Question:
Recently I have noticed that they are installing a fire alarm system in my building with pull stations and in some places detectors. As of now they have installed a bunch of boxes throughout the building with rigid pipe conduit and a single red wire fished through. I noticed that in one spot there is a run of about 4~5 feet in the ceiling where the red wire is exposed without conduit. It goes through the wall and into a junction box mounted in the garbage room. Is the purpose of this red wire only for a 9 volt signal between alarms? Is that why you don't need to run it inside conduit? Or is this a major code violation? It would seem silly to spend all of this money to secure our building from fire and them have a dumb mistake which compromises the entire system.

Answer: Long ago somebody told me the way the fire alarm systems work is there is a single (red) wire that runs around. Any site can declare an alarm by grounding this wire. Usually it is pulsed to indicate the box number but I believe just holding it down will work. So, there is no real reason to run the alarm wire in conduit. If you go out to your street and look at the utility poles you'll probably be able to spot the alarm wire. Usually the red insulation wears off after awhile.