Goodrive200A
inverters Appendix C
148
C.4.3 Routing the cables
Route the motor cable away from other cable routes. Motor cables of several drives can be
run in parallel installed next to each other. It is recommended that the motor cable, input
power cable and control cables are installed on separate trays. Avoid long parallel runs of
motor cables with other cables to decrease electromagnetic interference caused by the rapid
changes in the drive output voltage.
Where control cables must cross power cables make sure that they are arranged at an angle
as near to 90 degrees as possible.
The cable trays must have good electrical bonding to each other and to the grounding
electrodes. Aluminum tray systems can be used to improve local equalizing of potential.
A figure of the cable routing is shown below.
C.4.4 Checking the insulation
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 U, V and W.
2. Measure the insulation resistance between each phase conductor and the Protective
Earth conductor using a measuring voltage of 500 V DC.
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.
C.5 Breaker, electromagnetic contactor and leakage protection
switch
Due to the inverter output high frequency PWM voltage waveform, and the existance of
distributed capacitance between IGBT and heatsink in internal inverter and the distributed
capacitance between motor stator and rotor will cause the inverter inevitably generate
high-frequency leakage current to ground. The high-frequency leakage current will back flow
to grid through the earth to interference the leakage protection switch, thus causing the
leakage protection switch malfunction. This is due to the inverter output voltage
characteristics inherent in the decision.
To ensure the stability of the system, it is recommended to use the inverter dedicated
leakage protection switch which rated residual operation current 30mA or more(for example,
corresponds to IEC60755 Type B). If you are not using the inverter dedicated leakage
protection switch caused by malfunction, try to reduce the carrier frequency, or replace the
electromagnetic leakage protection switch which rated residual operating current of 200mA
