ECN Forum Forums Code Related Discussion NEC & other Code issues Bonding of metal studs

Just a thought...
Would a combo AFCI have tripped under the conditions of this accident?

"Track record? I think not ... 'freak accident' seems more appropriate.

There is a limit to "practical" safeguarding."

You are correct, insofar as there is a limit to 'practical' safeguarding. To me, it is very practical to require bonding a metal stud wall. What's it cost? 40 cents worth of wire? How long does it take? 30 seconds or less. What does it do? Protect against a one in a million fatality, of which one occurrence is documented. To me, that's reasonable regulation.

Here is what would be unreasonable regulation: suppose the drywall screw was the only element energized by the romex. Suppose a painter or drywall man touched it and got killed. That, to me, is a totally freak accident, and completely impossible to regulate against in any practical sense. That is a one in a billion accident.

Potentially energizing a metal stud wall is easy to prevent and a prudent regulatory measure, in my opinion. Besides, suppose you take the position that it isn't necessary to require that a metal stud wall be grounded, regardless of the death. Then, six months later, it happens again. What to you tell the victim's family?

The code is based on the idea that you need several things to go wrong before you present a hazard. In this case there was really only one mistake, either not maintaining the 1.25" setback or using a 2" screw. Take your pick.
The picture I saw showed this in the corner of the framing and it was hard to figure out how far it was from the surface of the closest framing.

John, I see no reason why the AFCI would have tripped until the victim had taken 30ma of fault current.

According to the article, it was a 1 1/8th inch screw, but looking at the picture, I think it was a 1 1/4 inch screw. In any event, it certainly was a rare event.

I agree, but I think it's too late for the next code cycle anyway, that is unless someone has already submitted a similar proposal.
So now that I think about it... wouldn't this mean that even if the NEC wanted to address this issue at all, it would have to wait until 2014 anyway?

My how the wheels of change grind slowly along in a bureaucracy... unless of course, it comes to something like handing out taxpayer dollars like a giant Pez dispenser or changing the tax code, which can seemingly be done overnight. But that's another bedtime story.

Some think the NEC is revised too frequently. Of course, it isn't a government mandated or even created code. It is simply adopted by many government agencies (as it should be) because it is the most comprehensive and thorough set of model regulations governing electrical installations. Regardless of whether it is required or not, I think it is simply good sense to bond a metal stud partition. It costs little, and can mean so very much.

I agree, but I think it's too late for the next code cycle anyway, that is unless someone has already submitted a similar proposal.
So now that I think about it... wouldn't this mean that even if the NEC wanted to address this issue at all, it would have to wait until 2014 anyway?


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Great example to promote Gregs' view of a 5 or 10 year code.
The new code is being written and half the country doesn't even know the current one.

Lee:

"Great example to promote Gregs' view of a 5 or 10 year code.
The new code is being written and half the country doesn't even know the current one."

I had a student ask last nite...'why are you (me) basing this class on the 2008 NEC, when NJ has not adopted it yet'

Last I heard from DCA the '08 was still pending adoption'.

Greg:

"John, I see no reason why the AFCI would have tripped until the victim had taken 30ma of fault current."

Would not a combo AFCI have detected this situation as a series fault, as it appears the screw hit the 'hot'?? I'm under the impression that a series arc (break/nick) in one conductor will cause a trip, and a parallel arc between two conductors will cause a trip, hence "combo". Is my summation correct, or am I not seeing something? Please remember, AFCI's are not required here in NJ yet...

Final thought from me on this subject. It is of course a tragedy that anyone would get hurt or worse killed. It could have been prevented possibly and there is no way of knowing of the numerous things that can happen. As an inspector, I can not ask a contractor to do something that appears to be a good idea. As a contractor I am hesitant to do something different than code because I think it is a good idea. If the code panel is convinced by way of substantiation that the code needs to be changed, it will be changed. The code is a reactive document not a proactive one.