Commissioning
7.1 Measures before commissioning
7.1.4
Testing the insulation resistance and polarization index
Hazardous voltage at the terminals
During and immediately after measuring the insulation resistance or the polarization index (PI)
of the stator winding, hazardous voltages may be present at some of the terminals. Contact
with these can result in death, serious injury or material damage.
● If any power cables are connected, check to make sure line supply voltage cannot be
● Discharge the winding after measurement until the risk is eliminated, e.g. using the
Measure the insulation resistance
1. Before you begin measuring the insulation resistance, please read the operating manual for
the insulation resistance meter you are going to use.
2. Short-circuit the ends of the temperature sensor cables before applying the test voltage. If
the test voltage is connected to only one temperature sensor terminal, the temperature
sensor will be destroyed.
3. Make sure that no power cables are connected.
4. Measure the winding temperature and the insulation resistance of the winding in relation to
the machine enclosure. The winding temperature should not exceed 40° C during the
measurement. Convert the measured insulation resistances in accordance with the formula
to the reference temperature of 40° C. This thereby ensures that the minimum values
specified can be compared.
5. Read out the insulation resistance one minute after applying the measuring voltage.
64
WARNING
delivered.
following measures:
– Connect the terminals with the ground potential until the recharge voltage drops to a
non-hazardous level
– Attach the connection cable.
1PC134, 1PC136 crane motors SH 132 ... 315
Operating Instructions, 02/2019, A5E43212221A