Ogrape1

oldjohnt and others, I have some good news based on your lengthy but excellent posts. I unplugged the 14x3 AWG cord from the inverter and... no GFCI tripping when plugging in to 20A shore power. I'll have to dig deeper but I'm suspecting I have multiple NG bonds. Having said that, I am tired of digging and kind of like having a solution that is so simple. We almost always boondock: I can put a "Note to Self" on the shore cord to unplug the inverter before shoring up.

The quasi mystery still for me is why this suddenly happened after months and months and months of connecting the same 30A shore power line with adapter to the same 20A GFCI outlets in my garage. I do not know of one change in any of the RV's equipment or devices, and no changes in the house/garage either. I can't see how turning on the inverter prior to connecting to the 20A GFCI shore power, as some have suggested here and on other sites, will work with the way my inverter is wired (rough schematic attached). The inverter sends power to everything that is 110v. in the coach. Thanks to all who have pitched in here. I appreciate it.

Well I've got a strange one. When I plug my 2019 Orion T24RB motorhome in to shore power (110 volt, 20 amp) the shore outlet's GFCI (at home) or breaker (at campgrounds) immediately trips. I've tried over three different 20 amp GFCI circuits and the same thing happens. I've tried three different 30 amp to 20 amp adapters and the same thing happens. I've tried two different 30 amp power cords with adapters and the same thing happens. Same if the rig's main panel breaker is switched off. You're noticing a pattern here. When I plug directly into any 30 amp shore power outlet, everything powers up. When I fire up the gen set, everything powers up. When I turn on the 2000 watt inverter you guessed it, everything powers up. Another pattern. I've traced and disconnected all the electrical lines from their source into and out of the automatic transfer switch. Into/disconnected = no 20 amp GFCI tripping. Out/disconnected = shore 20 amp GFCI trips. Recall there is no GFCI/breaker tripping with 30 amp shore power, only 20 amp. What the devil is going on here? Everything has been working perfectly for over a year until this started about three weeks ago, and nothing has changed. BTW the inverter wiring circuit has its own DPDT relay switch. I even replaced that (with a spare I conveniently had) but it made no difference. I'm stumped and would appreciate your wise counsel before I hand my wallet over to my local RV service dept. Thanks, Gary