Kyoritsu Electrical Instruments Works, Ltd. KEW 3124A User manual

INSTRUCTION MANUAL
HIGH VOLTAGE INSULATION TESTER
KEW 3124A
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CONTENTS
1. SAFETY WARNINGS···································································· 1
2. FEATURES················································································· 4
3. SPECIFICATIONS········································································ 5
4. INSTRUMENT LAYOUT ································································ 9
5. PREPARATIONS FOR TESTS······················································ 10
6. OPERATING INSTRUCTIONS······················································ 12
7. BATTERY CHARGING································································ 17
8. BATTERY REFRESH·································································· 20
9. BATTERY REPLACEMENT·························································· 21
10. BATTERY HANDLING PRECAUTIONS·········································· 22
11. CLEANING OF METER COVER···················································· 23
12. CONNECTION TO RECORDERS ················································· 23
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1.SAFETYWARNINGS
○This instruction manual contains warnings and safety rules which must
be observed by the user to ensure safe operation of the instrument and
to maintain it in safe condition. Therefore, read through these operating
instructionsbeforeusingtheinstrument.
#DANGER
●Read through and understand instructions contained in this manual
beforestartingtousetheinstrument.
●Keep the manual at hand to enable quick reference whenever
necessary.
●Theinstrumentistobeusedonlyinitsintendedapplications.
●Understand and follow all the safety instructions contained in the
manual.Itisessentialthattheaboveinstructionsareadheredto.
Failure to follow the above instructions may cause injury, instrument
damage and/or damage to equipment under test. Kyoritsu is by
no means liable for any damage resulting from the instrument in
contradictiontothiscautionarynote.
○Thesymbol#indicatedontheinstrumentmeansthattheusermustrefer
totherelatedpartsinthemanualforsafeoperationoftheinstrument.It
isessentialtoreadtheinstructionswhereverthesymbol#appearsinthe
manual.
#DANGER is reserved for conditions and actions that are likely to
causeseriousorfatalinjury.
#WARNING is reserved for conditions and actions that can cause
seriousorfatalinjury.
#CAUTION is reserved for conditions and actions that can cause
injuryorinstrumentdamage.
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#DANGER
●Do not attempt to make measurements in the presence of flammable
gasses.Otherwise,theuseoftheinstrumentmaycausesparking,which
canleadtoanexplosion.
●Neverattempttousetheinstrumentifitssurfaceoryourhandiswet.
●ThisinsulationtesterwillproduceahighDCVoltageof10kV.Donot
presstheTestbuttonwhenconnectingthetestleadstotheequipment
(circuit)undertest.
●Neveropenthebatterycompartmentcoverduringameasurement.
●To prevent possible electrical shock, do not touch the circuit under
test during an insulation resistance measurement or right after a
measurement.
#WARNING
●Never attempt to make any measurements if any abnormal conditions
suchasbrokencaseandexposedmetalpartsarenoted.
●DonotrotatetheFunctionswitchwiththetestleadsconnectedtothe
equipmentundertest.
●Do not install substitute parts or make any modifications to the
instrument.ReturntheinstrumenttoyourlocalKYORITSUdistributorfor
repairorre-calibration.
●Do not try to replace the batteries if the surface of the instrument is
wet.
●Inserttheplugintotheterminalfirmlywhenusingtestleads.
●Ensure that the instrument is switched off before opening the battery
compartmentcoverforbatteryreplacement.
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#CAUTION
●Beforestartingameasurement,confirmthattheFunctionswitchisatan
appropriateposition.
●SettheFunctionswitchtoOFFpositionafteruse.
Removethebatteriesiftheinstrumentistobestoredandwillnotbein
useforalongperiod.
●Do not expose the instrument to direct sunlight, high temperature and
humidityordew.
● Useadampclothwithalcoholforcleaningtheareasaroundthemeasuring
terminals.
●Whenthisinstrumentiswet,pleasestoreitafteritdries.
●Wait for a while until the voltage indicator shows 0 V, before
disconnecting the test leads from the equipment (circuit) under test,
whenacapacitivemeasurementisdone.
●Lowbattery voltage,as aresultofalong periodofnon-useorstoring
the instrument without setting the Function switch toOFF, may
trigger the internal over-discharging prevention circuit and further
measurementsmaybestopped.Inthiscase,chargethebatteries.
