboard,preferablyusinga“controllertestbench”(attacheddiagram).
Capacitancemeasurement:Checkthecapacitanceofeachstep.Onemeasurementbetweentwocapacitorterminalsissufficient: Referannexure2,formula4forQvalue(inkvar)analysisfromcapacitancemeasured.
Inspections and tests - Standards:IEC 60439
Assembly, Inspectionand Testing
5959
2nd routing test : Insulation testingDielectric test:Alldevicesmustbeconnected,withtheexceptionofthoseincapableofwithstandingthetestvoltage(disconnectthecontroller).Testsmustbedonewithallthecontactorsclosed.Foraswitchboardwithvoltageratedup690V,applyatestvoltageof2500V-50Hzfor1secondminimum,betweenallthelivepartsandtheinterconnectedframesoftheassembly.
Note: due to capacitor presence, the test must be performed between the 3 short-circuited phases and the earth.
Thetestsaresatisfactoryifthereisneitherpuncturenorflashoverbetweenthevariouspartsbeingtested.
Alternative solution: Iftheswitchboardisnotsubjectedtoadielectrictest,aninsulationmeasurementmustbetakenusinganinsulationtester,withavoltageofatleast500V(DC).Theminimuminsulationresistancevaluemustbehigherthan1000ohms/V.
3rd routine test : Protective measures Checkforthe presenceofbarrierstoprotectagainstdirectandindirectcontactswithliveparts.
Visually check that: Contactwashershave beenusedonallassemblies Earthingwireshavebeenfittedtodoors ThePEconductorispresentandmustbeconnected.
FinishingCleantheinsideoftheswitchboardCheckpresenceofswitchboardidentificationmarkersCheckexternalappearance:scratches,paintwork,etc.
ReportsCreateanonqualityinputdocumentusedtoquantifyfaults,evaluatetheirimportanceandassignthemtorelevantdepartmentthatmusttakethenecessaryactiontoensureconformityoftheelectricalswitchboard.
Practical rules
Conformity of production: Drawupalistofmissingitems Drawupalistofequipmentwhichwillbedispatchedseparately
fromtheswitchboard.
Conformity of operation: Issueatestreport Thisreportnotesanyanomaliesdetectedandtherequired
correctivemeasures Establishwiththecustomer,achecklistofallthepointstobe
checked(exampleenclosed) Issueatestreportthatremainsinthepanel-builder’spossession
butthatcanbesuppliedonrequest thisreportcertifiesthatallthetestshavebeencarriedoutand
avoidsrepeatingalltestsasecondtimeonceonsite.Eachpanel-builderhashisowntestdocuments.
DD
3823
56-6
9D
D38
2361
-69
Dielectrometer
Multimeter
Assembly, Inspectionand Testing
6060
Inspection operations Comments Q.I
1- dielectric test test 2500 V - 50 Hz - 1 second minimum insulation measurement at 500 V CC 2a- conformity Capacitor(kvar) conform notconformFuse(A) conform notconformContactor(type) conform notconformDR(mH) conform notconformDR(A) conform notconformCablecross-section conform notconformBusbarcross-section conform notconformConnectionpads conform notconformEarthcircuit conform notconformComponentidentification conform notconformConductoridentification conform notconformRatingplate conform notconformDocumentation conform notconformFramecontinuity conform notconformDegreeofprotection conform notconformLocking conform notconformPresentation,appearance conform notconform
Customer:.................................. Projectno:.................................. Cust.orderno:.................................. Workpost:.............................
Inspectionperformedby:..........................................Signatures:..................................Q.I:........................................................................
Device:..............................................................................................................................
kvar V Hz
Inspection Steps no. Comments Q.I
operations 1 2 3 4 5 6 7 8 9 10 11 12 2b- operationContactor OK OK OK OK OK OK OK OK OK OK OK OKController conform notconformIndication OK OK OK OK OK OK OK OK OK OK OK OK2c- capacitance measurement C between Ø (mF)Capacitorno.reading
Observations:...................................................................................................................................................................................................
