Extech Instruments 380940 User manual

UserGuide



TrueRMSAC/DCPowerClampMeter



Model380940



Model 38090A-EU-EN v1.0 2/14

Introduction

Congratulations on your purchase of the Extech 380940 True RMS Watt Clamp DMM. This

meter combines multimeter and clamp meter functionality in one convenient meter. Careful

useofthismeterwillprovideyearsofreliableservice.



Safety

1. NEVERexceedthespecifiedvoltage/currentmaximum

2. USEEXTREMECAUTIONwhenworkingwithhighvoltages.

3. DONOTmeasurevoltageifthevoltageonthe"COM"inputjackexceeds500Vaboveearth

ground.

4. NEVERconnectthemeterleadsacrossavoltagesourcewhilethefunctionswitchisinthe



currentmode.Doingsocandamagethemeter.

5. ALWAYSdischargefiltercapacitorsinpowersuppliesanddisconnectthepowerwhen

measuring.

6. ALWAYSturnoffthepoweranddisconnectthetestleadsbeforeopeningthebacktoreplace

thefuseorbatteries.

7. NEVERoperatethemeterunlessthe

backcoverandthebattery/fusedoorareinplaceand

fastenedsecurely.



InternationalSafetySymbols



Model 38090A-EU-EN v1.0 2/14

MeterDescription

1. Conductorundertest

2. ClampJaws

3. Jawtrigger–Opensthemeterjaws

4. ZERObutton–ZeroestheDCAreading

5. Positiveinputjack(forredtestlead)

6. Functionselectdial

7. HOLDbuttonfreezesthedisplayedreading

8. MAX/MINbutton–Presstotrackandview

highestandlowestreadings

9. LCDDisplaywithfunctionindicatorsandbargraph

10. COMinputjack(forblacktestlead)



FunctionSelectSwitch



Model 38090A-EU-EN v1.0 2/14

Displayicons

 Lowbattery

DC Directcurrent

AC  Alternatingcurrent

  Minussign

AUTO Automaticrange(frequencyonly)

APO AutoPowerOFF

ZERO Zero/Relativefunction

HOLD HOLDfunction

MAX Highestreading

MIN Lowestreading

 Audiblecontinuity

V Voltageunitofmeasure

A Currentunitofmeasure

M Prefix

MEGA(millionsofunits)

k PrefixKILO(thousandsofunits)

 Ohm(unitofmeasureforresistanceandcontinuity

Hz Hertz(unitofmeasureforfrequency)

OL Overload(whenreadingexceeds4032)

Bargraphdisplay

The40segmentbargraphdisplayshownbelowisagraphicalinterpretationofthemeasurement.

ItisdisplayedunderthedisplaydigitsontheLCD.

Thebarsinthebargraphindicateapresenceofanelectronicsignal.Themorebarsshowing,the

higherthesignal.Thedigitsbelowthegraphhelpthe

userseehowmanybarsareshowing.If40

segmentsareshowing,thebarswillreachthe‘40’mark,if20barsareshowingthebarswill

reachthe‘20’mark.

Thebargraphistobeinterpretedbasedontherangethemeterisinwhilethemeasurementisbeingmade.

Ifthebargraphshows40segmentslit,thenthesignalisatthehighestendofthemeter’spresentrange.



Model 38090A-EU-EN v1.0 2/14

Operation

AC+DCPowerWattMeasurements

1. Connectthetestleadstothevoltagesourceinparallelwiththeload(refertodiagram).

2. Clampontooneofthewiresconnectedtotheload.

3. SelecttheACorDCvoltagerangeusingthefunctionselectswitchandcheckthevoltage

reading.

4. SelecttheACor

DCcurrentrangeusingthefunctionselectswitchandcheckthecurrent

reading.

5. SelecttheappropriateWattrangeusingthefunctionselectswitch.

6. ReadtheKWvalueontheLCD.



ACCurrentMeasurements

WARNING:Toavoidelectricshock,disconnectthetestleadsfromthemeterbeforemaking

currentmeasurements.

1. SettheFunctionswitchtotheACCurrentposition.

2. Pressthejawtriggerandclamparoundasingleconductorfullyenclosingit.Donotallowa

gapbetweenthetwohalvesofthejaw.

3. ReadtheACAvalueontheLCD.

Model 38090A-EU-EN v1.0 2/14

DCCurrentMeasurements

WARNING:Toavoidelectricshock,disconnectthetestleadsfromthemeterbeforemaking

currentmeasurements.

1. SettheFunctionswitchtotheDCCurrentposition.

2. PresstheDCAzerokeytonullthemeterdisplay.

3. Pressthejawtriggerandclamparoundasingleconductorfullyenclosingit.Donotallowa

gapbetweenthetwohalvesofthejaw.

4. ReadtheDCA

valueontheLCD.

ACVoltageMeasurements

WARNING:Toavoidelectricshockordamagetothemeter,donotmakeanyvoltage

measurementsthatexceedthemaximumspecified.

1. SettheFunctionswitchtotheACVoltageposition.

2. Insertthetestleadstothemeterasfollows:Redleadto“V,,Hz”terminal;Blackleadtothe

COMinput.

3. Measurevoltagewiththepointedendofthetestleads.Rememberthatvoltage

measurementsaremadeinparallelwith

thedevice/circuitundertest.

4. ReadtheACVvalueontheLCD.

DCVoltageMeasurements

WARNING:Toavoidelectricshockordamagetothemeter,donotmakeanyvoltage

measurementsthatexceedthemaximumspecified.

