Motor And Motor Cable; It (Ungrounded) Systems; External Earth Fault In It (Ungrounded) Systems - ABB ACS800 Hardware Manual

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Motor and motor cable

Check the insulation of the motor and motor cable as follows:
1. Check that the motor cable is connected to the motor, and disconnected from the
drive output terminals U2, V2 and W2.
2. Measure the insulation resistance between each phase conductor and the
protective earth conductor using a measuring voltage of 500 V DC. The insulation
resistance of an ABB motor must exceed 100 Mohm (reference value at 25 °C or
77 °F). For the insulation resistance of other motors, please consult the
manufacturer's instructions.
Note: Moisture inside the motor casing will reduce the insulation resistance. If
moisture is suspected, dry the motor and repeat the measurement.
ohm

IT (ungrounded) systems

An EMC filter (option +E202) is not suitable for use in an IT (ungrounded) system. If
the drive is equipped with an EMC filter (option +E202), disconnect the filter before
connecting the drive to the supply network. For detailed instructions on how to do
this, please contact your local ABB representative.
WARNING! If a drive with an EMC filter (option +E202) is installed on an IT system
[an ungrounded power system or a high resistance-grounded (over 30 ohms) power
system], the system will be connected to ground potential through the EMC filter
capacitors of the drive. This may cause danger or damage the unit.

External earth fault in IT (ungrounded) systems

On ungrounded systems, an optional insulation monitoring device (Bender IRDH265
or IRDH275, option +Q954) is used. Refer to its documentation for set-up
instructions.
Electrical installation
U1
M
V1
3~
W1
PE