8.4
MEASURING THE CABLE AND MOTOR INSULATION
Do these checks if necessary.
The insulation checks of the motor cable
1
.
Disconnect the motor cable from the terminals U, V, and W and from the motor.
2
.
Measure the insulation resistance of the motor cable between phase conductors 1 and 2,
between phase conductors 1 and 3, and between phase conductors 2 and 3.
3
.
Measure the insulation resistance between each phase conductor and the grounding
conductor.
4
.
The insulation resistance must be >1 MΩ at the ambient temperature of 20 °C (68 °F).
The insulation checks of the mains cable
1
.
Disconnect the mains cable from the terminals L1, L2, and L3 and from mains.
2
.
Measure the insulation resistance of the mains cable between phase conductors 1 and 2,
between phase conductors 1 and 3, and between phase conductors 2 and 3.
3
.
Measure the insulation resistance between each phase conductor and the grounding
conductor.
4
.
The insulation resistance must be >1 MΩ at the ambient temperature of 20 °C (68 °F).
The insulation checks of the motor
1
.
Disconnect the motor cable from the motor.
2
.
Open the bridging connections in the motor connection box.
3
.
Measure the insulation resistance of each motor winding. The voltage must be the same
or higher than the motor nominal voltage, but not higher than 1000 V.
4
.
The insulation resistance must be >1 MΩ at the ambient temperature of 20 °C (68 °F).
5
.
Obey the instructions of the motor manufacturer.
8.5
INSTALLATION IN AN IT SYSTEM
If your mains is impedance-grounded (IT), the AC drive must have the EMC protection level
C4. If your drive has the EMC protection level C2, it is necessary to change it to C4. To do this,
remove the EMC jumpers.
For equivalents of EMC levels in Vacon AC drives, see 9.3 The compliance with the product
standard IEC/EN 61800-3 + A1.
WARNING!
Do not make changes in the AC drive when it is connected to mains. The
components of the drive are live when the drive is connected to mains.
CAUTION!
Before you connect the AC drive to mains, make sure that the EMC level of the drive
is correct. An incorrect EMC level can cause damage to the drive.
8.5.1
FRAMES FR4, FR5, AND FR6
Change the EMC protection of the AC drive to level C4.
1
Open the cover of the AC drive.
VACON · 124
COMMISSIONING AND ADDITIONAL INSTRUCTIONS
8
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