Fluke 1625 R E withclip − ontransformer, R E withoutclip − onTransfprmer, trnew = trold ⋅

Earth/Ground Tester

Procedure of Measurements

	1625 EARTH / GROUND TESTER
START			H/C2
TEST
DISPLAY			S/P2
MENU
		AC
	Earth/Ground Resistance 300 k	Resistance	DC Low Resistance 3k
		300 k
	RA	R	R
	4 POLE	2 POLE
			2 POLE
	3 POLE
	4 POLE		4 POLE
CHANGE	3 POLE		ES/P1
ITEM
	OFF
SELECT			E/C1
			edw017.eps

Figure 14. Correcting Clip-on Transformer Errors

2.Turn central rotary switch to position "ARE 3pole".

3.Press "START TEST"-button and note result of RE value.

4.Connect clip-on transformer.

	1625 EARTH / GROUND TESTER
START			H/C2
TEST
DISPLAY			S/P2
MENU
		AC
	Earth/Ground Resistance 300 k	Resistance	DC Low Resistance 3k
		300 k
	RA	R	R
	4 POLE	2 POLE
			2 POLE
	3 POLE
	4 POLE		4 POLE
CHANGE	3 POLE		ES/P1
ITEM
	OFF
SELECT			E/C1
			edw018.eps

5.Turn central rotary switch to position "ARE 3pole".

6.Press "START TEST" again.

If the thus measured value RE deviates from the RE value determined without clip-on transformer by more than 5 %, adjust the clip-on transformation ratio (tr) correspondingly:

trnew = trold ⋅	RE (withclip − ontransformer)
	RE (withoutclip − onTransfprmer)

43