............................................................................................................................................................................................................................
............................................................................................................................................................................................................................
............................................................................................................................................................................................................................
............................................................................................................................................................................................................................
............................................................................................................................................................................................................................
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
no:
Pre despatch factory inspections report model
Assembly, Inspectionand Testing
6161
Final inspection report model
Customer:...............................................................................................Customerorderno:..........................................................................
Projectno:...............................................................................................
List of equipment
Workpostnumber:...................................................................................Description:......................................................................................
Customer inspection Acceptance test organisation Inspector Q.I manager
Date:......................................... Date:......................................... Date:.........................................
Signature:................................. Signature:................................... Signature:...................................
Inspection performed
1- Conformity inspection
Enclosures : ..........................................................................................................................................................................
Switchgear : ...........................................................................................................................................................................
Conductors : ...........................................................................................................................................................................
2- Mechanical checks :..............................................................................................................................................................................
3- Electrical continuity of mechanical frames
Resistancevalue:......................................................mΩVisual:...........................
Electrical:......................
4- Dielectric tests(2500V-50Hz-1secondminimum):.........................................................................................................................
5- Insulation resistance monitoring(500VDC):.....................................................................................................................................
Resistancevalue:......................................................mΩ
6- Electrical operating tests:.....................................................................................................................................................................
Conclusion:
equipmentacceptedwithoutreservations. equipmentrefused,tobepresentedforre-inspection.
equipmentacceptedwithreservations.
Observations :..................................................................................................................................................................................................
............................................................................................................................................................................................................................
............................................................................................................................................................................................................................
............................................................................................................................................................................................................................
............................................................................................................................................................................................................................
Handling
6262
Packaging and Transport
Packingdesigniscarriedoutwithdueconsiderationtothemodeoftransport.
The packing design shall be based on the following Thepanelouterdimension. Totalweightofthepanel. Positionofcomponents/equipmentsmountedonthefront
Panel Positionofheavycomponentsplacedinsidetheenclosure Placeofdelivery Modeoftransport Typeofloadingandunloading Storageconditionsatsite
The panels are provided with the following Properliftingarrangement-forthepanelandthecomplete
assembly Protectionagainstrain,spillageofwaterorliquidsbyproperly
coveringtheentireenclosure. Protectionformetersdisplayandinstrumentsonthefrontpanel Desiccantstoensureremovalofmoistureduringtransportation
andstorage.
Packing Sequence ApplicationofHessianclothagainstshocks ThermoColetoprotectinstruments,meters-referFig1 Applicationofstretchfilm&bubblefilmonthepanel Placementofkurlonspaceronthepaneltoactasspacer
betweenpanelandside/top/rearshocks Inclusionofsilicagelbags Printing/labels/Signstoindicateuprightposition-referFig2
Handling of packed PanelsRoad Transport
DuringTransportitisnecessarytoprotectthepanelfromvibration&joltingbyproperanchoringinthetruckbed.
Whileloadingandunloadingthepanelontoorfromthetruck,useacraneorforklift,dependingontheweightandsizeofthepanel,especiallyaloadingplatformispreferable
DOnotpushthepanelupordownaramp. Alternatively,thecratecanbeliftedverticallybyslingandpulley
hook,toensuresafetytothepanelandpersonnel.
Itisalsonecessarytoinstructthesite/commissioningpersonneltohandlethepackingformovementofthepaneltoerectionsitebyusingcrane/trolleytrucktoavoidphysicaldamage.
Sea Transport
Stepsshouldbetakentoprotecttheequipmentfromcorrosion,humidityandrain.
Suitablemarksandindicationsshouldbegivenonthecrateforapplyingslingsforliftingontotheshipdeck.
Whileshipping,itisnecessaryfortheshippingagencytoproperlyanchorthepanelpackagetopreventrolloverduringtransit
Fig1
Fig2
Handling
6363
ThefollowingarethefiguresreferringtoDo’sandDon’ts
Wrong!
Wrong!
