7.3
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:
– Connecting the terminals with ground potential until the recharge voltage drops to a
non-hazardous level
– Connecting the connecting cable
Measure the insulation resistance
1. Before you begin measuring the insulation resistance, please read the manual for the
insulation resistance meter you are going to use.
2. Make sure that no power cables are connected.
3. Measure the insulation resistance of the winding in relation to the machine enclosure and
the winding temperature. The winding temperature should not exceed 40° C during the
measurement. Convert the measured insulation resistances to the reference temperature
of 40° C according to the formula in the following table. This thereby ensures that the
minimum values specified can be compared.
4. Read out the insulation resistance one minute after applying the measuring voltage.
Measuring the polarization index
1. To determine the polarization index, measure the insulation resistances after one minute
and ten minutes.
2. Express the measured values as a ratio:
PI = R
insul 10 min
/ R
insul 1 min
Modern measuring devices display these values automatically following the measurement.
Limit values for insulation resistance and polarization index of the stator winding
The following table shows the measuring voltage and limit values for the insulation resistance
and polarization index. These values correspond to the recommendations of IEEE 43‑2000.
Commissioning
7.3 Testing the insulation resistance and polarization index
LOHER CHEMSTAR 1PS5
70
Operating Instructions 03/2014
Содержание SIMATIC S5 1P 243
Страница 2: ...11 03 2014 02 49 V4 00 ...
Страница 12: ...Introduction LOHER CHEMSTAR 1PS5 12 Operating Instructions 03 2014 ...
Страница 20: ...Safety notes 2 11 Ventilation LOHER CHEMSTAR 1PS5 20 Operating Instructions 03 2014 ...
Страница 42: ...Preparations for use 4 11 Converter operation LOHER CHEMSTAR 1PS5 42 Operating Instructions 03 2014 ...
Страница 66: ...Electrical connection 6 2 Connecting LOHER CHEMSTAR 1PS5 66 Operating Instructions 03 2014 ...
Страница 124: ...Disposal 11 4 Disposal of components LOHER CHEMSTAR 1PS5 124 Operating Instructions 03 2014 ...
Страница 126: ...Service and Support A 1 Siemens Service Center LOHER CHEMSTAR 1PS5 126 Operating Instructions 03 2014 ...
Страница 136: ...Quality documents C 4 Data LOHER CHEMSTAR 1PS5 136 Operating Instructions 03 2014 ...
Страница 140: ...Index LOHER CHEMSTAR 1PS5 140 Operating Instructions 03 2014 ...
Страница 141: ...AC EC Declaration of Conformity U161 AB EC Declaration of Conformity U163 AA R No 20000h U165 ...