electrical problem

dug · January 12, 2011, 10:57:06 AM

This has nothing to do with my build but I was hoping there was an electrical genius here who could help me diagnose a problem.

I have an airstream trailer that had a problem with an outlet about a week ago. My wife noticed that it (the outlet) was getting hot, so I took it apart and found that the ground wire was very loose. I'm pretty sure that was the problem but I had another outlet here so I just replaced it.

This morning my wife plugged something into it and all the power went out, no breakers were tripped. I took it apart again and one of the neutral wires was severed right where it attaches to the outlet, a very clean cut that looked as if someone had clipped it with a side cutter.

The box is small and it was a tight fit when I was screwing the outlet back in so I was thinking maybe somehow I kinked it, but then why would it break the moment something was plugged in? I don't know if this is pertinent but when I stripped the wire back to reattach it the copper was not shiny, very dull.

I have always been paranoid about the safety of the electrical system in this trailer so I am anxious to figure this out.

muldoon · January 12, 2011, 11:57:38 AM

I have seen that happen before as well. I think you had poor wiring connection to your outlet in the first place and that was why it was getting warm. The resistance from a poor connection will generate heat. When you replaced it, you may have overtightened that neutral down which weakened it and caused it to snap off. dull copper is from oxidation, when you replace it, run it over with some 120 sandpaper to get it clean again. just my 2 cents

January 12, 2011, 12:25:29 PM

It could have been that I over tightened it. I got a lesson from an electrician friend once and I was surprised at how tightly he tightened the connections and wire nuts. He said it was important that they were really tight.

I may have been overzealous.

astidham · January 12, 2011, 12:29:56 PM

dug, I would run a check on all your outlets for ground faults that could be daisy chained to the outlet that had a severed wire.
I had an outlet in my bedroom that would work intermittently, the cords for what was plugged in the outlet would be hot.
The problem was a bad receptacle inline, we replaced it, everything has been fine.
when we tested our receptacles, it was only half that was bad.
we checked it with a 3 prong tester from lowes, it was around $5.00

astidham · January 12, 2011, 12:32:21 PM

when I said half was bad i meant the bottom half of 1 outlet, sorry

January 12, 2011, 01:36:22 PM

you should ensure your using the right size outlet and wire.

14 guage wire uses a 15amp breaker
12 guage wire uses a 20amp breaker

perhaps your overloading the 15 amp breaker and causing it to get too hot.

dug · January 12, 2011, 02:06:59 PM

Not positive on the wire gauge but I think It's at least 14 gauge and a 15 amp breaker. When I replaced the outlet it stopped getting hot so I think the loose ground wire was the deal. Just wondering if there was any electrical fault that could have caused the wire to break, or maybe it was just my install job.

I will check all the other outlets to make sure everything looks O.K.

MountainDon · January 12, 2011, 03:18:40 PM

Most likely the break was just from wire handling. Maybe it had a nick at the break point from when insulation was stripped back. That would provide a break point.

Don_P · January 12, 2011, 03:44:00 PM

I know just enough about power to let the magic blue smoke out of stuff fairly often

. i'd agree with checking everything on the circuit, junction boxes and the screws in the breaker panel too, I've found them loose pretty often.

January 12, 2011, 06:57:34 PM

Electrical connections are supposed to be tightened to specific torque values. Proper torque is actually quite high on larger wires and surprisingly high on others. Finding an inexpensive torque scre driver is not easy. Until one looks into gunsmithing tools. I have a couple made by Wheeler. $50 or so IIRC. More with a larger set of bits.

bayview · January 12, 2011, 08:15:37 PM

I have noticed that wire-cable that has previously gotten hot from a loose connection or wire-cable that was undersized will become brittle.

"More-than-likely" the end of the wire was brittle . . . It broke off when you pushed the outlet back into the box. You can "pig-tail" the wire with a wire nut if you have to cut a lot off. I pig-tail all of my outlets . . . You may want to consider replacing the "box" if it is to small.

A loose connection could be caused by not tightening enough. Over time expansion and contraction of the wire can also cause a loose connection. Especially if undersized. I use 12 gauge even if its an 15 amp circuit . . .

I have seen loose wires in the breaker box, too. Might be a good idea to turn off the elctrical service periodically and tighten the wires in the box. . . Note that the copper wire is connected to aluminum . . .

/.