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Joined: Aug 2006
Posts: 9
Junior Member
Two story building, first floor contains a Subway resturant and used furniture shop. Second floor is a three bedroom appartment. I have been requested to install smoke detectors in all three spaces with the requirement that all sound if any one unit "smells" smoke.

I have used three wire smokes many times, no sweat in a single residence where one circuit powers the entire loop.

Can I tie three different circuits to a single alarm loop using "conventional" three wire smokes? I can't see how and would appreciate some help.

Thanks, Takideezy

Building Codes & Related References
Joined: Oct 2007
Posts: 56
According to this link
they need to be on the same circuit. However, I don't know what qualifications this person possesses.
You could also try firing off an e-mail to this Firex technical support link

Good luck.


Joined: Jan 2005
Posts: 109
We had a similar situation with a bar and grill with Apt. upstairs. I had to run a dedicated circuit just for the smokes up and down stairs. Rod

Joined: Jul 2004
Posts: 9,672
Likes: 7
I was caught in a catch 22 in my house. I wanted the detached garage to be on the same smoke loop as the house but this would be a 225.30 violation. I got over it. I now have a circuit in the house off the garage panel that runs the smokes in both places. Since I was violating the code anyway I went ahead and added a receptacle next to the panel in the house so I would have a work light with the house main tripped. It is marked that way and has a red cover.
I am holding my nose and calling it an (E).

Greg Fretwell
Joined: Aug 2006
Posts: 9
Junior Member
Thanks for the input - I'm thinking that it will be one circuit from the primary service panel powering a single loop for all occupancies. Add a breaker lock and clear panel marking...and what could go wrong? Now if only the AHJ approves I'll be OK.

Joined: Aug 2007
Posts: 853
Just one thought, You may want this on a ckt that runs the Emergency lights/exit signs. This way you will know if the ckt is shut off. They all should have battery backup aswell.

Joined: Mar 2008
Posts: 3
New Member
do these units have seperate electrical services? if so, running a circuit from one unit to the other through fire walls would not pass in my area, I would look into a low voltage system possibly? Im not exactly sure that would pass either, just a possibility to check into. but actually, in my area, smokes arnt required for commercial, and you cannot live in a building with a business....

Last edited by ultramegabob; 03/31/08 10:04 PM.
Joined: Oct 2002
Posts: 482
This brings up some interesting questions.

What if you run them off of a circuit tied to only one of the services, and that service moves out for a period and has their account terminated? All of the smokes are now useless...

How about a wireless-link smoke system, where each smoke in the series communicates through radio preset signals (like a garage door opener). Is it time for something like this to be put on the market? This would also be great for retro-fitting an old building that was wired without the communication wire between the smokes.


Joined: Jul 2007
Posts: 85
How about a 4 zone conventional Fa. system. Install One inition zone per flr. And install Signaling devices where needed. This is the only way this would fly around here. 120v smokes generally are not installed in a public/ commercial space, which would require the Fa system. And typically in a residence like you describe there would be a local 120v smokes and a heat or smoke tied to the initialion loop of the Fa. The main reason for not putting 120v. smokes throughout, would be if youburn popcorn for instance the smoke throughout will sound, possibly causing havoc. Where if you install a 135 ror heat in the common area, and a 200 fixed in the kitchen area there is less chance of false alarming.Additionally the 120v smoke is in the residence as a backup. Not sure how it works in other areas this is just pretty common around this area.

Joined: Aug 2003
Posts: 64
Originally Posted by gfretwell
I was caught in a catch 22 in my house. I wanted the detached garage to be on the same smoke loop as the house but this would be a 225.30 violation...

I'm not sure that would be a 225.30 violation. I think 225.30(A) could apply here. Isn't a smoke detector an emergency system? and couldn't you say that the system has enhanced reliability if a smoke detector in the garage can make the detectors in the house sound?

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