Inverter question

Don't rely on any sort of a switch that could accidentally be set to have both the inverter and the shore power connected to the circuit simultaneously. A pair of breakers (one for shore power and one for the inverter) in itself would not be acceptable. You need to have some sort of a transfer switch, be it manual or automatic, that cannot permit the circuit to be energized by both sources of power simultaneously under any circumstances. (This is not only for the safety of the inverter, but for the safety of people in general. For instance, if both get connected together, everything in the RV would be live when you're disconnected, including the prongs of the shore power cord.)

I have seen some approved transfer switches available that consist of a pair of circuit breakers with a mechanical lever doohicky to make it impossible for both to be switched on simultaneously. Properly applied, something like that could work, but there are likely less expensive approaches.