AEMC 2620 User manual

GROUND FAULT/LEAKAGE
DETECTOR 2620
with the Artifical Neutral AN-1
CHAUVIN ARNOUX GROUP
®
ENGLISH User Manual

Statement of Compliance
Chauvin Arnoux®, Inc. d.b.a. AEMC®Instruments
certifies that this instrument has been calibrated
using standards and instruments traceable to
international standards.
We guarantee that at the time of shipping your
instrument has met its published specifications.
An NIST traceable certificate may be
requested at the time of purchase, or obtained
by returning the instrument to our repair and
calibration facility, for a nominal charge.
The recommended calibration interval for this
instrument is 12 months and begins on the date of
receipt by the customer. For recalibration, please
use our calibration services. Refer to our repair
and calibration section at www.aemc.com.
Serial #: ________________________________
Catalog #: 2125.52
Model #: 2620
Please fill in the appropriate date as indicated:
Date Received: _________________________________
Date Calibration Due: _______________________
Chauvin Arnoux®, Inc.
d.b.a AEMC®Instruments
www.aemc.com

Table of Contents
1. INTRODUCTION............................................................................... 3
1.1 International Electrical Symbols................................................3
1.2 DenitionofMeasurementCategories .....................................4
1.3 ReceivingYourShipment..........................................................4
1.4 OrderingInformation.................................................................4
1.4.1 AccessoriesandReplacementParts............................4
2. PRODUCT FEATURES ...................................................................... 5
2.1 Description................................................................................5
2.2 Connections..............................................................................6
3. SPECIFICATIONS............................................................................. 7
3.1 ReferenceConditions ...............................................................7
3.2 Electrical ...................................................................................7
3.3 Mechanical................................................................................8
3.4 Environmental...........................................................................9
3.5 Safety........................................................................................9
4. OPERATION .................................................................................. 10
4.1 PrincipleofOperation .............................................................10
4.1.1 MeasuringCurrentLeakage .......................................10
4.1.2 InterpretingtheMeasurement.....................................10
4.2 EquipmentTroubleshooting ....................................................11
4.3 TestingVariousCableCongurations.....................................12
4.3.1 MetalConduits............................................................12
4.3.2 GroundedNeutral .......................................................14
4.3.3 NeutralGroundedThroughanImpedance .................15
4.3.4 UngroundedSystem ...................................................15
4.4 CommonlyAskedQuestions...................................................15
5. ARTIFICIAL NEUTRAL.................................................................... 17
Warning...........................................................................................17
5.1 Description..............................................................................17

5.2 Specications..........................................................................19
5.2.1 Electrical .....................................................................19
5.2.2 Mechanical..................................................................19
5.2.3 Safety..........................................................................19
5.3 PrincipleofOperation .............................................................20
5.4 TestingUngroundedSystems.................................................21
6. MAINTENANCE ............................................................................. 22
6.1 Cleaning..................................................................................22
RepairandCalibration...........................................................................23
TechnicalandSalesAssistance ............................................................23
Limited Warranty ...................................................................................24
WarrantyRepairs...................................................................................24

GroundFault/LeakageDetectorModel2620 3
CHAPTER 1
INTRODUCTION
Warning
Thesesafetywarningsareprovidedtoensurethesafetyofperson-
nelandproperoperationoftheinstrument.
•Neverusethisclamponconductorswithavoltagepotentialabove
600Vrms.
•Neverclamparoundaconductorunlesstheclampisterminatedto
ameasuringinstrumentwithproperinputimpedance.
•Keep the jaw mating surfacesclean.Ifnecessary, use a slightly
oiledclothtoremoveoxidation.
•Ensurethatthecablesorbusbarareproperlycenteredwithinthe
clampjaws.
•Stayawayfromotherconductorswhichmaycreateinterference.
•Avoidleavingtheclampindampplacesorexposingittorunning
water.
•Duetoshockorrehazards,electricalconnectionsoftheinstrument
shouldbeperformedonlybyqualiedpersonnelandinaccordance
withlocal,state,andfederalelectricalrequirements.
1.1 International Electrical Symbols
Thissymbolsigniesthattheinstrumentisprotectedbydoubleor
reinforced insulation. Use only specied replacement parts when
servicingtheinstrument.
This symbol on the instrument indicates a WARNING and that
theoperatormustrefertotheusermanualforinstructionsbefore
operating the instrument. In this manual, the symbol preceding
instructionsindicatesthatiftheinstructionsarenotfollowed,bodily
injury,installation/sampleandproductdamagemayresult.
Risk of electric shock. The voltage at the parts marked with this
symbolmaybedangerous.

