VFD PE leakage current

[gaminn]

Hi,
I bought Lenze E82EV751_4C Lenze 400V AC VFD https://inverterdrive.com/file/lenze-8200-technical-manual but I'm unable to run it in my workshop as my 20mA residual-current circuit breaker (ground fault circuit interrupter) triggers everytime I turn the VFD on. I tested that with 75 VAC power supply, I get 20 mA leakage current via PE, so with 400 VAC power supply the leakage current is probably more than 100 mA. Is that normal or is my VFD damaged?

[BeBuLamar]

The leakage could be from the motor. I actually always find some current in the ground wire for a VFD. So perhaps you should use another circuit breaker.

[gaminn]

There is currently no motor connected to the VFD.

I realized that my main problem was that I intentionally connected 400V 3 phase VFD to 2 phase 230 V power supply - I just wanted to test the VFD and set some parameters to it. The VFD with 2 phase 230V connected to it shows under-voltage error but still it is possible to set parameters via its keypad.

I experimented a little bit with voltage and number of phases connected to the VFD (L1, L2, L3 terminals). I didn't connect PE of the VFD to PE in my socket.

230V 2phase: There is 112V/50Hz between PE of VFD and PE in my socket. Unable to measure current to PE as residual-current circuit breaker triggers immediatelly.
400V 2 phases only: 33,5V/150Hz between PEs, 12 mA residual current through PE.
400V all 3 phases: 22V/150Hz between PEs, 23 mA residual current via PE.

Why 400V power supply shows 150Hz voltage between PEs and why is there much higher PE leakage current for 230V 2 phase power supply?

[BeBuLamar]

Although I use a lot of the Lenze 8200 series, I always connect them to 400V 3 phase and with the motor. I did notice there was some current in the ground wire but otherwise everything worked fine. I never connect them to 230 or single phase power.

[gaminn]

Now I know that it is not a good idea to connect 3x400V VFD to 2x230V power supply.

I'm just curious what happens inside the VFD that the PE residual current is so much higher at 230V.

[BeBuLamar]

When you said 230V 2 phase is one of the phase at PE potential that is it's a neutral and the other is 230V to PE? Or both are 115V with respect to PE?

[gaminn]

It is neutral and 230V to PE.

[sicco]

VFDs with those ratings typically have EMC filters. Capacitors from all 3 Vin pins to PE and chassis. That makes the RCD’s trip. Sometimes you can disable the EMC filter by removing a screw. At the expense of no longer filtering and thus facing RF interference / compliance issues.