Power Factor Correction Guide for the Design and ... · Installation guidelines for APFC Panels...

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


Capacitors


Reactive energy

DE

9007

1_r.e

ps

Power generation



Reactive energy Reactive energy

Power generation


Capacitors


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


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


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


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


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


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


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


THDu (%) 3 5 6 8

SDuty

HDuty

Energy


15

General DesignRules

15


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*



*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


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


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


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


19

VarplusBoxTechnical Specifications


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


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


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


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


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


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


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


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


Power supply

Capacitor

After Switching

Inrush

Conventionalmultistagecapacitorswitchingwithnormalpowercontactor


Power supply

Capacitors already on

Capacitors to be switched

on


Power supply


Capacitors switched on

Before Switching After Switching

Inrush

MultiStageCapacitorSwitchingwithCapacitorDutyContactorStage1-Capacitorisswitchedthroughainrushcurrentlimiter

CapacitorSwitchingContactor

Power supply


Capacitors to be switched

on

Before Switching After Switching Stage 1


Power supply


Capacitor switched on

Limited Inrush

Stage2-CapacitorisswitchedthroughContactorandinrushcurrentlimiterStage3-inrushcurrentlimiterisremovedfromthecircuitandCapacitoriscompletelyswitchedon

After Switching Stage 2 After Switching Stage 3


Power supply




Power supply



Limited Inrush Normal Current

Parallel operation of capacitor and inrush current limiting capacitors in APFC panels

313131


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


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


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


35

Varlogic - Technical 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


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


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


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


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


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


(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




42

Fuse SelectionTheratingmustbechosentoallowthethermalprotectiontobesetto:

1.5InforSDuty/HDuty/EnergyCapacitors 1.35×InforHDuty/Energywith5.7%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


Individualcapacitorprotectionbycircuitbraker



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


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


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


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


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



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


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


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.


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


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


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


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.


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


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


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:

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no:

no:

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no:

no:

no:

no:

no:

no:

no:

no:

no:

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no:

no:

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no:

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no:

no:

no:

Pre despatch factory inspections report model


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 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.


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.


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

SchneiderElectricIndustriesSASHeadOffice35,rueJosephMonierCS3032392506Rueil-Malmaisonwww.schneider-electric.com

PFCED111008EN 10/2011

Asstandards,specificationsanddesignschangefromtimetotime,pleaseaskforconfirmationoftheinformationgiveninthispublication.

Thisdocumenthasbeenprintedonecologicalpaper.Design:SchneiderElectricPhotos:SchneiderElectric ©

2011-S

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