That isn't exactly true, not all parks have 240 volt power. Some parks have 208 volt power, hot leg to hot leg, but when measured hot leg to neutral, they do in fact measure 120 volts, and this is for both hot legs to the neutral. The reason this is OK, is that these rigs only require 120 volts on each hot leg, never 240 volts. This is the label next to the 50 amp socket on our rig.