melted receptacle mystery

[electricguy61]

Just something you need to understand here because it sounds like you have some kind of faith in AFCI. AFCI breakers are useless and about the only thing they do is transfer money from your wallet to the manufacturers bank account. What you witnessed is a perfect example that they don't work. No mystery or weirdness at all.

-Hal

Amen brother, Amen. AFCI’s are not only totally useless, they’re troublesome and expensive

IMHO, it’s a likely combination of the load and poor female connection. We probably repair at least 20 of those per year between fall and early spring. Bay Area homes just weren’t wired for space heaters.

I disagree with the backstabbing theory. To me, the damage is to the face of the receptacle, and the blade connections. I don’t see evidence of the back stab failing. Heat rises, and the melting appears to start low on the receptacle rising all the way to the top.

There is also evidence of over heating as both the top and bottom outlet faces are discolored.
But I’m just an electrician, not a forensic investigator

I recommend to customers they use radiant space heaters, only on the low setting.

https://www.homedepot.com/p/1500-Wa...iant-Portable-Heater-Grey-HD904-A7Q/205210318

 

[drcampbell]

It happens hundreds, if not thousands of times. Ask someone that has done residential service work for a while.

I said I was disappointed -- not surprised.

 

[MAC702]

It's almost always the neutral, too.

...Are there any backstab receptacles where you have to tighten the screws to properly hold the wire in the backstabs?

That's a back-wired, not a back-stabbed. HUGE difference in terminal security.

 

[romex jockey]

https://youtu.be/_2HyTRxzwXs

~RJ~

 

[GoldDigger]

Amen brother, Amen. AFCI’s are not only totally useless, they’re troublesome and expensive

IMHO, it’s a likely combination of the load and poor female connection. We probably repair at least 20 of those per year between fall and early spring. Bay Area homes just weren’t wired for space heaters.

I disagree with the backstabbing theory. To me, the damage is to the face of the receptacle, and the blade connections. I don’t see evidence of the back stab failing. Heat rises, and the melting appears to start low on the receptacle rising all the way to the top.

There is also evidence of over heating as both the top and bottom outlet faces are discolored.
But I’m just an electrician, not a forensic investigator

I recommend to customers they use radiant space heaters, only on the low setting.

https://www.homedepot.com/p/1500-Wa...iant-Portable-Heater-Grey-HD904-A7Q/205210318

A contributing cause to receptacle contact surface overheating may be one or more poor connections within the male plug attached to the heater. These can heat the plug blade which in turn heats the receptacle contacts, and possibly the spring. It may be hard initially to distinguish heat-caused damage to the plug with damage induced heating at the plug, indirectly heating the receptacle.

 

[growler]

Not a single back stabbed connection in my small collection. The common denominator for all mine was a space heater.

I don't keep a collection of burned receptacles but I can easily believe that space heaters would be a leading cause.

I can't think of any other continuous loads in a house that would match the power consumption of a space heater. Even the furnace motor (if it were cord and plug connected) would not draw as much current. Years ago window A/C units may have been as much but most were on dedicated circuits.

 

[hbiss]

I don't keep a collection of burned receptacles but I can easily believe that space heaters would be a leading cause.

I can't think of any other continuous loads in a house that would match the power consumption of a space heater. Even the furnace motor (if it were cord and plug connected) would not draw as much current. Years ago window A/C units may have been as much but most were on dedicated circuits.

Is there any reason that we shouldn't require receptacle manufacturers to up the quality and make all their receptacles capable of handling the full circuit rating continuously? I'm sure there wouldn't be a problem like this with spec grade but when you install the cheapest crap out there this is what can happen. Sure it may cost 3 or 4 times as much but if they can make you pay $$$ for AFCIs that don't work, at least pay for something that will.

-Hal

 

[K8MHZ]

Is there any reason that we shouldn't require receptacle manufacturers to up the quality and make all their receptacles capable of handling the full circuit rating continuously? I'm sure there wouldn't be a problem like this with spec grade but when you install the cheapest crap out there this is what can happen. Sure it may cost 3 or 4 times as much but if they can make you pay $$$ for AFCIs that don't work, at least pay for something that will.

-Hal

I think that you are forgetting that the number of severely melted receptacles is probably only a small fraction of a percent of the number installed. We don't need any more new requirements for receptacles. For all we know, the problem could have started in the cords of the heaters.

 

[gadfly56]

Is there any reason that we shouldn't require receptacle manufacturers to up the quality and make all their receptacles capable of handling the full circuit rating continuously? I'm sure there wouldn't be a problem like this with spec grade but when you install the cheapest crap out there this is what can happen. Sure it may cost 3 or 4 times as much but if they can make you pay $$$ for AFCIs that don't work, at least pay for something that will.

-Hal

When we moved into our current home I noticed that nearly every receptacle had such poor spring tension that you could make a plug drop out by slamming the door to the room. I bought a couple of packs of commercial grade receptacles and have never had a problem with any of them. Or, you can get the 10-pack for $4.99.

 

[K8MHZ]

It's almost always the neutral, too.

Of the four in my picture, only one was burnt on the neutral side. The other three were burnt on the line side.

