Dutch_12078 wrote:
The 50 amp RV service supplies 120 volts from the neutral connection to each of the two hot legs. 240 volts would be measured from hot leg to hot leg, a connection that's not typically used in most RV's. What may have happened, is the neutral connection somewhere between the park panel and the RV breaker panel neutral bus was lost due to a poor connection, possible from a loose terminal screw or poor plug contact. When that happens, the appliances on one hot leg are placed in series with those on the other hot leg, and can pull more current at a higher voltage through the lighter loads than they can safely tolerate. If the lighter loads are fuse or breaker protected, they may be basically ok, just needing the fuse replaced or the breaker reset.
I agree that the problem could be an open neutral, which is common to both of the hot legs. I do not feel that there is any way that the two different hot legs will run in series to increase the voltage to any appliance since the two out of phase hot wires are not connected in any way to the same circuits, even if the neutral is lost.