NOTHING in a RV is 220 volts. A properly wired 50A RV outlet has two 110V hot lines, which if are properly connect, will have 220v across them. Each side is 110v ONLY to the ground or neutral connection. Each 110v side has a 30-50A breaker, which allows up to 50A on each let. There is NO increase in voltage. Trying to connect any 220V appliance across the two legs will only produce disaster. Many Campgrounds actually have the same 110V wire connected to both sides of the 50A connector, which will provide exactly the same results for the RV.
However, as I am an registered OLD Fart, and it is common knowledge that many of us don't have any idea what we are talking about in the "MODERN" world, It is possible that some things may have changed, and I could be completely wrong. In that case I will not get my feelings hurt at all if some brilliant youngster that knows everything about everything tells you anything different.