Residential Smoke Alarms

[Jaybone812]

That's not even close to being accurate.

 

[Jaybone812]

@infinity I’m in complete agreement with you on that and it’s def a new one for me

 

[Little Bill]

UL would never list a smoke alarms that chirped when loosing the primary power source. Homeowners would remove the alarms every time the power went off leaving no protection. They only chirp on low or no battery.

I can guarantee the ones I installed would chirp on power loss. The battery was not low. I dealt with this for a few days while working there. They never chirped when the power was on. If the batteries were low, they would chirp with or without AC power.

 

[tortuga]

That's not even close to being accurate.

Do you agree that is the intent ??

I was pretty surprised the AHJ viewed it that way, but he said there was no code definition of a fire alarm system, so if you have a 15A fire alarm circuit that only supplies a Non Power Limited Fire Alarm circuit (NPFLA) it falls under 760, and 760.3 rules out 210.

 

[curt swartz]

I can guarantee the ones I installed would chirp on power loss. The battery was not low. I dealt with this for a few days while working there. They never chirped when the power was on. If the batteries were low, they would chirp with or without AC power.

Then they were defective or something else was going on.

No reputable manufacture would design a smoke alarm to beep on loss of primary source. Everyone I know, including myself would be removing them every time the power went off. Might as well not have a battery backup. At least you will have protection when the power comes back. If they get removed they may never get put back up.

If the smoke alarm is one of the 10 year battery models sometimes the battery does not get activated properly. My guys install the bases and pigtails during the main part of trim out. The smoke alarms don't get installed until all dusty activity, painting, etc. is done. Some Kidde models you had to turn the smoke alarms so hard to activate the batteries the base would move or come off the ceiling. They would keep one base off and use it to activate the alarms in their hands prior to installing on the ceiling.

If the battery didn't get activated properly they would beep low battery on power up. If you turned the power off they would still beep a couple time due to the stored charge in the smoke alarm.

 

[infinity]

I was pretty surprised the AHJ viewed it that way, but he said there was no code definition of a fire alarm system, so if you have a 15A fire alarm circuit that only supplies a Non Power Limited Fire Alarm circuit (NPFLA) it falls under 760, and 760.3 rules out 210.

You cannot say something in 760 applies unless all of the Article applies. For one the requirements for the powering of a fire alarm system required by Article 760 do not apply to residential smoke alarms. From Mike Holt:

Article 760 covers the installation of wiring and equipment for fire alarm systems. Residential smoke alarm systems, including interconnecting wiring, are not covered by Art. 760 because they are not powered by a fire alarm system as defined in NFPA 72, National Fire Alarm and Signaling Code.

NEC Requirements for Fire Alarm Systems

The reliability of a facility’s fire alarm system can determine whether people escape to safety or not.

www.ecmweb.com

 

[gadfly56]

We don't do residential smoke alarms as a matter of course, but we do occasionally get saddled with group home renovations. Our practice is to use some circuit that the occupants would definitely know is tripped/disconnected, such as the kitchen lights. Dedicated circuits aren't forbidden, but we consider them a sub-optimal solution.

 

[tortuga]

Article 760 covers the installation of wiring and equipment for fire alarm systems. Residential smoke alarm systems, including interconnecting wiring, are not covered by Art. 760 because they are not powered by a fire alarm system as defined in NFPA 72, National Fire Alarm and Signaling Code.

For some reason he thought that the power would need to originate at a fire alarm panel, A Non–Power-Limited Fire Alarm Circuit (NPLFA) does not need to originate at a fire alarm panel.

 

[Little Bill]

Then they were defective or something else was going on.

No reputable manufacture would design a smoke alarm to beep on loss of primary source. Everyone I know, including myself would be removing them every time the power went off. Might as well not have a battery backup. At least you will have protection when the power comes back. If they get removed they may never get put back up.

If the smoke alarm is one of the 10 year battery models sometimes the battery does not get activated properly. My guys install the bases and pigtails during the main part of trim out. The smoke alarms don't get installed until all dusty activity, painting, etc. is done. Some Kidde models you had to turn the smoke alarms so hard to activate the batteries the base would move or come off the ceiling. They would keep one base off and use it to activate the alarms in their hands prior to installing on the ceiling.

If the battery didn't get activated properly they would beep low battery on power up. If you turned the power off they would still beep a couple time due to the stored charge in the smoke alarm.

These were not the 10 year batteries. They weren't defective either as they have been in for 2 years. Have you not ever seen a UPS unit that beeps when on battery power?

