KYORITSU 4116A - Measurement of Prospective Short Circuit Current; Detailed Explanation; Measurement of Fault Loop Impedance and Prospective Fault Current

― 10 ―
5.3MeasurementofProspectiveShortCircuitCurrent
− (Models4118Aand4120A)
(1)Settheinstrumenttothe20kArange.
(2)Connectthetestleadtotheinstrument.
(3)Attachtheplugtothesockettobetested.
(4)CheckthattheLED'sarelitinthesequenceindicatedinsection5.1.If
not,disconnectfromthemainsandcheckthewiringatthesocket.
(5)Pressthe"PresstoTest"button.Theprospectiveshortcircuitcurrent
(PSC)willbedirectlydisplayedontheLCDwiththeappropriateunits.
Thiswillremainfor3sandthenreverttoACvoltagedisplay.
Anaudiblebeepwillsoundoncompletionofthetest.Forbestresults
alwaystestonthelowestpossiblerange.
Forexample a PSCmeasured on the2000A range may read60A
whilstonthe200Arangeitmayread56.0A.Toholdthereadingkeep
thebuttonhelddownorturnclockwisetolockforAutoTest.
Note:
● Forloopimpedancegreaterthan210Ω onPSC200Arangeand25
Ω on2000A,20kAranges,thefaultvoltagemaybecomehighand
dangerousduetotheD-LOKcurrent,therefore,theunitisdesigned
tolockoutPSCrangesshowing"Uf-Hi"symbol.
NormallyPSCtestsareconductedatpointoforigin,e.g.distributionboards,
betweenphaseandneutral.
WhenconductingPSC testsatsocket outlets,a testwillbe conducted
betweenphaseandearthduetothefixedwiringofthemouldedmainsplug.
WARNING
● Thisinstrumentisintendedonlyforuseinsinglephaseoperation
at230V+10% -15%AC phasetoearth orfor useinOLD-TT
systemphasetoneutral.
6.DETAILEDEXPLANATION
6.1 MeasurementofFaultLoopImpedanceandProspectiveFaultCurrent
Iftheelectricalinstallationsareprotectedby over-currentprotection
devicesorbyfuses,theFaultloopimpedanceshouldbemeasured.