5.2.2.2
Checking the insulation resistance and polarization index of the winding
Measure the insulation resistance
1. Follow the instructions in the Operating Manual of the insulation measuring instrument
used.
2. Ground other windings, integrated winding temperature sensors and, if applicable, other
mounted and installed components.
WARNING
Hazardous voltage at the terminals
Hazardous voltages are sometimes present at the terminals during and immediately after
measurement of the insulation resistance or polarization index of the winding. Contact with
these can result in death, serious injury or material damage.
• If power cables are connected, ensure that a line voltage cannot be applied.
If no power cables are connected, this reduces the effect of the I/O devices on the
measurement.
• Discharge the winding after measurement until the risk is eliminated, e.g. using the
following measures:
– Connect the terminals with the ground potential until the recharge voltage drops to
a non-hazardous level
– Attach the connecting cable.
3. 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.
4. 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.
6. Discharge the winding after performing the measurement.
Assembly
5.2 Preparing for installation
1LE5, 1PC4 shaft heights 280 ... 355
52
Operating Instructions, 11/2022, A5E41454666A
