AEMC 6416 Installation and operating instructions

99-MAN 100456
Technical Assistance [phone] www.aemc.com
Clamp-On Ground Resistance Tester
Model 6416
Step-by-Step Usage Guide
Clamp-On Ground Resistance Tester
Model 6416
Step-by-Step Usage Guide
1. Turninstrumentonbyrotatingtheselectorknobtothe“Ω+A”
position.
2. Allowinstrumenttobootupandbeginbeepingwith0RΩdisplayed
on screen.
3. Checkcalibration—locatethe5Ωcalibrationgaugesuppliedwith
thetesterandclampthemeteraroundanylegofthegauge.
4. Observeinstrumentreading–thereadingshouldbewithin0.2Ωof
gaugespecification(5Ω).Ifreadingiscorrectproceedtostep5.
Ifnot,cleaninstrumentandrepeatsteps3and4.If you are not
able to get the instrument to read within 0.2Ω after cleaning
instrument, do not proceed.Havetheinstrumentrepaired.
5. Removeinstrumentfromgauge.Observeinstrumentreadingwith
nothingintheclamps.Thereadingshouldbe0RΩ
 Ifthisconditionisobserved,continuetostep6.If
not,cleaninstrument(seeinstructionsbelow)and
repeatsteps3through5.If,aftercleaninginstru-
ment,youarestillunabletogettheinstrumentto
performasdescribedinsteps4and5,openthe
jawsapproximately1/2inchandletthemsnap
shut.Makesurethatthejawscloseproperly.If
the unit still does not perform properly, do not
proceed.Havetheinstrumentrepaired.
6. SwitchinstrumenttoCurrentMode.(Rotate
selectorswitchtothe“A”positionforAmps)
7. Clampinstrumentaroundthegroundwireorrod.
8. Observereading–iflessthan1.0A,proceedtostep9.Ifbetween1.0and5.0A,
makenoteofreadingandcontinuetostep9.Ifgreaterthan5A,terminatetestand
removeinstrumentfromthegroundwireorrodandcorrecttheproblembefore
re-testing.
9. SwitchinstrumenttoResistance(Ω+A)mode.(Rotateselectorswitchtothe“Ω+A”
position)
10.Waitforreadingtostabilizeandrecordreading.Lockreadingonthedisplayby
pressing“HOLD”.
11.Removeinstrumentfromgroundwireorrodandre-clamptogauge.
12.Observereading–thereadingshouldbewithin0.2Ωofgaugevalue.Ifreadingis
OK–measurementisvalid.Ifreadingiswrong,cleaninstrument(seeinstructions
below)andrepeatfromstep4.
1. Turninstrumentonbyrotatingtheselectorknobtothe“Ω+A”
position.
2. Allowinstrumenttobootupandbeginbeepingwith0RΩdisplayed
on screen.
3. Checkcalibration—locatethe5Ωcalibrationgaugesuppliedwith
thetesterandclampthemeteraroundanylegofthegauge.
4. Observeinstrumentreading–thereadingshouldbewithin0.2Ωof
gaugespecification(5Ω).Ifreadingiscorrectproceedtostep5.
Ifnot,cleaninstrumentandrepeatsteps3and4.If you are not
able to get the instrument to read within 0.2Ω after cleaning
instrument, do not proceed.Havetheinstrumentrepaired.
5. Removeinstrumentfromgauge.Observeinstrumentreadingwith
nothingintheclamps.Thereadingshouldbe0RΩ
 Ifthisconditionisobserved,continuetostep6.If
not,cleaninstrument(seeinstructionsbelow)and
repeatsteps3through5.If,aftercleaninginstru-
ment,youarestillunabletogettheinstrumentto
performasdescribedinsteps4and5,openthe
jawsapproximately1/2inchandletthemsnap
shut.Makesurethatthejawscloseproperly.If
the unit still does not perform properly, do not
proceed.Havetheinstrumentrepaired.
