Iskra MC320 - Reactive Power and Energy Calculation; Connection; Setting of Current and Voltage Ratios; Used Voltage and Current Range (MC350, MC350 H and MC330 Only)

SETTINGS

Measuringcentres
–
MC320,MC330,MC350&MC350H ‐ User’sManua
l
27
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Reactivepowerandenergycalculation 
Usercanselectbetweentwodifferentprinciplesofreactivepowerandenergycalculation:

Standardmethod:
Withthismethodareactivepowerandenergyarecalculatedbasedonassumptionthatallpower(energy)that
isnotactiveisreactive.
Q
2
=S
2
‐P
2

Thismeansalsothatallhigherharmonics(outofphasewithbaseharmonic)willbemeasuredasreactivepower
(energy).

Delayedcurrentmethod:
Withthismethod,reactivepower(energy)iscalculatedbymultiplicationofvoltagesamplesanddelayedcurrent
samples(seechapterEquationsonpage72):
Q=U×I|
+90°

Withthismethod,reactivepower(energy)representsonlytruereactivecomponentofapparentpower(energy).
Connection
PLEASENOTE

Settingsofconnectionsshallreflectactualstateotherwisemeasurementsarenotvalid.
Connection  
Whenconnectionisselected,loadconnectionandthesupportedmeasurementsaredefined(seechapterSurvey
ofsupportedmeasurementsregardingConnectionmodeonpage21).
MainmenuSettingsConnectionConnectionmode

Settingofcurrentandvoltageratios  
Beforesettingcurrentandvoltageratiositisnecessarytobefamiliarwiththeconditionsinwhichdevicewillbe
used.Allothermeasurementsandcalculationsdependonthesesettings.Uptofivedecimalplacescanbeset
(up/down).Tosetdecimalpointandprefix(up/down)positionthecursor(left/right)tolast(empty)placeor
thedecimalpoint.

Settingsrange VTprimary VTsecondary CTprimary CTsecondary
Maximalvalue 1638.3kV 13383V 1638.3kA 13383A
Minimalvalue 0.1V 1mV 0.1A 1mA

MainmenuSettingsConnectionVTprimary/VTsecondary/CTprimary/CTsecondary
Usedvoltageandcurrentrange(MC350,MC350HandMC330only) 
Settingoftherangeisconnectedwithallsettingsofalarms,where100%represents500Vand5A.Incaseof
subsequentchangeoftherange,alarmssettingsshallbecorrespondinglychanged,aswell.
Nominalfrequency(MC350,MC350HandMC330only) 
Avalidfrequencymeasurementiswithintherangeofnominalfrequency±32Hz.Thissettingisusedforalarms
only.
