Checking The Insulation Resistance - Siemens SIMOTICS M-1PH8 Series Operating Instructions Manual

Commissioning

6.4 Checking the insulation resistance

6.4 Checking the insulation resistance
After long storage or shutdown periods, the insulation resistance of the windings must be
measured to ground with direct voltage.
Danger to life through electric shock
During and immediately after the measurement, the terminals are in some cases at
hazardous voltages, which can lead to death when touched.
• Only check the insulation resistance if you are appropriately qualified to do this.
• Before measuring the insulation resistance, read the manual for the insulation
• Never touch the terminals when making measurements or immediately after the
• Check the connected supply feeder cables to ensure that the line supply voltage cannot
● Always measure the insulation resistance of the winding to the motor enclosure when the
winding temperature is between 20 and 30 °C.
● When performing the measurement, wait until the final resistance value is reached (this
takes approx. one minute).
Limits
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 6- 8
Measurement voltage
Minimum insulation resistance with new, cleaned, or repaired
windings
Critical specific insulation resistance after a long operating
time
114
WARNING
resistance meter you are going to use.
measurement.
be connected.
< 2 kV:
N
Stator winding insulation resistance at 25 °C
Rated voltage U < 2 kV
N
500 V (at least 100 V)
10 MΩ
0.5 MΩ/kV
1PH808/1PH810 main motors
Operating Instructions, 04/2017, 610.48004.40f