Looking for portable electric space heater for rv!

pianotuna wrote:

Elk Traveler, if it is the breaker in the RV that is flipping using an autoformer can improve things.

Sagging voltage will cause a space heater (and indeed any resistance heater) to consume less current--and, of course, use less power and produce less heat. An autoformer would make the breaker more likely to trip, not less likely. It would only help reduce tripping in the extraordinary case where the line voltage is too high and it reduces it to a correct nominal value.