MI 3108 EurotestPV
Safety and operational considerations
10
The measurement of contact voltage does not normally trip an RCD. However, the
trip limit of the RCD may be exceeded as a result of leakage current flowing to the
PE protective conductor or a capacitive connection between L and PE conductors.
The RCD trip-lock sub-function (function selector switch in LOOP position) takes
longer to complete but offers much better accuracy of fault loop resistance (in
comparison to the R
L
sub-result in Contact voltage function).
RCD trip-out time and RCD trip-out current measurements will only be performed
if the contact voltage in the pre-test at nominal differential current is lower than the
set contact voltage limit!
The autotest sequence (RCD AUTO function) stops when trip-out time is out of
allowable time period.
Z-LOOP
The low limit prospective short-circuit current value depends on fuse type, fuse
current rating, fuse trip-out time and impedance scaling factor.
The specified accuracy of tested parameters is valid only if the mains voltage is
stable during the measurement.
Fault loop impedance measurements will trip an RCD.
The measurement of fault loop impedance using trip-lock function does not
normally trip an RCD. However, the trip limit may be exceeded if a leakage current
flows to the PE protective conductor or if there is a capacitive connection between
L and PE conductors.
Z-LINE / Voltage drop
In case of measurement of Z
Line-Line
with the instrument test leads PE and N
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.
Power / Harmonics / Energy / Current
Before starting any Power measurement the current clamp settings in Settings
menu should be checked. Select appropriate current clamp model and measuring
range that are best fitted to the expected current values.
Consider polarity of current clamp (arrow on test clamp should be oriented toward
connected load), otherwise result will be negative!
PV measurements
A 1384 PV Safety Probe
must be used
for PANEL, UOC/ISC, I/V and INVERTER
(AC, DC), and ISO PV measurements.
A 1385 PV test lead
must be used
for INVERTER AC/DC measurements.
Before starting a PV measurement the settings of PV module type and PV test
parameters should be checked.
Environmental parameters (Irr, T) can be measured or entered manually.
Environmental conditions (irradiance, temperature) must be stable during the
measurements.
