Siemens 1PH818 Operating Instructions Manual page 49

Hazardous voltage
During the measurement, and immediately afterwards, hazardous voltage levels are
applied on some of the terminals and they should not be touched. Touching live
components can be result in death or serious injury.
Never touch the terminals when measuring or immediately after the measurement.
Check the supply feeder cables connected in order to ensure that the line supply voltage
cannot be connected.
● Always measure the insulation resistance of the winding to the motor enclosure when the
● When measuring, wait until the final resistance value is reached; this takes approximately
Limit values
The table below specifies the measuring circuit voltage as well as the limit values for the
minimum insulation resistance and the critical insulation resistance with a rated motor
voltage of U
Table 7-1
Measuring circuit voltage
Minimum insulation resistance with new, cleaned or repaired
windings
Critical specific insulation resistance after a long operating
time
Note the following:
A5E02605207A AA
Siemens AG Operating Instructions V1.0 1PH8
WARNING
winding temperature is between 20 and 30°C.
one minute.
< 2 kV:
N
Stator winding insulation resistance at 25 °C
Commissioning
7.3 Checking insulation resistance
Rated voltage U < 2 kV
N
500 V (at least 100 V)
10 MΩ
5 MΩ/kV
47