Garage GFCI trips while plugging in shore power – Inverter anomaly?

[Larry_M]

I apologize in advance for the long post. Through the process of elimination I’ve determined that our new 2020 25’ Flying Cloud’s inverter is causing the 20a GFCI in the garage to trip when I attempt to plug it in. There are two ways I’ve discovered to work around the issue.

If I turn on the inverter before plugging into the GFCI, I can then plug the power cord into the GFCI without tripping. Then, I just go back into the AS and turn off the inverter. Everything continues to work fine and the GFCI stays on.

The second way is to leave the inverter off, plug into the GFCI, let it trip, unplug cord, reset GFCI, and then quickly repeat this sequence about 3-4 times. After quickly doing this repeated sequence, the GFCI finally quits tripping and just stays on. This method also continues to work and the GFCI no longer trips.

I’m no electrical engineer, but I’ve concluded there’s something that gets “energized”, for lack of a better term, in the inverter. Once that is done there is no errant voltage / grounding that’s tripping the GFCI. In the first method of turning on the inverter prior to plugging in, it directly “energizes” something. In the second method with several tripping GFCI’s, it must have an accumulative effect that eventually provides just enough power to energize that mysterious “something” in the inverter.

I should also add that during our initial pre-delivery inspection the power remained on the entire ~4 hours of walk through without any issues. Of course, it wasn't plugged into a GFCI at the dealership. None of the AS breakers or GFCI’s ever tripped. I did use a GFCI tester on every outlet and they all indicated proper wiring and grounding. We just received the AS before the whole coronavirus mess so we haven’t had the opportunity to actually camp yet.

Regardless, is this just “the way it is” when plugging into sensitive GFCI outlets or is something wired incorrectly on the inverter’s ground / bus? Again, it seems to be directly related to the inverter as I’ve ruled out other things during the process of elimination.

[Al and Missy]

This is not the first time this has been reported. Use the search function to check look for similar threads to see the results of others.

GFCI's detect a current imbalance between the hot (black) and neutral (white) wires. If the difference exceeds a specified value, it trips. It would appear that either (1), your GFCI is overly sensitive, or (2) the inverter is the problem.

It is common practice to have an interference filter on the AC input to electronic devices. Often this is three capacitors, Hot to Ground, Neutral to Ground, and Hot to Neutral. These are often on the input to the filter, before any switch. Plugging the inverter in to shore power can result in leakage through the caps which can cause an imbalance that will trip a GFCI.

For a few $ you can change the garage GFCI. If that doesn't fix it a new inverter might (or might not).

Al