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looseleg

@dsl.lsan03.pacbell.n

How to identify Plenum cables?

I am going to buy some cables, but I know when I go ask for plenum cables, I will most likely get a confused look from the sales people. I am not too knowlegable about cables. I mean the reason why I want plenum is because it doesn't release toxic fumes in case of a fire. So what is a good way to make sure it is "plenum"? Would it usually be labled?



Nightfall
My Goal Is To Deny Yours
Premium,MVM
join:2001-08-03
Grand Rapids, MI
Reviews:
·ooma
·Comcast
·Callcentric
·Site5.com

We ran plenum in the office here and it is labeled on our cable. However, I am sure some are not labeled.

This plenum wire I have has a different outer jacket than normal CAT5e wiring as well.

If you want a major test, light it on fire and inhale deeply. (just kidding)
--
Nightfall - »www.nightfall.net


WareWolF2k

join:2000-11-14
Allentown, PA

Home Depot has plenum cable in clearly marked boxes, however a 1000 ft box is $180.00 vs. $50.00 for standard cat5e.



link222

join:2001-12-21
Cranbury, NJ
reply to looseleg

Plenum is also much stiffer (not as bendable) as regular PVC cable ....



tekmunki
Tekmunki
Premium
join:2001-12-06
Lake City, FL
reply to looseleg

Look for CMP marked on the cable. “CMP” means Communications Plenum Cable. If it does not, I would not trust it. Even if it is plenum cable, unless it's marked you will most likely fail an inspection, best go with marked cable.
--
TekMunki
I've got the ideal job, a badass PC, a fast car and a chick that frags. But I still find time for DSLR.


jspera

join:2001-11-09
Boca Raton, FL
reply to looseleg

The only reason you would need to run plenum is if the cables will be in a plenum ceiling or floor. By plenum ceiling or floor I mean when the ceiling or the floor is used for a return for air conditioning or heat.


Cyber2lz

join:2001-11-15
Odessa, FL
reply to looseleg

jspera is right on. If this is for your home, regular CAT5e from HD is fine. Just remember not kink it, nick it or make it go around tight corners. I like to leave "drip loops" at both the head end and the tail end. It should last 30yrs+.
--
If you're not livin' on the edge, you're takin' up too much space !



tekmunki
Tekmunki
Premium
join:2001-12-06
Lake City, FL
reply to looseleg

I agree, I figured this was why he was using plenum. I don't know of anyone who would WANT to spend that extra money for about 10% less smoke if the cable burns... Then again, better safe than sorry.
--
TekMunki
I've got the ideal job, a badass PC, a fast car and a chick that frags. But I still find time for DSLR.



TxKent
Premium
join:2001-05-18
Pflugerville, TX
reply to looseleg

We use strictly plenum rated cable at my work - because it's a Life Safety Code issue. Our facilities are JCAHO and ICF-MR certified and we are REQUIRED to use plenum. We fired a contractor and made him pull out all of his cat-5 recently for installing non plenum when he charged us for it.

I noticed it when looking at a bundle of Cat-5 one day - I said "hmm... this bundle is certainly shiny compared to the rest..." and there was several feet of scrap still in the trash can nearby. I picked up a piece, and looked at it, and said "whoa, wait a sec." What they had installed was Berk-tek CMR (riser rated) cable.
--
Kent-----------If the good Lord had intended us to walk he wouldn't have invented roller-skates. -- Willy Wonka



fmtek
Premium
join:2002-01-09
Little Falls, NJ
reply to looseleg

i installed cable for my uncle a few months ago, and he said he needed plenum cable from home depot.. now i couldn't think why he wanted to spend all that money for the same wire i've used in my house for cheaper, and i forgot to ask someone, but after seeing this post, i now know why...

1)less smoke
2)toxic fumes when burning...

thanks guys..
--
--fmtek



Red_Menace
poking around since 1978

join:2001-11-03
Littleton, CO
reply to looseleg

The National Electrical Code (NFPA chapter 70) defines a plenum as "a compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system". Although the space over a hung ceiling is sometimes used for environmental air-handling purposes, it is not a plenum.

As for being a Life Safety issue, the reasons for using a plenum rated cable vary depending on where you are. In the US the fire codes seem to be primarily about limiting property damage and liability so the emphasis is on fire and smoke detection and containment (plenum cable = low smoke and flame spread), while a lot of European countries are more concerned about saving lives - especially those of any responding emergency personnel (plenum cable releases very toxic fumes when it burns). Any use of plenum rated cabling would be due to the specifications of the particular job or requirements of the authority having jurisdiction, but for residential use it doesn't really matter much since you would most likely die from the fumes coming off your sofa or carpet - not to mention how big the fire would have to be in the first place before cables in your wall started to burn.

That said, I used plenum cabling in my house because the cable jackets tend to be a bit more robust and I happen to also use it for my work. As mentioned by others here, plenum cable would be marked as CMP, CL3P, or CL2P.
--
"Mooo - think they'll ever figure out we're doing the crop circles?"



looseleg

@dsl.lsan03.pacbell.n
reply to looseleg

Wow, thanks for all the insights.



AnonProxy
Premium
join:2001-05-12
reply to looseleg

They all have to be labeled. If it's not labeled CMP or Plenum, it just ain't. Doesn't matter what somebody tells you it HAS to BE on the CABLE itself, cable in a box labeled plenum, without CMP on the cable...is not plenum cable.


mybobbi

join:2002-03-18
Walled Lake, MI
reply to looseleg

Quite honestly...if my house is burning down, the last thing I will be worrying about is if my cable is plenum or not.