If there are residual current devices in the network tested, they should be bypassed by
bridging for the period of impedance measurement. However, it should be remem-
bered that the circuit tested is modified in this way and the results obtained may slight-
ly differ from the actual results.
Each time after completion of measurements, modifications introduced to the installa-
tion for the period of measurements should be removed and operation of the residual
current device should be checked.
The above remark does not apply to measurements of short circuit loop impedance
with the use of Z
L-PE
RCD function.
Connect test leads according to the drawing
a) for measurement in L-N circuit or
b) for measurement in L-L circuit