Right!
Handling
6464
Storage and Handling
TheAPFCPanelbuildermust,inallcontracts,providetheuserwithamanualonproperprocedurestobeadoptedduringthestagesofinstallation,commissioningandmaintenance.Thisisparticularlyimportantwhencustomersownstaffundertakeserectionandcommissioning.
Themanualcovers,asaminimum,thefollowingsubjects:-
Unloading,inspectionandstorageofpackedpanels. Unpackingandvisualinspectionofpanel. Installationandcablingatfinallocation. SettingofAPFCrelay. Livechecksandobservationstobemadewithsupply‘ON’,
precautionsneededduringthisphase. Recommendationforroutinecheckstobemadeafter
commissioning.
Inallcases,copiesofoperatinginstructionmanualofmajorcomponents,suchasAPFCcontrollerandprotectiverelays,publishedbytherespectivemanufacturers,shouldbeprovidedtotheuserforuseduringinstallation.
Unpacking Whileunpacking,careshouldbetakentoseethatnosharp
toolshits/hampersthesurfaceofthepanelandcreatesdentsanddamagethepowdercoatedfinishoftheenclosure.
AcopyofthisInstructionManualalongwithacopyoftheschematicdrawingofthepanelisalsoputinthepanel.Thesameshallbereadcarefullyandfollowedfortheinstallation,commissioning,andoperationoftheequipmentbytheconcernedofficialsatsite.
Ifanydamageintransitorlossofcomponentsisobservedduringunpacking,thishastobeintimatedimmediatelytotheconcerned.
Twopanelkeysarealsosuppliedalongwiththepanel.
Handling Attachropestotheliftinghooksofthepanelforhandling.Never
usehardtoolslikecrowbarswhichcandamagethepanelwhilehandling.Asfaraspossiblecranesshouldbeusedtoliftandmovethepanels.Donotpushandgivejerkstothepanel,andtherebyjerkstotheinternalcomponents.
Keepthepanelonaflat,firm,surfaceinthenormaluprightposition.Donotkeepitonsidewiseorupsidedown.
DonotusetheoperatinghandlesofMCCB,Switches,etc;forholdingwhilehandling.
Storage Donotstorethepaneluncoveredevenforashortperiod.Keep
itcoveredatleastwithapolyethylenesheet. Ifitisnottobeerected/commissionedforalongerperiod,keep
thepanelwiththepolyethylenesheetandstoreinacool,dry,wellventilated,place,wellprotectedfromdustandcorrosion,wetatmosphere.
Installation, Commissioning and Maintenance
65656565
Installation, Commissioning and Maintenance
Installation and CommissioningThepanelcanbegrouteddirectlyontheflooroftheswitchboardroom,providedthatpropertrenchforcablinghasbeenmadeandthefloorisleveledproperly.Nospecificfoundationisrequired.
Pre-commissioning check listsCheck list - 1ThefollowingpointsshouldbeverifiedbeforechargingcapacitorbanksinstalledinAPFCpanel.
Capacitorvoltageratingisequaltoormorethanthemaximumvoltagerecordedintheinstallation
Capacitorismountedandinstalledaspermountingandinstallationguidelinesinthisdocument
Theplanthasthefacilitytotripthecapacitorunderovervoltageconditions.(10%)
Ensureeachcapacitorbankisprovidedwithsuitableprotectiondevices.
Suitableinrushcurrentdeviceisconnectedinserieswithcontactortolimittheinrushcurrentorcapacitordutycontactorisconnected.
Capacitorisinstalledintheareafreefromentryofdust,chemicalfumesandrainwater.
PFControllerprovidedinthepanelshouldbesetfor60secondsOn-delay.(Notapplicableforcapacitorsusedwiththefastswitchingdevices-StaticSwitched)
ThecapacitorwithdetunedreactorbanksareprovidedwithMCCBforprotectionapartfromabovepoints.Usetheswitchgearselectionguidelinesforselectionofbreaker
Check list - 2FollowingpointsarerequiredtobeverifiedbeforechargingAPFCpanel.