 

[growler]

When we moved into our current home I noticed that nearly every receptacle had such poor spring tension that you could make a plug drop out by slamming the door to the room. I bought a couple of packs of commercial grade receptacles and have never had a problem with any of them. Or, you can get the 10-pack for $4.99.

I'm not surprised. Many of the older homes (over 20-25 years) do need the receptacles replaced. You can get a bit
more lifespan out of better quality receptacles but sooner or later they will also need to be replaced.

From a safety standpoint is probably just as good to install cheap receptacles and replace them after a few years and make sure all the connections are still tight.

Switches and receptacles were never ment to last forever.

 

[hbiss]

When we moved into our current home I noticed that nearly every receptacle had such poor spring tension that you could make a plug drop out by slamming the door to the room.

Many years ago I replaced the receptacles in my living room with Leviton contractor grade. Nothing is plugged into most of them except lamps, a TV, etc. A year or so ago I noticed that one, next to the fireplace where Christmas lights get connected once a year, you had to wiggle the plug to get it to work. So I replaced it and took apart the old one to see what the problem was. Not only was there no spring tension in the contacts, they didn't seem to be tempered at all. A heater plugged into that would surely burn it up. This is what I'm talking about. Crap.

-Hal

 

[steve66]

Originally Posted by steve66
That's interesting.

Is it just me, or does it also look like all the receptacles in K8MHZ's collection were all burnt on the bottom half?



​

Look at the heat pattern on the receptacle facing us. It was burnt on the top, and the ground was also on the top.

But I was referring to the bottom half when looking at the receptacle with the ground on the bottom. Not according to how the receptacle was installed.

Basically following Sparks4All's comment that the terminals don't overlap as much on the bottom. Or are you saying that receptacle is basically built backwards, so the terminal that burnt were the ones that completely overlapped the plug?

 

[Coppersmith]

Many years ago I replaced the receptacles in my living room with Leviton contractor grade. Nothing is plugged into most of them except lamps, a TV, etc. A year or so ago I noticed that one, next to the fireplace where Christmas lights get connected once a year, you had to wiggle the plug to get it to work. So I replaced it and took apart the old one to see what the problem was. Not only was there no spring tension in the contacts, they didn't seem to be tempered at all. A heater plugged into that would surely burn it up. This is what I'm talking about. Crap.

I'm not surprised. Here's the definition of contractor grade.

"Builder grade" or "contractor grade" is defined as inexpensive products made from low-grade materials, as opposed to quality grade or custom grade materials that are more durable.

https://www.networx.com/article/what-is-builder-grade

 

[gadfly56]

I'm not surprised. Here's the definition of contractor grade.

"Builder grade" or "contractor grade" is defined as inexpensive products made from low-grade materials, as opposed to quality grade or custom grade materials that are more durable.

https://www.networx.com/article/what-is-builder-grade

I know it's really "caveat emptor", but the Leviton's I buy are $17.98 for the 10-pack vs $4.99 and are listed as "commercial", not "contractor". There is a clear difference when you look at them side by side and heft them.

 

[K8MHZ]

But I was referring to the bottom half when looking at the receptacle with the ground on the bottom. Not according to how the receptacle was installed.​

Basically following Sparks4All's comment that the terminals don't overlap as much on the bottom.

I just went and looked at them, and you are correct, all four have the burnt terminals on the same end of the receptacle. That would be the bottom end if the ground was on the bottom. I never noticed that before.

 

[hbiss]

I'm not surprised. Here's the definition of contractor grade.

"Builder grade" or "contractor grade" is defined as inexpensive products made from low-grade materials, as opposed to quality grade or custom grade materials that are more durable.

My point exactly. Why is is something like this available?

It seems to me that if we tightened up the quality of our electrical devices as well as our installation methods, many of these incidents would not have happened.

-Hal

 

[MAC702]

Of the four in my picture, only one was burnt on the neutral side. The other three were burnt on the line side.

I did notice that, and thought it odd. Whether I find it on receptacles or cord caps, I get the neutral burned up on 96% of them.

 

[charles2]

Thanks for the replies, everyone.

Remind me not to use Cooper receptacles.

Are there brands that are not susceptible to this problem?

Not a single back stabbed connection in my small collection. The common denominator for all mine was a space heater.

Anybody know the statistics for what % of residential electrical fires are caused this way?

it sounds like you have some kind of faith in AFCI.

-Hal

I did, but I stand corrected.

Is there any reason that we shouldn't require receptacle manufacturers to up the quality and make all their receptacles capable of handling the full circuit rating continuously? I'm sure there wouldn't be a problem like this with spec grade but when you install the cheapest crap out there this is what can happen. Sure it may cost 3 or 4 times as much but if they can make you pay $$$ for AFCIs that don't work, at least pay for something that will.

-Hal

A related question: Would there be any improvement in safety by replacing 15A receptacles with 20A (leaving the breaker at 15A of course)?

 

[MAC702]

...Would there be any improvement in safety by replacing 15A receptacles with 20A (leaving the breaker at 15A of course)?

All else being equal, no. The only real difference is the prong configuration, with the 15A receptacle having basically a rejection feature of the sideways prong on the 20A plug.