6. SwitchinstrumenttoCurrentMode.(Rotate
selectorswitchtothe“A”positionforAmps)
7. Clampinstrumentaroundthegroundwireorrod.
8. Observereading–iflessthan1.0A,proceedtostep9.Ifbetween1.0and5.0A,
makenoteofreadingandcontinuetostep9.Ifgreaterthan5A,terminatetestand
removeinstrumentfromthegroundwireorrodandcorrecttheproblembefore
re-testing.
9. SwitchinstrumenttoResistance(Ω+A)mode.(Rotateselectorswitchtothe“Ω+A”
position)
10.Waitforreadingtostabilizeandrecordreading.Lockreadingonthedisplayby
pressing“HOLD”.
11.Removeinstrumentfromgroundwireorrodandre-clamptogauge.
12.Observereading–thereadingshouldbewithin0.2Ωofgaugevalue.Ifreadingis
OK–measurementisvalid.Ifreadingiswrong,cleaninstrument(seeinstructions
below)andrepeatfromstep4.
Cleaning the Heads
To ensure optimum performance, it is important to keep the probe jaw mating surfaces clean at all times.
Failure to do so may result in erroneous readings. To clean the probe jaws, use a lint free cloth or, if the
jaws are pitted, use a very fine sandpaper (600 grit) to avoid scratching the surface, then gently clean with
a soft cloth. Make sure that the instrument is oriented such that no debris or filings will fall into the unit while
cleaning. Check with your finger afterwards to be sure that no foreign material remains on the jaw surfaces
(both top and bottom).
Cleaning the Heads
To ensure optimum performance, it is important to keep the probe jaw mating surfaces clean at all times.
Failure to do so may result in erroneous readings. To clean the probe jaws, use a lint free cloth or, if the
jaws are pitted, use a very fine sandpaper (600 grit) to avoid scratching the surface, then gently clean with
a soft cloth. Make sure that the instrument is oriented such that no debris or filings will fall into the unit while
cleaning. Check with your finger afterwards to be sure that no foreign material remains on the jaw surfaces
(both top and bottom).
Step 3 Step 3
99-MAN 100456
Technical Assistance [phone] www.aemc.com

Technical Assistance [phone] www.aemc.com Technical Assistance [phone] www.aemc.com
Theclamp-ongroundresistancetestingtechniqueofferstheabilitytomeasuretheresistancewithout
disconnectingtheground.Thistypeofmeasurementalsoofferstheadvantageofincludingthebondingto
groundandtheoverallgroundingconnectionresistances.
Principles of Operation
Usually,acommondistributionlinegroundedsystemcanbesimulatedasasimplebasiccircuitasshownin
FigureAoranequivalentcircuit,showninFigureB.IfvoltageEisappliedtoanymeasuredgroundingsystem.
Rxthroughaspecialtransformer,currentIflowsthroughthecircuit.
Therefore,E/I=Rxisestablished.IfitisdetectedwithEkeptconstant,measuredgroundingresistancecanbe
obtained.ReferagaintoFiguresAandB.Currentisfedtoaspecialtransformerviaapoweramplifierfroma
2083Hzconstantvoltageoscillator.ThiscurrentisdetectedbyadetectionCT.Onlythe2083Hzsignalfre-
quencyisamplifiedbyafilteramplifier.ThisoccursbeforetheA/Dconversionandaftersynchronousrectifica-
tion.ItisthendisplayedonthescreenoftheModel6416meter.
Thefilteramplifierisusedtocutoffbothearthcurrentatcommercialfrequencyandhigh-frequencynoise.
VoltageisdetectedbycoilswoundaroundtheinjectionCT,whichisthenamplified,rectified,andcomparedby
alevelcomparator.Iftheclampisnotclosedproperly,an“openjaw”annunciatorappearsonthedisplay.
E
I
RxR1R2Rn-1 Rn
FIGURE A
E
I
R
xR1R2Rn-1 Rn
FIGURE B
Theclamp-ongroundresistancetestingtechniqueofferstheabilitytomeasuretheresistancewithout
disconnectingtheground.Thistypeofmeasurementalsoofferstheadvantageofincludingthebondingto
groundandtheoverallgroundingconnectionresistances.