Alltheelectricalconnectionischeckedforlooseterminationinthepanel.
TheCTislocatedbeforethecableconnectionofAPFCpaneltowardssource/mainbreakerofinstallation.EnsuretheCTsareconnectedtothePFController.
ItissuggestedtomountmeasurementC.ToftheAPFCRelayontheHighestcurrentcarryingphase(Eg:R)andtheVoltageinputfortherelayistakenfromothertwophases(Eg:YB).ThisisnotapplicableforathreephasesensingAPFCrelays.
Neutralcableisconnectedtothepanel. CurrentcarryingcapacityofcableintheAPFCpanelisrated
equaltoincomerswitchcurrentrating. Capacitorterminalsarecheckedforanylooseconnection. Earthingbusisconnectedtothepanel. Allthecontrolfusesareintact. IfMCBsareusedforstepprotectionmakesuretheyare
switchedon. Emergencypushbuttonisreleased. Panelareinstalledintheareafreefromentryofdust,chemical
fumesandrainwater.
Installation, Commissioning and Maintenance
666666
Check list - 3Verifythefollowingpointsintheinstallationbeforecommissioningcapacitorwithdetunedreactorbanks.
Capacitorbankswithoutreactorshouldnotbepermittedonthesecondarysideoftransformercircuitwhichishavingcapacitor+Detunedreactorbanksconnected.Inthiscasepleaseremovecapacitorswithoutreactorsfromthesamenetwork.
Capacitorsusedwithreactorsarealwaysofhighervoltagethannetworkvoltage.Pleasedonotusenormalcapacitorratedfornetworkvoltage.
Earthingshouldbedoneatcapacitorsandreactorsseparately. Makesureallthecableandterminationguidelinesarefollowed. Forcedcrossventilationshouldbeprovidedintheinstallation
area.Ifthefilterbanksareinstalledinsidethepanelthefansneedtobeprovided.
Detunedreactorsareprovidedwiththermalprotection,theNormallyClosed(NC)drycontactmustbeusedtodisconnectthestepintheeventofoverheating.
Installation guidelines for APFC panel Shiftthepaneltothelocationwhereitisrequiredtobeinstalled.a.Positionthepanelonthefoundationandlockthepanelbase
framewiththefoundationboltsforfreestandingpanels,byusingspiritlevelandplumberblockforachievinghorizontalandverticalleveling.
b.Positionthepanelonthewallorstructureandfixwithwallmountingbracketsprovidedalongwiththepanel.Levelingshouldbedoneherealsoasexplainedabove.
Connecttheearthconductortothepanelterminalprovidedoneithersideofthepanel.
Usethekeyprovidedtoopenthedoorofthepanelandmakesurethatelectricalconnectionofallequipmentsareintact.Thisisparticularlyimportantsincevibrationintransportationsometimesmayhaveresultedinlooseconnections.
Thecableratedforcurrentcapacityequivalenttomainincomerofpanelshouldbeused.Usesuitablesizelugsforconnectingthepowercables.
Connectthecabletotheterminalsprovidedforthepowersupply.Makesurethatthecorrectphaseidentificationismaintainedwhileconnectingtheincomingterminalstothepanelwithrespecttophasesofsupplyline,asanymistakewillleadtothemalfunctioningofrelay.
ConnecttheAPFCrelayasmentionedinthechecklists. CheckthepresetvaluesoftheCTsecondarycurrentofthe
relay.ItshouldmatchwiththeCTused.
Commissioning of APFC panel Connectthe3-phaseincomingcabletotheIncomingterminalof
theIncomerSwitch/CircuitbreakeroftheAPFCpanel. IftheAPFCcontroller/relayareprogrammabletype,program
thevarioussettingsasperinstructionsgivenintherespectiveinstructionmanual.
EnsurethattheCTshortinglinksareremovedaftertheCTsecondaryconnectionsaremadeproperly.
