Interconnected Smoke Alarms -- Options/Wiring -- Wireless?

I own a tenant-occupied, 2-story, 5 Bedroom, Colonial Style single family detached home with an attached 2-car garage and an unfinished basement. The home currently has individual battery powered smoke detectors and CO detectors, but none of the detectors are interconnected. That meets the current code for an existing single family home like this. So, under the current code, I don't need to do anything.

However, I am considering installing a 110-volt interconnected alarm system with battery backups so that if one detector alarm sounds, they all sound at the same time.

I have two sets of questions.

The first is about how to wire a 110-volt interconnected alarm system.

And, the second is about whether there is such a thing as a battery powered completely wireless interconnected alarm system that I could install so I would not have to physically run wires to interconnect the detectors in the new alarm system, but still have it function like an interconnected alarm system where if one alarm goes off, they all go off.

1) Questions about wiring a 110-volt interconnected alarm system that is NOT WIRELESS:

I know that one way to do the wiring is to run 14/2.from the electrical panel to the first alarm, then 14/3 to the next alarm, then 14/3 to the next alarm, and so on -- meaning that the wiring loop goes from the first alarm, then to the next one, then the next one, until I get to the last one, in one continuous loop.

But, to do that, I think it would be difficult to fish the wires in a way so that one loop goes to all of them one after the other.

My question is, can I junction off of the first one, for example, and split that into two circuits -- one going to the alarms on the right side of the house and one going to the alarms on the left side of the house? I have been doing Google searches to see if I could find an example of this type of wiring diagram but I can't find one.

2) Questions about WIRELESS interconnected alarms:

While researching this, I am seeing wireless smoke alarms that appear to be able to communicate with each other so that if one goes off they all go off. But, I can't quite tell if that means that it is possible to create a whole new interconnected wireless alarm system for the whole house without having to run any interconnecting wires through the walls and ceilings etc. That sounds too good to be true, but is that really an option? -- an all wireless interconnected alarm system?

Thanks for any help or suggestions.

Reply to
TomR
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Here is my question.

Alarms are generally quite loud. If one goes off, a tenant should be able to hear it anywhere within the house.

Maybe you could test and verify because interconnected alarms may not be necessary.

A localized alarm has the advantage of letting the occupant know exactly where the problem is.

BTW: Hopefully you do have fire extinguishers on all floors.

Reply to
philo

I think new construction requires 110V (w/battery backup). Too many folks removing batteries to silence nuisance "battery replacement reminders" have led to increased fatalities (that the detectors were supposed to prevent)

Run power to the alarms (they draw very little power so not an issue). I *think* they might need to be on the same branch circuit (at least that's how ours are wired).

Additionally, you add a "signal cable" -- a discrete wire -- that they use to talk to each other.

IIRC, the "signal lead" is just another "shared" conductor. I.e., there is no "loop" or "daisy-chaining" involved. Any alarm that signals puts a signal on that conductor; all alarms monitor the conductor and alarm in sympathy with it if they sense that signal!

(there is a method you use to determine which alarm is actually originating the signal -- if you suspect it to be false).

Note that you probably can't mix and match detectors from different vendors!

It's just "a third conductor" SHARED among all.

I am not sure you can run 14/3 and rely on the third conductor in that "cable" for this; it's technically a *signalling* conductor, not a power conductor.

I'd be leary about relying on wireless for anything safety critical. Our neighbor's home alarm is wireless; I am sorely tempted to hack it just to see to which sorts of exploits it would be vulnerable! :<

Reply to
Don Y

Excellent point and something I did not think about: human nature.

I still recall hearing the low battery warning on an alarm at a friend's house. When I mentioned it, she just said, "That's the landlord's responsibility and not mine."

People can certainly be idiots.

Reply to
philo

You sound like all kinds of fun, as a neighbor.

Reply to
Stormin Mormon

At my church, they put in two monoxide detectors.

