Electrical wiring question - melted receptacle

[Scarpozzi]

I have a 2014 clothes washer that's wired off a 15amp circuit with 12/2 and the quality Cooper receptacles. I normally would use a wire nut and pigtail, but didn't on this circuit. I just had the circuit go through the receptacles point to point and then have the washer circuit coming off one of them. The circuit has been in service now for maybe 3 years.

The motor for wash and spin cycles must have heated up the connection enough...maybe it was loose and arcing inside the receptacle....but it ended up melting the point where the hot wire connects to the washer receptacle. We never smelled burning smells before, so this apparently is a very recent issue. In the past few days, it's burned the hot side of the plug and I cut off a solid inch and a half of 12 gauge wire because the insulation was brittle/burned from the heat. (only the wire feeding the washer).

The hexagon is the breaker....the 4 diamond shapes are the receptacles....and the box is the washer. The diamond shape in the middle is the receptacle that melted, not the one next to the washer.


I installed a new receptacle, but am wondering now if I need to go back and make these connections a little more robust. (maybe even soldering the wires together instead of wire nuts)

I have these push on connectors as well wire nuts, but not sure how they would handle this load.


If the receptacles were lower grade, I would expect failures, but perhaps the connection was just loose and it would have happened anyway.

Anyone have experience with this kind of thing?

 

[echo4747]

probably something like a loose connection or component in the receptacle created resistance and heat ... corrosion could be another cause ... Cooper/Hubbell are generally good products.. I would replace the receptacle with a 20amp commercial grade ( make sure your wire is clean)

 

[NutBucket]

Don't use the push on wire nuts. I bought some for "emergency" use but I'm not convinced they'll hold up over time under heavy load

Were any of the receptacles backstabbed? I see nothing wrong with using the receptacle to join cables so long as you're using the screw terminals.

Anyway, I agree it's probably just a fluke. Everything wears out over time.

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[waffleironhead]

Maybe I read it wrong, but Im wondering how you wired two downstream outlets off of that second one without using wire nuts. It looks like 3 sets of wires are going out of one box, which would require wire nuts.

 

[Scarpozzi]

Maybe I read it wrong, but Im wondering how you wired two downstream outlets off of that second one without using wire nuts. It looks like 3 sets of wires are going out of one box, which would require wire nuts.

Don't use the push on wire nuts. I bought some for "emergency" use but I'm not convinced they'll hold up over time under heavy load

Were any of the receptacles backstabbed? I see nothing wrong with using the receptacle to join cables so long as you're using the screw terminals.

Anyway, I agree it's probably just a fluke. Everything wears out over time.

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More like side-stabbed. The wires go straight into a hole where plate is tightened down by a screw. There are 2 screws on each side and you can connect 2 wires per screw connection....so a total of 4 wires + ground can be connected through the receptacle.

I've still not put the face cover back on. I keep sticking my nose in the box while the washer is running and want to check the circuit on spin cycle to see if I can detect any heat or burning plastic smells while it's under the most load it will see. Unfortunately, it lasted a few years before. I replaced it with the exact kind of receptacle that failed. I think Cooper changed their name to Eaton, but I'm pretty certain what failed was a 20amp receptacle. The neutral side has that T like this:

 

[NutBucket]

I like those screw terminals with the extra plate. Basically any sort of real mechanical connection that doesn't rely on spring tension is what you want.

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[Scarpozzi]

I like those screw terminals with the extra plate. Basically any sort of real mechanical connection that doesn't rely on spring tension is what you want.

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Yeah....these aren't springs or anything that should wear out.

 

[Paperdoc]

I always have used wire nuts for making connections among cable wires in a box. Then I only run a single wire pigtale from a the nut to the screw terminal on a receptacle.

