Posted 2021-03-05 3:10 PM (#173523) Subject: Trailer frame had electrical charge when plugged into shore power
Veteran
Posts: 236 Location: Little town in Pa
So my dear husband was greasing my hubs the other day and said he was getting shocked when he used the screwdriver to remove the grease cap. I checked it out with a voltmeter and he was correct. Not only did the hub have an electrical charge, the whole frame of the trailer had an electrical charge. The electrical charge of the frame went away when we unplugged the shore power line. I turned off all the breakers in the LQ and the frame still had a charge while plugged into shore power. I assumed the wire from the exterior 30 am plug had a short in it but when I check it out, it was good and solid, no shorts. I also looked as far as I could behind the service entrance inside the trailer and I saw no break in the wire coming from the exterior 30 am plug. The trailer was plugged into a 20 am outlet on the side of our garage via an adapter. We keep it plugged in just to keep the batteries charged up. I tried testing the outlet on the garge to make sure that there was no power on the neutral or ground line. The adapter that I had was a 20 amp/ 30 amp adapter with no ground. ( not sure where we got it or even why I would use such a piece of crap). Anyhow, when I replaced this adapter with one that had a ground, the problem was resolved and the frame of the trailer had no charge. We tested it back and forth a couple times, and when we used the adapter with no ground, the frame had an electrical charge. When we replaced the adapter with one that had a ground, the frame had no electrical charge. Can any electricians out there explain to me how the frame got an electrical charge
Posted 2021-03-09 8:33 PM (#173531 - in reply to #173523) Subject: RE: Trailer frame had electrical charge when plugged into shore power
Expert
Posts: 2953 Location: North Carolina
Not an electrician ... Seems like you have a connection between the trailer and the neutral. Since you turned off all the breakers, I suspect the problem is your CB panel or the wires to it. The neutral wires should be isolated from the ground wire and the box. Some times there is a bonding screw on the neutral bar. This should be removed. Your trailer panel should be wired as a sub-panel. * Meaning the neutral and ground should be separate in all cases. Otherwise as you have found, the electricity is looking for the shortest path, and the neutral is not it... charging the trailer frame while it seeks the lowest potential.
Do post back what you find for the benefit of others.
*the only time a ground and neutral is connected together is at the utility entrance panel. Nothing after it should connect the ground and neutral. Grounding is a safety issue not a power wire.
Posted 2021-03-13 6:38 AM (#173535 - in reply to #173523) Subject: RE: Trailer frame had electrical charge when plugged into shore power
Elite Veteran
Posts: 785 Location: Tenn/Ala.
Again, like HP not an electrician- but I do wonder also about a hot being in contact somewhere. It is not uncommon for a staple or screw to nick a wire and cause this. You may be able to use a quality ohm meter and check for continuity between the shorecord pins, and the trailer frame.
For what it is worth, one of the last step in a certified LQ build is the performance of a Hi-Pot test. The Hi-pot device hooks to each pin that carries electricity and the trailer frame while it inputs 1080 volts through the cord. Any voltage showing up in the frame/ground indicates a problem. Now- it is possible to pass the test, and after miles of driving and vibration later have an issue.
Also- You can do some prelim testing by turning all the breakers off and see if you feel it. Then turn them on one by one to see which circuit it is in.
Another also- I'd use a circuit tester to make sure the receptacle I was plugged into was good. A hot & nuetral reversed will cause this, yet everything else will seem to operate just fine. I tried to post the tester pic and can't. It is this one.
Trailer frame had electrical charge when plugged into shore power