4 GroundFault/LeakageDetectorModel2620
1.2 Definition of Measurement Categories
CAT II: For measurements performed on circuits directly connected to
the electrical distribution system. Examples are measurements
onhouseholdappliancesorportabletools.
CAT III: For measurements performed in the building installation at
the distribution level such as on hardwired equipment in xed
installationandcircuitbreakers.
CAT IV: For measurements performed at the primary electrical supply
(<1000V) such as on primary overcurrent protection devices,
ripplecontrolunits,ormeters.
1.3 Receiving Your Shipment
Uponreceivingyourshipment,makesurethatthecontentsareconsistent
withthepackinglist.Notifyyourdistributorofanymissingitems.Iftheequip-
mentappearstobedamaged,leaclaimimmediatelywiththecarrierand
notifyyourdistributoratonce,givingadetaileddescriptionofanydamage.
Savethedamagedpackingcontainertosubstantiateyourclaim.
1.4 Ordering Information
Ground Fault/Leakage Detector Model 2620................... Cat. #2125.52
Includes user manual and warranty card.
1.4.1 Accessories and Replacement Parts
Adapter–4mmNon-insulatedforSafetyLeads................. Cat. #1017.45
(Converts male safety plugs to non-shielded male plugs)
ArticialNeutralModelAN-1................................................ Cat. #1971.01
Includes instrument with soft carrying case; eight 1.5 V “AA” batteries; four 5 ft (1.5 m) color-
coded leads (green, red, black, blue) and user manual.
Bag–LargeClassicToolBag .............................................Cat. #2133.71
Bag–SmallClassicToolBag............................................. Cat. #2133.72
Lead–Replacement ...........................................................Cat. #2950.29
Set of 4 Color-coded 5 ft Safety Leads (4mm straight banana plugs on both ends) for use with
the Articial Neutral Model AN-1. Rated 600V CAT IV

GroundFault/LeakageDetectorModel2620 5
CHAPTER 2
PRODUCT FEATURES
2.1 Description
TheModel2620measuresleakagecurrentshuntedtogroundcausedby
insulationbreakdownor leaks. Itenablestheoperator to locatefailures
whenorbeforetheyoccur,withoutshuttingdownequipmentorspending
hourstrouble-shooting.
It is designed specically for locating low current faults on high current
loads.ThedetectorisasensitiveACcurrenttransformercapableofmea-
suring di󰀨erential or leakage current from 500µA, and may be used to
measurecurrentupto400Acontinuousduty.
TheModel2620provides,on tworanges,1mV/mAACor1mV/AAC.The
outputleadsareterminatedwithstandard4mmbananaplugscapableof
interfacingwithanystandardmultimeter.
Useofadigitalmultimeterwithanalogbargraphisrecommended:
Digitaltoprovidethepropervoltageinputimpedance,andananalogbar
graphtotracktrends.
Whenthe2620isusedasacurrentleakagedetector,itmakesnodi󰀨erence
ifthesystemissingle-phaseorpoly-phase,orifthecurrentsarein-phase
oroutofphase,balancedorunbalanced.
Thenetmagneticeldatanyinstantintimewillbezeroifalltheconductors
surroundedbythecurrentleakagedetectoraresupplyingallthecurrent
deliveredtoandreceivedfromtheload.
Ifany currentisdiverted throughanyalternate pathtoground, suchas
aninsulationbreakdown,thenetlosswillbedetectedproducingaoutput
proportionaltotheamplitudeofthefaultcurrent.
TheModel2620mayalsobeusedsimplyasahighlyaccurateclamp-on
currentprobe.Withits4"jawopeningandrangeof500µAto400A,the2620
providesaversatile way toanalyzeunbalancedcurrent measurements,
leakagevaluesongroundingconductorsandgroundloopcurrents.

