smoke detector

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j9DuBois

Member
Location
Bay Area
I am trying to find out if a smoke detector in a residence needs to be on a dedicated 15 amp cb or can it be on a branch circuit with lighting? thank you
 

Dennis Alwon

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Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
You need to check with your local authority. Here in NC they use to require the smokes on a circuit with the lighting but it is not required any more. We never had to have them on a separate circuit.

Remember they have to be on an arc fault circuit when they are installed in a residential bedroom.

BTW-- this is not in the NEC but a building code issue
 

Brady Electric

Senior Member
Location
Asheville, N. C.
Smoke Dectors

Smoke Dectors

Dennis Alwon said:
You need to check with your local authority. Here in NC they use to require the smokes on a circuit with the lighting but it is not required any more. We never had to have them on a separate circuit.

Remember they have to be on an arc fault circuit when they are installed in a residential bedroom.

BTW-- this is not in the NEC but a building code issue
Dennis, Hear in Ashville most of us have the smokes on a seperate circuit and they are linked togeather so if one goes off all will go off. One in each bedroom, outside of each bedroom and on each floor including basement. I wire them on 14/2 for the first one and 14/3 between smokes. In the smoke dector box thats what the instructions say. Semper Fi.
 

Dennis Alwon

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Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Brady Electric said:
Dennis, Hear in Ashville most of us have the smokes on a seperate circuit and they are linked togeather so if one goes off all will go off. One in each bedroom, outside of each bedroom and on each floor including basement. I wire them on 14/2 for the first one and 14/3 between smokes. In the smoke dector box thats what the instructions say. Semper Fi.

Yes they have to be linked together so if one goes off the other will also but they do not need to be on a separate circuit. I always put them on with one of the bedroom circuits.

What brand SD are you using. I have never seen one that says put on a separate circuit.
 

bphgravity

Senior Member
Location
Florida
The model building codes (ICC - Section 313) doesn't indicate one way or the other. In most cases, this is a matter of design and preference. Always follow the manufacturer's instructions.
 

Brady Electric

Senior Member
Location
Asheville, N. C.
Sorry Dennis I was wrong it doesn't say seperate circuit. The reason I put them on seperate circuit is so if you have trouble you can cut them off to replace or work on without cutting off anything else. I have had one bad and it took one hour to find the one. Everyone has there own way of doing things and your way seems O.K. to me. I have also found my inspectors like the way I do it. Thanks for your feed back. Semper Fi
 

kjw444

Member
Location
detroit, mi
Up here we always feed the smoke circuit from one of the bedrooms since they draw very little current. Shouldn't they also be afci protected in a residence?
 

mdshunk

Senior Member
Location
Right here.
I hope no jurisdiction is requiring smokes on a dedicated circuit. That would be a complete waste of material for absolutely no benefit.
 

winnie

Senior Member
Location
Springfield, MA, USA
Occupation
Electric motor research
IMHO it is _good design_ to place the smokes on a circuit shared with some small but frequently used loads, eg. the front hall light. Ideally _not_ lights that you would want on when working on a detector :)

-Jon
 

Dennis Alwon

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Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
winnie said:
IMHO it is _good design_ to place the smokes on a circuit shared with some small but frequently used loads, eg. the front hall light. Ideally _not_ lights that you would want on when working on a detector :)

-Jon


Exactly-- I agree wholeheartedly. I am curious as to why our state changed that ruling. They use to req. the SD on a lighting cir.--- no more
 

iwire

Moderator
Staff member
Location
Massachusetts
Dennis Alwon said:
Exactly-- I agree wholeheartedly. I am curious as to why our state changed that ruling.

IMO they changed it because safety codes are not supposed to be design manual.

A dedicated circuit is not inherently unsafe, the SDs have battery back up and make noise without 120 AC.

Now you can say 'what if they take out the batteries?

Well what if the bring the TV into the shower?

At some point people need to be responsible for their own safety and at this point in time I find it unlikely that many people do not know that SDs need batteries.

That said I would likely tie them into a lighting circuit to save money.
 
Smoke Detectors

Smoke Detectors

Many of the cities are requiring smoke detectors to be on AFCI. Is that an NEC requirement?
 

kkwong

Senior Member
knightstar-I think that is because they (the city) wants the power to be pulled off a bedroom circuit or/and because smokies are required in bedrooms. as far as it being an NEC requirement, I am not sure.

In the past I've ran a single receprtical on the smoke circuit. I think though, it was per the engineer's plans. the uniform (haha I know it's going away) bulding code had a requirement, but I can't think of where I read it...
 

Cavie

Senior Member
Location
SW Florida
THe NEC does not require smokes be on AFC. They end up there by default because the are reqired to be in the bedrooms in which all outlets are required to be AFC therefor they also end up on the lighting circuit so you will know they have power on them.
 

stickboy1375

Senior Member
Location
Litchfield, CT
Cavie said:
THe NEC does not require smokes be on AFC. They end up there by default because the are reqired to be in the bedrooms in which all outlets are required to be AFC therefor they also end up on the lighting circuit so you will know they have power on them.


Connecticut does not require AFCI protection on smokes, and I don't feed them off a lighting circuit either...
 
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