Wire for In-Wall

[bobm]

What does that actually mean when wire is rated for in-wall use? Sometime they have CL-2 or CL-3 rating on the wire. Plenum???

Thanks Bob

[bobm]

I found a good link for this:

http://akamaipix.crutchfield.com/HTIG/2003HTIGArticles/Wiring.PDF#search='wire%20inwall'

[suemarkp]

In wall means it is an NEC listed cable for use inside buildings or dwellings. You mentioned one series of uses -- low voltage class 3 and 2 cables which are marked CL3 and CL2. There are also communications cables CM, fire alarm wires, and some others. Then, there are the P (plenum), R (riser) suffixes, and an X suffix which is usually only allowed in dwelings. It is OK ro use P and R wires in walls, but you usually don't need to and they cost a lot more. Then there is regular house wiring with cables like NM, UF, SE, and individual wires like RHH, THHN, THW, etc.

The cable listing category(ies) is usually marked on its jacket. However, I do have some zip cord speaker cable that says CL2 on the spool but is unmarked on the cable. Someone may have you rip cable out if it has no markings on it indicating what it is.

For security alarms, CL2 is what you want, although I believe you are allowed to substitute CM for CL2 uses (there's a whole substitution table in the NEC). Smoke detectors may require one of the fire alarm types of cabling if low voltage, otherwise I think normal building wire is OK.

[bobm]

thanks Mark,

One of the resons I was looking into this was that I purchased a 500' roll of alarm 4-22 wire from HomeDepot. The roll was $59 and I see 4-22 on the interenet for $39. I was surprised Homedepot was so much more but their wire is CLR rated.

thanks Bob