Paul, some years ago a member, Ed Buker, clued us in to the idea that GFCI’s come in different qualities. Some are just too sensitive to the slightest variance in the circuit, which is what they’re supposed to do. But there are higher quality ones out there that are “smarter” and do their job without repetitive annoyances. Your issue may be a builder’s cheaper bulk purchased storage GFCI.
I had one in my garage at the workbench. Replacing it per Ed’s comments resolved the problem... it hasn’t tripped in years. I think I got the better device at Lowe’s, as Ed suggested; but realize that the better made units may cost more, and don’t go cheapskate here. These days it is common to find them with arc fault technology included. A good American brand is Square D, probably the most common, easily found brand - Lowe’s, Ace, Home Depot, etc.; but still be sure it’s best quality for your application.
All that said, it doesn’t mean there isn’t another cause relative to the coach itself, as others here reference. If the batteries are for some reason low when you park, like a bad alternator, then the inverter’s charger kicking in while set at the wrong voltage parameter (as Mike suggests) may kick the storage breaker and with no relation to ground fault... just plain over current. What current rating is the storage outlet? With a Magnum inverter unit on an ‘06 coach, on its remote (over your entry door?) scroll to the incoming source current setting and make sure it matches your storage outlet’s rating, and remember to adjust it according to any campsite’s power in the future. If you need guidance on using the remote, there may be a section in the ‘06 Thunder manual here in our Private Members Only Coach Assist section.
If it’s not happening at campsites or a relative’s garage circuit on the road when you plug in to those with GFCI breakers (if you happen to have only 20amp) then I’d check into getting the storage one switched out.
Joel