Symbols
Dangerofpossibleelectricshock
#Usermustrefertothemanual
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2.FEATURES
●Suited for heavy duty electrical maintenance and servicing of industrial
installations,cables,transformers,generatorsandswitchgearswherehigh
voltageinsulationtestsarerequired.
●Measures high voltage insulation resistance up to 100GΩ at a variable
voltagebetween1kVand10kV.
●The digital display indicates set voltage at 100GΩ and output voltage.
After a test, it also shows remaining charges stored in the circuit or
equipmentundertest.
Easy-to-read auto-ranging dual scales for 100GΩ range that are colour
coded for high and low resistance ranges. The LEDs illuminate in
matchingcolourtoindicatewhichrangeisoperative.
●After tests, automatically discharges the charges stored in the circuit
undertest.Completionofdischargingcanbecheckedbyvoltagereadings
onthedigitaldisplay.
●OutputterminaltoprovideDCvoltageinproportiontothetestvoltageand
testcurrentforconnectiontosuchequipmentasachartrecorder.
●OperatedbyNi-MH(Nickelmetalhydride)batterieswhichcanbecharged
fromACpowersourceor12VDCcarbattery.
●Duringinsulationtests,thebuzzerwarnspresenceofhighvoltage.
●BatteryAlarmwarnsbyalternatingitscolour,whenbatteryvoltagelowers.
●Battery Charging Indicator shows completion of battery charging by
alternatingitscolour.
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3.SPECIFICATIONS
●HighVoltageRangeatVariableTestVoltage
NominalTestVoltage 1kV-10kV/DC(Variable)
MeasuringRange 0-1.6GΩ/1-100GΩ
(Autoranging)
Accuracy
Insulation
Resistance
0.05-50GΩ ±10%ofrdg
OtherRanges
±1%ofscalelength
(Whentestvoltageisbelow
2kV, the accuracy is not
guaranteedat50-100GΩ)
Output
Voltage
±2%ofsetvalue±2dgt
(onOpenCircuit)
●1kV/100MΩRange
NominalTestVoltage 1kV
MeasuringRange 0-100MΩ
Accuracy
Insulation
Resistance
1-100MΩ ±10%ofrdg
OtherRanges ±1%ofscalelength
Output
Voltage
OpenCircuit 1kV±10%
10MΩload
45%ormoreofNominalTestVoltage
●OutputVoltageandSetVoltageIndicator
MeasuringRange 0-10kVDC
Accuracy ±2%ofreading±2dgt
●DCVoltageOutputforRecorders
VoltageOutputEARTH-LINECurrent 10 0mVDC/10μA
VoltageOutputEARTH-LINEVoltage 100mVDC/1kV
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CurrentConsumption: 80mAapprox.instand-bystate,
300mAmax.inoperation
BatteryAlarm: As battery voltage lowers, the illuminating Battery
Alarm (BATT. ALARM) alternates its colour to
Green,YellowandRed.
ThresholdvoltagesbetweenGreenandYellow,and
Yellow and Red are approximately 9.6V and 9.1V
respectively.
Yellow shows that batteries need to be charged
and Red indicates that the instrument is going
inoperative.
BatteryCharging
Indication:
While charging, the Battery Charging indicator
(BATT. CHARGE) illuminates in Red and turns
into Green to indicate completion of charging.
The threshold voltage is approximately 11V.
(Charge current of approximately 330mA falls to
approximately60mAafteracompletionofcharging.)
AutomaticPowerOff: The instrument automatically shuts off power as
batteryvoltagefallsbelow9.0to8.5V.
The instrument does not become operative unless
thebatteriesarecharged.(Thisfunctionisprovided
toprotectbatteriesfromdamagebyover-discharge.)
Temperatureand
Humidityfor
GuaranteedAccuracy:
23℃±5℃at85%max.relativehumidity
OperatingTemperature
andHumidity:
0℃to40℃at85%max.relativehumidity
StorageTemperature
andHumidity:
-20℃to+60℃at75%max.relativehumidity
(notapplicabletobatteries)
InsulationResistance: 1000MΩmin. at 1000Vbetweenelectricalcircuit
andhousingcase.
