XITRON XT2640 - Supply, XT2640 and EUT Wiring

XT2640OperatingManual 13July2016 Page88of187
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EN61000‐4‐7:2002+A1:2009withcorrigendaAug.2004,May2005andNov.2011.
TestingandMeasurementTechniques–
Generalguideonharmonicsandinterharmonicsmeasurementsandinstrumentation,forpowersupplysystemsandequipment
connectedthereto.
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Note:
TheXT2640iscapableofperformingmeasurementstotherequirementsofEN61000‐4‐7,andperformingassessmentsof
aEUTtotherequirementsofEN61000‐3‐2or‐12,onlywhenconfiguredtodoso.
Inthefuturetheremaybelaterversionsofthesestandardsandthoselaterversionswillhavedifferenceswhichmayaffect
assessmenttestingtothosestandardsusingtheXT2640.YouarerecommendedtocontactXiTRONshouldthisoccurto
determineifanyactionneedstobetakeninthisregard,generallytheXT2640canhavefieldinstalledfirmwareupgrades
whichmaybeneededtoaccommodatesuchfuturechangestothesestandards.Atthistime,therearenohardwareaspects
oftheXT2640whichareforeseenaslimitingtheabilitytoaccommodatechangesinthestandards,howeverthatcannotbe
guaranteedasitcannotbeforeseenwhatfuturechangesmaybemade.XiTRONcannotbeheldliableinanymannerfor
futurechangestostandards.
TheassessmentcontainedintheXT2640assumesthatthenormativereferencesinEN61000‐3‐2and‐12onlyrequirethat
themeasurementsbecompliantwithEN61000‐4‐7,andtheportionsofEN61000‐4‐7whichareeithernotmeasurement
relatedorareadditionalmeasurementsnotusedbyEN61000‐3‐2and‐12arenotrelevant.
Throughoutthissectionofthemanual,andwithintheassessmentcontainedwithintheXT2640,itisassumedthatwhena
“primary”levelstandard(suchasEN61000‐3‐2or‐12)callfora“secondary”levelstandard(suchasEN61000‐4‐7),and
bothstandardscontainconflictingoverlappingrequirements,thentheindustrynormisappliedthattheprimarystandard
overridesthesecondarystandard.ItshouldalsobenotedinthisregardthattheEN61000‐3‐2and‐12standardsalsopost‐
datetheEN61000‐4‐7standard.Forexample‐
Boththeprimarystandards(EN61000‐3‐2and‐12)andthesecondarystandard(EN61000‐4‐7)containexplicitbut
overlappingandinconsistentrequirementsforthesupplyvoltagetotheEUT,thewiringtotheEUT,andtheimpedance
ofthecurrentsensorintheXT2640.Insofarasthisoccurs,therequirementsoftheprimarystandards(EN61000‐3‐2
and‐12)havebeenassumedintheXT2640andinthisdocument.
18.1.2 SUPPLY, XT2640AND EUT WIRING
BothEN61000‐3‐2and‐12containrequirementsonthewiringbetweenthesupplysourceandtheEUT,includingtheXT2640
currentmeasurement.Youmustensurethatthesupplysourceandthewiringmeettheserequirements.
ForEN61000‐3‐2seeFiguresA.1andA.2
ForEN61000‐3‐12seeclause7.2andnotethattheimpedanceofthiswiringformspartofthecalculationsregardingthevalueof
RscewhichisdefinedandreferencedinmanyclausesofEN61000‐3‐12.
18.1.2.1 XT2640VOLTAGECONNECTIONSANDTHEADJUSTSETTING
Thewiringusedforthevoltageterminalconnectionscarryverylittlecurrentandarenotcoveredbyanystandardrequirements.
Thiswiringonlyneedstohavesufficientinsulationratingforthevoltagebeingcarriedandimpedancesashighasseveralohmshave
virtuallynoeffectonthemeasurementresults.
EN61000‐3‐2,‐12,andEN61000‐4‐7allrequirethatyouconnectthevoltageterminalsoftheXT2640acrossthevoltagesupply
directlyattheEUT.TheXT2640allowsyoutodothis,andifyouhavedonesotheXT2640alsoallowsyoutoadjustthemeasured
currenttothatofjusttheEUTbycorrectingtheapparentcurrentsignalforthecurrentdrawnbythevoltageterminalsofthe
XT2640,thisisselectedbyselectingaADJUSTsettingofLOAD(V@LOAD)intheMEASCONFIGscreen.
Note:
FortheADJUSTsettingsotherthanNONE,thesettingisshownintwoparts‐
The1
st
part(LOADorSRCE)defineswheretheresultsaretobeshownfor.InthesecasesitisalwaystheEUT
loadwhichisrequiredsoonlytheLOADselectionsareapplicable.
The2
nd
part(V@LOADorV@SRCE)defineswherethevoltagemeasurementisconnectedto.Ifconnectedtothe
supplysourcethenV@SRCEshouldbeselected,otherwisethevoltagemeasurementisconnectedtotheEUTso
V@LOADshouldbeselected.
Recommendations:
ForEUTloadsofover1Armsperphaseyoushouldfollowthestandardsandwirethevoltagemeasurementstothevoltage
supplyattheEUTandalsoyoushouldusetheLOAD(V@LOAD)ADJUSTsetting.
ForEUTloadsbetween0.05Armsand1Armsperphaseyouarerecommendedtousewhicheverwiringmethodisthemost
convenientforyouandselecttheapplicableLOAD(V@LOAD)orLOAD(V@SRCE)ADJUSTsetting.Atthesepowerlevels,
forasinglephasesupplyandEN61000‐3‐2testing,itmaybemoreconvenienttousetheLPA‐1adaptoravailableforthe
XT2640(whichiswiredwiththeVterminalsonthesupplyside)anduseaADJUSTsettingofLOAD(V@SRCE).Ifyouuse
thevoltagemeasuredatthesupplysourcemethodthenyoumustensurethatthewiringtotheEUT(includingtheXT2640
currentshunt)islessthan0.1Ω(whichisusuallyeasilyachieved).
ForaEUTloadsofbelow0.05ArmsperphaseitishighlyrecommendedtousetheVterminalsconnectedtothesupply
sourcemethod(whichincludestheLPA‐1adaptor)asitprovidessuperioraccuracyassumingthatthewiringbetweenthe
supplysourceandtheEUT(includingtheXT2640currentshunt)islessthan1Ω(whichisusuallyveryeasilyachieved).
TheNONEADJUSTsettingisrecommendedbutLOAD(V@SRCE)canalsobeused.
18.1.2.1.1 Multi‐Ph aseSupplieswithoutaNeutral
Whenusingamulti‐phasesupplywithnoneutral,EN61000‐4‐7suggestsusinganartificialneutralresistivenetworktoproducethe
commonvoltagemeasurementreferencepoint,thisisnotnecessarywiththeXT2640asthevoltageterminalimpedanceitself
effectivelyprovidessuchanetwork.