Faulty Wiring - Electrical Fire

[Dan W]

This evening as I was dozing off on the couch, my wife heard "snap, crackle and pop" in the basement. At about the same time my son was in his room and yelled that his lights flickered and then went out. I headed to the basement and immediately smelled the elecrical-fire smell and saw the smoke. I found a section of 14-3 AWG completely burned through...with a charred staple right in the center of the burned portion of the wooden I-beam. Imagine that...

For what it's worth, the breaker did trip.

The home is about 9 years old and we're the second owners; we've been in it 2 years. The wiring is clearly part of the original construction.

How common an occurance is this? I've lived in many homes during my time in the 'Corps (including some well-worn base housing!) but have never had this happen.

Do I have any recourse with the builder? Any recommendations on my next step?

Thanks in advance and Semper Fi.

Dan

[Mikey]

Do I have any recourse with the builder? Any recommendations on my next step?

If you can find the builder, and he's an exceptionally nice guy, you might get a good deal on the repair. However, after 9 years and 2 owners, who can say who put the errant staple there? Maybe the original electrician did the original job OK, but somebody down the line decided the staple looked a little loose and gave it an additional whack.

Next step: fix it. Replace the cable from the service panel to a little bit beyond the failure point, and join up the new cable with the old in an accessible junction box. Can't tell how extensive the fix would be without knowing the layout, but the big effort is likely routing the new cable through the ceiling, walls, etc. If it's an easy run to the panel, it's an easy job.

You could probably get away with replacing a small segment of cable around the failure point (2 boxes), but I'm leery of heat-damaged cable. Cut out a big enough chunk to be sure the remaining cable is undamaged.

Now wait for a real electrician to comment.

[Billy_Bob]

For "many homes at once" new construction electrical work, they get the low bidder. The low bidder has inexperienced "newbies" working under the supervision of an electrician (to keep their costs low).

Typical is that the newbies will run the wiring and install the switches and outlets. After the wiring has been installed (rough), the experienced electrician will give it a general look over. Mostly to be sure all the wires were run where they should. But he is not going to look at every staple. (The experienced electrician will wire the main panel.)

A lot of the "newbies" want to go on to become electricians, so most know what they are doing. But I suppose you could get one who does not care, it is just a job for now, then go on to something else. Staple in middle of wire, who cares?

With that said, you might want to look at the rest of the staples on your wiring (that you can see). If more are found going through the wiring, then make a big thing about it with the builder. Maybe lawyer time? If not, then I would forget about it.

In general I would guess that if you can inspect all visible wiring in the basement and attic and not find any more staples going through the wiring, then probably a fluke. If more are found, then good reason to suspect that there might be more in the walls.

When driving a staple through a wire, what are the chances it will nick the copper in the wire as opposed to going between two wires and not damaging any wire? (I don't know, but if anyone has some spare time on their hands...)

Otherwise so far as notifying the builder. Might want to call and see what they say. If it is going to be a big battle to get them to do anything, then might want to drop it (as not much damage done). I suppose if it is a battle with lawyers and so forth you could spend more on lawyers/time/stress than worth it, as opposed to just calling an electrician and having him fix the problem.

(The way I would look at it.)

[Mikey]

It wasn't clear whether the staple actually penetrated the wire, or just squashed it. In either case, BillyBob's advice to check as many other staples as possible is excellent.

As for lawyers, I'd rather spend my money on electricans than lawyers any day of the week.

[Wrex]

This is why I avoid the U Nail Style NM cable staples.

When houses were still constructed with Armor Clad cable these nails were fine but now that the outer cable insulation is non-metallic these fasteners are less forgiving.

I use the plastic cable staples with the two little nails.

http://news.thomasnet.com/images/large/023/23446.jpg

I use the cable fasteners on the right rather then the ones on the left.

IMO the ones on the right are MUCH easier to install and go in straight EVERY TIME.

They cost a bit more but I don't have to worry about pinching cable if I accidentally drive it in too far as you do with the U nail design.

In any case I'm glad that the breaker did its job and you avoided a fire.

[Dan W]

Gents,

Thanks for your time and insight.

I'll fix it as I consider how to tackle Pulte Homes. The bozos that wired this place give amateurs a bad name. This particular circuit has fixtures in 5 different rooms on two floors. I sure wish I could replace the cable from the panel, but it runs from the panel in the basement up to the 2nd floor, then down to the 1st floor back to the basement and back up to the 1st floor (as far as I can tell). I'll have to work a splice in around the failure point.

On the bright side, I'm using this incident to re-evaluate my fire-safety approach. It's escape ladders for the 2nd floor and fire extinguishers at the ready.

S/Fi,
Dan

[hj]

Unless your area has a very stringent new home warranty requirement, the most the builder is on the hook for is two years, and even that may be to the original owner. After 9 years, all Pulte is going to say is, "It's a good thing the house didn't burn down."

[Mikey]

I'll have to work a splice in around the failure point.

Odds are this will work OK. If you look at the wire near the failure, you'll see the copper is discolored from the heat, but the discoloration will fade as you get further away from the fire. Frankly, I don't know how the heating of the wire will affect its electrical characteristics, but I'd feel better chopping back to where the wire looks nice and bright and splice in the new section there. I suspect the failure was pretty sudden once the short circuit was established, and the breaker did its job immediately, so there won't be much wire affected.

[hj]

If an arc can be generated by a short circuit, it will NEVER blow the circuit breaker. It will continue until the gap becomes too great for the arc to cross it, or until the house burns down.

[Billy_Bob]

Arc Fault Circuit Interrupters (AFCIs)...
http://www.afcisafety.org/qa.html

Understanding the Combination AFCI Expansion in NEC-2008...
http://www.iaei.org/subscriber/magaz..._a/unseld.html

[hj]

And how would you know which circuit was going to fail some day, or would you just replace all the breakers with AFCI's?

[Mikey]

And how would you know which circuit was going to fail some day, or would you just replace all the breakers with AFCI's?

...or would you wait for a Code change that required that all breakers be changed to AFCIs -- no grandfathering? (AKA The Electrical Contractors and Circuit Breaker Manufacturers Relief Act of 2011)

[hj]

(AKA The Electrical Contractors and Circuit Breaker Manufacturers Relief Act of 2011)

Actually it would be referred to as the, "Electrical industry economic recovery act of 2011".

[Norcal01]

The # 1 thing to remember about tract homes is they are built by the lowest bidders to the lowest standards they can get away with.( I refuse to say built to minimum code standards).

[hj]

The # 1 thing to remember about tract homes is they are built by the lowest bidders to the lowest standards they can get away with

And that also applies to many custom homes as any contractor who bids on them can testify. The builder will play the contractors against each other and the winner has to cut corners to make a profit.