Extech Instruments MG310 User manual

USER MANUAL
InsulationResistanceTester
WithContinuityandACVoltagemodes
ModelMG310

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Introduction
ThankyouforselectingtheMG310InsulationResistanceTester.Thismetermeasuresinsulation
resistance,continuity,andACVoltage.TheMG310isCATIII600VACandidealformeasuring
insulatingmaterialsandelectricalequipmentsuchastransformers,cables,switches,and
appliances.Applicationsincludemaintenance,testing,andinspection.Properuseandcareofthis
meterwillprovidemanyyearsofreliableservice.
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Safety
ThistesterisdesignedandmanufacturedincompliancewiththeIEC61010standard.Thisuser
manualincludesdetailedinformationrelatedtothesafeoperationandcareofthisinstrument.
Pleasereadcarefullybeforeusingtheinstrument.
Pleasereadandunderstandthisusermanualbeforeusingthedevice.
Alwaysusethedeviceasspecifiedintheusermanual,retainthemanualforfutureuseand
checkthewww.extech.comwebsitefornewerversionsoftheusermanual.
Misuseofthisdevicemaycausepersonalinjuryanddamagetotheinstrumentand
connectedequipment.
Thissymbolontheinstrumentindicatesthatforsafeoperationtheusermustusethe
instrumentasdescribedintheusermanual.
Dangericons:Alerttoconditionsandactionsthatmaycauseseriousorfatalinjury.
Warningicons:Alerttheusertothepotentialofelectricshock.
Cautionicons:Alerttoconditionsandactionsthatmaycausedamagetotheinstrumentor
thatmayaffecttheinstrumentaccuracy.

Danger
Donotmeasurecircuitswithvoltagesgreaterthan750VAC.
Donotusethisinstrumentinareaswhereflammableconditionsexist.
Donotusethisinstrumentinareasofhighhumidity.Donotoperatethisinstrumentwith
wethands.
Donottouchconductivesectionsofthetestleadswhentakingmeasurements.
WhentestleadsareshortedandconnectedtotheinstrumentsdonotpresstheTESTbutton.
Donotopenthebatterycoverduringtests.
Donottouchthetestedcircuitsorwiresduringinsulationmeasurements.
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Warning
Iftheinstrumentexhibitsfaultyoperationpleasediscontinueuseandhavetheinstrument
serviced.
Beextremelycarefulwhentheinstrumentsismeasuringvoltagesthatexceed33VACrms,
46.7VACrms,or70VDC;electricalshockispossible.
Whenhighresistancemeasurementsareconducted,strayelectricalincircuitsundertest
mustbedischarged.
Donotreplacethebatterieswhentheinstrumentiswet.
Ensuresecureconnectionswiththetestleadsandtheinstrument’stestleadterminals.
Shuttheinstrumentdownbeforeopeningthebatterycompartment.
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Caution
Circuitsundertestmustbecompletelydischargedandisolatedfrompowercircuitsbefore
takingresistancemeasurements.
Ifthetestleadsoradaptorsneedtobereplacedduetodamage,replacewithtestleadsor
adaptorsofthesamemodelorelectricalspecifications.
Donotusetheinstrumentiflowbatteryindicatorshowsthelowbatteryindicator.Ifthe
instrumentwillnotbeusedforalongperiod,pleaseremovethebatteryandstoresafely.
Donotstoreoroperatetheinstrumentinareasofhightemperature,highhumidity,flameor
explosivepotentials,orwherestrongelectromagneticfieldsexist.
Cleantheinstrumenthousingwithadampclothandmildcleaningagent;donotuse
abrasivesorsolvents.
Iftheinstrumentiswet,pleasedrybeforestoring.
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ElectricalSafetySymbols
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Riskofelectricalshock
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Doubleinsulationorreinforcedinsulation
ACMeasurement
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Ground
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MeterDescription
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1. EARTHterminalforInsulationResistanceandContinuitytesting.
2. GUARDterminalforACVandContinuitytesting.
3. VterminalforACVtestingandSelf‐Testmode.
4. LINETerminalforInsulationResistancetestingandSelf‐Testmode.
5. BacklitLCDDisplay
6. ZERObutton(shortpress)andLCDBacklightON/OFFbutton(longpress)
7. PI/DARTestingselectionbutton
8. TESTbutton
9. Rotaryfunctionselectswitch
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Note:Securebatterycompartmentlocatedonrearofunit.
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ControlButtons
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1. PI/DARbutton:PresstoselectPIpolarizationindexandDARdielectricabsorptionratiotest
modes.
2. ZERO/Backlightbutton:Longpresstoenable/disableLCDbacklightorshortpresstoresetthe
displaytozeroforlowresistancemeasurements.
3. TESTbutton:Engage/disengagetestingforIR,Continuity,andACVoltagetests.
4. Rotaryfunctionswitch:SelectanIRoutputtestvoltage(250V/500V/1000V),measurelow
resistance(Continuity),ormeasureACVoltage(ACV).