Principles of Operation
Usually,acommondistributionlinegroundedsystemcanbesimulatedasasimplebasiccircuitasshownin
FigureAoranequivalentcircuit,showninFigureB.IfvoltageEisappliedtoanymeasuredgroundingsystem.
Rxthroughaspecialtransformer,currentIflowsthroughthecircuit.
Therefore,E/I=Rxisestablished.IfitisdetectedwithEkeptconstant,measuredgroundingresistancecanbe
obtained.ReferagaintoFiguresAandB.Currentisfedtoaspecialtransformerviaapoweramplifierfroma
2083Hzconstantvoltageoscillator.ThiscurrentisdetectedbyadetectionCT.Onlythe2083Hzsignalfre-
quencyisamplifiedbyafilteramplifier.ThisoccursbeforetheA/Dconversionandaftersynchronousrectifica-
tion.ItisthendisplayedonthescreenoftheModel6416meter.
Thefilteramplifierisusedtocutoffbothearthcurrentatcommercialfrequencyandhigh-frequencynoise.
VoltageisdetectedbycoilswoundaroundtheinjectionCT,whichisthenamplified,rectified,andcomparedby
alevelcomparator.Iftheclampisnotclosedproperly,an“openjaw”annunciatorappearsonthedisplay.
E
I
RxR1R2Rn-1 Rn
FIGURE A
E
I
R
xR1R2Rn-1 Rn
FIGURE B
The important points to consider for proper use of the clamp-on ground tester are:
1. There is a series-parallel resistance path down stream from the measurement point that is lower
in resistance than the point being measured.
2. That the earth is the return path to the point where the clamp-on meter is connected and not wire
or other metal structures (see Figure C).
3. If the measurement point is not connected to a series-parallel low resistance network (such as
the case with a single rod), a temporary path may be created by connecting a jumper cable from
the measurement point to a low resistance like a pole ground (see Figure D).
The important points to consider for proper use of the clamp-on ground tester are:
1. There is a series-parallel resistance path down stream from the measurement point that is lower
in resistance than the point being measured.
2. That the earth is the return path to the point where the clamp-on meter is connected and not wire
or other metal structures (see Figure C).
3. If the measurement point is not connected to a series-parallel low resistance network (such as
the case with a single rod), a temporary path may be created by connecting a jumper cable from
the measurement point to a low resistance like a pole ground (see Figure D).
Clamp-On Ground Resistance Testing Clamp-On Ground Resistance Testing
FIGURE C FIGURE D FIGURE C FIGURE D
Interpretation of Readings:
0.00-0.10 Local“GroundLoop”mostlikelypresent.Alsoindicatestheconductorisbondedtootherelectricpaths.This
readingcannotbeusedtojudgethequalityofthepathtoearth.
0.10-5.0 MostlikelyaLocalGroundLoopbutalsocouldindicateaVERYgoodgroundpathtoearth.
5.0-25 GroundResistanceValueofasinglelocalrod.HigherreadingmightindicateapoorBONDisalsopresent.
25-OL ReadingsinthisrangeareanindicationofaPOORpathtoearthAND/ORaVERYPOORbond.
OLindicatesthelackofanybondtoearth.
Interpretation of Readings:
0.00-0.10 Local“GroundLoop”mostlikelypresent.Alsoindicatestheconductorisbondedtootherelectricpaths.This
readingcannotbeusedtojudgethequalityofthepathtoearth.
0.10-5.0 MostlikelyaLocalGroundLoopbutalsocouldindicateaVERYgoodgroundpathtoearth.
5.0-25 GroundResistanceValueofasinglelocalrod.HigherreadingmightindicateapoorBONDisalsopresent.
25-OL ReadingsinthisrangeareanindicationofaPOORpathtoearthAND/ORaVERYPOORbond.
OLindicatesthelackofanybondtoearth.