Raceway and Fire Alarm Cable

Status
Not open for further replies.

Saveem2

Member
We have Low-Power Network-Powered Broadband Communications
Cables running in a raceway. The contractor wants to run the fire alarm cables in same raceway. I can't find anything in NFPA 72 or 70 that would prevent this from being allowed. The fire alarm audios is power limited fire alarm circuits in shielded cable.

Thanks!
 

OTT2

Senior Member
Location
Orygun
We have Low-Power Network-Powered Broadband Communications
Cables running in a raceway. The contractor wants to run the fire alarm cables in same raceway. I can't find anything in NFPA 72 or 70 that would prevent this from being allowed. The fire alarm audios is power limited fire alarm circuits in shielded cable.

Thanks!
760.139(C) allows PLFA cables in the same raceway as Low-power network-powered broadband communications circuits.
 

__dan

Senior Member
I'm looking at similar code references, class 2 wiring in FA raceways. I want it taken out and cannot find the right code references.

From what I have seen, if the FA system wiring and the com wiring are both power limited class 2, sharing the same raceway may be OK. It's crap and I want it fixed but cannot that in find the code.

FA system wiring cannot share raceway with electric power, class 1, .. 760.55

You may want to request an Authority interpretation, a PE or Inspector review, to protect yourself from liability.

Ask the FA system manufacturer if their circuits are class 1 or class 2 power limited, or a mix of both, maybe class 1 for signaling device circuits. Class 1 and class 2 cannot share the same raceway, it's in the code.
 

nhfire77

Senior Member
Location
NH
We have Low-Power Network-Powered Broadband Communications
Cables running in a raceway. The contractor wants to run the fire alarm cables in same raceway. I can't find anything in NFPA 72 or 70 that would prevent this from being allowed. The fire alarm audios is power limited fire alarm circuits in shielded cable.

Thanks!
So are they putting 70.7V fire alarm speaker cables in the same raceway as low power network powered broadband communication cables?
 

OTT2

Senior Member
Location
Orygun
So are they putting 70.7V fire alarm speaker cables in the same raceway as low power network powered broadband communication cables?
Good point.

Do the Fire Alarm audio circuits originate from the Fire Alarm equipment? If so IMHO these are fire alarm circuits not audio circuits as covered in article 640, Informational Note No. 2 of 640.1
 

Saveem2

Member
Thanks

Thanks

Talked to NFPA as well in the meantime and it is allowed. I don't like it eithier but that is life. Thanks to all that answered my post!
 

nhfire77

Senior Member
Location
NH
Good point.

Do the Fire Alarm audio circuits originate from the Fire Alarm equipment? If so IMHO these are fire alarm circuits not audio circuits as covered in article 640, Informational Note No. 2 of 640.1
I agree. It just seems like its a poor design. I would not mix 70.7V with class 2 or 3 circuits.
 

dhalleron

Senior Member
Location
Louisville, KY
Some 70.7V fire alarm audio is power limited and some is non-power limited depending on the brand.

Even though it might be power limited, some manufacturers such as Silent Knight still recommend keeping the 25 and 70 volt audio in a separate conduit from other circuits such as strobes.
 
Status
Not open for further replies.
Top