# Smoke alarm.interconnect wire



## rjniles (Feb 5, 2007)

They make smokes that are interconnected wirelessly. Here is one but there are tons out there.



https://www.amazon.com/Wireless-Interconnectable-Professional-Anti-Insect-Function/dp/B08PBRSDYT?th=1


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## SW Dweller (Jan 6, 2021)

Sorry , the interconnect wire is 120v ac. There is no step down transformer that I have ever seen inside a smoke detector.

First how old are they? If you beyond 5 years old I would consider replacing them with the interconnect being wireless. Detectors should be replaced every 10 years. 

Next you can run 12-3 from the first to second, then to all the others in the string. 
The code now requires detectors to be on a separate circuit and most installers use 14 as it is cheaper. Re wiring them could be a real hassle and more expensive than replacement depending on access available.
For your inspection
BRK First Alert - SA521CN-3ST
about $45 each. Going to big A or the box store may cost you close to double.
Shop around on line there are other MFG's


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## rjniles (Feb 5, 2007)

SW Dweller said:


> Sorry , *the interconnect wire is 120v ac*. There is no step down transformer that I have ever seen inside a smoke detector.


Actually the interconnection is 6-9VDC. Otherwise the feature would not work during a power failure.


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## SW Dweller (Jan 6, 2021)

that is very true, but when the power is on it is 120v. I always go to the higher voltage


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## JaneD (Jun 15, 2011)

Thanks for all the great replies and info they are all 2021 smoke alarms with voice so it makes it very easy to know what alarm is going off. It's just a very long thin house and worried that I might not hear the alarm. 

The interconnect was what I was referencing as a lower voltage on how it sends it's signal to the next alarm (I am not trying to step down voltage). I have easy access and there is a push to go wired interconnect as it will hook in to my alarm panel vs using a wireless interconnect option.


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