NM and power limited F/A system

[wyboy]

A large home is installing a power limited F/A system. To avoid fishing more wire than necessary, is it allowed to use the NM cable previously used for smoke alarms for the new smoke detectors fed from the new F/A panel.

 

[iwire]

I am not sure about your question but I will point out that in many areas a power limited fire alarm system cannot replace smoke alarms.

Often the local laws require smoke alarms not smoke detectors which is what is installed with an FACP.

 

[Strathead]

I am not sure about your question but I will point out that in many areas a power limited fire alarm system cannot replace smoke alarms.

Often the local laws require smoke alarms not smoke detectors which is what is installed with an FACP.

Really? What is the sense in that?

 

[iwire]

Really? What is the sense in that?

Maintenance, up keep, etc.

Something worth looking into before ripping out the line voltage stuff.

 

[Strathead]

Maintenance, up keep, etc.

Something worth looking into before ripping out the line voltage stuff.

I still don't see it. NFPA 72 requires a fire alarm system to have a yearly inspection. This isn't waived because it is a residence, so from a perspective of up keep it would be more expensive, but it would also be far more thorough. Shoot, I haven't changed the batteries in my smoke detectors in three years. Most of the newer systems have automatic testing to determine dirt depreciation and other things that affect performance on a constant basis. From a purely safety aspect with cost not an object, a full blown fire alarm system would be far superior in every way.

 

[GoldDigger]

I still don't see it. NFPA 72 requires a fire alarm system to have a yearly inspection. This isn't waived because it is a residence, so from a perspective of up keep it would be more expensive, but it would also be far more thorough. Shoot, I haven't changed the batteries in my smoke detectors in three years. Most of the newer systems have automatic testing to determine dirt depreciation and other things that affect performance on a constant basis. From a purely safety aspect with cost not an object, a full blown fire alarm system would be far superior in every way.

Which has absolutely no relevance to any code requirements that specifically call out smoke alarms and do not explicitly say that an F/A system can be used instead.
It might not make sense, but that is common when looking at edge cases of general codes.

 

[GrayHair]

From NFPA 72 (2013) --

Testing
14.4.4* Testing Frequency. Unless otherwise permitted by other sections of this Code, testing shall be performed in accordance with the schedules in Table 14.4.3.2 or more often if required by the authority having jurisdiction.

14.4.6.1 Testing. Household fire alarm systems shall be tested by a qualified service technician at least annually according to the methods of Table 14.4.3.2.

Smoke Alarms vs. Smoke Detectors
29.3.3(2) The required minimum number and location of smoke detection devices shall be satisfied (independently) through the installation of system smoke detectors. ...

29.5 Detection and Notification. The use of fire alarm system smoke detectors and notification appliances shall be permitted to meet the fire-warning requirements for smoke alarms specified in 29.5.1.

 

[iwire]

Many areas do not use 72 for dwelling unit smoke alarms.

 

[GoldDigger]

I would call that explicit.
Now, as long as local ordinances just reference NFPA 72 the issue is covered.

 

[gadfly56]

I would call that explicit.
Now, as long as local ordinances just reference NFPA 72 the issue is covered.

Many jurisdictions, NJ among them, use the IRC or modified version thereof to cover single and dual family homes. IIRC, until the 2009 version, the requirement was if the control panel disappeared the smoke detectors had to continue to operate. This was in response to the scorched earth policies of ADT and the like where they'd come in and yank the panel off the wall if you didn't re-up with their service. Suddenly, no fire protection. So if a jurisdiction is under the 2006 version, you're stuck with 120vac smoke alarms. Usually they'll let you put in a low voltage system in addition, but not in place of. In NJ, if you had a McMansion that simply could not be covered with 12 interconnected smoke alarms you could go the the AHJ for a variance and get relief. But it had to be physically impossible to get the coverage, not just your preference.

 

[GoldDigger]

Thanks for the information and the graphic imagery!