# Smoke Detector Circuit



## Achilles (Sep 11, 2014)

I've been scouring through the NEC 2011. Can anyone post the section of the code that allows me to install residential smoke detectors on a shared circuit?

I can not find where the code addresses smoke detectors outside for fire alarm systems 760


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## macmikeman (Jan 23, 2007)

Achilles said:


> I've been scouring through the NEC 2011. Can anyone post the section of the code that allows me to install residential smoke detectors on a shared circuit?
> 
> I can not find where the code addresses smoke detectors outside for fire alarm systems 760



NEC does not address smoke detectors, other building codes do. NEC covers wiring methods employed in powering and connecting smoke detectors together such as no nm above drop ceilings in other than dwellings and the like.


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## Achilles (Sep 11, 2014)

NEC 760.41 (B): The branch circuit supplying the fire alarm equipment(s) shall supply no other loads ..... This branch circuit shall not be supplied through ground-fault circuit interrupters or arc-fault circuit interrupters.

I'm "assuming" 760 only applies to fire alarm panels, but I can not find any where in the code that allows me to install smoke detectors on say a bedroom AFCI circuit.


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## macmikeman (Jan 23, 2007)

Achilles said:


> NEC 760.41 (B): The branch circuit supplying the fire alarm equipment(s) shall supply no other loads ..... This branch circuit shall not be supplied through ground-fault circuit interrupters or arc-fault circuit interrupters.
> 
> I'm "assuming" 760 only applies to fire alarm panels, but I can not find any where in the code that allows me to install smoke detectors on say a bedroom AFCI circuit.


You won't find it. And therefore it is allowed. I do it almost daily.


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## Achilles (Sep 11, 2014)

So a residential smoke detector is simply considered an outlet and wired in accordance to NEC 210?


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## AK_sparky (Aug 13, 2013)

No help to you in the states, but in Canada:

32-110 Installation of smoke alarms and carbon monoxide alarms in dwelling units
(see Appendices B and G)
32-110
The following requirements apply to the installation of permanently connected smoke alarms and carbon monoxide alarms in dwelling units:
(a) smoke alarms and carbon monoxide alarms shall be supplied from a lighting circuit, or from a circuit that supplies a mix of lighting and receptacles, and in any case shall not be installed
(i) where prohibited by Rules 26-720 to 26-724; and
(ii) where the circuit is protected by a GFCI or AFCI;


I'm surprised it's not similar south of the border.


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## 480sparky (Sep 20, 2007)

Achilles said:


> NEC 760.41 (B): The branch circuit supplying the fire alarm equipment(s) shall supply no other loads ..... This branch circuit shall not be supplied through ground-fault circuit interrupters or arc-fault circuit interrupters.
> 
> I'm "assuming" 760 only applies to fire alarm panels, but I can not find any where in the code that allows me to install smoke detectors on say a bedroom AFCI circuit.



Resi smoke detectors are not fire alarms. 760 does not apply to them.


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## macmikeman (Jan 23, 2007)

Achilles said:


> So a residential smoke detector is simply considered an outlet and wired in accordance to NEC?


fify





Correct.


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## backstay (Feb 3, 2011)

Achilles said:


> So a residential smoke detector is simply considered an outlet and wired in accordance to NEC 210?


Yes.


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## Achilles (Sep 11, 2014)

Thank you all for your time


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## janagyjr (Feb 7, 2011)

Heh, I've been putting the line-voltage ones on a dedicated circuit.


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## 480sparky (Sep 20, 2007)

janagyjr said:


> Heh, I've been putting the line-voltage ones on a dedicated circuit.


I always use the master BR circuit. That way, if there's a problem with the smokies, the HO is likely to want to fix it.


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## wildleg (Apr 12, 2009)

480sparky said:


> i always use the master br lighting circuit. That way, if there's a problem with the smokies, the ho is likely to want to fix it.


fify


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## janagyjr (Feb 7, 2011)

On the flip side of this, though, the installation instructions that come with the ones I've installed say that they cannot be on a circuit with more than 1000' of wire between the last detector on the circuit and the breaker (the one's I've installed will set all of them off if one of them goes off).


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## 480sparky (Sep 20, 2007)

wildleg said:


> fify


No. BR circuit. I don't separate lights & receps.

Besides, people can 'survive' if the lights go out (and may actually prefer this). But if his 60" flat screen or her plug-in heater quits working, they're gonna be calling me.


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## wildleg (Apr 12, 2009)

480sparky said:


> No. BR circuit. I don't separate lights & receps.
> 
> Besides, people can 'survive' if the lights go out (and may actually prefer this). But if his 60" flat screen or her plug-in heater quits working, they're gonna be calling me.


really ? I don't do too much resi, but the little I've done I separated them. hmmm.


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## backstay (Feb 3, 2011)

wildleg said:


> really ? I don't do too much resi, but the little I've done I separated them. hmmm.


Why, just one more arcfault breaker to fail.


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## Pete m. (Nov 19, 2011)

wildleg said:


> really ? I don't do too much resi, but the little I've done I separated them. hmmm.


It's rare that I ever see them separated.

Pete


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## 480sparky (Sep 20, 2007)

wildleg said:


> really ? I don't do too much resi, but the little I've done I separated them. hmmm.


I only separate 'em if it's a job spec.


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## janagyjr (Feb 7, 2011)

backstay said:


> Why, just one more arcfault breaker to fail.


AFAIK, the lighting circuit doesn't have to be AFCI'd so I'm not sure why you'd say that.


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## backstay (Feb 3, 2011)

janagyjr said:


> AFAIK, the lighting circuit doesn't have to be AFCI'd so I'm not sure why you'd say that.


 I'd don't know what code cycle you're on, but any thing in the bedroom/hall area has been arcfault for at least two cycles here. A switch controlling a light outside the bedroom(outside) was exempt, but that's changed now too.


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## janagyjr (Feb 7, 2011)

2008 (still) in TN but I can't find such a requirement for strictly lighting circuits for the hall or bedroom in the 2011, either.


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## 480sparky (Sep 20, 2007)

janagyjr said:


> AFAIK, the lighting circuit doesn't have to be AFCI'd so I'm not sure why you'd say that.



Lighting circuits contain outlets, don't they?



> *210.12 Arc-Fault Circuit-Interrupter Protection(A) Dwelling Units. *All 120-volt, single-phase, 15- and 20-ampere branch circuits supplying outlets or devices installed in dwelling unit kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, laundry areas, or similar rooms or areas shall be protected by any of the means described in 210.12(A).........


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## backstay (Feb 3, 2011)

janagyjr said:


> 2008 (still) in TN but I can't find such a requirement for strictly lighting circuits for the hall or bedroom in the 2011, either.


You need to brush up on resi code.


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## macmikeman (Jan 23, 2007)

janagyjr said:


> On the flip side of this, though, the installation instructions that come with the ones I've installed say that they cannot be on a circuit with more than 1000' of wire between the last detector on the circuit and the breaker (the one's I've installed will set all of them off if one of them goes off).


That 1000 foot is equal to 4 250 ft rolls of romex, the most commonly used style. 

I've never even used a single roll on one circuit yet that I can ever remember.


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## zen (Jun 15, 2009)

It seems that when I did resi. Every bedroom was on a arc fault circuit of its own. Simple to wire id say. H/R to 2 gang then around the room. Smokes on a circuit of their own. Staple the farthest one then make the loops back to the panel

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