Fluke 1625 - Page 51

Earth/Ground Tester
Procedure of Measurements
43
R
RA
R
Earth/Ground Resistance 300k
AC
Resistance
300k
DC Low Resistance 3 k
CHANGE
ITEM
SELECT
START
TEST
DISPLAY
MENU
H/C2
S/P2
ES/P1
E/C1
4 POLE
3 POLE
4 POLE
2 POLE
2 POLE
4 POLE
OFF
3 POLE
EARTH / GROUND TESTER
1625
edw017.eps
Figure 14. Correcting Clip-on Transformer Errors
2. Turn central rotary switch to position "A RE 3pole".
3. Press "START TEST"-button and note result of RE value.
4. Connect clip-on transformer.
R
RA
R
Earth/Ground Resistance 300k
AC
Resistance
300k
DC Low Resistance 3 k
CHANGE
ITEM
SELECT
START
TEST
DISPLAY
MENU
H/C2
S/P2
ES/P1
E/C1
4 POLE
3 POLE
4 POLE
2 POLE
2 POLE
4 POLE
OFF
3 POLE
EARTH / GROUND TESTER
1625
edw018.eps
5. Turn central rotary switch to position "A RE 3pole".
6. Press "START TEST" again.
If the thus measured value R
E
deviates from the R
E
value determined without
clip-on transformer by more than 5 %, adjust the clip-on transformation ratio
(tr) correspondingly:
)(
)(
meronTransfprpwithoutcliR
merontransforwithclipR
troldtrnew
E
E
−
−
×=