Fluke Fluke 4325162 Manual De Usuario
Los códigos de productos
4325162
Earth/Ground Tester
Advanced Operation
23
Measurement of Single Earth Electrode Resistances in Mesh Operated Earthing
Systems Using Selective Clamp Method
Systems Using Selective Clamp Method
This measuring method has been created to measure single earth electrodes in
permanently wired or mesh-operated systems (for example, a lightning protection system
with several electrodes or high voltage pylons with earth cabling). By measuring the
actual current flow through the earth electrode, this special measuring method provides
the unique possibility to measure selectively only this particular resistance by means of a
clip-on transformer (accessory). See Figure 5. Other parallel resistances applied are not
taken into account and do not distort the measuring result.
permanently wired or mesh-operated systems (for example, a lightning protection system
with several electrodes or high voltage pylons with earth cabling). By measuring the
actual current flow through the earth electrode, this special measuring method provides
the unique possibility to measure selectively only this particular resistance by means of a
clip-on transformer (accessory). See Figure 5. Other parallel resistances applied are not
taken into account and do not distort the measuring result.
A disconnection of the earth electrode before the measurement is therefore no longer
necessary.
necessary.
G
I
I
Z
tr
V
A
Aux. Earth
Electrode
Electrode
Probe
I
3
U
meas.
R
E1
R
E2
R
E3
R
S
R
H
R
E3
=
U
meas.
I
3
=
U
meas.
tr
. I
Z
edw014.eps
Figure 5. Measurement of Single Earth Electrode Resistances in Mesh Operated Earthing
Systems
Errors of the current transformer can be corrected as described in Clip-On Transformer
Errors Correction.
Errors Correction.