3 prong 50 amp plug to 4 prong 50 amp ????

GlennLever wrote:
I have been using my welding outlet in the garage to power the motor home for over a year.

It is true that the three prong outlet has no neutral, it contains two hot leads and a ground, 110 on one led to the ground and 110 on the other leg to the ground. There is 220 cross the two hot legs.




The four prong plug contains two hot leads, one ground, and one neutral.

It also has 220 potential across the two hot leads.





The different between the two is that the four prong contains the neutral.

What most people forget is the natural and ground are connected together on the same buss bar in the breaker box.



Note in this circuit breaker panel that the white netrual wire and the bare ground wire are connected to the same buss bars.



So if the natural and ground are connected together at the plug it will work just fine. It is not code. Every electrician will tell you not to do it, but it works.

What I did is I went to Home Depot and purchased a drier cord, and a four pin outlet that fits the Motor Home. I wired the plug and wire to the outlet, one outside wire (one leg) to one hot prong, the other outside wire to the other hot prong (other leg)and connected the ground and neutral together.

I thought you had to have a neutral wire of equal or larger gauge wire than the hot wires, to keep from crossing to 220 in the MH. That is the way I wired mine. The ground in a 3 wire is not heavy enough.