Installation, Commissioning and Maintenance
67676767
KeeptheAuto/off/ManualselectorswitchintheAutoposition. EnsurethatthepowersupplytotheIncomerswitchis‘ON’from
theglowingoftheindicatinglamps‘R’,‘Y’,and‘B’.Crosscheckthesystemvoltage.
Switch“ON”theIncomerSFU/MCCB/ACBoftheAPFCPanel.
TheAPFCrelaywillbeenergizedanddisplaysthepresentpowerfactor,whenR-PhaseloadCTconnectionsandphasesequenceofvoltage(Y&B)arecorrect.
Note: Before interchanging the C.T. secondary wires, ensure that the terminals of the C.T. are shorted by a small wire, which should be removed after the inter change.
Periodic MaintenanceThefollowingperiodicchecksarerecommendedtobeconducted
Visualcheckofcomponentsandcurrentcarryingparts,especiallybusbar.
Checktightnessofallelectricalconnections. Checkcurrentdrawnbytheindividualcapacitorsteps. Checktheoperationofcontactorsmanuallybyswitchingofthe
APFCequipment Visuallycheckforrustandcorrosionsinbolts,nutsandother
accessories Visuallycheckforthesparksandburnoutsinthepanels.
Annexures
686868
Annexure I
Trouble Shooting in CapacitorSymptoms
Capacitorterminaloverheating
Overheatingofcapacitorunit
Capacitordrawingless current
Powerfactorisnotimproved
Shortcircuitdeviceoperatingfrequently
Cause
1.Propersizeforlugisnotused2.Looseconnection3.Ratingofcableisnotadequate4.Capacitordrawingovercurrent
1.Poorventilation2.Drawingexcessivecurrent3.Overvoltage
1.Lowvoltage2.Failureofcapacitorelements
1.Capacitorinstalledisnotoperated.2.Supplytransformerfixedcompensationisnotprovided3.Capacitorsarenotselectedproperly
1.Shortcircuitrating/settingisimproper2.Harmonicoverloading
Remedial Action
1.Checkthesizeoflugsusedandreplacewithsuitablesize2.Tightenthelooseconnections3.Checkthecablecurrentcarrying capacity and changeifrequired4.ChecktheharmonicsinSupplyvoltage
1.Ensuretheventilationfortheinstallationarea2.Checkfortheharmonicpresence3.Checkthesystemvoltageandcapacitorratedvoltage.Ifrequiredreplacewithcapacitorofproperratedvoltage
1.Voltagetobemaintained2.Shouldbecheckedifthecapacitorsareinstalledandoperatedaspertheguideline given3.Incaseofelementsfailureduetoexcessiveharmoniccurrents,capacitorshouldbereplacedwithreactorandhigherratedcapacitor.
1.Checktheconnectionsofthecapacitors2.Transformershouldbeprovidedwithfixedcompensation3.Dotheproperselectionofcapacitoraspertheguidelinesgiven.
1.Doproperselection/settingofshortcircuitdevice2.Usespecialcapacitordutycontactorsforinrushcurrentlimitingincaseofparallelswitching3.ifitisharmonicoverload,capacitorshouldbereplacedwithreactorandsuitablecapacitor.
Annexures
69696969
Annexure IIImportant analysis formulas
Formula -1Thekvarofcapacitorwillnotbesameifvoltageappliedtothecapacitorandfrequencychanges.Theexamplegivenbelowshowshowtocalculatecapacitorpowerinkvarfromthemeasuredvaluesatsiteandnameplatedetails.
QM =( fM / fN ) × ( UM / UN )2 × QN
UN = Rated VoltagefN = Rated FrequencyQN = Rated powerUM = Measured voltagefM = Measured frequencyQM = Available power in kvar
Example:1.Nameplatedetails–15kvar,3phases,440V,50Hzcapacitor.Measuredvoltage-425VMeasuredfrequency-48.5Hz
QM=(fM /fN)×(UM/UN)2 ×QN
QM=(48.5/50)×(425/440)2 ×15=13.57kvar.