6 GroundFault/LeakageDetectorModel2620
2.2 Connections
The Model 2620 is compatible with most DMMs, voltmeters, or other
voltagemeasuringinstrumentswiththefollowingfeatures:
• Rangeandresolutioncapableofdisplaying1mVACofinput.
• Voltmeteraccuracyof0.75%orbettertotakefulladvantageofthe
accuracyoftheprobe.
• Minimuminputimpedanceof1MΩ.
Connecttheprobetothemultimeterorotherinstrument.
SelecttheappropriateACvoltagerangeonyourmultimeter.
TheModel2620hastwoselectableoutputranges.The4Arangewillpro-
duceamV/mAwithanoutputof4VACat4A.The400Arangeproduces
1mV/Awith400mVAC at 400A.
Warning: User Safety
Always use a DMM, voltmeter or other displaying device, appropriately
ratedfortheworkingvoltageandforsafety.

GroundFault/LeakageDetectorModel2620 7
CHAPTER 3
SPECIFICATIONS
3.1 Reference Conditions
Ambient temperature: 23°C ± 3K
Relative humidity: 20to75%RH
Position of the conductor: Centeredinthejaws
Current frequency and form: Sinusoidal50/60Hz±0.2Hz,distortion<1%
Superimposed DC current: NoDCcurrent
Continuous magnetic eld: Eartheld<40A/m
Alternating magnetic eld: Noexternalalternatingmagneticeld
Proximity of external conductors: None
Measuring device’s impedance: ≥10MΩ/100pF
3.2 Electrical
4A Range
Nominal Current: 4AAC
Measurement Range: 0.5mA to 4AAC
Output Signal: 1mVAC/mAAC
4A Range 0.5 to 10mA 10 to 100mA 100mA to 4A
Accuracy 3%ofR±1mV 0.5%ofR±0.5mV 0.5%ofR±0.5mV
PhaseShift – < 15° < 10°
400A Range
Nominal Current: 400AAC
Measurement Range: 0.5A to 400AAC
Output Signal: 1mVAC/AAC
400A Range 0.5 to 10A 10 to 100A 100 to 400A
Accuracy 0.5%ofR±0.5mV 0.35%ofR±0.5mV 0.35%ofR±1mV
PhaseShift – < 1° < 0.6°

8 GroundFault/LeakageDetectorModel2620
Overloads
• Iplimitcurrent:permanent400ACRMS
• Peakcurrent:<1000A
• Permissibletransientdi/dt:≤30A/μs
• Conductortemperature:≤70°Cwithamaximumpeakof90°C
Load Impedance (DMM):1MΩmin
Frequency:48to1000Hz
Errors caused by external inuences:
Ambient temperature <0.1%per10K
Position of the gripped conductor
(maxwithnotcentredconductor)
0.1%typicofVOUT(non-di󰀨erential
current);0.2%max
Residual di󰀨erential
(maxwithnotcentredconductor)
0.1%typicofIP(di󰀨erentialcurrent);
0.2%max
External elds, 1V/A (1) <60mVofVs
External elds, 1mV/mA (1) <100μVofVs
Coupled DC current, 1V/A (2) <1mVforcontinuous1A
Coupled DC current, 1mVm/A (2) <0.1mVforcontinuous1A
Frequency, 1V/A (3) <1.5%from30Hzto1KHz
Frequency, 1mV/mA (3) <0.5%from30Hzto1KHz
(1): 400 A/m 50Hz eld perpendicular to the clamp opening
(2): DC current coupled onto an AC current
(3): Limited to 1KHz for 100A
3.3 Mechanical
Dimensions: 11.2x6.9x1.8"(285x175x45mm)
Weight:2.9lbs(1300g)approx
Jaw opening: 4.4"(112mm)
Maximum Jaw Gap:9.8"(250mm)
Maximum Clamping Capacity: Max4.5"(115mm)Øcable

GroundFault/LeakageDetectorModel2620 9
3.4 Environmental
Operating Temperature:
-14°to131°F(-10°to55°C);0to85%RH(non-condensing)
Storage Temperature:
-40°to158°F(-40°to70°C);0to85%RH(non-condensing)
Operating Altitude: ≤2000monuninsulatedconductors
Transport Altitude: ≤12000m
3.5 Safety
Electrical Safety
EN61010,600VCATIII
PollutionDegree:2
Electromagnetc Compatibility
IndustrialEnvironment:CriterionB
Emissivity(EN61326-1)
Susceptibility(EN61326-1)
Self-extinguishing Capability
JawsandCasing:VO(UL94)

