I've got a new fifth wheel on 50 amp service. Recently we have lost power to all of our outlets and both electric fire places. After checking each plug, checking to ensure no breakers are popped, all fuses are intact, and the source is good this is what I've discovered.The power supply cord is supplying 120v on both legs. When plugged into the RV our LED light above plugs shows power. At the breaker panel however, the red leg shows 120v and the black leg shows 70v. which matches the voltage I'm getting at the outlets. This is BEFORE it even reaches the breaker. I am assuming that the issue is in the inlet plug on the wall of the RV. Either a loose wire or it just needs to be replaced. I'll be opening it up tomorrow to take a look and replace it. Any other ideas, something I might be missing?Thanks-Dre

Are you plugged in at home or at a CG?

Home. On a subpanel. I've checked the main panel and the sub and haven't found any issues or popped breakers there.

WASTATELIVING wrote:Home. On a subpanel. I've checked the main panel and the sub and haven't found any issues or popped breakers there.When you say sub panel, what do you mean? The most common method for plugging in at home is a dogbone to plug into a 20 A outlet. Do you have an inverter? Most newer RV's have an inverter that controls the outlets.

You state Sub panel. Is this something you or an electrician installed JUST to power your RV? The CORRECT voltage on 50 amp is 120 on EACH Leg. THEN there should be 240 volts when testing between each Leg. IF NOT, you do not have a correctly wired 50 amp sub panel. usually that 70 volts means you have miswired the subpanel and do not have the correct Neutral leg connection. We are assuming that you had NO PROBLEM either at the Dealership or at a Campground with 50 amp service. You just have this problem at your home receptacle. DougPS, I have 42 years as a RV tech and one thing I have learned over those years is that even LICENSED ELECTRICIANS, have problems understanding 30 and 50 amp RV plugs.

Thanks Doug,I said home to make it easy. We are staying at a friends home and have been for 2.5 months now. No issues what so ever until just a few nights ago. Which makes me think that its not a problem at the source. I can clarify that on the power cord I've got 120v on EACH leg.

Electrical issue on 50amp service | Good Sam Community

Cummins12V98
Explorer III
Nov 05, 2021
Had a neutral come loose and lay on a hot leg giving me 220V at the micro, smoked it!!!
Winnipeg
Explorer
Jan 04, 2022
Great discussion and information.

We are at an RV park and our auto transfer was jumping in and out last night. Never had a problem with it before so I disconnected for the night and used batteries and propane.

This morning I dug out a volt monitor (very handy, just plug in and look at it occasionally), and I noticed the power generally a little high, average 126v. We also picked up an inline 50a surge protector.

Power was OK all day until about 6pm, then the transfer started jumping in and out again and I saw volts go up to about 160. Yikes! On my dash to shut off the main I noticed the surge protector indicator lights were steady blue/green (normal) with occasional red (Open neutral).

A few simple tools revealed the problem. It's easy to get lazy about monitoring your connections, especially if you have never had a problem. But it is no fun doing repairs while on vacation.

BTW, we blew out a water line 2 years ago due to water pressure surge and not using a regulator. What a pain to repair that, not to mention no water for the remainder of the trip. And...I still forget to use the regular.
wolfe10
Explorer
Jan 04, 2022
Voltage to 160 STRONGLY suggests a bad neutral.

Suspect if you check voltage on the other line (L1 vs L2) to neutral or ground it would be LOW.

No idea if this is in your coach or shore power cord or in the CG wiring.
Bobbo
Explorer II
Jan 04, 2022
Winnipeg wrote:
Power was OK all day until about 6pm, then the transfer started jumping in and out again and I saw volts go up to about 160. Yikes! On my dash to shut off the main I noticed the surge protector indicator lights were steady blue/green (normal) with occasional red (Open neutral).

A few simple tools revealed the problem. It's easy to get lazy about monitoring your connections, especially if you have never had a problem. But it is no fun doing repairs while on vacation.

Care to share the specific diagnosis and repair? You have implied a bad neutral, but that leaves a lot of possibilities.

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Electrical issue on 50amp service

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