Scenario 1: You have an RV with 120/240 split phase shore power. You plug into a 120/240 volt receptacle but the neutral is floating. So what you get between each leg and neutral could be anywhere between 0 and 240 volts.
Scenario 2: You have an RV with 120 volt single phase shore power. Because of a misfire, what you end up with is 240 volts between neutral and hot.
I'd expect the Multi to reject the AC input but will damage to the unit occur?