MI 3325 MultiServicerXD
143
Test results / sub-results
t
Discharging time
Up
Peak value of supply voltage at disconnection time
Note:
Interpretation of the ‘
Repeat
’ message:
It is not possible to differentiate between a disconnection moment at very low voltage
and a machine with a very low discharging time. In both cases the reading will be 0.0 s
together with the “Repeat” warning. If after few repetitions the result is always 0.0 s with
the “Repeat” message it can be considered as a valid 0.0 s result.
A 0.0 s reading without the “Repeat” message is a valid result.
Test limits
Limit U
Voltage limit [34 V, 60 V, 120 V]
Limit (t)
Time limit [1 s, 5 s]
Measuring principle
The measuring principle of the discharging time function is as following:
Phase 1:
The DUT is connected to the supply voltage via an external socket.
The instrument monitors the voltage (on supply or internal connections) and
internally stores the peak voltage value.
Phase 2:
The DUT is disconnected from the supply voltage and the voltage at the test
terminals starts to fall. Once the rms voltage falls for 10 V the instrument starts
to measure time.
Phase 3:
After the voltage drops below an internally calculated voltage value, the timer is
stopped. The instrument re-calculates the measured time to a value as it would
be, if the disconnection occurred at the maximum voltage value.
(1) peak voltage
(4) Ulim
(2) voltage at disconnection time
(5) moment of disconnection
(3) calculated voltage value
(6) discharging time
Figure 6.125: Discharging time measuring principle