But if I were connecting TWO wires together under a single receptacle screw, FIRST I would twist the two wires together tightly, similar to what happens inside a twisted-on wire nut. Then I'd take that twisted pair, bend it into a hook to fit around the screw, and tighten the screw onto the twist. I would not simply bend each wire individually, slip both hooks under the screw and expect the screw pressure to ensure adequate contact among all the metal surfaces. Just my thinking, but I'm not a pro electrician.

 

[Scarpozzi]

I always have used wire nuts for making connections among cable wires in a box. Then I only run a single wire pigtale from a the nut to the screw terminal on a receptacle.

But if I were connecting TWO wires together under a single receptacle screw, FIRST I would twist the two wires together tightly, similar to what happens inside a twisted-on wire nut. Then I'd take that twisted pair, bend it into a hook to fit around the screw, and tighten the screw onto the twist. I would not simply bend each wire individually, slip both hooks under the screw and expect the screw pressure to ensure adequate contact among all the metal surfaces. Just my thinking, but I'm not a pro electrician.

This receptacle design takes straight stripped wire tips on the sides and when you tighten the screws, a plate compresses to secure the wires. You only wrap the ground wire around the ground screw.

What's tricky about wiring these with wire nuts is the number of wires in the box. These are the largest capacity boxes made for 2x4, 1 gang boxes, but it would be a pain to wire nut them because it would be bringing 4 wires together twice in the box... (It's where those Ideal-branded push-on connectors are tempting)

 

[Greenman]

This receptacle design takes straight stripped wire tips on the sides and when you tighten the screws, a plate compresses to secure the wires. You only wrap the ground wire around the ground screw.

What's tricky about wiring these with wire nuts is the number of wires in the box. These are the largest capacity boxes made for 2x4, 1 gang boxes, but it would be a pain to wire nut them because it would be bringing 4 wires together twice in the box... (It's where those Ideal-branded push-on connectors are tempting)

Box fill is a thing. I had an inspector that had a real problem with box fill limits.

 

[Steltek]

This receptacle design takes straight stripped wire tips on the sides and when you tighten the screws, a plate compresses to secure the wires. You only wrap the ground wire around the ground screw.

What's tricky about wiring these with wire nuts is the number of wires in the box. These are the largest capacity boxes made for 2x4, 1 gang boxes, but it would be a pain to wire nut them because it would be bringing 4 wires together twice in the box... (It's where those Ideal-branded push-on connectors are tempting)

Instead of push-on connectors, use Wago 221 series lever nuts (don't get the 222 series, which are cheaper) - you can get them on Amazon. They are more expensive than push-on connectors, but are far safer and better in every way than simple push-ons. And, as a bonus, they don't take up anywhere near as much space in a recepticle box as wire nuts do.

You might also need to consider that there is damage somewhere to the supply wire itself (such as caused by a misplaced staple or screw) in the wall. If this happens, it can cause recepticles to heat up or melt if the circuit is running a higher draw device.

 

[Scarpozzi]

Instead of push-on connectors, use Wago 221 series lever nuts (don't get the 222 series, which are cheaper) - you can get them on Amazon. They are more expensive than push-on connectors, but are far safer and better in every way than simple push-ons. And, as a bonus, they don't take up anywhere near as much space in a recepticle box as wire nuts do.

You might also need to consider that there is damage somewhere to the supply wire itself (such as caused by a misplaced staple or screw) in the wall. If this happens, it can cause recepticles to heat up or melt if the circuit is running a higher draw device.

Thanks for the tip. I'll check the Wago 221s out and may flip it over. I didn't see any lever nuts when I was looking a few years ago, but probably would have done that over the push-ins had I seen them. I reluctantly used a lot of the push-in connectors because they had 5 conductor ones. I had the same concerns everyone else does about anything that might loosen over time from temp fluctuations. Hopefully they last longer than I do.

I thought about damage up the line as well. I'm the one that stapled it...I know I was careful not to pinch the insulation, but you never know. This circuit is on AFCI, so at least there's that.

 

[Scarpozzi]

Box fill is a thing. I had an inspector that had a real problem with box fill limits.

