Attaching wire above ceiling.

[franklin97355]

Somewhere I saw a reg that required cables above a suspended ceiling to be run within a foot of the support (ceiling or roof) but I can't find this. Can someone point me in the right direction? It would be the NEC 2002 or some Oregon statute. Thanks.

 

[WaitronUnit]

I've heard of this before, but not sure where... I do remember, however, that it *mostly* (vague, I know) applied to coax so it's quite possible that such a reg has been updated. Also, I don't know about anything that's geared toward being Oregon-specific but in some states there are definite regs (still in effect) that deal with plenum-grade stuff, etc.

Best bet might be to contact the building inspector (or whoever issues certificates of occupancy) for the particular county your client's in. I deal strictly with restaurants and I've always gotten my answers this way.

You might also contact your supplier... most states require that suppliers/wholesalers maintain current regulation records on *everything* they purvey - especially if they also move stuff that has to be documented with material safety data postings, etc.... hope this helps.

 

[Jtodd]

Never seen that before. The only thing I've seen is a minmum of 3-6 inches ABOVE the t-bar. But nothing about the maximum distance it could be away from the roof. Some places I've worked, that would be very unpractical.
Example. One place we worked, the front half of the building was two floors of office space, and the back half was only first floor R&D manufacturing space. In the back half, above the T-Bar was open upto the the 30 roof.. So would that mean that an outlet in the back of the R&D section would have to go the 30 feet up to the roof, be supported within 1 foot of it. Then back down to the first floor IDF up in the office space? If that's the case, some one really needs to take a look at the regulation and do something about it, because that seems way out of line to me.


Justin T. Clausen
Physical Layer Implementation
California State University, Monterey Bay

 

[franklin97355]

Jtodd: Sorry if I didn't make myself clear. The reg I saw was that the cable had to be within a foot of EITHER the top of the grid or the roof (or whatever the wires were supported from.) So if you had a grid below a 30' roof the wires only needed to be in the first 12 inches of the grid but could not be 15 feet up in the air.

 

[Jtodd]

Ok, that does make more sense. But honestly, I don't think within 12 inches of the grid is much better either. Obviously the height of the ceiling is a deciding factor, but I would think anything lest than 12inches above the grid would be in jepardy of preventing the tile from being easily removed. Granted, I've moved plenty of tiles with sprinkler pipe, HVAC ducting, you name it, just a couple inches above the tile, but I've bitch-an-moaned about it the whole time. I would be hesitant to intentionally put my cable in that same place, whether by my design, or some one elses requirement.

The other thought is, single floor building which floor to ceiling heigth of 18' with grid at 9'. That leaves 9' of space above the grid to the ceiling. Would it then be wrong to put the cable say at 13' leaving four feet below and above for HVAC, water, BAS and others to have both access and space to work?
Do note, I'm not trying to argue the point directly with you fraklin, if its code or regulation, then I guess it's got to be done. But at the same time, not all codes and/or regulations make sense (maybe did at one time) and they should be questioned on whether they are valid any more or not.

Justin T. Clausen
Physical Layer Implementation
California State University, Monterey Bay

 

[Ghostin]

As far as i know, there is no national standard for this. Each municipality makes their own regs in regard to installation requirements.

 

[Servamatic]

There is a national standard, its called the EIA/TIA 569-A.
As for codes, which I think is what you meant, that does vary from AHJ to AHJ.

Richard S. Anderson, RCDD

http://www.servamatic.net

 

[Ghostin]

Yes, I was referring to the local ordenance building codes, which as you know, can vary quite a bit from the EIA/TIA & IEEE standards.