As Tequila mentioned 50 amp services is rare. Even then it may not be a real 50 amp service or the wiring is not very heavy. I would never hard wire that devic device. Risk of fire. Even th Hughes autoformer is risky. Some campgrounds do not allow that device. Connecting a modern motorhome in Mexico is always risky. Lots of electronics that are voltage sensitive. John and Angela are no longer active in this forum. He was travelling with a 30 amp smaller Class c. When the voltage was low he had a smart charger that would run on low voltage. I think it was 90 volts. He would plug that into the shorhe power. No worries.