10 GroundFault/LeakageDetectorModel2620
CHAPTER 4
OPERATION
4.1 Principle of Operation
4.1.1 Measuring Current Leakage
WhenageneratorsuppliesanACloadthroughapairofwiresinaninsulated
cable,thecurrentgoingoutononewireisequaltothecurrentreturning;
their vector sum equals zero.A ground fault changes this equality, and
theleakagecurrentdetectorpicksitup,measuresit,andprovidesanAC
voltageoutputproportionaltotheseverityoffaultcausingtheunbalance.
Thegroundconductormustnotpassthroughthedetector.
4.1.2 Interpreting the Measurement
Figure1isaschematicofasingle-phaseinstallationofamotorandan
oven,bothgrounded.Thenumbersindicatetheamplitudesofthecurrents
in di󰀨erent conductors. This installation has no faults. If you clamp the
detectoraroundthecablesatpointsA,B,CorD,itwilloutputzero.
115V/230V
15A
15A
10A
10A
AB
CD
5A 5A 10A10A
10A
5A
GND
MOTOR
ZERO
AMPERE
ZERO
AMPERE
OVEN
GND
Figure 1

GroundFault/LeakageDetectorModel2620 11
InFigure2,thereisafaultintheinstallation.AtpointA,theModel2620
detects 1A (the di󰀨erence between 16A and 15A), indicating a fault
downstream.AtpointC,itdetectszero;therefore,thefaultisnotinthe
oven.AtpointsBandD,thedetectorpicksup1A,showingthatthefault
isinthemotor.Ifitgetsworse,theleakagecurrentwillincreaseandthe
circuit breaker will trip. This motor should be disconnected immediately
andrepaired.
115V/230V 15A
15A
10A
11A
AB
CD
5A 5A 10A 11A
10A
5A
GND
MOTOR
1A
1A
OVEN
GND
1A
RESIDUAL CURRENT: 1A
Figure 2
In a three-phase installation the principle is the same. But here it is
necessarytopassallactiveconductorsthroughthedetector,includingthe
neutralifoneisused.Ifthisisdoneproperly,thedetectoroutputwillbe
zeroifthereisnocurrentleakingtoground.Ifitdetectssomethingother
thanzero,thereisagroundfaultthatshouldberepaired.
4.2 Equipment Troubleshooting
Tolocateafaultquickly,beginyourtroubleshootingattheincominglow-
voltagedistributionheader.Successivelycheckeachfeeder.IftheModel
2620 detects a ground fault, follow the feeder downstream, branch by
branch,totheequipmentwiththeproblem.
It is useful to take measurements periodically to create a history of the
qualityoftheinsulation.Thisisgoodpreventivemaintenancewhichcould
provevaluablelater.Ifyoudetectafaultcurrentthatisverylowinitially
butincreasesfromdaytoday,thismeansthatelectricalfailureisimmi-
nentand shouldbe takencare ofduring thenext plannedmaintenance
shutdown.

12 GroundFault/LeakageDetectorModel2620
Forbestresults,centertheconductorswithintheclampjaws.Checkthat
theedgesofthejawsareperfectlycleanandthattheyclosetightly.Tryto
avoidplacingtheconductorsnearthegaps,andgroupthemasmuchas
possible.
Ifyouarecareless,youcana󰀨ectthemagnitudeofthereading,depend-
ingonthecurrentbeingcarriedintheconductors.Incertain casesthis
requires an interpretation. Normally, however, the absolute value of the
groundcurrentisnotimportant.Allyouneedtoknowiswhethertheread-
ingiszero.
4.3 Testing Various Cable Configurations
Olderinstallationshave awidevariety ofelectricaldistribution systems.
Cablesareclampedtowallsandpassthroughmetalconduits,andthere
aremanycaseswhereashieldedcablewasinstalledduringrevampingof
anareaoradditiontoabuilding.Ifacableisclampedtowalls,detachit
andpullitawayfromthesurfaceatseveralpoints,sotheclampcansur-
roundalltheconductors.
4.3.1 Metal Conduits
Cablesenclosedinmetalconduitswhicharegroundedarenotaproblem.
Simplyapplytheclamparoundtheconduit;themetaltubewillnotblock
themeasurement.Cableswithametalshieldcanbehandledinthesame
wayascableinmetalconduit.
Agroundedshieldmaypresentaproblem.Ifitisasimplemetalshield,like
athinmetalwrapping,itcanbeconsideredinthesamewayasthemetal
conduit.Ifthearmorisgroundedbyaconductor,itmaybeaninconve-
nience,dependingontheterminalconnections,aswellasonthenumber
andtypeofgroundconnectionsalongthecable.
InFigure3thedetectorsensesthefaultbecause theshield isnotcon-
nected to the motor frame and the leakage current cannot ow back
throughthedetector.
InFigure4,however,theinstrumentcannot“see”thefaultbecausethe
shield is connected to the motor frame, letting the fault current return
through the detector and causing it to read zero. If possible, take your
measurementwhereyoucanavoidclosingtheshieldintheclamp,such
asthenearestcontrolpanelorinsidetheconnectingboxofthemotor.

