Interconnected smoke detectors - no circuit breaker?

That is why they are supposed to be interconnected. If you are really doing this right, the smoke going off anywhere will set off all of the bedroom smokes. Prior to the interconnection rule, the smoke was required to be in the hall outside the sleeping rooms ... and it still is. Now you need a smoke in each sleeping room, one outside the sleeping rooms and at least one on every other floor. This will be triggered if a permit is pulled for any other renovation and the only exceptions are if you can't do it any other way but opening up drywall you were not going to be in anyway. This is defined in ICC building code R.314 which is derived from NFPA

1. These codes tend to be adopted by states as their own.

That's what they do with new construction here. Which solves the problem Doug is talking about, ie whether one inside the bedroom or one just outside, may miss early detection. Given how many fires start from smoking in bed, requiring one inside the bedroom seems like a very good idea to me. And like you say, the interconnection is a big plus, a fire starting in the basement you'd get alerted long before smoke reaches a second floor bedroom.

Still, from casual observation of the news, it seems that probably 95%+ of the protection comes from just having a working, unconnected alarm near or inside a bedroom. All the fatal fires I can recall reading about, there were either no smoke detectors, broken ones, disconnected ones, dead batteries, etc. But getting an early warning from interconnected alarms, multiple alarms, etc can also lessen the fire damage or avoid an actual fire, by getting to whatever is going on before it's too late.

the breaker. You mean open the breaker box? What do you mean by 2 hot wires? Two red wires? Connected to the breaker switch? First time homeowner, forgive me for needing more simplified instructions. I only recall seeing black switches, not wires in the breaker box.

He means two wires connected to one circuit breaker. But this is mostly wrong. Most circuit breakers aren't rated for having two wires connected. And AFAIK you could also have the smoke alarms connected to whatever breaker by just wiring them into the circuit, AFAIK it doesn't have to be done at the breaker. What is your actual problem or issue?

Two red wires?

The wires are visible once you remove the panel cover. But if you're not familiar with panels, I would not suggest removing the cover or at least look at some online videos first. It's simple, but you want to make sure after it's loose you pull it straight off. You don't want to be holding it and have the top corner dip inside and contact the live service conductors.

I've tried every circuit breaker in the house except.for the master and the smoke detector has remained hot. I suspect that my smoke detectors are wired together but supplied by two different circuits so that they will go off together. I'm simply going to cut power to the whole house to change the hard wired units rather than try to solve a very complicated puzzle.

Hot like 120v present or just functioning? They usually have battery backup. If they really are being fed from 2 circuits, fix that first or you might be needing those smoke alarms.

If they really are supplied by two circuits, it would be easy to prove it. Just turn off all breakers and the smoke detectors would lose power. Then turn them on one at a time until finding one breaker where they have power again. Turn that breaker off and proceed to try all the remaining breakers. Also IDK why he didn't just open the main breaker, that would have proven whether they are battery backed up and that was what was going on.

I want to interconnect smoke detectors change but I don’t find power off switch so can I change with power leave on

On Sat, 6 Mar 2021 17:31:22 +0000, Bhagvati posted for all of us to digest...

Engage an electrician to find the circuit they are on so you can work safely.

I guess 'double tapping' a breaker means that that breaker was originally designed as a two pole breaker for two ungrounded conductors of different phases.

Turn off the main breaker.