[rohrmann]

You must have all the breakers turned off. You will need the converter on to maintain the batteries, and with that breaker on, you will not have enough power to run the fridge. If you reverse things between those two breakers, your batteries will go dead. So, what I'm getting at, it can't be done on a 20 or possibly 15 amp circuit. If the outlet you are plugged into has the round hole for the ground terminal and two vertical slots, that is a 15 amp outlet, regardless of what breaker is feeding it. Really, you should forget about running the fridge in storage and just use the power available to maintain the batteries. Your residential fridge will chill down fast enough that you don't need to keep it on. Also, plugging an RV, any type, into a GFI circuit is usually a problem, and generally the 30 or 50 amp outlets in campgrounds are not GFI, so you never have that issue. It's possible that there is a slight moisture issue in the RV, or even a loose connection in the rig that could be causing a problem. If you do decide to just run the converter while in storage and are plugged into a GFI, you must keep all the connections to the outlet perfectly dry. If you have an extension cord with a connection that is exposed to rain, your GFI will trip.