MI 3101 EurotestAT: Safety and operational considerations
Warnings and notes
8
Notes related to measurement functions:
General
Indicator means that the selected measurement can't be performed because of
irregular conditions on input terminals.
Insulation resistance, varistor test
,
continuity
functions and
earth resistance
measurements shall be performed on de-energized objects, i.e. voltage between
test terminals should be lower than 10 V!
PASS / FAIL indication is enabled when limit is set to ON. Apply appropriate limit
value for evaluation of measurement results.
In case that only two of three wires are connected to test electrical installation, only
voltage indication between these two wires is valid.
Insulation resistance
When measuring insulation resistance between installation conductors all loads
must be disconnected and all switches closed!
The instrument automatically discharge tested object after finished measurement.
Keep the TEST key pressed for continuous measurement.
Continuity functions
Parallel resistance paths and interfering currents in measured circuit will influence
the test result!
If necessary compensate test lead resistance before performing continuity
measurement, see
5.2.3.
Measuring the resistance of wire wound components like transformer or motor
windings is possible only in continuous function (
R7mA
) due to great influence of
the winding inductance.
RCD functions
Parameters set in one function are also kept for other RCD functions.
The measurement of contact voltage will not trip-out RCD of tested installation if
selected rated test current is the same as rated I
N
of observed RCD. However, the
RCD trip-out may occur and Uc measurement is affected as a result of PE leakage
currents caused by appliances that are connected to the tested installation.
The RCD trip-out current test and Uc measurement could be affected as a result of
potential fields of other earthing installations.
RCD trip-out current and time will be measured only if pretest of those functions
gives contact voltage lower than the selected conventional limit contact voltage.
L and N test terminals are reversed automatically according to detected terminal
voltage.
In case the RCD trips-out during safety pretests it is possible to continue
measurements just by recovering the RCD. Possible reasons for trip-out are
incorrect RCD sensitivity (I
N
) selected, relatively high leakage currents in tested
installations or defective RCD.