Electrician Wired 50Amp RV Power Box 110/240

[SpringerPop]

Yup. I revised the above a bit.

It's when the neutral is missing, and the imbalance exists between the two legs (as is almost always the case) that things fry.

Pop

[babock]

Originally Posted by david_reaves

emm-dee, that EXACTLY the way I understand it. The RV is setup to isolate each leg of the 120 into separate circuits... the 240 appliance uses them both together.

That's only because there is a neutral. The loads are between one of the hot legs and the neutral.

The 50A plug is wired identically to a 4 prong dryer plug. Don't let this electrician wire up your dryer.

[WY Husker Fan]

“Even though (for instance) a dedicated dryer plug might be wired with two hots and a ground (green), and "maybe" a neutral isn't necessary for the dryer to function, if it's a 4-hole receptacle, it needs a neutral. Any receptacle wired for an RV MUST have that neutral for things to work. If it doesn't, that's when bad things can (and will) happen. It MUST also have the ground (green), too.”

If a dryer receptacle is wired without a neutral it is wired WRONG. Even back when 3wire dryer and range receptacles were allowed, they were always 2 hots and a neutral. The code allowed the appliances to have the metal frames tied to the neutral to essentially provide the ground. The motor in the dryer as well as the stove top burners on a range are 120 volt. The dryer heating element is 240 volt as is the oven elements. Statements like this can lead other unknowledgable people astray. If you don’t know for sure what you are writing about you should not reply. I have seen a lot of misinformation spewed forth in these threads that is really quite dangerous if taken seriously.

[Bama Rambler]

As said several times above, there is a lot of confusion about RV power.

The 50 amp 240 volt service to an RV is exactly the same as the split phase service to a home. Wired the same and everything. Two hots, a neutral, & a ground.

We really should look at it just like that. Part of the confusion comes when we try to explain that RV's don't use 240 volts, and that 50 amp service is really 100 amps of power. I also think we should drop trying to inject this into the discussion.

With the 30 amp 120 volt service, a lot of the confusion started many years ago. It was a big mistake to use the triangulated blade configuration for RV power. It's just too close to the old three prong dryer plug, so electricians that were used to wiring up dryers naturally assumed that the RV plug/receptacle was the same. That's why still today a lot of them get wired for 240 volts.

They should have just used the standard 5-30R or the L5-30R twist-lock configuration. That would have made things a lot simpler in keeping the wiring straight, But, as they say, that's water under the bridge.

I'm not sure we'll ever solve the confusion, but we can strive to explain it in simple terms to hopefully lessen the confusion a bit.

[wmtire]

Got an update from Bob on this as follows. It seems the converter was on the leg that didn't get 240 volts and thus was spared:

Brought in an RV electrician ($200) and power connections tested fine. I suspect that the old electrician found his mistake while we were talking to him and fixed it on the sly. We had too many witnesses...you me and the other gentleman you helped on phone to believe otherwise.

Final damage was limited to a microwave ($300) and TV ($300). So $800 dollars later all is perfect.

Electrician promised to make payments, but so far I have not received anything. Doubt he will pay.
_____________

What Bob is referring to as "on the sly" is the electrician had opened up the outlet before Bob got there, but after Bob had explained to him on the phone what had occurred.

I spoke with this electrician on the phone on Bob's behalf, and was less than impressed with his answers/knowledge.

[CedarCreekWoody]

Miswiring is common on 30 amp circuits, but rarely seen on a 50 amp. The electrician using all white wires without color coding them (as required by the NEC) and then failing to verify the instalation does not speak highly of him. Thanks to both of you for the update.