1. SettheFunctionswitchtotheDCVoltageposition.

2. Insertthetestleadstothemeterasfollows:Redleadto“V,Ω,Hz,”terminal;Blackleadtothe

COMinput.

3. Withthepointedendofthetestleadsmeasurevoltage.Rememberthatvoltage

measurementsaremadeinparallel

withthedeviceorcircuitundertest.

4. ReadtheDCVvalueontheLCD.

FrequencyMeasurements

1. SettheFunctionswitchtotheHzposition.

2. Insertthetestleadsintothemeter’sinputterminals.

3. Connecttheotherendsofthetestleadsinparallelwiththedevice/circuitundertest.

4. ReadtheFrequencymeasurementontheLCDinHz.

Model 38090A-EU-EN v1.0 2/14

MIN,MAXFunction

PressingtheMIN/MAXkeyallowsthemetertodisplayONLYthehighestandthelowest

readingsencountered.PresstheMIN/MAXkeyoncetoviewtheminimumreading,pressit

againtoviewthemaximumreading.TheLCDwilltogglebetweentheMINandMAXvalues.

PressandholdMIN/MAXbuttonfor

morethan2secondstoreturntonormaloperating

mode.ZerofunctionwillbedisabledwhenMIN/MAXisenabled.MIN/MAXisnotavailablein

Hzmode.

DataHold

TofreezethecurrentreadingontheLCD,presstheDataHoldkey.ToreleasetheDataHold

functionandreturnthemetertonormaloperation,presstheDataHoldkeyagain.

RelativeMode

1) PresstheZEROkey.ThedisplayedreadingwillzeroandthewordZEROwillappearonthe

upperportionoftheLCD.

2) Allsubsequentmeasurementswillnowbedisplayedwithrespecttothezeroedreading.For

example,ifa20Areadingiszeroedanda30Areadingissubsequently

measured,theLCDwill

display10A.

3) Pressthezerobuttononcemoretoreturntonormaloperatingmode.

4) NotethatRelativemodeisnotavailableifMIN/MAXmodeisenabled.

5) LCDdisplaysrelativenumericalvaluewithoutbargraph.

Model 38090A-EU-EN v1.0 2/14

AutoPowerOFF

Toextendbatterylife,themeterwillautopoweroffafter15minutesofoperation.Toresume

operationeitherturnthemeterOFFandthenONagainorpresstheHOLDbutton.



BatteryReplacement

1. WhenthelowbatterysymbolappearsontheLCD,thebatteriesmustbereplaced.

2. Turnthemeteroffandremovetherearbatterycompartmentscrew.

3. Liftoffthebatterycompartmentcoverandreplacethetwo1.5VAAcells.

4. Replacethecompartmentcoverandsecurethescrew.

You,

astheenduser,arelegallybound(Batteryordinance)toreturnallusedbatteries

andaccumulators;disposalinthehouseholdgarbageisprohibited!

Youcanhandoveryour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

Cleaning

Useonlyadryclothtocleantheplasticcase.



Model 38090A-EU-EN v1.0 2/14

Specifications

GeneralSpecifications

Display 3‐3/4digit(4032count)LCDwith40segmentbargraph

Functions Watts,ACA,DCA,ACV,DCV,Frequency

Polarity “‐“indicatesnegativepolarity;positiveassumed

Currentsensor Halleffectsensortype

Overloadindication OL

DCAzeroadjust Onetouchzerokey

Displayrate 3readings/second(30readings/secondforbargraph)

AutoPowerOff Meterturnsoffautomaticallyafter15minutes

Battery Two1.5VAAbatteries

Operatingtemp.‐10

Cto50

C(4

Fto122

F)

OperatingHumidity <85%RH

Powerconsumption Approximately10mADC

Weight 190g(6.7oz)includingbattery

Dimensions 183x63.6x35.6mm(7.2x2.5x1.4”)(HWD)

Jawopening 23mm(0.9”)maximumconductorsize

Standards IEC1010CategoryIII300V,CategoryII600V

Model 38090A-EU-EN v1.0 2/14

RangeSpecifications

Function Range Resolution Accuracy Overloadprotect

ACPower 40kW 10W ±(1.5%+3dgts) 250V,400A

Note:50/60Hz,PF0.6to1,Vpeak<360V

240kW 100W ±(1.5%+3dgts) 600V,400A

Note:50/60Hz,PF0.6to1,Vpeak<850V

40kW 10W ±(2.5%+3dgts) 250V,400A

Note:40Hzto100Hz,PF0.6to1,Vpeak<360V

240kW 100W ±(2.5%+3dgts) 600V,400A

Note:40Hzto100Hz,PF0.6to1,Vpeak<850V

DCPower 40kW 10W ±(1.5%+3dgts) 250V,400A

240kW 100W ±(1.5%+3dgts) 600V,400A

DCCurrent 400A 100mA ±(1.5%+3dgts) 600ADC

ACCurrent

TrueRMS,

Crestfactor<

4

 50/60Hz 40to100Hz

400A 100mA ±1.5%±3dgts ±2.5%±4dgts 600AAC

DCVoltage 400V 0.1V ±(1.0%+2dgts) 800VDC

ACVoltage

TrueRMS,

Crestfactor<

4,Input

impedance

10MΩ

 50/60Hz 40to1kHz

600V 1V ±(1.5%+2dgts) ±(2.0%+4d) 800VAC

Frequency 1Hz‐

100kHz

0.001‐

100Hz

±(0.8%+2dgts) Sensitivity10V 600VAC



Allrightsreservedincludingtherightofreproductioninwholeorinpartinanyform

www.extech.com



Extech Instruments 380940 User manual

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