sundance-communications.com/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring plenum or not???

Is this a plenum air return?
It's a pretty easy question to ask the G.C. when your doing a new install.
Plenum cable is VERY expensive. Only use it when you have to.

Here is one catch. All new commercial constuction in a building that congregates more than 100 people all wires must be fire rated even if the ceiling is non-plenum.

Is this a local code? Where did you get this information?

It depends on the scrap yard. There is one recycler here that will take it jacket & insulation still on. We usually save our scraps from terminating 25-pair on blocks, plus all scrap from CO installation work and turn it in about twice a year. Enough money for a couple of lunches for all three techs.

Charlie:

Is that some local code? The reason that I ask is that there aren't any requirements like that here at all. It's strictly building architecture that mandates code enforcement here.

Of course, I can't imagine a wood-frame structure designed to house more than 100 people. We have plenty of new one-story office buildings that may have more than 100 occupants, but as long as regular firewalls and partitioning are performed, non-plenum cable is perfectly legal.

Around here, it's all a matter of air return (plenum) ceilings that mandate plenum cabling, but again, most construction here is new or current.

AN electrical contractor read that to me out of the Code book and even showed it to me. Im from Boston and I have been torn on both directoins with it up here. It might have been only a code for the boston area. This happend on a commerical new construction job and it was non plenum and he made me run plenum.

I didn't argue the customer paid.

I know what you mean about that Charlie. There is a code issue with "meeting halls" (code terminology) which refers to any building that will accommodate more than 100 persons. He was correct in referring to the site as a "meeting hall" in your case.

Still, he was probably pointing you in the direction that all wiring must be installed in conduit instead of using flexible cable (MC or "BX"). He is right there, you can't use non-metallic wiring for ELECTRIC circuits. This does not apply to low-voltage wiring, as in 50 volts or below. Nowhere in article 800 is there any mention of plenum-rated cable being required in a non-plenum environment.

Help me here, Hal!

That's right ED he used the term meeting hall and made me run plenum.

NEC article 518, Places of Assembly.

518.1 Scope. This article covers all buildings or portions of buildings or structures designed or intended for the assembly of 100 or more persons.

518.4 Wiring Methods.
(A) General. (Here the article specifies the required methods for class 1 wiring which we are not interested in. What we are interested in are the exceptions, below.)

Exceptions: Fixed wiring methods shall be as provided in:

(a) Audio signal processing, amplification, and reproduction equipment- Article 640.
(b) Communications circuits- Article 800.
(c) Class 2 and Class 3 remote control and signaling circuits- Article 725.
(d) Fire alarm circuits- Article 760.

So, as far as Places of Assembly, the NEC low voltage requirements are the same as any other type of occupancy. That doesn't mean that there can't be local ammendments that would require otherwise so again, learn to do your own research. Know where local codes can be obtained. DON'T take some sparkie's word, they often know less about codes than you think.

-Hal

I think your plenum cable question has been covered off.
But as for your copper salvage question: I have taken in old jacket, Cat 3-6 4 pair and received (the last time) 40 cents a pound. I have no idea if 12 pair and up would be worth more or not. I throw in the smaller rolls and save the larger for future projects.
Last time I looked copper at the smelter was worth over $4 a pound so maybe they go 10% of that.