ECN Forum Forums General Topics of the Trade General Discussion Area Motor Home Wiring?

I looked at a large Motor Home a customer wants power to. It has a 6-3 w/grd 50a 240v cord on it. I checked the continuity from neutral to ground and no connection. He said he plugs it in to a camp ground with a 3 prong adaptor and it works (2 prong with ground). How would this work if there is no connection to neutral at the motor home panel. And the adaptor has no connection between nuetral to ground on the plug itself. Is there something different about how a motor home is wired?

The neutral and ground are isolated in the panel.

But then why would it work when he plugged it in at the camp park? Theoreticly there would be no connection for the neutral.

The 3-wire to 4- wire adapter plugs into a 125 volt 3-wire receptacle. It connects L1 and L2 of the motor home together so all 120 volt electrical items will function but you will be limited on how many items that can be used at the same time.

Curt

Then how would his 240v A/C work? Something doesn't make sense.

There are no 240V loads in the motorhome* the adapter jumpers both hots so it can be used for 30A 120V service.

* At least in any that I have seen.

Yes, that makes sense, I do remember campers being about the only 120v 30a service. The customer said it was 240v, but that is wrong.

Another thought:
The motor home has a 4 prong 240v 50a cord & plug. Without the adaptor, someone could could plug that into a 240v outlet and smoke the MH.

Why would that be a problem? Isn't there 2 hots, neutral and ground at the plug?

-Hal

hbiss, No there isn't, as I said early there is an adaptor changing it to a 3 prong.