12
EMI connections:
It is very important that the connections between the inverter, the shielded motor cable, and
the EMI filters are tested as follows.
Use a metal grounding plate and place the frequency inverter and the EMI filter on the plate.
Use a shielded motor cable with 4 connectors (U, V, W, and Earth). Don't use the shielding as
safety earth (shield is high frequency earth)
Remove any paint around the two metal coupling nut holes so that the metal coupling nuts
(and the shielding) make contact with the frequency inverter and the motor.
Don't solder a conductor to the shielding.
Use a metal clamp to connect the shielding from the motor cable with the metal grounding
plate. Now there is a perfect high frequency earth connection between frequency inverter,
grounding plate, and EMI filter.
Keep the distance between the frequency inverter and the EMI filter as short as possible
(<30cm). If longer, use a shielded cable with a metal coupling nut and a metal clamp to con-
nect the shielded cable to the frequency inverter and metal grounding plate.
The only earth connection between the line and the test plate should be via the EMI filter. Use
a motor which equals the power rating or below of the inverter rating. Install a noise filter for
inverter onto the output side of the primary circuitry can suppress conducting noise.
'ULYH
'ULYH
Class B:
Class A:
