VFD gnd fault on power-up

[ApEEng]

I have a piece of equipment in the field that is maybe half a year old. It has two 460VAC 3ph motors, each driven by an ABB VFD (a mature design). In mid-October, the drum motor was leaking oil and we replaced it. Since then, the customer says that whenever they power the equipment up, that is, turn the switch to power up the control panel, this VFD shows a ground fault [F0016], and at no other time.

I poked around online some, and concerns of corroded fuse clips upstream of the VFD, and water around the cable resounded most. The machine is new, in a clean facility, indoors, has an IP54 box, but is sitting within 8 feet of a dock door. I have checked with the customer to see if any oil or water is sitting around at or near the motor cable or its (very large) M-F connector plug. It is pretty expensive to travel there.

In the past, I have run tests, disconnecting the motor, cable, etc and found ground faults in the motor and wiring, but this ground fault only shows up on system power-up, not motor power-up.

What do you think?

 

[Aleman]

Put a megger on it but unhook the vfd 1st.

 

[Besoeker]

I have a piece of equipment in the field that is maybe half a year old. It has two 460VAC 3ph motors, each driven by an ABB VFD (a mature design). In mid-October, the drum motor was leaking oil and we replaced it. Since then, the customer says that whenever they power the equipment up, that is, turn the switch to power up the control panel, this VFD shows a ground fault [F0016], and at no other time.

I poked around online some, and concerns of corroded fuse clips upstream of the VFD, and water around the cable resounded most. The machine is new, in a clean facility, indoors, has an IP54 box, but is sitting within 8 feet of a dock door. I have checked with the customer to see if any oil or water is sitting around at or near the motor cable or its (very large) M-F connector plug. It is pretty expensive to travel there.

In the past, I have run tests, disconnecting the motor, cable, etc and found ground faults in the motor and wiring, but this ground fault only shows up on system power-up, not motor power-up.

What do you think?

Unless there is a physical disconnect between the VSD and the motor, the motor will see voltage to ground. I'm with Aleman. I think the motor is the probable area of concern.