Siemens SIMOTICS HT Series, Operating Instructions & Installation Instructions

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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?
As such, 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 47)
5.2.3 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:
– Connect the terminals with the ground potential until the recharge voltage drops to a
non-hazardous level
– Attach the connection cable.
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.
Assembly
5.2 Preparations for installation
SIMOTICS HT Series HT-direct 1FW4...1......A
Operating Instructions 11/2018
47