GroundFault/LeakageDetectorModel2620 13
Figure 3 Figure 4
OnewaytocircumventthisshieldedcableproblemisshowninFigures
5and6.Heretheshieldisloopedthroughthedetectortwice,sothatthe
readingwillbethatofthefaultcurrent.
Figure 5 Figure 6

14 GroundFault/LeakageDetectorModel2620
4.3.2 Grounded Neutral
It is easy to take measurements on this type of network, where major
faultstripthecircuitbreaker. Here,thedetectorcansense minorfaults,
sorepairs canbemadebeforetheproblemgets worse.Theinspection
methodisthesameasforasingle-phaseinstallation.Rememberthaton
athree-phasenetwork,thecurrentsaddaccordingtothevectorsumlaw.
TheModel2620measuresthevectorsumoftheenclosedcurrents.Ifyou
have,forexample,a400mAfaultanda250mAfaultonthesamephase,
theModel2620 willdetect650mA. Butifthetwo faultsareon di󰀨erent
phases,theyaddvectoriallyandmayevensumuptozero.
Figure7showsanexampleinwhichtherearetwoseparatefaults:400mA
on a machine in one shop, 250mA on a machine in another shop. The
vectorsumisnot650mA,but350mA.Ifyouswitcho󰀨themachinewiththe
250mAfault,thereadingincreases,indicatingfaultsondi󰀨erentphases.
Shop 2
Shop 1
Fault on Phase
1
400mA
Fault on Phase
2
250mA
Figure 7

GroundFault/LeakageDetectorModel2620 15
4.3.3 Neutral Grounded Through an Impedance
Followtheprocedurethesamewayasforagroundedneutralinstallation,
butwithcare.Whentheneutralisgroundedthroughanimpedance,afault
(evenaseriousone)maynottripthecircuitbreaker,andthecircuitwill
stay live.
4.3.4 Ungrounded System
In order to measure on an ungrounded system, the optional Articial
NeutralModelAN-1mustbeusedinconjunctionwiththeModel2620.
For measurement procedures, see the information in this manual in
Chapter5.
4.4 Commonly Asked Questions
Q. I have found an indication of 40 to 50mA on one of the main feed-
ers with 300A on the line. Is this value a fault?
A. With300Aontheline,itispossibletondanundesiredcurrentofthat
magnitude. Di󰀨erent cables in the installation may not have equivalent
capacitanceandresistance.Thesecablesprovidefor high current and,
ofcourse,weapplyahighcurrent.Therefore,wemayhaveacapacitive
inuencewhichcorrespondsto45mA.
Q. Must the conductors be centered within the jaws?
A. Youshouldavoidplacingtheconductorscloseagainstthemagnetic
circuit near the gaps, and should group the conductors as much as
possible. Best results are obtained while centering the conductor. You
mustalsoensurethatthejawmatingsurfaceareperfectlycleanandthat
nothingpreventsthemfromclosingtightly.
Q. Is it possible when checking cables which run parallel, yet supply
the same load, to clamp the detector over each cable separately?
A. Whenthereareparallelcables,themeasurementisvalidonlyifthe
detectorincludesthecablestogether.Infact,ifyoutakeeachonesepa-
rately, it is highly probable that the distribution of current in the parallel
cablesisnoteven.Thesedi󰀨erencescanbecausedbythefactthatthe
cablesmaynothaveexactlythesameimpedance.