WithstandVoltage: 5000V AC for 1 minute between electrical circuit
andhousingcase.
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PowerSource: EightNi-MHrechargeable
AAsizebatteries,HR15/51
(1)Ratings
Ratedcapacitymin.1900mAh
(atdischargerate0.1CmA)
Nominalvoltage1.2V
(2)Chargeconditions
See
section7forBatterycharging.
(3)Storageconditions
At a temperature of -20℃ to +30℃ and low
humidity,wheretherearenocorrosivegasses
(4)Batterylife
The number of tests is not less than 500,
underappropriatecharge,dischargeandstorage
conditions.
When the number of tests per one charge
largely decreases, battery replacement is
needed.(See section9forBatteryreplacement .)
TypicalNumberof
Tests:
With incorporated batteries, 70 to 80 tests of
5-minute duration per one charge, depending on
operatingconditions.
Accessories: Model9176CarryingCase
Model8266:120Vor
Model8267:230V
BatteryCharger
Model7084EarthandGuardLeads
Model7082LeadsforRecorder
Model7083LeadsforBatteryCharging
EightNickelMetalHydriderechargeable
batteries,HR15/51(installed)
Instructionmanual
Dimension: 200(L)×140(W)×80(D)mm
Weight: Approx.1600g
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KEW3124A
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4.INSTRUMENTLAYOUT
①LineProbe   ⑪OutputVoltage
②GuardTerminal  andSetVoltageIndicator
③EarthTerminal  ⑫MeterMovementZeroAdjust
④BatteryAlarm  ⑬TerminalforBatteryCharging
⑤BatteryChargingIndicator ⑭OutputTerminalforRecorder
⑥HighScale   ⑮TestButton
⑦LowScale   ⑯FunctionSwitch
⑧1kV/100MΩScale ⑰OutputVoltageSetKnob
⑨HighScaleIndicator  ⑱EarthLead(Black)
⑩LowScaleIndicator  ⑲GuardLead(Green)
⑱⑲
②③
④⑤
⑧
⑪
⑬
⑥
⑦
⑨
⑩
⑭
⑰
⑫
⑮
⑯
Fig.1
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5.PREPARATIONSFORTESTS
5-1MechanicalZeroAdjustment
With the Function switch set to the OFF position, check the meter
pointer lines up with the "∞" mark on the scale. If not, adjust it by
rotatingtheMeterMovementZeroAdjustwithasmallscrewdriver.
5-2Testleadsconnection
ConnecttheEarthlead(black)totheEarthTerminaloftheinstrument.If
necessary,connecttheGuardlead(green)totheGuardTerminalofthe
instrument.(See section6-3forHowtousetheGuardterminal. )
5-3BatteryCheck
(1)Make sure that the Test button is not locked down and set the
FunctionswitchtotheH.V.SETposition.
(2)If the Battery Alarm illuminates in Green, proceed to step (4). If in
YelloworRed,chargebatteries.
(See section7forBatteryCharging. )
Batt.voltage >9.6V 9.6〜9.1V <9.1V
BatteryAlarm Green Yellow Red
(3)IftheBatteryAlarmisnotlitorthedigitaldisplaydoesnotoperate,
confirm that the batteries are installed correctly and charge the
batteries.
(4)SettheFunctionswitchtotheOFFposition.
#DANGER
●Do not press the Test button where the Function switch is set to any
positionotherthanOFFtoavoidgettingelectricalshock.
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#CAUTION
●The internal over-discharging prevention circuit will be active when
thebatteryvoltagedropsto9.0‒8.5Vorlessandthemeasurement
functionswillbecompletelydisabled.
If the Battery Alarm is not lit or the digital display does not operate,
confirm that the batteries are installed correctly and charge the
batteries.(See section7and9. )
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6.OPERATINGINSTRUCTIONS
6-1Checkingforabsenceofvoltage
Thecircuitbreakeroftheequipment(circuit)undertestmustbeturned
off.Useahighvoltagedetectorandverifythereisnovoltagepresence
beforemakingameasurement.
6-2Insulationtestswith1kV-10kV/100GΩrange
#DANGER
●Confirmthatnoelectricalchargesexistonthecircuitundertestbefore
ameasurementbyusingahighvoltagedetector.