I don't ever buy boxes at Home Depot/Lowes anymore for that reason. Carlson makes a bunch of blue boxes that these stores sells to home owners, but my local electrical supply shop has these industrial black boxes that are the maximum size possible. Dimensional 2x4s are 3.5" wide, so you could potentially go with near 3.5" boxes....but you likely want to have something just a little less for fluctuations in lumber. I'd probably see what you can find in a supply house and go with something from Hubbell or elsewhere that is over 3" deep. Not just for code requirements, but for ease of installation and keeping the wires straight.

1-Gang Rectangular Nonmetallic Cable Box, 3-3/16 in. Deep: Electrical Boxes: Amazon.com: Tools & Home Improvement

1-Gang Rectangular Nonmetallic Cable Box, 3-3/16 in. Deep: Electrical Boxes: Amazon.com: Tools & Home Improvement

www.amazon.com

 

[Red Squirrel]

I would personally just run a dedicated 15 or 20 amp for the washer. Don't like the idea of piggy backing stuff off that circuit.

And yeah avoid backstabbing outlets. Never been a fan of those and they are also annoying to deal with if you want to disconnect them.

 

[Scarpozzi]

Dryers need 30 amps. Do you have a FPE panel by chance? I'm surprised it was not tripping the breaker. Hope someone did not just put a 30 amp breaker on wiring that is suppose to be 20 amps...

I would personally just run a dedicated 30 amp for the dryer. Don't like the idea of piggy backing stuff off the dryer circuit.

And yeah avoid backstabbing outlets. Never been a fan of those and they are also annoying to deal with if you want to disconnect them.

You're the only one talking about a dryer here. It's a clothes washer on the circuit I'm talking about.

120v @ probably 15amps max. The receptacles and the circuit breakers are 20amp with the breaker being AFCI. Had there been an arc, it should have tripped the breaker. The receptacles aren't the spring-style backstabbers either. Most major brands don't sell those anymore that I've seen. The ones I'm using allow you to use a straight wire on the sides and a plate compresses when you tighten the screws to put pressure on the wire. It works great most of the time. I'm not sure where the failure happened here. I've not had any other receptacles melt like this before.

I'll likely rewire those connections again this week in the box and pigtail the receptacle.

 

[Red Squirrel]

Right don't know why I was thinking dryer when I read it. Either way a washer should probably be on it's own circuit.

 

[Steltek]

If rewiring the outlet doesn't work, you might need to consider the possibility that the washer motor is defective. It may be pulling too much juice through the circuit which could cause a melted outlet.

Might be worth testing the circuit with a clamp meter while the washer is running.

 

[Micrornd]

The ones I'm using allow you to use a straight wire on the sides and a plate compresses when you tighten the screws to put pressure on the wire.

I use those too, but loosen the screw enough to loop the wire under the plate. Doesn't loosen, doesn't heat, applies even pressure. Try it

 

[Sukhoi]

If rewiring the outlet doesn't work, you might need to consider the possibility that the washer motor is defective. It may be pulling too much juice through the circuit which could cause a melted outlet.

Might be worth testing the circuit with a clamp meter while the washer is running.

That shouldn't cause a melted outlet if the circuit breaker is working properly.

 

[Red Squirrel]

I always like to use the screws for outlets, switches etc and not the back stab. I strip enough wire to loop around, loop it slightly so I can get it in, and when I turn the screw it loops it more. Make sure that you insert it so that turning the screw is pulling on the wire and not pushing on it, you get more grip that way. At least that's been my experience.

 

[Steltek]

I always like to use the screws for outlets, switches etc and not the back stab. I strip enough wire to loop around, loop it slightly so I can get it in, and when I turn the screw it loops it more. Make sure that you insert it so that turning the screw is pulling on the wire and not pushing on it, you get more grip that way. At least that's been my experience.

That is actually the way you are always supposed to do it.