Residential fire alarm

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adavey

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Are the smoke/carbon monoxide detectors in residential fire alarm systems (120V) to be supplied with 3 conductors; Hot, Neutral and one wire for interconnecting of devices ???????????
 
Are the smoke/carbon monoxide detectors in residential fire alarm systems (120V) to be supplied with 3 conductors; Hot, Neutral and one wire for interconnecting of devices ???????????
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Yes, this requirement comes from the building codes.

Chris
 
Thank You !!!

I checked the NYS Building code which had very little info but referred me to NFPA 72 which had some good info. However, it referred me to the NYS Fire Code. It never ends !!!!!!!!!!!
 
adavey said:
Are the smoke/carbon monoxide detectors in residential fire alarm systems (120V) to be supplied with 3 conductors; Hot, Neutral and one wire for interconnecting of devices ???????????
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Sort of. Typically they are "supplied" by a two wire home run to the first detector, then three wire to the rest, with the third wire being the required interconnect. All of this is in the building code, not the NEC, and frequently subjected to local amendment. For that reason, you need to check the specific requirements for the jurisdiction for which you are designing. The NEC kicks in because the building code requirement for detectors in each bedroom means the branch circuit serving them must be protected by an AFCI.
 
Talking to a couple of guys I know at the fire department the other day, they had some interesting commentary.

Their opinion was in placing the CO detector, don't place it in the furnace room! They are getting way to many "false positives' because people think that it is the ideal place for it. They were a lot bigger on placement in a common hall to sleeping areas, followed by the kid's rooms.

Then there was the usual stay away from the kitchen and bathrooms by 20 ft if possible...
 
I generally use a HEAT detector in a furnace room, it's by no means a life safety device as listed as such, so you still need a smoke in the basement, In Connecticut, we are required to install Carbon Monoxide detectors outside of each sleeping area,

Exception:Carbon monoxide detectors shall not be required in dwelling units not containing a fuel-burning appliance, fireplace or attached garage.
 
Ut Oh....... We are more than half way thru a 126 unit condominium project and the smoke detectors are not on AFCI breakers. Each bedroom has its own AFCI circuit. The four smoke detectors in each unit are interconnected but the home run comes off a hallway receptacle that is not AFCI protected. Half of the project has already passed inspection and the inspector didn't notice.
 
I have heard some areas have ammended the NEC requirement of having Smoke Alarms on an AFCI, might this area be one of these.

Also, what NEC cycle is being used?

Roger
 
This area is using 2005 NEC as of July 2006. The project was started during the 2002 NEC cycle. Most of the work is already covered with drywall now. I figure the inspector just isn't that picky or knowledgable. I didn't think about it myself until I saw it in this thread. I've heard that the AFCI's usually get replaced with regular breakers later on because they are a nuisance. Stuff like hair dryers usually cause them to trip. Or sometimes just a light bulb burning out will trip them. So building maintenance usually replaces them anyway.
 
adavey said:
Thank You !!!

I checked the NYS Building code which had very little info but referred me to NFPA 72 which had some good info. However, it referred me to the NYS Fire Code. It never ends !!!!!!!!!!!
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adavey
Where in the NYS building code did you look?

R317.1 is the reference you will need to look at. It is in the Residential building code book. There is also a technical bulletin on the state website that gives more information as to the smoke alarm/fire alarm system requirements.

Pay particular attention to detail, as there is alot said in those few paragraphs referenced.
 
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