[Bill]

John, with a voltmeter, measure across the flat sockets. It should be 240 volts. Then from the flat to ground or neutral you should have 120 volts. It takes two separate sources of 120 volts to make it work. Anything else, your wiring is not correct. Let us know what you find.

[glen]

John, I am assuming you have no issues with 50 amp connections in an RV park so you can rule out anything related to the bus or power cord as the issue.

The receptacle at the house has only 4 wires and they should be as follows. The rounded connection is the ground. It needs to be connected to the ground in the house junction box,

The outer two flat blades are for the two “hot” wires coming from the house junction box. Between them you have 240V. Each wire goes to a different leg in the house junction box via a two pole circuit breaker.

The remaining center flat blade is the common and goes to the common in the house junction box. Between this blade and either of the two “hots” is going to be 120V.

[Jon]

Good stuff and I’d be sure not to use that electrican again if they can’t wire a 50 amp RV plug…

[Art]

Be sure the wired are connected to a breaker like this. Your 50 amp service provides 2 – 50 amp legs for a total of 100 amp service.

[Art]

Your transfer box (ATS) might not be connecting,Like they said check from neutral to each of the side spades 120v each and then from the round ground to each of the side spades 120v each if the ground isn’t present the ATS box won’t work. I’ve see people plugging into a external generator and with grounding the generator to coach the ATS won’t pull in the relay.

[Jimmy]

Thanks for the picture Bill.

John, the electrician should have used colored wires but you need to verify that. The colors don’t correct errors, but they make tracing easy for you.

Green is ground and it needs to be connected to the ground in the box and the rounded pin.

The two “hots” are going to be red and black and each should be connected to a lug on the breaker Bill showed and end up at the flat blade outer part of the receptacle. The remaining wire should be white, or the common and it should be connected to the remaining center flat blade.

This is something you can verify by opening the panel, and looking at the connections on each end. If the electrician did not use colored wires you are going to have to somehow verify they go where they are supposed to.

I have a bad feeling about the electrician’s skills.

[Dave]

RV plugs are different then house plugs the electrician needs to know the difference. Pop the cover off your ATS box and check for volts- neutral-ground.

[Bill]

Thanks for the replies guys. The electrician is coming back today and I will work with him on this. I will check the 240 across the blades myself after work and report back!

[Hugh]

Check ALL positions. 240V between the red/black wires on the 2 vertical outside posts. 120V between the red/ground and black/ground. No voltage between ground and neutral.

[Bernard]

Billl you are assuming a guy that screwed this up used colored wires.

[Davy]

Did he use a GFCI breaker? If your grounds and neutrals are not isolated on the coach (which most older coaches are not) it will trip the GFCI breaker instantly.

[Bill]

Here is a web site that explains 50 Amp plug wiring…

https://www.myrv.us/electric/

Dave

[Archived]

“Billl you are assuming a guy that screwed this up used colored wires. “

No, I was assuming the OP’s description of the wires used was correct.

[Billy]

If you’re adding shore power to your home, bus barn, storage facility, etc. … make sure you spec and use the ONLY Prevost Community approved and endorsed shore power outlet … available ONLY from Jamestown Advanced Products!

I highly recommend configuring for two 50amp/240 volt RV outlets and a 20amp/120 volt courtesy outlet. That way you’ll have an outlet for your coach and any of freeloaders from the PC Forum who talk our way into spending a week or so on your electric bill.

https://www.jamestownadvanced.com/t/category/rv-power-outlets/access-door-lighted

[Ronald]