2.Nameplatedetails–25kvar,3phases,480V,60Hzcapacitor.Measuredvoltage-464VMeasuredfrequency-59.5Hz
QM=(fM /fN)×(UM/UN)2 ×QN
QM=(59.5/60)x(464/480)2x15=23.16kvar.
Formula - 2Thecurrentofcapacitorwillnotbesameifvoltageappliedtothecapacitorandfrequencychanges.Theexamplegivenbelowshowshowtocalculatecapacitorcurrentfromthemeasuredvalueatsite.
UN = Rated VoltagefN = Rated FrequencyIN = Rated CurrentUM = Measured VoltagefM = Measured frequencyIM = Capacitor Current
Example:Consideracapacitorof15kvar,440V,50Hz,3PhaseCapacitorRatedCurrentfromnameplate=19.68A
MeasuredValuesare:Voltage:425V,Frequency:49.5Hz,
Note:Please ensure that the measurement is done using true RMS clamp meter
( )IM =19.68
=18.43A
425x48.5
440x50
( )IM = IR
UM x fM
UR x fR
Annexures
707070
Formula - 3Formulaforcalculatingratedcurrentofcapacitorwithratedsupplyvoltageandfrequency.
IN=kvarx103/(√3xUN)
Example1.50kvar,3phase,400V,50Hzcapacitor.IN=kvarx10
3/(√3xUN)IN=(50×1000)/(1.732×400)IN=72.16A
2.37.7kvar,3phases,525V,50Hzcapacitor.IN=kvar× 103/(√3×UN)IN=(37.7×1000)/(1.732×525)IN=41.45A
Formula - 4Thecapacitancevalueofacapacitorcanbecalculatedusingfollowingformulaefordeltaconnected3phcapacitor.AssumethatcapacitanceofthethreedeltaconnectedcapacitorsareCasshowninthefigure.
C = QN × 109 / (4πfNUN2)for3phasecapacitor.
Example1.15kvar,3phases,415V,50HzcapacitorC=15× 109/(4x3.142× 50 ×(415×415))=138.62μF
2.15kvar,3phases,440V,50HzcapacitorC=15x109/(4x3.142x50x(440x440))=123.31μF
Formula - 5kvarcalculationfromthemeasuredcapacitancevalueofacapacitor.QM = 2/3 × (Ca + Cb + Cc) × UN
2 × (2πfN )/ 109-forthreephasecapacitor
Example 1:Consideryouhavemeasuredacapacitorratedfor440volts,50Hzwhereinmeasuredcapacitancevalueisasfollows.1.197μf(betweenR&Yphase)-Ca2.196μf(betweenB&Yphase)-Cb3.200μf(betweenR&Bphase)-Cc
QM =2/3×(Ca+Cb+Cc)×UN2×(2πfN)/10
9
QM=2/3×(197+196+200)×(4402)×2×3.14×50/109=24.04kvar
2:Consideryouhavemeasured acapacitorratedfor480V,60Hzwhereinmeasuredcapacitancevalueisasfollows.4.236μf(betweenR&Yphase)-Ca5.238μf(betweenB&Yphase)-Cb5.237μf(betweenR&Bphase)-Cc
QM =2/3×(Ca+Cb+Cc)×UN2×(2πfN)/10
9 QM=2/3×(236+238+237)×(4802)×2×3.14×60/109=41.19kvarThe tolerance of capacitance of a capacitor is -5% t0 +10% of capacitor as specified in the IEC Standards.
C C
C
Notes
SchneiderElectricIndustriesSASHeadOffice35,rueJosephMonierCS3032392506Rueil-Malmaisonwww.schneider-electric.com
PFCED111008EN 10/2011
Asstandards,specificationsanddesignschangefromtimetotime,pleaseaskforconfirmationoftheinformationgiveninthispublication.
Thisdocumenthasbeenprintedonecologicalpaper.Design:SchneiderElectricPhotos:SchneiderElectric ©
2011-S
chneiderElectricIndustriesSAS-Allrightsreserved