50 Amp Coach Plug

N9ID · 05-20-2013, 08:34 PM

Just got our RV back from being repaired. Funny thing: a post jumped out and hit the side of the RV while I was turning a fairly sharp corner.

One thing that had to be replaced was the 50 amp coach plug (i.e. the plug where the power cable plugs in to the coach). I have the other end of the power cord plugged in to a 15 amp plug in the garage. There is power to the 15 amp plug and power in the coach to the main breakers on the WFCO in the coach. I have a Fluke power sensing device so I know the power gets to the main breakers. There are smaller breakers on either side of the main house breakers. One side is hot and the other side is not. The microwave works, but the television, ceiling fan and fireplace do not.

Before the coach went in to be repaired, the television, ceiling fan and fireplace worked when plugged in to the house power. I can't honestly say that I ever tried the microwave before. I am going through a 15 amp to 30 amp adapter and then a 30 amp to 50 amp adapter.

My question is this: when they replaced the 50 amp coach plug, does it sound like they switched the hot wires? I really would like the television etc. to work. I don't need the microwave when we are at home because I can go inside to nuke something if I want it. Is the fix to swap the hot wires at the coach plug? If not, does anyone have any ideas (Herk, Turbs, anybody?)?

Thanks for your help.

Mike

TURBS · 05-20-2013, 08:38 PM

Mike,
I have to think they forgot to hook up one of your legs of incoming power.

I dnt think its possible for them to switch wires or it would trip your breaker where your plugged in to.

You might have to take receptical off the side of the camper.

Turbs

**ependydad** · 05-20-2013, 08:40 PM

Sure sounds like something is wired wrong!

BarryD0706 · 05-20-2013, 08:45 PM

Be very careful with this. If you (or they) do it wrong, you can put 240v across your 120v circuits which will be a disaster. Everything needs to be checked very carefully. Don't just assume it's because they left a wire disconnected. They might have swapped wires as well.

Broadway Joe · 05-20-2013, 09:34 PM

Your coach electric system is two separate 120 volt systems, with a common neutral and common ground. It sounds like when the receptacle was replaced the two hot leads were swapped. If hooked up to 50 amp service everything will work fine, if hooked up to 30 amp your secondary circuit is now improperly hooked up.

If you are not comfortable working on electric systems or are not familiar with the 50 amp rv plug go back to your service center.

BarryD0706 · 05-20-2013, 09:45 PM

Quote:

Originally Posted by joenic53

Your coach electric system is two separate 120 volt systems, with a common neutral and common ground. It sounds like when the receptacle was replaced the two hot leads were swapped. If hooked up to 50 amp service everything will work fine, if hooked up to 30 amp your secondary circuit is now improperly hooked up.

Sorry, but that's not right. A 30->50 adapter puts power on both of the hot legs so swapping them wouldn't cause this problem. Also, as I said before, "assuming" that everything will work fine when plugged into a 50-amp outlet may cause a disaster.

(Furthermore, it's not "two separate 120 volt systems". It has to be a center-tapped 240 service or the neutral will melt.)

fonzie · 05-21-2013, 06:56 AM

Quote:

Originally Posted by BarryD0706

Sorry, but that's not right. A 30->50 adapter puts power on both of the hot legs so swapping them wouldn't cause this problem. Also, as I said before, "assuming" that everything will work fine when plugged into a 50-amp outlet may cause a disaster.

(Furthermore, it's not "two separate 120 volt systems". It has to be a center-tapped 240 service or the neutral will melt.)

You are correct if the 30 to 50 amp adapter was purchased at a store and made for RV purposes. If it was a user made adapter, maybe only one hot leg was wired in the 50 female plug. Most likely as you said, the repaired done by the dealer is at fault and needs to be checked again for proper connections.

N9ID, I would not connect into a 50 amp pedestal/receptacle until this has been fixed otherwise 240 volts could be applied to your equipment.

Top B · 05-21-2013, 07:18 AM

Take it back and have them fix it correctly.

TURBS · 05-21-2013, 08:00 AM

Quote:

Originally Posted by Top B

Take it back and have them fix it correctly.

Yep!

BarryD0706 · 05-21-2013, 08:03 AM

Two more little points.

I guess this is somewhat of a rare case, but wanted to point out that a Hardwired Surge Protector would be useful in this case, whereas a portable one at the pedestal would not.

Also, FYI, there is nothing wrong with switching around the two hot leads (Red & Black) on a 50-amp service. They are symmetrical and no circuit tester will ever be able to the the difference. (However, if there are color labels on the connections, they should be followed to avoid confusion.)

TURBS · 05-21-2013, 08:05 AM

Quote:

Originally Posted by BarryD0706

Also, FYI, there is nothing wrong with switching around the two hot leads (Red & Black) on a 50-amp service. They are symmetrical and no circuit tester will ever be able to the the difference. (However, if there are color labels on the connections, they should be followed to avoid confusion.)

Thanks ! Did not know this.

N9ID · 05-21-2013, 09:01 PM

Worked a bit today on this issue. I talked to the tech who replaced the 50 amp plug on our RV. He said the plug is easy to wire up; match the wire color to the color of the ring around the hole where the wire goes. I pulled the plug off the side of the RV and verified that the plug is wired correctly.

I went to the distribution panel and verified that the wires went to the correct places (red and black to the two 50 amp breakers, white to common and bare wire to ground).

Based on my experience and training (by education I am an electrical engineer and was an electronics technician for 15 years before that; I have also been an active ham radio operator for over 40 years), I was pretty sure everything is wired up correctly.

I switched the red and black wires and now the buss with the TV, ceiling fan, etc. is working. The other buss is now dead. The 15 amp outlet in my garage only supplies one 15VAC circuit, so it makes sense to me that only one buss or the other has power. Anyone agree / disagree?

The issue now is that the convertor is on the buss that has no power. Not good! I will have to switch the hot wires back to the original configuration so I can charge the battery. This is more important than having a working TV. It will probably help me get more work done.

I am going to call Cedar Creek tomorrow to see about moving the convertor circuit to the buss that also runs the TV / fan, etc. That buss has breakers for the washer/ dryer and the 2nd A/C, which we will never install. If I could put all the things I want on one buss, than I would be pretty happy.

Thanks for all your comments. Please let me know if you know about any major issues with moving the convertor to the other buss.

Mike

BarryD0706 · 05-21-2013, 09:20 PM

Mike,

see posts #6 & 7. There is something wrong with your 30->50 adapter.

N9ID · 05-22-2013, 01:47 PM

Quote:

Originally Posted by BarryD0706

Mike,

see posts #6 & 7. There is something wrong with your 30->50 adapter.

Barry, you were right. While checking the power cord and adapter I discovered that there was a disconnect between the 30A male and one of the hot wires on the 50 Amp power cord. Somehow, one pin of the male 50 amp connector got slightly bent, and was not making contact with the corresponding pin in the 30 - 50 amp adapter. I straightened the pin, re-plugged everything and all the connectivity checks passed. Plugged in the coach and the power works as expected.

Thanks for all your help.

Mike

BarryD0706 · 05-22-2013, 04:21 PM

Glad to help. If I were you I'd probably buy a different 30->50 adapter. If a slight bend will disconnect it, it's probably not making a good low-resistance connection even when it is working.

You may also like: