Motor And Motor Cable; Checking The Compatibility With It (Ungrounded) And Corner-Grounded Tn Systems - ABB ACS355 User Manual

48 Electrical installation

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.
Checking the compatibility with IT (ungrounded) and
corner-grounded TN systems
WARNING! Disconnect the internal EMC filter when installing the drive 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. This may cause danger or damage the drive.
Disconnect the internal EMC filter when installing the drive on a corner-grounded TN
system, otherwise the drive will be damaged
Note: When the internal EMC filter is disconnected, the drive is not EMC compatible
without an external filter.
1. If you have an IT (ungrounded) or corner-grounded TN system, disconnect the
internal EMC filter by removing the EMC screw. For 3-phase U-type drives (with
type designation ACS355-03U-), the EMC screw is already removed at the factory
and replaced by a plastic one.
EMC screw in R0...R2.
In R3, the screw is a little further up.
1
EMC
VAR
ohm
EMC screw in R4, IP20
(behind cover in R4, NEMA 1)
U1
M
V1
3~
W1
PE
1
EMC