Burnt Receptacle...

Status
Not open for further replies.
Strahan said:
Yes I agree I just don't rely on the recpt for feed through applications I'd rather pigtail everytime just my opinion everyone has there own way. Plus makes it easier to change.
Click to expand...

I'm not really concerned about how easy it is to change somewhere down the road.

I just think it's quicker and easier to install just 3 wires on a receptacle than 5.
 
WOW,the ho was very lucky.i would say a loose connection but would guestion the (15 amp receptacle) on the 20 amp circuit. and what else was connected on that circuit passing thru that 15 amp receptacle.yes you said 1 heater now,what size,how about the summertime.how about bedrooms window ac units...and if i remember right i don't think you can backstab a 15 amp receptacle with a #12 wire.it won't fit.
 
stickboy1375 said:
This is what I found at a service call I went on yesterday, owner complained of a burnt receptacle... This was located in his daughters bed room, and happened over night, nothing plugged into the receptacle but a space heater down stream, I told him he was a lucky man.













My guess is that the grounded conductor screws were never tightened from day one, but the damage made it very hard to tell what exactly caused the meltdown
Click to expand...

I had a call that could have been this ones twin. It was in a little boys bed room, he had tried plugging in a radio but was not strong enough to push the plug in all the way. The loose connection caused almost the same situation.
 
COFFEE TIME said:
WOW,the ho was very lucky.i would say a loose connection but would guestion the (15 amp receptacle) on the 20 amp circuit. and what else was connected on that circuit passing thru that 15 amp receptacle.yes you said 1 heater now,what size,how about the summertime.how about bedrooms window ac units...and if i remember right i don't think you can backstab a 15 amp receptacle with a #12 wire.it won't fit.
Click to expand...

15amp receps on a 20amp circuit is pretty common. Probably the standard. Also legal. What is your problem with it?
 
well it looks to me that the box and plate cover did a good job in containing the arc.
I think that space heaters are the real problem here. They should come with arc faults built in. At Home Depot I see heaters for sale that are under 20 bucks. Made in China to boot.
In the past Ive noticed that if you dont really crank down on the screws with number 12 wire attached , the screw and wire do almost a quarter turn on itself.
 
480sparky said:
In this particular case, pigtailing may have prevented it. But it was still a loose connection, and pigtailing cannot cure loose connections. It merely relocates them.
Click to expand...
no offense intended but this statement makes absolutely no sense to me. Strahan is right that pigtailing would have prevented this (as long as the pigtailed connections are tight and proper).
 
Not to get off topic, but my real intentions of posting the pics was to remind us how important it is for good installs and the dangers of bad ones, this was in a childs bedroom and the worst case scenero is very hard for me to swallow.
 
COFFEE TIME said:
WOW,the ho was very lucky.i would say a loose connection but would guestion the (15 amp receptacle) on the 20 amp circuit. and what else was connected on that circuit passing thru that 15 amp receptacle.yes you said 1 heater now,what size,how about the summertime.how about bedrooms window ac units...and if i remember right i don't think you can backstab a 15 amp receptacle with a #12 wire.it won't fit.
Click to expand...
read the thread a little closer to find out that this wasn't a backstabbed connection. Also it is legal to use a 15 amp recep on 20 amp circuit.
 
hillbilly1 said:
Pigtailing may or may not have prevented it, I've seen many a wirenut burnt to a crisp in j-boxes. Res grade receptacles are not designed for heavy loads anyway, as most on average do not have a heavy load plugged into them, with the exception of kitchens and bathrooms. I always use spec grade there.
Click to expand...
So your saying the big box with a bunch of loose receptacles for .50 each isn't
a good choice?:grin:
 
stickboy1375 said:
Not to get off topic, but my real intentions of posting the pics was to remind us how important it is for good installs and the dangers of bad ones, this was in a childs bedroom and the worst case scenero is very hard for me to swallow.
Click to expand...

I sometimes contemplate my own desire to be in the industry because I do not want to make that kind of mistake. I am not above it, I know that. It just makes me, hopefully, try that much harder to be safe.
 
Sparky Jr. & I were trimming a big custom house. Jr. wants to pigtail all
receptacles. I said no dice Jr. In his case, it would just add an additional place for something to go wrong. We also backstab 15A receptacles. Jr. too...
 
Which ever way you prefer to hook your recepts up is merely up to you and your preference. I do agree with Sparky a loose connection is a loose connection whatever it pertains to. I prefer backstabbing over hooking the wire around the screw and prefer pigtailing over all of them. I don't install recepts for a living so I don't mind taking extra time to install as I prefer,but I still have a problem relying on the recept for a continuous path. Many times I have heard and seen recepts crack from overtightening and in this case not tightening enough.
I'll take the time to put a wirenut on. Yes if it is not a good connection it will cause a problem to but I will rely on a connection I make with a wirenut over any made through a recept.:D
 
tonyou812 said:
well it looks to me that the box and plate cover did a good job in containing the arc.
I think that space heaters are the real problem here. They should come with arc faults built in. At Home Depot I see heaters for sale that are under 20 bucks. Made in China to boot. ...
Click to expand...
This type of damage is not caused by an arcing fault...it is just a high resistance connection that produces excessive heat. An AFCI does not directly detect this type of fault...it only acts to open the circuit when the heat has caused enough damage to create a ground fault or a parallel arcing fault.
 
wbalsam1 said:
As you know, it only takes 175 degrees to burn a wooden stud that a 2-hour box might be fastened on. An electrical arc can reach upwards of 10,000 degrees! I have the sense that the fire-resistance rating does not subject a plastic box to 2 hours of arcing temperatures. :smile:
Click to expand...

The more I look, it's actually lower than 350*C, it's around 300*C.

"Consider an external heat source (an overheated wire) in contact with a combustible material(wood, for example). The temperature at the surface of the wood increases steadily to 100 ? C, at which point water is driven off as steam. As the temperature continues to increase, the wood starts to undergo pyrolysis; that is, it starts to decompose into volatiles (vapors) and char. The volatiles, being hotter and hence less dense than the surrounding air, rise and mix with the air.
At around 300 ? C, this mixture of volatiles and air can ignite, producing a flame. Some of the heat generated by the flame escapes with the rising hot gases, but a portion of it is 'fed back' to the fuel (by radiant, convective or conductive heat transfer), causing its temperature to increase further and pyrolysis to proceed at a greater rate. In turn, the flame grows. If the heat feedback to the fuel is sufficient to cause it to pyrolyze and burn by itself, one has 'sustained flaming combustion'. The original ignition source is no longer needed . ."
(J.R. Mehaffey, Ph.D.The Combustibility of building materials. 1984.)
 
Last edited:
Status
Not open for further replies.
Top