ABB ACS380 Series, Hardware Manual

Page: 62 / 186

62 Electrical installation
Measuring insulation

Drive
Do not do voltage tolerance or insulation resistance tests on the drive. The drive was
tested for insulation between the main circuit and the chassis at the factory. The drive
has voltage-limiting circuits which decrease the testing voltage automatically.

Input power cable
Before you connect the input power cable, measure its insulation according to the
local regulations.

Motor and motor cable
Measure the insulation of the motor and motor cable as follows:
1. Make sure that the motor cable is disconnected from the drive output terminals
T1/U, T2/V and T3/W.
2. Measure the insulation resistance
between the phase conductors and
between each phase conductor and the
protective earth conductor. Use a
measuring voltage of 1,000 V DC. The
insulation resistance of an ABB motor
must be more than 100 Mohm (reference
value at 25 °C or 77 °F). For the
insulation resistance of other motors,
refer to the manufacturer’s instructions.
Moisture in the motor casing decreases the insulation resistance. If you think that
there is moisture in the motor, dry the motor and measure again.

Brake resistor assembly
Measure the insulation of the brake resistor assembly as follows:
1. Make sure that the resistor cable is
connected to the resistor, and disconnected
from the drive output terminals R+ and R-.
2. At the drive, connect the R+ and R-
conductors of the resistor cable together.
Measure the insulation resistance between
the combined conductors and the PE
conductor with a measuring voltage of
1 kV DC. The insulation resistance must be
more than 1 Mohm.
ohm
M
3~
U1
V1
W1 PE
ohm
R-
R+
PE