Smoke detectors
- Thread starter kamchatka
- Start date
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charlie
Senior Member
- Location
- Indianapolis
Re: Smoke detectors
The NEC tells you the wiring requirements, the Building Codes tell you where, how many, and how they are to perform.
The NEC tells you the wiring requirements, the Building Codes tell you where, how many, and how they are to perform.
inspector 102
Senior Member
- Location
- Northern Indiana
Re: Smoke detectors
NFPA 72 will also indicated installation requirements for location and spacing. I believe it states that detector should be mounted at least 4" away from walls or ceilings but not greater than 12" below a ceiling. If they are mounted to close to a wall/ceiling corner then the detector might not work effectively due to a thermal turbulance created at this location. Detectors shall not be located in areas where the temp is less than 32 or exceed 100 and shall be at least 3 feet from the door to a kitchen or bathroom and 3 feet from supply registers of a force air heating or cooling system unless specifically listed for these locations.
NFPA 72 will also indicated installation requirements for location and spacing. I believe it states that detector should be mounted at least 4" away from walls or ceilings but not greater than 12" below a ceiling. If they are mounted to close to a wall/ceiling corner then the detector might not work effectively due to a thermal turbulance created at this location. Detectors shall not be located in areas where the temp is less than 32 or exceed 100 and shall be at least 3 feet from the door to a kitchen or bathroom and 3 feet from supply registers of a force air heating or cooling system unless specifically listed for these locations.
- Location
- Windsor, CO NEC: 2017
- Occupation
- Hospital Master Electrician
Re: Smoke detectors
The instructions that come with the smoke detector are pretty darned informative. I was suprised. They sometimes include quotations from NFPA documents too.
The instructions that come with the smoke detector are pretty darned informative. I was suprised. They sometimes include quotations from NFPA documents too.
aelectricalman
Senior Member
- Location
- KY
Re: Smoke detectors
Basically each bedroom is required to have one and the hall immediately out side the bedrooms (in a central location) is required to have one. Also, one on each floor. If there are open stairs leading down or up, put one at the top of the stairs over the opening. If there is a door between levels just make sure one is on each floor. I think that is it! Never put one in the garage. Your asking for call backs. Put a heat detector. Here in my city and state on all new construction, they are required to all be linked so they are all triggered as one. As a nice rule of thumb, if your building inspector allows, place a couple of lights which will be used often on with the smoke detector circuit. This way if the lights quit working your smokes will quit too and you will be more likely to get the problem fixed. Assuming the batteries arent dead, the smokes will let you know that there is no power, but some people just don't understand the concept of battery back up.
Basically each bedroom is required to have one and the hall immediately out side the bedrooms (in a central location) is required to have one. Also, one on each floor. If there are open stairs leading down or up, put one at the top of the stairs over the opening. If there is a door between levels just make sure one is on each floor. I think that is it! Never put one in the garage. Your asking for call backs. Put a heat detector. Here in my city and state on all new construction, they are required to all be linked so they are all triggered as one. As a nice rule of thumb, if your building inspector allows, place a couple of lights which will be used often on with the smoke detector circuit. This way if the lights quit working your smokes will quit too and you will be more likely to get the problem fixed. Assuming the batteries arent dead, the smokes will let you know that there is no power, but some people just don't understand the concept of battery back up.
- Location
- Windsor, CO NEC: 2017
- Occupation
- Hospital Master Electrician
Re: Smoke detectors
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Editted per Roger and Kendog's corrections. Wanted to keep a clean list, I might print it out later.
