electrical fires

[billdozier]

Hey guys buddy got me wondering what causes electrical fires. My thoughts are obviously poor wiring. With the biggest being too much ampacity on too small of a wire. What do you guys think and do you have a kink I can research thanks

 

[walkerj]

Cut/frayed lamp cords under drapes or newspaper.

Loose connection in switches or receptacles.

 

[peter d]

First you need to divide the wiring into two categories - premises wiring (covered by the NEC) and non-premises wiring (generally not covered by the NEC.)

Many so called electrical fires are caused by non-premises wiring, namely, the improper use of extension cords. Furthermore, many fires labeled "electrical" in origin are simply caused by an appliance that uses electricity, but the actual cause of the fire is not an electrical fault at all - space heaters for instance.

It is my belief that very, very few fires are truly caused by faulty premises wiring, and certainly far less than fires caused by extension cords, lamps, and electric space heaters.

 

[Mule]

Hey guys buddy got me wondering what causes electrical fires. My thoughts are obviously poor wiring. With the biggest being too much ampacity on too small of a wire. What do you guys think and do you have a kink I can research thanks

The biggest reason is non experienced installers......here's an example that happened today....

You wont believe this but my Son-inlaw (my apprentice) is also a fireman. They got a call today (attic fire). So he's in the attic making sure they got it out, and was listening to the HO through a hole they cut in the ceiling. They couldnt find an electrician, so he says...."Call Mule" !!! So the son-in-law gets to fix it tomorrow as he's my attic monkey ....

The fire was small, burnt the 2x4 bottom rung of a truss and associated wiring, as a exposed door bell transformer was buried under cellulous insulation.....open wire nuts.....also burnt a home run, and a HO job where someone pulled a single piece of THHN for a second switch leg to a ceiling fan....So we are fixing the whole thing.....

Now that's conflicting interest if I ever heard of it ....:smile:

 

[B4T]

Loose connections in splice boxes or outlets I think are most dangerous. A good example is this outlet pictured here. The screws were loose and wire loops put on backwards. It got so hot the plastic melted. If there was a couch or drapes nearby it would of caught fire. The flash point of common household material is lower than the melting point of plastic.

 

[sii]

Loose connections in splice boxes or outlets I think are most dangerous. A good example is this outlet pictured here. The screws were loose and wire loops put on backwards. It got so hot the plastic melted. If there was a couch or drapes nearby it would of caught fire. The flash point of common household material is lower than the melting point of plastic.

I bet I know a couple of guys who could still jam a plug in there though!:grin:

edit: WOULD, not could

 

[don_resqcapt19]

Hey guys buddy got me wondering what causes electrical fires. My thoughts are obviously poor wiring. With the biggest being too much ampacity on too small of a wire. What do you guys think and do you have a kink I can research thanks

I think that overloaded wire is way down on the list of fire causes. Just look at the 90?C ampacity. The conductor won't exceed 90?C at that current and 90?C is way below the ignition point of the building materials. The most common issue that would result in a fire, in my opinion, would be a poor connection of some type. Low current through a poor connection can produce a lot of heat and the resistance of the connection limits the current to a point well below the OCPD trip point.

 

[don_resqcapt19]

Loose connections in splice boxes or outlets I think are most dangerous. A good example is this outlet pictured here. The screws were loose and wire loops put on backwards. It got so hot the plastic melted. If there was a couch or drapes nearby it would of caught fire. The flash point of common household material is lower than the melting point of plastic.

First only flammable liquids have a "flash point"(and that is not the temperature at which the product ignites, it is much lower). The correct term is ignition point and I would like to see some documentation that the melting point of plastics is lower than the ignition point of common household materials.

 

[brian john]

The biggest reason is non experienced installers......here's an example that happened today....:

I am not sure I buy into this statement, unless you have some facts to back this up. Of all the electrical fires I have been on (all commercial). The work was completed by electricians or those working for electricians.

 

[Duke E]

Good topic. So much of what we do in this field is pertaining to preventing fires (masked as an installation of an electrical system).

In my experience, common ignition sources from the electrical system are likely to be from loose connections or connections that have become resistive (oxidized).

 

[vncntjksn]

Well guys, I came across one such kind of article and just thought of sharing this article with you all, this can be useful source to know electrical fire is also a cause of home fire and the perevntion of electrical fire.
Read this:
http://www.thebigredguide.com/news/electrical-fire-a-major-cause-of-home-fires.html

 

[charlietuna]

I once worked for a general contractor who specialized in burnouts--house fire repairs. It was nasty dirty work. But after a while realized how many house fires were blamed on the electrical system without true proof. Of course about 50 percent were kitchen fires and obvious to us that it was started by something left on the stove. When there is any doubt, the fire marshe would blame it on "ELECTRICAL IN NATURE".

 

[480sparky]

 

[K8MHZ]

Shouldn't the soap dish have an 'in use' cover on it?

 

[480sparky]

Shouldn't the soap dish have an 'in use' cover on it?

Soap dishes aren't considered receptacles in the NEC. :grin:

 

[K8MHZ]

Today's electrical fire

Today's electrical fire

 

[K8MHZ]

Here is the mess the POCO has to deal with now that the fire is out.

Both pics are cropped from a larger picture. They were shot with a pocket camera, my Canon A590. I was two full spans back, about a half a city block when I took the pictures. Sorry about the 'grain' but it's the best I could do with what I had. I don't think I have anything to crab about for a camera the size of a pack of cigarettes.

My house is 3 or 4 miles from the fire and my UPS units kicked in 3 times as the reclosers tried to clear the fault. Apparently it did but caused this fire.

 

[K8MHZ]

Here is how far away I was when I took the pics. The white spots on the lens are from the dry chemical fire extinguishers. The stuff got all over the cop's car and I got some on my van, about a 100 feet or so farther back than the cruiser.

 

[peter d]

Mark, it looks like that pole was long overdue for a replacement. Where are you located?

 

[K8MHZ]

Mark, it looks like that pole was long overdue for a replacement. Where are you located?

I am in Muskegon, Michigan. The sad part is that less than a year ago a crossmember broke about six blocks away and started a sub on fire that was a couple miles from the short. It blew up a transformer next to a Taco Bell. The bottom half of the transformer was all that was left and it was on fire big time. The fire in the sub burned for about 6 hours. I live 3 miles from the sub. We were without power for a half day or so but the worst part was the smell. The stink persisted for days, even as far away as we were.