If you have a 50 amp on your trailer a properly configured 220 v service should not have caused a problem.
(50amp is 2 110 volt legs the trailer is just divided into 2 curcuits) is in reality a 220 v system.
What may have happened is the two legs of the 220 was connected but the neutral was not.
Or one of the legs was connected to the neutral.
In a properly wired trailer the neutral is floating (not connected to ground) the reason the supply circuit breaker does not trip when a leg is connected to the neutral.
If you have a 30 amp on your trailer then one of the 220 legs was probably connected to the neutral. This should have tripped the supply breaker but a lot of damage can occur as a result.
For those who do not understand the 30 amp on travel trailers confuse it with what looks like a 220v home clothes dryer cord.
