XITRON XT2640 - Page 96

XT2640OperatingManual 13July2016 Page96of187
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TheUnomlevelwhichyoushouldsetisthatforthephasevoltage,nottheinter‐phasevoltage.
WiththeexceptionoftheRscevalue,theactualvaluesentereddonotchangetheassessmentpass/failresult,theymerely
setthelevelsatwhichasupplyerrorisraisedifthemeasuredvoltageand/orfrequencyisbeyondtheallowedrangefrom
theenterednominalvalue.
Aspreviouslydescribedinsection18.1.4.3,settingazerovalueforRsceallowstheXT2640toautomaticallycomputethe
RscevaluewhichwouldbeneededfortheEUTtohaveaPASSassessmentstatusonallsupplyphases(ifpossible).
However,youmayberequiredtoperformasecondfullassessmentinthissituationifthesupplysourceand/ortheEUT
wiringdonotmeetthenewRscevaluerequirements.UnlessyouareusingasupplysourceandEUTwiringwhichmeets
therequirementsforallpossibleRscevaluesthensomeiterationmayberequired.
18.4.3.2 CONFIGURINGTH EEUTDETAILS
TheEUTDETAILSsectionallowsyoutoselecttheEUTclassificationandtosetthereferencelevelsforthelimitsselectedaccording
tothatEUTclassification.Seesections18.1.4.1or18.1.4.2fordetailsregardingtheEUTclassificationselections.
Note:
ThesesettingsmaybechangedeitherduringorafteranassessmentifdesiredbypressingtheREASSESSbuttonasnoneof
theseaffectthemeasurementsmadeduringanassessment.
Inmostsituationsazerovalueforanyreferencelevelisrecommended,althoughthestandardssuggestthata
manufacturer’svalueshouldalwaysbeusedandreportedevenifitisnotusedinthefinalassessmentresult.Settinga
referenceleveltozeroforcestheuseofthemaximummeasuredvalueencounteredduringtheassessmentasthereference
level.Seesection18.4.2regardinghowthereferencelevelswhichyouconfiguremaybeoverridden.Theusageof
referencelevelsisdefinedintheEN61000‐3‐2and‐12standards,tosummarizethese‐
AWattsreferenceisonlyusedwhenEN61000‐3‐2table3isselectedandaffectsthelimitsforallharmonics.
AnAmpsreferencelevelisonlyusedforallEN61000‐3‐12tables,forEN61000‐3‐2table2,andforthespecial
variantofEN61000‐3‐2ClassC,andaffectsthelimitsforallharmonics.NotethattheAmpsreferencelevelused
byEN61000‐3‐12istheArmsvalueandthatforEN61000‐3‐2isthefundamentalcurrentvalue.Alsonotethat
theAmpsreferencelevelforEN61000‐3‐12assessmentsaffectswhichharmonicsareincludedintheTHCand
PWHCassessmentmeasurementsaswellasaffectingthelimitsapplied.
APowerFactorreferencelevelisonlyusedforEN61000‐3‐2table2andonlyaffectsthelimitforthe3
rd

harmonic.
ItisunclearfromtheEN61000‐3‐2standardwhethertheWattsreferencelevelshouldbethatfortheentireEUTorthatof
asinglephase.Youshouldresolvethisinthosesituationswherethismayoccur(thosetypesofEUTwhichrequireaWatts
referencelevelwouldrarelyhavemulti‐phasesupplies).TheXT2640assumesthatthisistheWattsreferenceforasingle
phase,ifyoudecidethatthisisnotthecasethenyoushouldenterthetotalWattsandselectforUSERREFStopreventit
beingoverridden,andthenmanuallycheckthemeasuredWattsresultsshownbytheXT2640todetermineifthereference
needstobealteredandifneededusetheREASSESSbuttontochangeit(thisdoesnotrequirethattheassessment
measurementitselfberepeated).
ForEUTsassessedaccordingtoEN61000‐3‐2AnnexC.16.2theWattsreferencesettingisasdescribedintheequation
containedinthatclause(whichresultsinasinglephaseWatts)andyoushouldselectforUSERREFStopreventitbeing
overridden.
18.4.3.3 CONFIGURINGTH EASSE SSMENTTIMING 
TheASSESSMENTTIMINGsectionallowsyoutoselectthetimingtobeusedfortheassessment,whethertheassessmentistobe
performedinmultipleintervals,andwhethertheassessmentwillalsobeaffectedbytheEUTstartingand/orstopping.
TESTTIME:Thisallowsyoutoenterthetimeofanassessmentorofanintervalwithintheassessment.Youenterthetimeindays,
hours,minutesandsecondsandthiscanbeanyvaluebetween1secondand99days,99hours,99minutesand99seconds.Notethat
thisisthetimeactuallyassessingtheEUT,anytimespentwiththeassessmentpausedisnotcountedtowardsthistime.
InthedataentryscreenforTESTTIMEtherearefourentries,oneforeachunitofdays,hours,minutesandseconds.
Thescreenalwaysstartswiththedaysdataselected;youcanjumptoanyofthefourentriesdirectlybypressingthe
respectiveentryarea.
Youcanenteranumericbetween0and99intoanyofthefourentries.Theactualtimeusedisthetotaltimecreatedby
combiningallfourentrieswiththeirrespectiveunits.
WhentheENTbuttonispressedtheselectedentryareaautomaticallychangestonextentrytotheright,unlesstheseconds
entryisselectedwhentheactionissameaspressingtheRETURNbutton.
Recommendation:
Thissettingdirectlyaffectstherepeatabilityoftheassessmentmeasurementresults.Youshouldcarefullyconsiderthe
valuetouse.Seesection18.1.3forfurtherdetailsregardingthis.
TheXT2640enforcesnominimumassessmenttimeotherthan1second.ForsometypesofEUTAnnexCofEN61000‐3‐2
doesprovideaminimumassessmenttimeand/oraminimumintervaltimewhenmultipleintervalsarerequired,butfor
mostEUTtypesthestandardsprovidenominimumassessmenttimeaslongasitis“
ofsufficientdurationtomeetthe
requirementsforrepeatability
”.IftheEUTandsupplysourcearestableenoughtomeetthisrequirementwitha1second
assessmenttime,thensuchatimemaybeused,howeveryoumustensurethatthe1.5secondfilteringrequiredbythe
standardshasfullysettledpriortostartinganassessmentsotheEUTmusthavebeenpoweredandstableforatleast10
secondspriortostartingtheassessment,theXT2640doesnotenforcethisandingeneraltheEUTwillactuallyrequire
longerthanthistostabilize.