16 GroundFault/LeakageDetectorModel2620
Q. I have detected faults of 400mA and 250mA on branch circuits
being supplied by the feeder. But clamping onto the incoming feeder
resulted in an indication of 350mA. Can you explain why 400mA +
250mA = 350mA?
A. Thedetectormeasuresresidualcurrent;inotherwords,thevectorial
sumofthecurrents.Ifyouhavea400mAfaultanda250mAfaultonthe
samephase,youhaveeverychanceofnding650mA.But,ifyouhave
twofaultsondi󰀨erentphases,theyaddasvectorsactually,inaverytheo-
reticalcasewecouldevenndzero.
Q. The Model 2620 detects faults caused by insulation failures. How
does detecting faults with the detector dier from information result-
ing from megohmmeter insulation tests?
A. TheModel2620willdetectelectricalfaultswhiletheequipmentisstill
inoperation.Thiso󰀨erstwodistinctadvantages.First,itisnotnecessary
toshutthe equipment down,eliminatingcostlydown time; andsecond,
you may detect faults that would not be evident under non-energized
conditions.
Q. Would it be possible to clamp the Model 2620 directly around the
grounding detector?
A. Yes,insomeinstancesitmaybepossibletodetectfaultcurrentona
specicmotorifthereisadedicatedgroundingpath.However,ifseveral
devicesaresharingacommonground,itshouldbenotedthatthefault
maybeoccurringonanyone(ormultiple)ofthedevices.

GroundFault/LeakageDetectorModel2620 17
CHAPTER 5
ARTIFICIAL NEUTRAL
Warning
• Themeasurementofleakagecurrentisdonespecicallywithaclamp
designedforthispurpose.
• TheArticial Neutral must be connected to a known low resistance
ground.
• Iffaultndingexceeds15minutes,removetheArticialNeutralfrom
itscarryingcase.
• TheArticialNeutralmustalwaysbeintheOFFpositionwhencon-
nectingtheleads.
• Always make connections from the instrument to the circuit under
test.
• Alwaysinspecttheinstrumentandaccessoryleadsforserviceability
priortouse.Replacedefectivepartsimmediately.
• Neverusetheinstrumentonelectricalconductorsratedabove600V.
5.1 Description
TheArticialNeutralisanaccessoryfortheAEMCModel2620Ground
Fault/LeakageDetector.Itgeneratesagroundedarticialneutraltoallow
themeasurementoffaultcurrentsonungrounded3phasesystems.
Inanungroundedsystem,theimpedancebetweenthetransformer,neu-
tral,andgroundisinnity.Therefore,independentoftheloadcurrent,no
groundfaultcurrentshouldow.TheArticialNeutralcreatesanintermittent
return path for the ground fault current enabling the troubleshooter to
distinguishitfromloadcurrent.
TheArticialNeutralisgroundedintermittentlythrougharelaydrivenby
aninternalclock.Thisperiodicgroundingtechniqueperformsthreefunc-
tions:
• Limitsthepossibilityofinsulationfaultswithinthecase.
• Allowsbetterdiscriminationofactualfaultcurrent.
• Limitsinstrumentoverheating

18 GroundFault/LeakageDetectorModel2620
Relayclosuretimeisselectedexternally(FastorSlow)sothattheground
faultclampcanbeusedoneitherananalogordigitaldisplay.Whenusing
ondigitalmultimeter,placetheswitchintheslowposition;whenusingan
analogmultimeter,settheswitchtothefastposition.
An internal buzzer, also driven by the relay, is activated each time the
neutralconnectionisgrounded.Threelights,oneforeachphase,show
thepresenceofeachofthethreephasesintheArticialNeutralpriorto
measurement.Afourthgreenlightindicatestheinstrumentisoperating.
WARNING
Connect and disconnect
only in the OFF position
ARTIFICIAL NEUTRAL
MODEL AN-1
ON
Slow
OFF
ON
Fast
SPECIFICATIONS
Working Voltage: 100 to 600V
Frequency: 45 to 65Hz
Batteries: 8 x 1.5V AA (LR6)
EN 61010, 600V, Cat. III, Pol. 2
600V max
ON
ON light
(green)
Male-male safety leads,
4 mm Ø, length 5 ft (1.5 m) double insulation
Carrying
Strap
Ventilation holes
3 position switch: •
ON, Slow test
•
OFF
•
ON, Fast test
[Carrying case not shown]
Safety alligator clips
C
V3
A
V1
B
V2
Red light, showing
voltage present and
phase fault
Figure 8