How do I deal with overheated/burnt wiring?

[ConstableDuffy]

I am renovating a home built in 1977. Many of the duplex receptacles do not work, only have one working outlet, or can supply only a limited and inconsistent amount of current.

When I removed one of the problematic receptacles, I found that the white wires had been burnt and/or had overheated, and the receptacle had also been burnt/melted where the white wires were inserted into the back of the receptacle. Please see following photos for clarification.

It is obvious I need to replace the receptacle. But how do I deal with the overheated/burnt white wires? Can I use them as-is? If not, how would I go about repairing or replacing them?

Thanks!

 

[telectrix]

pull some cable slack down and strip back to undamaged cable refit outlet. if no slack available, refit the box a few inches higher. replaster hole where box was originally.

 

[Lucien Nunes]

Hmm, a classic case of bad contact in the back-stab connections. As above, first try to pull a little more Romex into the box, to see if you can strip back to where the insulation is not discoloured or hardened. Depending on how much length you can gain if any, and how much of it is damaged, you might either be able to wire to the outlet directly (use side wire screws, not back-stabs) or you can pigtail a single extension onto the two ends and connect that to the outlet.

If you go for pigtailing, I recommend lever nuts like the Wago 222, as they use the least amount of wire length and can be fitted easily onto short wires that don't reach out of the box. Whatever method of connection you use, ensure the surface of the copper wire is clean and bright without any trace of corrosion or tarnish, as that will cause the newly made connection to overheat again through high resistance.

If you cannot get even enough undamaged cable to a position where you can fit a lever nut, then you will have to start making holes in your wall to install a junction box or move the outlet.

 

[FatAlan]

How about these? Smaller than the lever connectors, if you can't get enough slack on the existing good conductors.

 

[Lucien Nunes]

Or those, indeed, although my thinking was that in the deep, narrow box of a duplex outlet, if the ends are short it might be easier to slide a 222 or 221 onto them and flip the levers down, that to apply enough pressure to engage them into a push-in Wago.

 

[FatAlan]

Or those, indeed, although my thinking was that in the deep, narrow box of a duplex outlet, if the ends are short it might be easier to slide a 222 or 221 onto them and flip the levers down, that to apply enough pressure to engage them into a push-in Wago.

Know what you're saying Lucien. In a confined space I'll sometime use long nose pliers to push the conductor in to the push fit. Need that satisfying feel of the conductor pushing in to the connector securely. Must admit that I sometimes have an irrational fear that when I close up a box with lever connectors they'll get knocked and a lever will release ??

 

[westward10]

He has another thread about the difference between residential and commercial receptacles. The commercial ones don't appear to have the push fit connections which seem to be disliked as they are prone to overheating if poorly connected.

 

[Lucien Nunes]

Many of those back-stab connections are / were very crude and in no way equivalent to the contacts of a push-on Wago, even though they fulfil the same purpose. Literally a bit of bent brass on the side of the of the contact stamping, bent back towards it to create a snare for the wire end. It is surprising the UL didn't throw them straight back at the manufacturers.

There are also receptacles with rising clamp back-wire terminals which are excellent, as well as the traditional side-wiring binding-head screws.

I sometimes have an irrational fear that when I close up a box with lever connectors they'll get knocked and a lever will release

I think that's very unlikely with a 222. More so with a 221, and IME it's also possible to pull a wire out of a 221. I use them and like them for certain applications but they don't have the mechanical security of a 222. You have a point about the permanence of a 743 in that there is no way a connection could be loosened by accident no matter what you do; only a very deliberate process will release it.

 

[FatAlan]

Many of those back-stab connections are / were very crude and in no way equivalent to the contacts of a push-on Wago, even though they fulfil the same purpose. Literally a bit of bent brass on the side of the of the contact stamping, bent back towards it to create a snare for the wire end. It is surprising the UL didn't throw them straight back at the manufacturers.

There are also receptacles with rising clamp back-wire terminals which are excellent, as well as the traditional side-wiring binding-head screws.



I think that's very unlikely with a 222. More so with a 221, and IME it's also possible to pull a wire out of a 221. I use them and like them for certain applications but they don't have the mechanical security of a 222. You have a point about the permanence of a 743 in that there is no way a connection could be loosened by accident no matter what you do; only a very deliberate process will release it.

I told you it was an irrational fear ?