Recomendation for low voltage smoke alarm

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tortuga

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
I am looking at installing inter-tie smoke alarm system in an occupied old multi story house.
Wood framing, insulation, Lath and plaster with wood blocking etc.
The residential standard here in Oregon is 120V 3 wire 14/3 to each smoke alarm unit.
I would like to avoid dust and unnecessary cut-in 18cuin 3/0 boxes.

Years ago in Philadelphia I used to install intertie smoke alarms in old brick row houses with a now retired electrician. He had a small "fire panel" he used for residences and I cant remember the brand. It ran off low voltage cable like commercial fire alarm panel. All this unit had was a battery back up and a 24VDC power supply. Then 4 wire red 18-4 daisy chained to low voltage smoke/alarm heads or heat detectors/alarm heads. very simple.

I would like to find a similar product.
Any thoughts?
Thanks in advance
Note I do not want to install a commercial fire alarm panel in the house.
 
First, there is no need for an "FACP" (fire alarm control panel). If you were allowed to install 24 vdc powered smoke alarms, a power supply with battery backup is all you would need. A basic power supply such as Altronix would suffice. Check out there website???..http://www.altronix.com/index.php?pid=2&section=2&lang=1

However....If the local standard requires 120 volt smoke alarms which is pretty typical for residential housing across the country, how will they allow 24 vdc powered smoke alarms? Not sure if they would even allow a resi fire/burg alarm panel to operate the smoke alarms instead of 120 vac house powered devices.

Also, whether these are 24 vdc, or 120 ac you still need to provide some sort of device box, such as a plastic cut in box. Seems to me, no matter how they are installed, cutting into the ceilings is a given.

If you find the local jurisdiction will allow 24 vdc smoke alarms, Altronix power supplies are available at most fire/security wholesale houses like ADI.

Good luck,
 
I think one of the reasons this is not allowed is, in a 120v interconnected system with individual battery back up, each smoke detectors will still operate if the fire involves other units, and because each unit has it's own battery supply, it will operate even if the power is involved with the fire.

With the 24 volt system, the fire only has to take out the supply cable and the whole system stops working.

I think it's about the reliability of the rest of the alarms still functioning even if some of the smokes are damaged in the fire.:)
 
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