50 amp service - is RV service wiring the same as others?

I agree with Rick. To my way of thinking it is not rocket science.

Bobbo wrote:
I suspect that if he was that comfortable with electrical wiring, he would never have asked the question in the first place.

Not necessarily, he just may not be familiar with welder outlets, and his cousin might not be familiar with RV outlets. :)

But if either one IS familiar with regular ol' 120VAC receptacle wiring, the existing wiring can be used so that he can plug in during his stay. Or they could pull a separate neutral wire and adapt it to 4 wire service, but that's probably more work, depending upon how long the run is. But seeing as the OP only has 30A service on his RV anyway, this probably wouldn't be the way to go unless he planned on a.) upgrading his RV in the future and b.) plans to visit his cousin often. :)

Just trying to toss out ideas so he can plug in during his stay.

~Rick

Most welder outlets are 3-wire L-1, L-2 safety ground (no neutral) and not suitable for RV use.

HOWEVER it it is 4 wire and the 50 amp end fits... Go for it.

BUT.. before you plug in the rv, take a volt meter and mneasure the voltage between the two FLAT blades on the 30 amp outlet.. Should be 110-125 volts, if it's not, No joy.

The 220 and 30 amp circuitry seems to be one of the most controversial electrical queries on the RV forums.
Because of the serious damage that could be done to your RV if you guess wrong, I'd suggest you enlist the advice of a professional electrician to see and examine the supply and make the assessment. You can lose a lot by guessing.

Rick Jay wrote:
Now, if it IS a three wire, and you or your cousin are comfortable wiring up electrical things, you can use the wiring to that outlet if you change the breaker in the panel to a single pole 30A unit and change the receptacle to the 30A 120VAC RV outlet. That will enable you to use that outlet for your 30A service while you're visiting. Then when you leave, you can rewire it the way it was.

I suspect that if he was that comfortable with electrical wiring, he would never have asked the question in the first place.:E

OK, I believe your original question has been answered. Three wire 240VAC, NO. Four wire 240VAC, should be fine. If it's a four wire, measure to make sure: 120VAC between each hot and ground/neutral, 240 VAC across the two hots. Or if you plug in your dogbone, you should measure the 120VAC between hot & neutral, near 0VAC between neutral and ground.

Now, if it IS a three wire, and you or your cousin are comfortable wiring up electrical things, you can use the wiring to that outlet if you change the breaker in the panel to a single pole 30A unit and change the receptacle to the 30A 120VAC RV outlet. That will enable you to use that outlet for your 30A service while you're visiting. Then when you leave, you can rewire it the way it was.

~Rick

At a bare minimum check the voltage after you plug in your adapter and before you plug your RV into it.

unless you know what is there assume nothing…

if you don’t know for sure, don’t use it or have it checked by someone you trust that understands it first…

RedG wrote:

The old 50 amp plugs were 3 prong and were straight 220v. The newer 4 prong 50 amp plugs are 2 110's which will work for your rig.

This is not correct. No residential service in North America has "straight 220v (volts)" All residential service in North America has two 120 volt lines and one neutral producing three wires for service into a residential dwelling. A fourth wire, the ground, is generated within each service.

So, the three wire outlet could have a three wire 240 volt service, two 120 volt hot wires and one neutral. Many of these three wire 240 service female plugs are identical to and match the 30 amp 120 volt RV male plug. This is where problems occur. 240 volt service is entered into a system designed for 120 volts.

Bobbo wrote:
Like everyone else has said, if it is a 4 prong outlet, maybe.

If it is a 3 prong outlet, ABSOLUTELY NOT!

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