As the physical facilities rep, I'd think I would know about changes like that. But, no. I found out only by asking very direct and pointed questions of the paid guys when I saw them on the wall. I can imagine some day the alarm goes off. No one in the building has any idea what the device is, or what to do when it sounds. So, they ignore it.

If you put in alarm and or extinguishers, it's a good idea to have drills, so the tenants know what to do, and how to do it.

- . Christopher A. Young learn more about Jesus .

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. .

Reply to
Stormin Mormon

Oh, that thing making noise? We'll just ignore it, or put a blanket over it till it quits. Like we did the last few times. Honey, where's the Tylenol, my headache is killing me. And you look kind of red and rosy, dear.

Reply to
Stormin Mormon

It is apparently a BIG factor in recommendations regarding smoke detectors! E.g., you'd *think* that the kitchen would be a great place for one (source of heat/combustion). But, apparently enough false alarms ("Dinner will be served at the sound of the smoke alarm...") that this location is NOT recommended.

Another annoying aspect is getting a straight answer from folks regarding local code, etc. I ended up calling the fire department and *they* were dumbfounded about what locations SHOULD be protected and which not (garage? furnace room?)

We make a point of replacing the batteries as part of our "New Year's routine". Batteries are cheap. If you wait until it starts chirping (every minute??) to tell you of a battery failure, you will end up removing the detector (to silence it) -- and be WITHOUT protection until you happen to remember to buy batteries AND install them!

Reply to
Don Y

Thanks for the replies so far. Regardless of how I do the system, the plan will be to use detectors that have built-in 10-year Lithium batteries. The detectors themselves are supposed to be replaced every 10 years anyway, and the Lithium batteries are theoretically supposed to last 10 years. And, with built-in lithium batteries, the occupants don't take them out to power their electronics which does happen with 9V batteries and AA or AAA batteries. Some localities now require the 10-year batteries in battery operated smoke detectors for that reason. Plus, the detectors will have "Hush" buttons on them that the occupants can use to silence unwanted alarms. That avoids them taking the batteries out to silence the alarm. I won't be putting a detector in the kitchen so cooking fumes don't set off the alarm. In kitchens, it is possible to put in a heat detector instead of a smoke detector, but I probably won't do that. Also, the purpose of the

14/3 is to provide a black (hot) wire, a white (neutral) wire, and a third (red) wire for the signal between the units. I am writing all of this just as side information as an FYI, but it does not resolve the original questions that I still have about the wiring diagram and about the possibility of using wireless interconnected detectors.
Reply to
TomR
[snip]

If I removed the battery from a detector, I know which one was beeping. That's MOST of the work done already.

Reply to
Mark Lloyd

And I'm saying that using the third wire in a 14/3 cable for "signalling" may not comply with code! Any more than my using it as an audio output from an amplifier (neutral referenced) would...

Reply to
Don Y

In our case, remembering to buy the batteries is the bigger chore (unless it is a 'scheduled event' -- like New Year's). I think the only things we have that use 9V batteries *are* the smoke/CO detectors!

Reply to
Don Y

I do it a week or so before Halloween. The 'old' batteries are still at

80%, but we are not supposed to let them go until the detector beeps because their warning capacity is also reduced to almost nothing.

Then I solder them to a resistor in series with an LED and use them to illiminate hollowed-out pumpkins for a week or so.

Reply to
Mike Duffy

I already know that the way that 110 volt interconnected smoke detectors are wired is with 14/3 (or it could be 12/3 as an alternative), and the third (red) wire is the "signal" wire that allows them all to go off when one goes off. That is the code compliant way of wiring them.

What I don't know for sure are my original questions about the wiring diagram, the wireless possible alternative, etc.

Reply to
TomR

Using 14/3 is how every linked smoke detector I've seen installed around here is done. And the certainly sell replacement ones that are compatible with that. It sure seems like it would be easy to just pull up the install instructions for some typical alarms available at HD, etc and read them.

