[Guy]

Our coach is old. so no 240 volt devices., and no double pole breakers in the electric panel, with the exception being the main 50 amp 2 pole  breaker. But we do have a 50 amp 240 volt ( 2  120 volt inputs , a ground and a neutral. ) We use an off the shelf Walmart 50 to 30 adapter. It sends the same 120 volt input to both sides of the electric panel in the coach. We have to be very judicious in our electric use, keeping in mind that our water heater can demand 12 amps at any time if we don't turn it off. We are limited to 1 a/c unit when running a 30 amp adapter.