ABB ACQ80-04 Series, Hardware Manual

Page: 66 / 170

Also, there are voltage-limiting circuits inside the drive which cut down the testing voltage
automatically.
￭ Input power cable
Check the insulation of the input cable according to local regulations before connecting it
to the drive.
￭ Checking the insulation of the motor and motor cable
WARNING!
Obey the safety instructions of the drive. If you ignore them, injury or death, or
damage to the equipment can occur.
If you are not a qualified electrician, do not do installation or maintenance work.
1. Stop the drive and do the steps in section Electrical safety precautions (page 14) before
you start the work.
2. Check that the motor cable is disconnected from the drive output terminals U2, V2 and
W2.
3. Measure the insulation resistance between the phase conductors and then between
each phase conductor and the Protective Earth conductor. Use a measuring voltage of
1000 V DC. The insulation resistance of an ABB motor must exceed 100 Mohm
(reference value at 25 °C [77 °F]). For the insulation resistance of other motors, consult
the manufacturer’s instructions.
Note:
Moisture inside the motor casing reduces the insulation resistance. If moisture is
suspected, dry the motor and repeat the measurement.
1000 V DC,
> 100 Mohm
U1-V1, U1-W1, V1-W1
U1-PE, V1-PE, W1-PE
M
3~
U1
V1
W1 PE
ohm
ohm
Checking the compatibility with IT (ungrounded) and
corner-grounded TN systems
￭ EMC filter
The internal EMC filter is not suitable for use on an IT (ungrounded) system or on a
corner-grounded TN system. Disconnect the EMC filter before connecting the drive to the
supply network. Check the table in
Ground-to-phase varistor (page 67) .
WARNING! WARNING!
Do not install the drive with the internal EMC filter connected on an IT system (an
ungrounded power system or a high-resistance-grounded [over 30 ohms] power
system), otherwise the system will be connected to ground potential through the
EMC filter capacitors of the drive. This can cause danger, or damage the drive.
66 Electrical installation