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DisplayDescription
1. Batterystrengthindicator
2. DC/ACVoltagemodes
3. Voltagepresentalert
4. PItestmode
5. DARtestmode
6. Time1forPI/DARtests
7. Time2forPI/DARtests
8. PI/DARTesttimer(minutesandseconds)
9. Testvoltageoutput[V]
10. Units[G:Gigaohm;M:Megaohm]andVoltage[V]andResistance[Ω]modesymbols
11. Mainmeasurementdisplay
12. ZEROfunction
13. UnderRange<
14. OverRange>
15. Audiblecontinuityalertbeeper
OperatingInstructions
WARNING:Riskofelectrocution.High‐voltagecircuits,bothACandDC,areverydangerousand
shouldbemeasuredwithgreatcare.
1. ALWAYSturnthefunctionswitchtotheOFFpositionwhenthemeterisnotinuse.
2. If“OL”appearsinthedisplayduringameasurement,thevalueexceedsthemeter’srange.
3. Ifthebatteriesareweakreplacethembeforeperformingtests.Thebatteryindicatoronthe
upperleftalertstheuserwhenbatterypowerislow.Thebatterycompartmentisaccessed
throughthebackofthemetersecuredbyonePhillipsheadscrew.
DISPLAYBACKLIGHT
Pressandholdthebacklightbuttonfor2secondstoswitchthebacklightonoroff.Forbest
batteryefficiencyusethebacklightonlywhenneeded.
HOLD
Theautomaticholdfunctionfreezestheinsulationresistancereadinginthedisplayforashort
periodoftimeforconvenience.
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LOWBATTERYINDICATION
Whenthe iconappearsinthedisplay,thebatteriesshouldbereplaced.Refertothebattery
replacementsectionofthisusermanual.

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INSULATIONRESISTANCEMEASUREMENTS
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1. Selectthedesiredtestvoltageusingtherotaryfunctionswitch.Selectthe250V,500V,or
1000Vswitchpositionforthecorrespondingoutputtestvoltage.
2. Connecttheredtestleadtothemeter’sLINE(4)jackandtheblacktestleadtotheEARTH
(1)jack.Connecttheprobeendofthetestleadstothecircuitundertest.
3. PresstheTESTbuttontotest.The
buttonwillself‐lockandthebutton
lampwilllight.
Note:Ifthecircuitundertestislive
andhasavoltagepotential(AC/DC)
over30V,themeterwillnottest(the
displaywillshowthe“>”iconand
thesymbolwillflash;thebuzzer
willalsosound).Ifthecircuitunder
testisnotliveorifitsvoltageisless
than30V,themeterwillbegin
applyinghigh‐voltagetothecircuit
undertest.
4. Theprimarydisplaywillshowthe
insulationresistanceinMΩ
(megaohms)orGΩ(gigaohms).
5. Thetestvoltage(VDC)valuewillbe
indicatedintheright‐mostauxiliary
display,thesymbolwillflashandthecautionbuzzerwillsound.
6. PresstoreleasetheTESTbuttontostopthetest.Thehighvoltagewillswitchoffandthe
resistancevalueindicatedintheprimarydisplaywillhold.
7. Subsequently,themeterwillinternallydischargethebalanceoftheinsulationtestvoltage.
Note:Turningthefunctionswitchtoanothertestpositionwillabortthetest.
8. Areadingof>5.50GΩindicatesthatthemeterreadingisabovetheresistancethresholdof
thatmeasurementrange.
CAUTION
Beforetakingmeasurementsdisconnecttheunitundertestfromallpowersourcesandisolateit
fromanystrayresistance.
Donotshortcircuitthetestleadswhenvoltageisoutputfromthemeter.
Allowsufficienttimebetweentestsfordevicesundertesttostabilize.
Whenredandblackclipsareconnectedtothecircuitundertest,highvoltageisoutputfromthe
LINEjackandcurrentfromtheEARTHjack.
Atthecompletionofatest,donottouchanypartsofthecircuitundertest.Componentsmayhave
becomechargedduringthetestandcoulddischargewhentouched.

