What happens if you plug a 50 Amp RV into 22V welder plug

KMLsquared wrote:
I might be mistaken but I did not think the utility even provided a neutral?

I believe this is correct if referring to the old 240V dryer/welding outlets. There is no neutral.

Not sure what SMKettner is suggesting unless he is referring to the 120/240V 1phase 4 wire 50 amp service. But the question seemed about a garage dryer/welder outlet.

The right answer as posted is measure the voltage across all pin combinations.

Atom Ant wrote:
If it ever worked for welding, there has to be some confidence that the neutral is neutral or the welder wouldn't have worked at all.

VERY BAD AND DANGEROUS ADVICE! A neutral is not needed for 220vac.

If it ever worked for welding, there has to be some confidence that the neutral is neutral or the welder wouldn't have worked at all.

One of three things will happen:

1. It is wired correctly and everything works great
2. You have it wired wrong, but not seriously, nothing work or only half the outlets work.
3. You have it wired so that 240 volts go across half of your circuits and you burn up everything plugged into half of your rv circuits!

The 50-amp plug on an RV requires a neutral, two hot leads, 180 degrees out of phase (but that isn’t really necessary if nothing is actually 240 volts), and a ground.

Neutral has to be neutral or you are in deep trouble. If you wire one of the hot input lines to neutral and the neutral input to one of the hot lines, that half of the circuit will get 120 volts and all will work properly. The other half will have one of the hot input lines as the neutral and the other hor input line as its hot line. The result is 240 volts across that “neutral” to hot connection and everything on that half of the circuits will get 240 volts, possibly blowing up your frig, microwave, TV, or anything else!

Plugging in blind you have a 50/50 chance of a bad outcome. It has less to do with what the outlet was originally installed, it has more to do with how the actual outlet was wired.

If you follow this testing you can validate if the plug is compatible or not.

KMLsquared wrote:
I might be mistaken but I did not think the utility even provided a neutral?

Yes standard single phase service provides 240v and the transformer center tap as the neutral. The main distribution panel needs to have its own earth ground.

KMLsquared wrote:
I might be mistaken but I did not think the utility even provided a neutral?

A 50 amp RV service has four contacts.
2 110vac - Protected by double 50 amp circuit breaker in the pedestal
1 neutral
1 ground

A 30 amp RV service has three contacts.
1 110vac - Protected by single 30 amp circuti breaker in the pedestal
1 neutral
1 ground

I might be mistaken but I did not think the utility even provided a neutral?

LostinAZ wrote:
What isn't being mentioned when we discuss two 110 V legs is they have to be out of phase to create 220V service. My understanding is that the 50 Amp service we hook into at RV Resort/Park pedestals, the two 110V 50 amp legs are not out of phase and therefore 220V is never present inside the RV.

Not so. If that was the case, the neutral would carry 100 amps if you were able to use all 50 amps on each hot leg. They must be opposite phase. If done correctly, when the load is the same on each hot leg the neutral carries nothing. The neutral only carries the difference between the hot legs. You can plug into any properly wired 220vac outlet as long as the plug and receptacle match (or you have the properly wired adapters).

It's all done in the RV. Each load is wired across only one hot leg and the neutral so the load will only see 110vac. A load would need to be wired across both hot legs to see 220vac.

Edit: It must have a neutral and ground. Any receptacle with no neutral (like a welder plug) should never be used for a RV.

You will lose your converter, could loose you microwave, fridge, waterheater etc. like I did. Make sure before you plug in.