 

[curt swartz]

These were not the 10 year batteries. They weren't defective either as they have been in for 2 years. Have you not ever seen a UPS unit that beeps when on battery power?

A UPS is not a life safety device and the beeps can be turned off.

I don't know anyone that would be willing to listen to their smoke alarms beeping when the power is off. They will remove the batteries to stop the beeping.

 

[Jaybone812]

I was pretty surprised the AHJ viewed it that way, but he said there was no code definition of a fire alarm system, so if you have a 15A fire alarm circuit that only supplies a Non Power Limited Fire Alarm circuit (NPFLA) it falls under 760, and 760.3 rules out 210.

Just like you hearing that is a first for me but the inspector was completely incorrect in saying any part of 760 is applicable to the installation of 120 volt interconnected smoke alarms and in turn created a violation of 210.12(b)

 

[tortuga]

Just like you hearing that is a first for me but the inspector was completely incorrect in saying any part of 760 is applicable to the installation of 120 volt interconnected smoke alarms and in turn created a violation of 210.12(b)

The guy is a smart inspector and more knowledgeable in fire alarm code / terms than me
Would you agree a NPLFA Circuit in a residential occupancy is not subject to 210.12?

 

[kwired]

No, the power was on. I only remove the tabs after the green light was on showing AC power. Even if the tab was shifted before AC power, the battery would run a long time before it would be depleted. The chirping with no power is to let you know the power is off.

The BRK ones are what I mostly always used. If you apply AC power but don't pull the battery tab it chirps periodically because it not sensing any/enough battery voltage.

 

[kwired]

All I know is I was completely unaware of it until we had a job with a regular 15A breaker on a circuit that supplied smoke detectors in a dwelling unit, and the inspector asked that it have red identification, per 760.41(B), his interpretation was that as soon as you interconnect smoke alarms you have met the minimim definition of a system, and since 760 prevails over 210 the exception does not even come into play (Non-Power limited fire alarm circuit)

May be debatable as to whether this becomes a fire alarm once interconnected, but if it is then I believe it should be required to be on an individual branch circuit as well.

AFAIK these are just "smoke alarms" and not classified the same as "fire alarm systems" or even "smoke detectors" that are a part of a true fire alarm system.

The ones that are AC powered and have a backup battery still function when power is lost and do warn you when the battery needs replacing.

 

[tortuga]

May be debatable as to whether this becomes a fire alarm once interconnected, but if it is then I believe it should be required to be on an individual branch circuit as well.

Yeah the circuit in question was a 15A individual circuit that powered nothing other than interconnected residential smoke alarms possibly a heat detector.
The question becomes if NPLFA Circuit in a residential occupancy is subject to 210.12?
AHJ said no

 

[Jaybone812]

The guy is a smart inspector and more knowledgeable in fire alarm code / terms than me
Would you agree a NPLFA Circuit in a residential occupancy is not subject to 210.12?

No I wouldn’t I disagree .and 760.41(b) says as much, and if it was 120 volt interconnected smoke alarms would need to be supplied by a individual branch with a disconnecting means that has a red identification . A fire alarm system is monitored as well

 

[Jaybone812]

The guy is a smart inspector and more knowledgeable in fire alarm code / terms than me
Would you agree a NPLFA Circuit in a residential occupancy is not subject to 210.12?

I feels it’s clear 210.12 is applicable because any outlets or devices in a location/area in 210.12(b) require afci protection and the point in the circuit our branch circuit conductors connect to a 120 volt interconnected life safety device is the outlet according to the nec defined term

 

[Jaybone812]

The guy is a smart inspector and more knowledgeable in fire alarm code / terms than me
Would you agree a NPLFA Circuit in a residential occupancy is not subject to 210.12?

If a actual fire alarm system was installed in a residential dwelling which does happen, then the circuit supplying the power for the fire alarm system would be considered NPLFA and 760.41(b) prohibits afci/gfci protection of that circuit

 

[Jaybone812]

The guy is a smart inspector and more knowledgeable in fire alarm code / terms than me
Would you agree a NPLFA Circuit in a residential occupancy is not subject to 210.12?

while the explanatory material in the NFPA enhanced content is not part of the nec enforceable code , this speaks to how the NFPA feels about this which is that 120 volt interconnected smoke alarm outlets/branch circuits are subject to the requiremts of 210.12 .

 

[tom baker]

I wired my 120v smokes with 14-3 as they are interconnected on a separate ckt. Building dept required them to be interconnected. They are battery backed up. Now thankfully smokes have a ten year battery which is the life of a smoke det