5.2.2
Insulation resistance
5.2.2.1
Insulation resistance and polarization index
Measuring the insulation resistance and polarization index (PI) provides information on the
condition of the machine. It is therefore important to check the insulation resistance and the
polarization index at the following times:
• Before starting up a machine for the first time
• After an extended period in storage or downtime
• Within the scope of maintenance work
The following information is provided regarding the state of the winding insulation:
• Is the winding head insulation conductively contaminated?
• Has the winding insulation absorbed moisture?
From this, you can determine whether the machine needs commissioning or any necessary
measures such as cleaning and/or drying the winding:
• Can the machine be put into operation?
• Must the windings be cleaned or dried?
Detailed information on testing and the limit values can be found here:
"Testing the insulation resistance and polarization index" (Page 42)
1PC134, 1PC136 crane motors SH 132 ... 315
Operating Instructions, 12/2023, A5E43212221A
Assembly
5.2 Preparing for installation
41