[ January 28, 2005, 09:29 PM: Message edited by: georgestolz ]
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- <font size="2" face="Verdana, Helvetica, sans-serif">One in each bedroom (to wake people up). I personally feel that any room that is similar to a bedroom (den, office) that has a closet of any size should get one, IMO. Could be a bedroom someday.</font>
- <font size="2" face="Verdana, Helvetica, sans-serif">One on each level, including basement.</font>
- <font size="2" face="Verdana, Helvetica, sans-serif">If a ceiling on any level has an elevation change of 24", each elevation needs one. Example: Vaulted living room on same floor as 8' ceiling for back hall, den, laundry.</font>
- <font size="2" face="Verdana, Helvetica, sans-serif">No closer than 3' to any cold air return or supply, or ceiling fan. Nuisance alarms due to dust attraction are common when this is done, and the sensitivity can diminish.</font>
- <font size="2" face="Verdana, Helvetica, sans-serif">No closer than 4" to peak of vaulted ceiling, or wall edge. Smoke rolls in corners, bypassing detector.</font>
- <font size="2" face="Verdana, Helvetica, sans-serif">No farther than 3' from peak of vaulted ceiling.</font>
- <font size="2" face="Verdana, Helvetica, sans-serif">Interconnection of detectors is required.</font>
- <font size="2" face="Verdana, Helvetica, sans-serif">Per 210.12, AFCI protection required.</font>
Editted per Roger and Kendog's corrections. Wanted to keep a clean list, I might print it out later.
[ January 28, 2005, 09:29 PM: Message edited by: georgestolz ]
Re: Smoke detectors
You'll want to check out the National Fire Alarm Code (NFPA 72) and the National Life Safety Code (NFPA 101).
Just be sure what year code your state and AHJ has adopted. Alot of states are still using the 1999 NFPA 72. If so, check out Chapter 8 for residential dwelling units.
You'll want to check out the National Fire Alarm Code (NFPA 72) and the National Life Safety Code (NFPA 101).
Just be sure what year code your state and AHJ has adopted. Alot of states are still using the 1999 NFPA 72. If so, check out Chapter 8 for residential dwelling units.
Re: Smoke detectors
# No closer than 1' to peak of vaulted ceiling, or wall edge. Smoke rolls in corners, bypassing detector.
you might want to double check this. I know as far as the 2002 NFPA 72 they must be a least 4" from the highest point in the ceiling and no more than 36" if installed on the ceiling and not on a wall. this measurement is verticaly or horizontaly not diagonaly.
Interconnection is required and your also required to have smoke detectors 3' from paddle fans to
# No closer than 1' to peak of vaulted ceiling, or wall edge. Smoke rolls in corners, bypassing detector.
you might want to double check this. I know as far as the 2002 NFPA 72 they must be a least 4" from the highest point in the ceiling and no more than 36" if installed on the ceiling and not on a wall. this measurement is verticaly or horizontaly not diagonaly.
Interconnection is required and your also required to have smoke detectors 3' from paddle fans to
Re: Smoke detectors
Ken, here are the specifics to go with your post
2002 NFPA 72, 11.8.3.3 Sloped Ceilings Smoke alarms or smoke detectors mounted on a sloped ceiling having a rise greater than 1m in 8m (1ft in 8in) horizontally shall be located within 914mm (36 in) of the high side of the ceiling, but not closer than 102mm (4 in) of the adjoining wall surface.
Roger
Ken, here are the specifics to go with your post
2002 NFPA 72, 11.8.3.3 Sloped Ceilings Smoke alarms or smoke detectors mounted on a sloped ceiling having a rise greater than 1m in 8m (1ft in 8in) horizontally shall be located within 914mm (36 in) of the high side of the ceiling, but not closer than 102mm (4 in) of the adjoining wall surface.
Roger
- Location
- Windsor, CO NEC: 2017
- Occupation
- Hospital Master Electrician
Re: Smoke detectors
Corrected my previous post.
Roger, does NFPA 72 make mention of interconnection? I don't have a copy. (I don't doubt you Kendog, just seeking confirmation, fer sure, fer sure!).
Corrected my previous post.
Roger, does NFPA 72 make mention of interconnection? I don't have a copy. (I don't doubt you Kendog, just seeking confirmation, fer sure, fer sure!).
Re: Smoke detectors
George,
11.5.1.2 Notification
(A) Fire-warning equipment for dwelling units shall provide a sound that is audible in all occupiable dwelling areas.
