My Bedroom's Melting Receptacle

31b

yeah in the case of a GFCI you would use both terminals as line and load for it to detect the current difference.

jrclen

Overload? If those conductors are protected by the proper size OCPD and the connections are tight, how would an overload cause that damage? That picture looks like a classic loose connection. And feeding 20 amps through the terminal screws of a 15 or 20 amp receptacle will not cause any problems, that is why the practice is not prohibited by the NEC.

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John

31b

the connections were definitely tight on 4 of the 5 terminals. The other one as I stated I started to unscrew myself before the picture was taken, but just said screw it after the whole terminal was somewhat moveable on the melting frame, and I just cut the wires. It might have been somewhat loose possibly, but it appeared to be screwed down tight on the wire at the time. In the picture though, yes that terminal has been loosened.

There is the possibility of overload, as it was not a heavy duty grade receptacle. It was a cheap 15 amp receptacle on a 20 amp OCPD (was 12 wire though), daisy-chained sharing the entire load of everything (and then some that shouldn't have been on that circuit) down the line.

God knows how old the breakers are, who's to say they'd actually trip either - there could have been more than 20 amps flowing through that. In theory the wire is rated for up to 30, but that receptacle is not. Regardless though, problem solved... new wire, quality receptacles and a AFCI breaker

woodchuck2

X2, any time i have found a melted rec in a home it was due to loose connections and not excessive load. I found one once behind a dresser that had actually caught fire and the flames had singed the wall and back of the dresser about three feet up. Both power and neutral were loose on that one.

ChillaWatt

When I started out doing residential remodel work the electricians I worked under never used their linemans to twist the wires together before putting the wirenuts on. This was because they were in a hurry to get the splices done, covers on and out of the attic. Aside from adding dedicated circuits, they never shut down the circuit they were working on at the panel because they didn't want to inconvenience the homeowner and it would require multiple trips into the attic. They even showed me how to test whether a circuit was switched or not while up in an attic and found that you had forgot your voltage tester...with your finger!! Such a stupid practice. When I went to work for a commercial electrician I was shown the right ways and the importance of twisting the wires before putting on the wirenuts, and to make sure no copper is seen under the wirenuts. It's easy to think that all is good once you put push the wires back into the box and put that cover on. Double check them and you'll sometimes find a wirenut is just barely on. A little heat through those wires could cause them to dump that wirenut and contact something else, or loosen up and arc.

Nothing wrong with daisy chaining them, but the GFCI has to be first in the series in order to protect the other receptacles.

-Chilla

ChillaWatt

An important fact espoused by AC/DC(the band not the current)

"Loose wires cause fires
Gettin' tangled in my desires, so
Screw 'em up and plug 'em in
Then switch it on and start all over again
I'm gonna get it up
Never gonna let it up, no
Tickin' like a time bomb, oh yeah
Blowin' out the fuse box"

-Chilla

brian11973

1. Pretwisting wires is only as good as the prewisting. I have seen many prewisted connections where the twist is bad & the wirenut is loose. ( Something about the boss did it 50 years ago, big deal). I will put my un prewisted connections againist your prewisted ones! I never said I did 'um loose. Oh, TRY to pretwist stranded!

2. The Code specifically states that all parts of a circuit must be rated for the circuit amps.

3. There is an exception that states that a 15A receptacle may be installed on a 20A circuit. BUT THE RECEPTACLE CAN NOT BE PART OF THE CIRCUIT!!!! Thus NO FAST TAPPING THE PLUGS!! Under the screws counts as fast tapping. Pull 20A through a 15A plug, well IT'S GOING TO MELT! The 15A GFCI's are rated for 20A through them.

kirbymurphy

You can't overload a receptacle that has the proper wire size and proper sized current protection in place, at least for more than a moment or two.

That problem is likely a loose wire; screw not tight or loosened when the wires were folded back into the box. Either way too loose.

Could also be a loose contactor inside the recept that grasps the plug. That would transfer the heat to the screw base. I'm assuming the recept is CU and not AL, like the wires, but can't really see.

When I saw the topic I expected to see a recept with the push-in connections. I NEVER use them. I've seen several meltdowns from them and I'd bet they caused many house fires. They shouldn't be allowed.

JohnJ0906

Incorrect. the only difference between a 15 amp receptacle and a 20 amp receptacle, of the same grade, is the plastic face. The guts are the same.


Also,

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John from Baltimore
"One Day at a Time"
All replies based on the 2008 NEC