●Putonapairofinsulatedglovesforhighvoltage.
●Always set the Function switch and Test button to OFF before
connectingthetestleads.
While the Function switch is at1 kV/ 100 MΩorH.V. OUT, high
voltage is being generated at the tips of the test leads and also the
circuitundertest.Donottouchthemtoavoidgettingelectricalshock.
●The battery compartment cover must be closed before making a
measurement.
●Donotstartameasurementwhenthunderrumbling.
●MakesuretoconnecttheEarthlead(black)totheearthterminalofthe
circuitundertest.
Note:
◦KEW3124A may indicate unstable readings when the insulation
resistanceoftheequipmentundertestisnotstable.
◦Ittakestimetomeasureacapacitiveload.
◦At an insulation resistance measurement, positive voltage is outputted
fromtheEarthterminalandnegativevoltagefromtheLineterminal.
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(1)MakesurethattheFunctionswitchissettotheOFFposition,theTest
buttonisnotlockeddownandtheFunctionswitchissettoOFFposition.
(2)Connect the clip of Earth lead (black) to the earth point of the circuit,
equipment or cable under test. If necessary, connect the clip of Guard
lead(green)toanappropriatepoint.
(See
section6-4forHowtousetheGuardTerminal. )
(3)Connect the clip of Line probe (red) to the circuit, equipment or cable
undertest.
(4)SettheFunctionswitchtotheH.V.SETpositionandsetoutputvoltage
with the output voltage set knob. Set voltage is shown on the digital
display.
(5)Set the Function switch to the H. V. OUT position and press the Test
button.
(6)When the high scale indicator (green) illuminates, read the high scale
markedingreen,andwhenthelowscaleindicator(red)illuminates,read
thelowscalemarkedinlightred.
If an insulation resistance indication varies when testing a cable that
containshighcapacitance,waituntiltheindicationbecomesstable.
Forcontinuousoperation,presstheTestbuttonandturnitclockwiseto
lockitdown.Toreleasethebutton,turnitcounter-clockwise.
(7)KEW3124Ahasauto-dischargefunction.
Keep the test leads connected to the circuit under test and unlock
the Test button when a measurement completes. The auto-discharge
functionoperatestodischargetheelectricalchargesonthecircuitunder
test.
Confirmthattheoutputvoltageindicatorshows0V.
(8)SettheFunctionswitchtotheOFFpositionanddisconnecttheclipsof
leadsfromthecircuit,equipmentorcableundertest.
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#DANGER
●Nevergroundyourselfwhenconductingelectricaltests.
Donottouchexposedmetalpipes,outlets,fixtures,etc.,whichmightbe
atgroundpotential.Keepyouisolatedfromgroundbyusingdryclothing,
rubbershoes,rubbermats,oranyapprovedinsulatingmaterial.
●Toavoidgettingelectricalshock,nevertouchtheequipmentundertest
ordisconnectthetestleadsuntiltheauto-dischargeprocesscompletes
afterameasurement.
#CAUTION
●If an insulation breakdown occurs in the circuit, equipment or cable
under test, the insulation resistance indication falls to zero or its
approximatevalueinthelowscale.ImmediatelyreleasetheTestbutton
andwaituntilthedigitaldisplayreadszero.
ThenturntheFunctionswitchtotheOFFposition.

TestbuttonwithLockdownfeature
◦Pressing and turning the Test button clockwise locks the button in
the continuous operating position. Press and turn the button counter-
clockwiseandrestoreittotheinitialpositionafterameasurement.

Auto-dischargefunction
◦Electricalchargesstoredintheequipmentundertestareautomatically
discharged after a measurement. The voltage output indicator shows
thedischargingprogress.
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6-3Insulationtestswith1kV/100MΩrange
#DANGER
●Confirmthatnoelectricalchargesexistonthecircuitundertestbefore
ameasurementbyusingahighvoltagedetector.
●Putonapairofinsulatedglovesforhighvoltage.
●Always set the Function switch and Test button to OFF before
connectingthetestleads.
WhiletheFunctionswitchisat1kV/100MΩorH.V.OUT,high
voltage is being generated at the tips of the test leads and also the
circuitundertest.Donottouchthemtoavoidgettingelectricalshock.
