[Cl906um]

Service call today had a drill press that nuisance tripped gfi. No ordinary drill though. Plugs into 120 and has its own phase converter/ drive for speed control to three phase motor. Tried it into another gfi and it tripped it as well. No instruction manual, so did grounding assured test on it , gave it a single dedicated recept, and taped the cord green for spring. Then walked away.

 

[micromind]

If there are MOVs on the line side of the VFD, they can cause a GFI to trip when there is no actual ground fault.

 

[Cl906um]

The last time I installed a phase converter, just looking at it, I knew it was over my head. Crap pile of resistors and capacitors.

 

[Big John]

I would be really hard pressed to come up with a circumstance where a piece of equipment tripped a GFCI and did not have a ground fault.

Hate to say it, but you likely put a bandaid on the problem.

 

[Cl906um]

A lot of components involved in a phase converter. Especially when derived from a grounded circuit. I am open for answers. I am over my head troubleshooting. Ohmed ground to neutral on cord. Not even gonna think about meggering.