Refrigerator tripping GFI gets more complicated

[T74]

Had a call for refrigerator in garage tripping GFI. When plugged into another GFI receptacle (different location) it wouldn't trip. Plugged it into a third GFI and it did trip again. Turns out the one location that worked had an open ground.

Is that open ground preventing the GFI from sensing something the other two did?

 

[infinity]

I'm guessing that with the refrigerator not being grounded the leaking ground current had no where to leak to. Run an external ground to the frame of the refrig and it will likely trip.

 

[don_resqcapt19]

Had a call for refrigerator in garage tripping GFI. When plugged into another GFI receptacle (different location) it wouldn't trip. Plugged it into a third GFI and it did trip again. Turns out the one location that worked had an open ground.

Is that open ground preventing the GFI from sensing something the other two did?

If there is no current path there is nothing for the GFCI to see. It appears that there is excessive leakage current on the refrigerator and when you connect it to a receptacle that has an EGC, the GFCI trips, when you connect it it the receptacle without an EGC, the metal parts of the refrigerator remain energized. If a person takes the place of the EGC, the GFCI should open the circuit.

 

[LarryFine]

It confirms that the leakage is internal.