Testing The Insulation Resistance And Polarization Index - Siemens SIMOTICS XP 1LA5 Compact Operating Instructions

Installation
5.1.2.2

Testing the insulation resistance and polarization index

WARNING
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 delivered.
Discharge the winding after measurement until the risk is eliminated,
•
e.g. using the following measures:
–
–
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. Make sure that no power cables are connected.
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. 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.
4. Read out the insulation resistance one minute after applying the measuring
voltage.
100
Connect the terminals with the ground potential until the recharge
voltage drops to a non-hazardous level
Attach the connection cable.
Explosion-protected machines
56100000002002, 01/2016