METREL MI 3122 Instruction Manual page 7

MI 3122 Smartec Z Line-Loop / RCD
RCD functions
Parameters set in one function are also kept for other RCD functions.

The Contact voltage test will normally not trip-out RCD of tested installation.

However, the RCD trip-out may occur and Uc measurement is affected as a result
of existing PE leakage currents in the installation.
RCD trip-out current and time will be measured only if the contact voltage - pretest

passed successfully.
L and N test terminals are reversed automatically according to detected terminal

voltage (except in UK version).
It can happen that the RCD trips-out during the safety pretests. Possible reasons for

trip-out are incorrect set RCD parameters (I
defective RCD.
Z-LOOP
The Z-LOOP impedance function will trip-out the RCD in RCD protected installation

that is tested. Use the Zs
The Zs impedance function takes longer time to complete but has much better
rcd

accuracy then R
Specified accuracy of tested parameters is valid only if mains voltage is stable

during the measurement.
L and N test terminals are reversed automatically according to detected terminal

voltage (except in UK version).
Z-LINE
In case of measurement of Z

connected together the instrument will display a warning of dangerous PE voltage.
The measurement will be performed anyway.
Specified accuracy of tested parameters is valid only if mains voltage is stable

during the measurement.
L and N test terminals are reversed automatically according to detected terminal

voltage (except in UK version).
impedance function to prevent the trip-out.
rcd
sub-result in RCD: Uc function.
L
Line-Line
), existing leakage currents or
N
with the instrument test leads PE and N
7
Warnings and notes