On my last coach... a Class C Outlaw 29H.... it had a 1000W Inverter and I rewired it so the Inverter could power any outlet. I wired it like my home is wired for the backup generator.
I added a 15A breaker to the WFCO Power Distribution Panel and wired the Inverter to backfeed the breaker box through that circuit breaker. This breaker would always be off unless I wanted to use the Inverter.
When I wanted to use the Inverter, I would turn the main breaker off so as not to send power out to the shore power connector (just as I woud do at home so as not to feed AC current out to the power lines on te street). I would then turn off every breaker except for the circuit I wanted to use. I would then turn the breaker on I added for the Inverter and it would power that circuit.
When I was done with the Inverter, I would turn off the breaker for the Inverter to shut own power to the breaker box and then turn all of the other breakers back on. That worked great..... as long as you know what you are doing. I had a written procedure and check-list in case I was not around to do it.