●The battery compartment cover must be closed before making a
measurement.
●Donotstartameasurementwhenthunderrumbling.
●MakesuretoconnecttheEarthlead(black)totheearthterminalofthe
circuitundertest.
(1)Make sure that the Function switch is set to the OFF position, the
Test button is not locked down and the Function switch is set to OFF
position.
(2)Connect the clip of Earth lead (black) to the earth point of the circuit,
equipment or cable under test. If necessary, connect the clip of Guard
lead(green)toanappropriatepoint.
(Seesection6-4forHowtousetheGuardTerminal.)
(3)Connect the clip of Line probe (red) to the circuit, equipment or cable
conductorundertest.
(4)SettheFunctionswitchtothe1kV/100MΩposition.
(5) Press the Test button and read the 1 kV/ 100MΩ scale (the inner
scale).
 Forcontinuousoperation,presstheTestbuttonandturnitclockwiseto
lockitdown.Toreleasethebutton,turnitcounterclockwise.
(6)ReleasetheTestbuttonandwaituntilthedigitaldisplayreadszero.
 (SeeAuto-dischargefunction.)
(7)SettheFunctionswitchtotheOFFpositionanddisconnecttheclipsof
leadsfromthecircuit,equipmentorcableundertest.
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KEW3124A Fig.2
6-4HowtousetheGuardTerminal
Incableinsulationtests,windaconductivewirearoundinsulationofthe
cable under test and connect it to the Guard terminal with the Guard
leadasperFig.2.
This is to move out the surface leakage resistance of the cable
insulationtomakethetestresultsaccurate.
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7.BATTERYCHARGING
#DANGER
●Donotopenthebatterycompartmentcoveriftheinstrumentiswet.
●Never replace batteries during a measurement. To avoid a risk of
electricalshock,donotconnectthetestleadstotheequipmentunder
testandsettheFunctionswitchtoOFFwhenreplacingthebatteries.
●Toavoid gettingelectrical shock,thebatterycompartment covermust
beclosedduringameasurement.
#CAUTION
●Use the Ni-MHbatteries specified forKEW3124A. Do notuse NiCad
rechargeable batteries, alkaline nor manganese batteries to prevent
batteryleakorexplosionwhichmaydamagetheinstrument.
●Do not mix the different types of batteries. Always replace all the
batterieswiththenewonesatthesametime.
●Insert batteries with observing correct polarity marked on the battery
compartmentarea.
7-1Whentochargethebatteries
(1)If the Battery Alarm alternates its colour from Green to Yellow or
Red during a battery check or insulation test, charge the batteries
accordingto
section7-2. 
Note:
◦Green shows that battery voltage is sufficient, Yellow indicates that
batteries need to be charged and Red warns that the instrument is
aboutto shutoffpower. Whenbattery voltage fallsbelow 9.0Vto8.5V,
the Automatic power off function turns the instrument into inoperative
condition.
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(2)IftheinstrumentdoesnotturnoperativewiththeFunctionswitchset
to the H.V. SET position, charge the batteries according to
section
7-2.
Propertemperatureforbatterycharging
●
Temperatures between 10℃ and 30℃ are optimum and recommended
forbatterycharging.
●Do not charge batteries at temperatures 0 ℃  or lower and 40 ℃  or
higher;otherwisethebatterieswillbedamaged.

7-2Howtochargethebatteries
(1)SettheFunctionswitchtotheOFFposition.
(2)Plug the battery charger into mains socket outlet, or connect the
redand blackclipsof theleadsfor batterychargingto the+and -
terminalsofacarbatteryrespectively.
(3)Connect the plug of the battery charger or the leads for battery
chargingtotheTerminalforBatteryChargingoftheinstrument.
Thenthebattery chargingindicator (BATT.CHARGE)illuminatesin
red.
ThebatterychargingindicatorturnsintoGreentoshowthebatteries
havebeenchargedby80%and5morehourstogountilcompletion
ofcharging.
(4)Waitforatmost11hours.Chargingtimedependsontheremaining
batteryvoltage.
(5)After charging, disconnect the plug of the battery charger or the
leadsforbatterycharging.
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