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POLARIZATIONINDEX(PI)TESTING
ReadandunderstandalloperationsandsafetyinformationcontainedintheInsulationResistance
(IR)measurementsectionaboveandtheSafetysectionbeforecontinuing.
1. Connectthemetertothedeviceundertestasshowninthetestsectionabove.
2. Selectthedesiredoutputtestvoltageusingtherotaryfunctionswitch(250/500/1000V).
3. UsethePI/DARbuttontoaccessthePItestmode.
4. ThedisplaywillshowthePIiconwhenthePImodeissuccessfullyaccessed.
5. Thetwotesttimes(Time1andTime2)willalternatelyshowontheupperright.
6. Thefirsttestwillrunfor1minute(Time1)whentheTESTbuttonispressed.Ifthetestfails
(noisdisplayed)thesecondtestwillnotautomaticallyrunandtestingisnowcomplete.If
thetestpasses(YESisdisplayed)theTime2testwillrunfor10minutes.
7. Thetestresultwilldisplayafterthe10‐minuteTime2interval
8. PresstheTESTbuttontostopthetestandtobegindischargingthedeviceundertest.
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DIELECTRICABSORPTIONRATIO(DAR)TESTING
ReadandunderstandalloperationsandsafetyinformationintheInsulationResistance(IR)
measurementsectionaboveandintheSafetysectionbeforecontinuing.
1. ConnectthemetertothedeviceundertestasshownintheIRtestsectionabove.
2. Selectthedesiredoutputtestvoltageusingtherotaryfunctionswitch(250/500/1000V).
3. UsethePI/DARbuttontoaccesstheDARtestmode.
4. ThedisplaywillshowtheDARiconwhentheDARmodeissuccessfullyaccessed.
5. Thefirsttwotesttimes(Time1andTime2)willalternatelyshowontheupperright.
6. Thefirsttestwillrunfor30seconds(Time1)whentheTESTbuttonispressed.Ifthetest
fails(noisdisplayed)thesecondtestwillnotautomaticallyrunandtestingisnowcomplete.
Ifthetestpasses(YESisdisplayed)theTime2testwillrunfor1minute.Thetestresultwill
displayafterthe1‐minuteTime2interval
7. ToaccessthesecondsetofTime1andTime2testspresstheDARbuttonthreetimesand
repeatthesamestepsaboveinthissection.Forthe2ndsetofteststhetimesare15
seconds(Time1)and1minute(Time2).
8. WhencompletedpresstheTESTbuttontostopthetestandtobegindischarging

8 MG310-en-GB_V1.0 12/15
.
ACCURACYSELF‐TESTFUNCTION
TheMG310featuresa10MΩaccuracycheck
featurefortheInsulationResistancemode.
Toverifytheaccuracy:
1. Connectawirejumpertothemeter
betweentheLINE(4)andV(3)
terminalsasshowninthe
accompanyingillustration.
2. Selectoneofthethreetestvoltage
(250/500/100V)switchpositions.
3. PresstheTESTbuttontobeginthetest.
4. Whentestingiscomplete,themeter
willdisplay10.0MΩ(±0.1MΩ).Ifthe
meterdoesnotshowanaccurate
readingpleasehaveitserviced.
LOWRESISTANCECONTINUITYTESTING
WARNING: To avoid electric shock, never measure continuity on circuits or wires that have
voltage on them.
1. Setthefunctionswitchtothe
(continuity)position.
2. Inserttheblacktestleadbananaplug
intotheGUARD(2)jack.
Inserttheredtestleadbananapluginto
theEARTH(1)jack.
3. PresstheTESTbutton.Thebuttonlamp
willlightindicatingthattestingcan
begin.
4. Touchthetestprobetipstothecircuit
orwireyouwishtocheck.
5. Iftheresistanceislessthan
approximately20Ω,theaudiblesignal
willsoundandtheaudioiconwillbe
displayed.Ifthecircuitisopen,the
displaywillindicate>220Ω.
6. PresstheTESTbuttonagaintodisengagethetestmode(thelampwillswitchoff)before
removingthetestleadsfromthecircuitundertestandfromthemeter.
M

