fire alarm wire protection

[JeffD]

What are the requirements for running open fire alarm cable in concealed walls? Are you allowed to run just the open cable and not in conduit in a commercial application? I can't find anything in the NEC and my nfpa72 is at home. I am used to seeing conduit to above ceiling but can't find anything saying it has to be that way. Also assuming it doesn't have to be in a raceway concealed in walls when going through metal studs or entering metal boxes I assume grommets or bushings would be required to protect the cable. Can I refer to 300.4 to back that up even though the section refers to NM cable? If not is it required and what can I point to to justify it?

 

[gadfly56]

What are the requirements for running open fire alarm cable in concealed walls? Are you allowed to run just the open cable and not in conduit in a commercial application? I can't find anything in the NEC and my nfpa72 is at home. I am used to seeing conduit to above ceiling but can't find anything saying it has to be that way. Also assuming it doesn't have to be in a raceway concealed in walls when going through metal studs or entering metal boxes I assume grommets or bushings would be required to protect the cable. Can I refer to 300.4 to back that up even though the section refers to NM cable? If not is it required and what can I point to to justify it?

If you are running power-limited fire alarm wiring, just about anything goes. Article 760.52(B) of NEC 2005 says the only thing that applies is 110.3(B) 300.11(A) and 300.15. And there is an earlier mention of 300.4(D) as well as 300.22, but that's it.

In a commercial application you can run FPLP nekkid above a drop ceiling used for "other environmental air" as long as it's "adequately supported". You have to run your own supports; no cheating off the ceiling grid! We'll use Caddy fasteners or bridle rings depending on how much cable we're running. Your splices still have to go in a box and you'll need bushings as you suggested. Inside a wall you really don't need anything special. There is apparently a natural tendency for our installers to gravitate to Chapter 3 methods to satisfy the "workmanlike" requirement, but even the wire manufacturers seem to have little to say about installing their product.

Any need for metal raceways and whatnot is up to local code requirements or the installation specification from the owner/architect/engineer.