Low voltage fire smoke dampers? Class 2?

[Greg Richey]

This is probabbly a dumb question but i will ask it anyway.

I install energy management systems that are 24 volts or less. We run the wiring exposed in attic spaces on bridle rings. Now and then the job has fire/smoke dampers that close in the event of a fire alarm. Sometimes the electrical contractor on the job does not have the fire/smoke dampers included in his bid and my company is asked to interlock them with the air conditioner so that when the fire alarm sytem shuts down the air conditioners the 24 volt fire/smoke dampers close also.

My questions is: Since they are fire/smoke dampers are they automatically considered class 1 wiring because of the life safety involved. I am thinking I need to install fire/smoke dampers 24 volt wiring in conduit.

One guy I discussed this with commented that the fire alarm cable is life safety but it is run free air in the attic. After thinking about that though I realized th fire alarm wiring is supervised so that may be the reason for that.

Any input is appreciated.

 

[DHkorn]

Good Question.
I rember seeing the requirements for low voltage wiring being reclassified as Class 1 but I cant remember where now. However, my understanding is that that requirement applied only to a situation where the failure of the wiring would create an iminent life safety hazard, as in boiler safeties or industrial flame guard situations and the like.
While the failure of fire dampers is an important safety issue its not an iminent life safety issue.

 

[DHkorn]

PS. If I see a power supply rated NEC Class II, I'm done, as long as no local requirements trump it.

 

[DHkorn]

Btw: Nec 725.11