ABB ACS880-M04 - Checking the Insulation of the Assembly; Drives; Input Power Cable; Motor and Motor Cable Insulation

Electrical installation 75
Checking the insulation of the assembly
 Drives
Do not make any voltage tolerance or insulation resistance tests on any part of
the drive as testing can damage the drive.
Every drive has been tested for insulation between the main circuit and the chassis at
the factory. There are also, voltage-limiting circuits inside the drive which cuts 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.
 Motor and motor cable insulation
Check that the motor cable is disconnected from the drive output terminals T1/U, T2/V
and T3/W.
Measure the insulation resistance between the phase conductors and 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 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.
 Break resistor assembly insulation
Check that the resistor cable is connected to the resistor, and disconnected from the
drive output terminals R+ and R-.
At the drive end, connect the R+ and R- conductors of the resistor cable together.
Measure the insulation resistance between the combined conductors and the PE
conductor by using a measuring voltage of 1 kV DC. The insulation resistance must be
higher than 1 Mohm..

ohm
M
3~
U1
V1
W1
PE
ohm
R-
R+
PE