Actually 220 is set up with 2 110V lines, a neutral & a ground as opposed to 110 with a single 110 v line a neutral and a groung. On RV's its usually referred to as 30 amp (110V) and 50 amp (220 V). Adapter plugs are available that just pick off one of the 110 V lines to go from 50 A to 30 A. Most RV supply outfits should have one. But you can't go from 110 to 220.