Steam,
I worked for years as a ship's electrician and a lot of what you wrote makes no sense..
Did you actually measure ~220V anyplace? Or is this just an assumption based on what you saw in the panel.
An RV-30 receptacle should have: A Ground, A Neutral, and a Hot terminal. If the breaker it is on has a connection to the neutral, then I would expect it to also have a test and reset buttons because it is a GFCI. Many of the older GFCI were in a double breaker body.
I suspect you have other problems you have not yet located. I suggest that you drop your shore power connection and open the MH AC distribution panel and check every screw for tightness and then do some checking inside there.
The house lights on every RV I have known run from the house battery bank. Again, check fuses and connections there before you do anything else.
I did a lot of this stuff before the depression hit. I have seen a lot of terminals come loose on their own. RVs are worse than boats for this.
Matt