(B) Where more than one smoke or heat alarm is installed for new construction, they shall be arranged so that the operation of any smoke or heat alarm causes the alarm in all smoke and heat alarms within the dwelling unit to sound.
Roger
George,
yes it does.
11.5.1.2 Notification
(A) Fire-warning equipment for dwelling units shall provide a sound that is audible in all occupiable dwelling areas.
(B) Where more than one smoke or heat alarm is installed for new construction, they shall be arranged so that the operation of any smoke or heat alarm causes the alarm in all smoke and heat alarms within the dwelling unit to sound.
Roger
- Location
- Windsor, CO NEC: 2017
- Occupation
- Hospital Master Electrician
Re: Smoke detectors
Thanks, Roger!
Thanks, Roger!
jdelectric
Member
Re: Smoke detectors
keep smoke detectors about 3 feet from ceiling fans.
keep smoke detectors about 3 feet from ceiling fans.
allenwayne
Senior Member
Re: Smoke detectors
Maybe this thread and AFCI`s and call backs should be combined . smokes and afci`s are killing our profit margin !!!!
Maybe this thread and AFCI`s and call backs should be combined . smokes and afci`s are killing our profit margin !!!!
Re: Smoke detectors
Just a thought, I have done alot of troubleshooting being that I work in a modular plant as a tester for few years. I have seen alot of different and alot of times out right weird things cause problems with gfcis and now afcis. I'll mention a couple of them to keep a eye on, hopefully this helps with some of your service call backs.
1, Wire staples driven to tight or bent to far. Didn't matter if they were insulated or not. It also didn't matter if there bend radius was to code. We figured out if you drive the staple just enough to be snug and still have plents of room to let the wire move freely under the staple alot of these problems went away. As far as bends are concerned we started using the way I was taught, which is to bend the wire around the handle of a screw driver at all bend points, this fixed all with wire bends.
2, Small nicks in conductors do to cable rippers or utility knife. Whick became simply an awareness issue.
3, Grounds tied together from different circuits, Yikes.
4, Loose connections.
5, To much wire inside a box.
Most of these problems will show up in a dielectric strength test. Which I strongly reccomend doing.
Hope this helps.
Just a thought, I have done alot of troubleshooting being that I work in a modular plant as a tester for few years. I have seen alot of different and alot of times out right weird things cause problems with gfcis and now afcis. I'll mention a couple of them to keep a eye on, hopefully this helps with some of your service call backs.
1, Wire staples driven to tight or bent to far. Didn't matter if they were insulated or not. It also didn't matter if there bend radius was to code. We figured out if you drive the staple just enough to be snug and still have plents of room to let the wire move freely under the staple alot of these problems went away. As far as bends are concerned we started using the way I was taught, which is to bend the wire around the handle of a screw driver at all bend points, this fixed all with wire bends.
2, Small nicks in conductors do to cable rippers or utility knife. Whick became simply an awareness issue.
3, Grounds tied together from different circuits, Yikes.
4, Loose connections.
5, To much wire inside a box.
Most of these problems will show up in a dielectric strength test. Which I strongly reccomend doing.
Hope this helps.
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: Smoke detectors
I thaught that all grounds in a box had to be connected>
I thaught that all grounds in a box had to be connected>
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: Smoke detectors
allen don't rule out that your smokes are from a bad batch.Perhaps change brands.
allen don't rule out that your smokes are from a bad batch.Perhaps change brands.
Re: Smoke detectors
We never hook grounds from separate circuits together. We have questioned this with several inspectors and they all said that this was ok. Not saying that this is 100% correct but from a safety stand point I wouldn't want a fault from one circuit jumping to another circuit either.
We never hook grounds from separate circuits together. We have questioned this with several inspectors and they all said that this was ok. Not saying that this is 100% correct but from a safety stand point I wouldn't want a fault from one circuit jumping to another circuit either.
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