9 MG310-en-GB_V1.0 12/15
ACVOLTAGEMEASUREMENTS
WARNING:RiskofElectrocution.Theprobetipsmaynotbelongenoughtocontactthelivepartsinside
some240Voutletsforappliancesbecausethecontactsarerecesseddeepintheoutlets.Asaresult,the
readingmayshow0voltswhentheoutletactuallyhasvoltageonit.Makesuretheprobetipsaretouching
themetalcontactsinsidetheoutletbeforeassumingthatnovoltageispresent.
CAUTION:
DonotmeasureACvoltagesifamotoronthecircuitisbeingswitchedONorOFF.Largevoltagesurges
mayoccurthatcandamagethemeter.
Donotmeasurevoltagehigherthan750VAC.
Pleaseuseextremecautiontoavoidhighvoltageelectricalshockwhileoperatingthisinstrument.
Disconnecttestleadsfromtestedcircuitsandmeterterminalsaftertesting.
V
V
AC
1. SetthefunctionswitchtotheV(ACV)position.
2. InserttheblacktestleadbananaplugintotheGUARDjack(2).
InsertredtestleadbananaplugintotheVjack(3).
3. PresstheTESTbuttontoengagethetestingmode(thebuttonlampwilllight).
4. Touchtheblacktestprobetiptotheonesideofthecircuit.
Touchtheredtestprobetiptotheothersideofthecircuit.
5. Readthevoltageinthemaindisplay.
6. PresstheTESTbuttonagaintodisengagethetestmode(thelampwillswitchoff)before
removingthetestleadsfromthecircuitundertestandfromthemeter.

10 MG310-en-GB_V1.0 12/15
Maintenance
WARNING:Toavoidelectricshock,disconnectthetestleadsfromanysourceofvoltagebeforeremoving
thebackcoverorthebatteryorfusecovers.

WARNING:Toavoidelectricshock,donotoperatethemeteruntilthebatterycoverisinplaceand
fastenedsecurely.
Thisinstrumentisdesignedtoprovideyearsofdependableservice,ifthefollowingcare
instructionsareperformed:
1. KEEPTHEMETERDRY.Ifitgetswet,wipeitoff.
2. USEANDSTORETHEMETERINNORMALTEMPERATURES.Temperatureextremescan
shortenthelifeoftheelectronicpartsanddistortormeltplasticparts.
3. HANDLETHEMETERGENTLYANDCAREFULLY.Droppingitcandamagetheelectronicpartsor
thecase.
4. KEEPTHEMETERCLEAN.Wipethecaseoccasionallywithadampcloth.DONOTusechemicals,
cleaningsolvents,ordetergents.
5. USEONLYFRESHBATTERIESOFTHERECOMMENDEDSIZEANDTYPE.Removeoldorweak
batteriessotheydonotleakanddamagetheunit.
6. IFTHEMETERISTOBESTOREDFORALONGPERIODOFTIME,thebatteriesshouldbe
removedtopreventdamagetotheunit.

BATTERYINSTALLATION
WARNING:Toavoidelectricshock,disconnectthetestleadsfromanysourceofvoltagebefore
removingthebatterycover.
1. Turnpoweroffanddisconnectthetestleadsfromthe
meter.
2. Opentherearbatterycoverbyremovingthescrewusinga
Phillipsheadscrewdriver.
3. Insertthe6x1.5V‘AA’batteriesintothebatteryholder,
observingcorrectpolarity.
4. Putthebatterycoverbackinplace.Securewiththescrew.

You,astheenduser,arelegallybound(EUBattery
ordinance)toreturnallusedbatteries;disposalinthe
householdgarbageisprohibited!Disposeofusedbatteries/accumulatorsatcollectionpointsin
yourcommunityorwhereverbatteries/accumulatorsaresold!
Disposal:Followthevalidlegalstipulationsinrespectofthedisposalofthedeviceattheendof
itslifecycle
WARNING:Toavoidelectricshock,donotoperatethemeteruntilthebatterycoverisinplace
andfastenedsecurely.