Metal Truss plates

[davedottcom]

Can someone tell me where the 2002 NEC mentions that "NM wire must be completely Isolated from Metal Truss plates"? I had a few wires running parallel to a few of them. (NOT touching ANY sharp edges!) The inspecter failed the rough wire because of it. I can't find any mention of it anywhere. I can "Isolate" the wires easy enough by nailing a few pieces of wood over the plates, and then restapling the wires, but I would like to read the actual article if someone could help me find it!

Thanks

Dave

 

[bphgravity]

Re: Metal Truss plates

There is no wording that specificaly states "isolated from metal truss plates". However, you are required to ensure protection from physical damage and the AHJ must feel there was some risk of damage. If in doubt, ask the AHJ exactly what the problem is.

 

[bryonb]

Re: Metal Truss plates

They might be refering to 250.4(A)(4). "Likely to become energized" is rather vague and open to nterpretation.

 

[jxofaltrds]

Re: Metal Truss plates

Dave

He is correct. When the truss collapes it will damage the wire.

If it would become energized where would it go.

I can think of nothing to combat his opinion in the NEC.

I think his thoughts are chicken $h!^.

Mike P.

[ March 07, 2003, 09:09 PM: Message edited by: jxofaltrds ]

 

[roger]

Re: Metal Truss plates

Mike,

He is correct. When the truss collapes it will damage the wire.

I agree

I had an insurance policy on a truck once that was as rediculous as this inspector.

It specifically stated that the paint on this truck was not covered in the event of nuclear fallout. Like getting my truck repainted would be a major concern in this event. :roll:

Roger

 

[jxofaltrds]

Re: Metal Truss plates

Dave

What does he say when your wires are touching the heat runs in the basement? You know what I mean. Under or over round duck (duct) work.

Mike P.

 

[luke warmwater]

Re: Metal Truss plates

I would prefer not to staple wires to the plates for added precaution, but running past them is not much of a concern.
Our proposals now have a clause that adds extra for time and materials lost due to some of these type of inspectors.
There is one town inspector(not electrical) who requires all NM running horizontal through a cold air return must be wrapped with aluminum duct tape. The builder didn't want to pay us, so they do it themselves.

 

[david]

Re: Metal Truss plates

I just inspected the replacement of a main panel in a brand new manufactured home that already had its first electrical fire. The NM cable cut into a metal truss plate resulting in a fire two weeks after the building was energized. The wire was ether dragged across the plate during the installation phase or the wire was pulled into the plate when the electrician needed more slack while trimming out the panel. The truss plate in question was only three trusses back from the main panel.

P.S.
THeir was more fire damage to the buildig above the pannel at the orgin of the fire the fire spreed down the wall and took out the main panel.

The whole Building would have been lost except it was right across the strret from the fire Department.

[ March 08, 2003, 11:50 AM: Message edited by: david ]

 

[davedottcom]

Re: Metal Truss plates

David, I'm very much aware of the risk of running NM across, close to, or touching ANY sharp edges of the truss plates, however I was talking about running the wire "Parallel" to the plate. (When a wire is stapled to the side of a wooden truss and simply passes by a Flat, metal truss plate running parallel to both the wire and the truss itself) The flat, smooth side of the plate hardly seems to be anymore dangerous then the wooden truss itself, especially when the wire isn't even stapled within a foot of the plate. It would take some kind of structual damage to the truss to cause the wire any harm.

The inspector was quoting the 2002 NEC saying the wire "Must be Isolated" from the plate??? Funny, he didn't mention the article reference number though!
The builder was the one who relayed the message to me and I've never spoken to the "inspector of the week" and probably never will. There are dozens and dozens of inspectors in my area and so far he is the only one who knows about this code!?!?! :roll:
And before all you inspectors get up in arms against me I want you to know that I respect MOST of you! Inspecting is a serious and very necesary part of building, I'm just trying to see where this guy is getting his info.
I have thousands of wires passing by truss plates in the "Nonthreatening" way I described previously and I know I'll have no problem sleeping tonight! But thanks for the horror story David!
Good night all...zzzzzzzzzzzz

 

[david]

Re: Metal Truss plates

As long as there are no sharp edges to be concerned about I do not see a problem.

 

[michael nye]

Re: Metal Truss plates

I've seen this before, to get around any problem I just install a peice of cardboard over the web and the inspector doesnt say any thing. On the other hand I am with you, if the wireman is doing quality work he wont install it so as to create a problem, either with creative stapling or protective devices.