30 amp 240 volt mistake!!

mxdad777 wrote:
I recently bought a 2018 Rockwood 5th wheel with a 50 amp service. I have a 240 v 50 amp outlet in my RV cover that I’ve used for years to plug my motorhome into. Since I still have my motorhome and it’s parked in the RV garage I decided to hook up my 5er temporarily to my 30 amp 240 volt welder outlet. I had no idea that RV 30 amp cords were 120v only. Long story short, after connecting my 30 to 50 adapter I sent 240 volts down one leg of the buss bar. So everything on that side of the bus bar received 240 volts while the other side received zero. My question now is what will I need to replace? My refrigerator, GFCI, rooftop A/C were all on that side. The A/C seems to be working fine, but the fridge isn’t and the GFCI is smoked. Although I’ve wired up many homes, I certainly learned something about RV’a and their wiring today. I’m hoping just the circuit board on the fridge can be replaced. Anyone else have any experience with this? I’m sure this can’t be the first time this has happened. Stupid me!!

Happens all the time with DIY electricians and some real electricians when it comes to RV's because they do not read the information printed right on the plugs and receptacles.

1st, you adaptor should not have fit into a 30 amp 240 volt outlet. Seems that you have the wrong outlet and cord for your welder. The problem usually comes when a electrician or DIY wire 240 volts to a 120 volt RV receptacle. Which sounds like what you have done with your welder. I would start by fixing that first. A 120 volt 30 amp RV male plug cannot physically fit into a 30 amp 240 volt female outlet. You didn't run 240 down one leg but you did run 120 down the neutral leg.


Fridge, Furnace, Water Heater all have circuit boards that can be replaced. Fridge will have a glass fuse in back that may have blown and saved the fridge. Microwave also has an internal fuse.