Reply to
trader_4

+1

Here's one diagram that shows the interconnect wire shared in common, not daisy chained, which is how I would expect it to be, because:

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1 - There is no reason for it to be daisy chained into one alarm and then out to the next 2 - It makes for a more reliable system. 3 - It's easier to install.

Wireless, IDK anything about, other than obviously there are easier to install because you don't have to interconnect them. The big downside of course is that they are wireless and we all know that wireless is less than perfect. And that what works today may not work two years from now, then some other wireless device comes into the home, a neighbor's home, etc. It definitely would not be my first choice, but it's better than no interconnect that's for sure. Might want to check local code on what's allowed, etc.

Reply to
trader_4

Thanks. That helps a lot.

That's an excellent website. I think that I may have seen that website in the past when I was trying to learn about 3-way wiring diagrams, but I had lost track of where that website was. For example, it has 3-way wiring diagrams (

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) that I think I remember seeing in the past. That showed various ways of wiring

3-way switches depending on where the power enters the system, whether the lights are before or after or in between the 3-way switches, etc.

I had not found the fire alarm installation diagram before. I am pretty sure that the way that the diagram is drawn, it means that it is okay to have the individual detectors come off of the 14/3 wiring in any manner as long as all of the black hot wires are connected to black, all the white neutrals to white neutrals, and all of the red wires tied to red wires for the interconnection signal.

I am not sure what the "Lifessaver Relay Module Model 120X -- Optional Accessory" is or means in the diagram so I will trying looking that up to see what it is.

I too do not know anything about the Wireless interconnected alarm systems, but I have some of the same reservations about them that you mentioned. But, one thing that I am wondering from what I have seen online so far is if wireless detectors can be used to extend an existing 100 volt interconnected system to another part of the structure without having to run the hardwiring to the other area. I would guess that a hardwired "wireless" detector could be included in the original 110 volt hardwired system and then another battery operated wireless detector could be put in the additional hard-to-reach location in the structure. So, maybe there could be a combination of a hardwired interconnected alarm system with one or two remotely placed wireless battery-operated detectors.

So much to learn, so little time.

Reply to
TomR

I found this website link that explains the wireless devices and how they can be used to extend an existing hardwired system to additional devices wirelessly to avoid having to run additional hardwiring:

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Reply to
TomR

So they can be used as essentially a bridge to connect two segments. I'd be more comfortable using it that way, than relying on wireless to connect them all. As long as the two are near enough, with no reason to expect blockage between them, then the link should be more reliable.

I guess if you relied on strictly wireless, the wireless signal just has to go from the tripped one to any one of the others. If it then trips any other one, that one will be trying to trip all the remaining ones, etc. A chain reaction effect. That would increase the reliability of the wireless connection part. So, maybe wireless is more reliable than I thought it would be.

Reply to
trader_4

I meant to reply earlier but then forgot to do so.

This is a unique situation which I didn't bother to try to explain in my original post. It is a detached single family home, but the family that lives there has some government funding which means that the home itself is inspected by a representative from that funding source/agency. They "recommended", but are not "requiring" an interconnected alarm system with a control panel etc. I do not plan on doing what they "recommend" because it is overkill, unnecessary, and not a code requirement etc. But, I have thought about just putting in a 110-volt interconnected alarm system (no alarm panel, no outside monitoring, etc) just as a way to please them and show that we did more than what the code requires for existing single family residential homes.

As far as what is there now -- the battery operated smoke and CO detectors all operate independently and they are all loud when they go off. They are all loud enough for anyone anywhere it the home to easily hear the alarm no matter which one goes off.

Meanwhile, I just read in another post where someone said that "philo" is an electrician. If that is correct, and if you do happen to know the answer to my original question about how to wire a 110-volt interconnected alarm system, that would be great. I think that I may already have that question figured out, but if you know the answer, that would be helpful information.

Reply to
TomR

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