Loss of electrical ground - Montana Owners Club

budnikfl · 02-02-2009, 03:32 PM

We plug in our unit at home to a 15A receptacle via a 50A-30A adapter cord and a 30A-15A adapter plug. When I was under the camper and happened to touch bare metal I received a mild shock. There was a 3.2VAC reading from any bare metal to ground. I took a receptacle tester and checked the 15A receptacle at the house and it was fine. When I tested the receptacles in the camper they all indicated a loss of gound. The next time we went out and hooked up to a 30A power source at the campground (using the 50A-30A adapter cord) everything was fine, no bare metal shocks and the receptacles all tested good. There also were no problems when connected to a 50A power source. Thinking the problem was in the 30A-15A adapter plug I tried three different ones with the same results (shocks at bare metal and loss of ground). Has anyone else run into this problem?

Fred Budnik

BB_TX · 02-03-2009, 02:51 AM

Did you test the 30-15 adapter at the campground where the 50-30 adapter worked fine? Not clear if it failed at both or only at your home.

ole dude · 02-03-2009, 03:58 AM

Yepper, had that happen, found the ground wire-slick wire- loose in the main plug where you plug in the shore power. At the time I found that I looked at all the various places where the unit is grounded and tightened those connections as well as the connections in the electrical panel.

farmboy · 02-03-2009, 04:26 AM

I also wonder why you had any voltage at all between frame and earth. The idea of the ground is to drain any stray voltage that happens to get on the frame. Mine was the same, but when i plug into a 50 amp. recpticale the 50 amp circuit breaker popped open immediately. A short circuit was the problem. As my unit was new i took it to a Keystone dealer. At first they told me there was nothing wrong, but after a heart to heart with them they found the wire between the rear of the couch and the power panel was pinched between frame and floor causing one of the hot wires to be rubbed bare. They fixed it and i have no more problems. I had a talk with the selling dealer about this sugesting the virify all system operations using the 50 amp. or 30 amp plugs as apropriate. The had not done this in predelivery chechs. I must also say that the rubbing probably occured during transport and my first trip or two. Have dealer check it out. Good luck.

budnikfl · 02-04-2009, 10:04 AM

I did not test the 30A-15A adapter plug at a campground only at home so there is one more thing I can look at. My camper is in winter storage right now so it will be a few months before I can get at it again (lots of snow in Michigan this time of year). Thanks for the responses but everything sure seems to point at that 30A-15A adapter. I think if there was a wire rubbed bare and grounding out the problem would appear no matter what configuration of power cords I was using. Ole Dude's suggestion of checking all the ground connection is one I also will look into.

farmboy · 02-05-2009, 04:03 AM

In regards to your grounding issue the ground wire in the cable from back of unit to panel in camper is probably broken also. Thus a loss of ground indication. I can not stress enough that there should never be any voltage reading between any part of rig and earth. On mine the wife was shocked when she was barefooted and stepped from steps to wet ground. Could have been worse. On my rig the circuit breaker would not trip when plugged into 30 amp service by way of an adapter, only when plugged into 50 amp service. If i sound a little hard headed on this issue it is because i don't want to see anyone hurt. I am also an electrician with over 20 years experience. Good luck in getting fixed & happy camping. If you have any other questions please feel free to e-mail me at winsfarm@msn.com.

happy campers · 02-06-2009, 02:12 AM

Assuming that most campgrounds have GFCI's, wouldn't the service at the park pedestal disconnect the power if there was a fault in the trailer? We had an incident where our older RV worked fine at home, but would trip the GFCI at the park. After checking, I found the neutral shorted to ground in the main panel of the RV. Hope you figure it out.

budnikfl · 03-11-2009, 07:00 AM

Just an update on my grounding problem. I spoke with a RV repair shop and they also suspect the 30-15a adapter plug. I have purchased a 30a-15a adapter cord to see if this will cure the problem but of course I cannot test it until I bring the unit home. I will let all you know when I try the new adapter cord. Thanks again for the feedback.

Devildog · 03-11-2009, 07:11 AM

I had this exact same problem at my home. For the life of me, could not figure it out. Until, I replaced the 15A outdoor electrical cord with a 30 cord from Home depot, heavier gauge and corrected the grounding problem. Those other cords are just too light to handle the grounding activities, and with the roll up and twisting they go through from being used for Christmas lights, saws and other things, my ground had probably broken in the cord.

HamRad · 03-11-2009, 07:41 AM

When my setup did that it turned out to be the extension cord. I was using a heavy duty cord but the ground stem had gotten broken off. Thus I had no ground when plugged into that cord. Replaced the plug and all was good. But I did check all the grounds just to make sure.

HamRad

stevemc · 03-11-2009, 07:42 AM

I had a similar situation once. I was just plugged in to a regular 30A RV outlet I have installed by the house and got a mild shock from the front landing gear legs. I never did find the problem and have never had it occur again either at home or on the road. Always kind of bothered me not knowing what caused it. I intend to check all the grounds I can find again but so far I've not found the problem. Could also be a pinched wire somewhere. Electrical problems can be tough, especially when they are intermittent.

You may also like: