Manual

Gossen Metrawatt GmbH 29
In the case of permanent-field motors, inter-turn short circuit
measurement is dependent on rotor position. This also applies to
squirrel cage motors with large inductances which result in more
frequently occurring remanence. In this case, the bipolar setting
must be selected for the inter-turn short circuit measurement.
First of all, measurement must be performed at each coil with
positive polarity. Afterwards, each coil is measured once again
with reversed polarity. The connections between the COIL
Adapter’s terminals and the motor coil are reversed to this end.
The instrument generates a mean value based on both measure-
ment results which, to a great extent, is independent of rotor posi-
tion.
8.3.1.3 Ending the Measurement and Discharging
➭ Measurement is ended automatically. The measurement can
be aborted by pressing the Stop softkey.*
After measurement has been ended, any remain-
ing residual voltage (Uext) is displayed (message:
“Discharging ... “), which may result from cable ca-
pacitance. The instrument’s internal 1 M resis-
tor causes rapid discharging.
Contact to the motor coils must be retained to this end.
Do not disconnect the DUT until voltage has fallen
below 25 V, i.e. until after the “Discharging ...” message has been cleared
from the display.
**
As of firmware version 1.003.000.
*
As of firmware version 1.003.000 – in the case of older firmware versions, end
measurement by pressing the Stop softkey.
+
–
0V!
Discharge