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wiring smoke detectors

Before giving thought to purchasing an alarm system, I have wired all my smoke detectors with 14-3 romex. Im looking at installing an M1 Gold with all the window, door and motion sensors. I noticed that smoke detectors are available. Wiring opitons say 2 or 4 wire and it looks like they wire into the control panel. My current (havent purchased yet) detectors get wired into the main electrical panel with a 14-2 to the first unit and then 14-3 to the remaining.
If I use the i3 series detectors, do I need to re-wire the current boxes I have set up for detectors? Do all the decectors go to the M1 panel or just one?
 

AutomatedOutlet

Senior Member
Not an expert at this but I'll try.

Since it looks like you're going with 120 VAC power on the units (I know some areas require this but I think it's silly), you need to make sure you get the 120 VAC power sensors. They aren't on the sight but I can get them up pretty fast.

As far as the contact wiring, home running them back to the panel will give you the most options. That way you can decide if you want them on the same zone or separate zones. Other than that, most people run them in series so that if any smoke sensor gets tripped, the alarm will trigger.
 

BraveSirRobbin

Moderator
Martin:

You know of a way to get traditional 120 VAC powered smoke detectors to work with security panels?

I thought most smoke detectors that were installed for a security panel were 12 volt operated and provided a contact closure to the panel's zone (i.e. different from traditional smoke detectors). I'm not an expert at all on this one though.
 

Squintz

Senior Member
I can also add the from my recent research of electrical codes the NEC 2005 codes require you to have your smoke detectors wired from the homes source. This is vague and is usually left up to the inspector to determine if putting a transformer in line to step it down to 24 or 12 volts is still considered from the houses source. I would check with you local board of electricians before you buy them just to make sure that when you go to sell the house (If you ever do) that you will pass the inspection.

Not something most people worry about though
 

AutomatedOutlet

Senior Member
Well, they do make smokes that are 120 VAC powered with output contact relays. It really doesn't make much sense to me though. I would rather have my smoke sensors on the back-up battery power from the alarm panel.
 
I will check with my inspector. They are pretty easy to get along with so I dont see a problem as long as they are all connected (all go off if one goes off). Would it be possible to wire the first SD in the line to the alarm panel and then use my existing wiring of 14-3 to the rest? Or, do they all get wire to the alarm panel seperately?
 

AutomatedOutlet

Senior Member
I think the best way would be to wire them all together with cat5. As far as connecting to the panel, you can either wire them separately or together - either way.
 

jrfuda

Active Member
The home I live in has the remnants of a security system. The owner or previous owne had one installed, but the control panels are no longer there (although the other stuff is).

the smoke detectors in the house appear to have all been linked to the panel and are powered off of 120VAC, but still need 9V batteries in them as backups.

Perhaps that's how the other detectors that use 120VAC get their backup power since they are not wired to the panel's 12 or 24VDC.
 

dsmithut

Member
I connected my M1 to my Firex interconnected smoke detectors using the firex relay that they sell to activate strobes for deaf people. It was about $13 if I remember correctly special order at home depot. I would assume other brands would have similar relays.

I just bought their combo smoke/CO detector and hope it too will inteface.
 

Spanky

Senior Member
dsmithut is right. You will need a relay installed into the 120VAC smoke detectors and run its contacts back to the control. The relay separates the operation of the 120 VAC smokes from any other equipment for UL. Some smoke detectors do not have the capability for this relay, so make sure you check for it before you buy the smokes.

Unfortunately, the 120 VAC smoke detectors do not allow the smoke detector fire alarm verification feature in the controls to work because the control can not turn off the smoke detectors and turn them back on. The verification routine powers down the smoke detectors when they detect smoke for 20 seconds. Then powers them back up and if smoke is detected again within 30 seconds, triggers the fire alarm. It keeps the fire department from showing up when you burn the bacon.

One nice feature in the two wire, 12 VDC smokes from GE is the Clean Me feature. It tells you when the smoke chamber is dirty from dust and needs to be cleaned. The M1 and EZ8 supports this feature.

Like what was said earlier, check with the local inspector to see what he will allow.
 

upstatemike

Senior Member
One nice feature in the two wire, 12 VDC smokes from GE is the Clean Me feature. It tells you when the smoke chamber is dirty from dust and needs to be cleaned. The M1 and EZ8 supports this feature.

I am a big fan of two wire smokes in general and really like the idea of the "clean me" feature but I need more than 1 fire zone. Any chance the M1 will support multiple zones of two wire smokes in a future update?
 

Spanky

Senior Member
You can put multiple two wire smoke detectors on a two wire smoke zone. Currently, zone 16 on the M1 and zone 8 on the EZ8 supports two wire smoke zones. The reason there is not more is because there are hardware differences between a two wire smoke zone and a regular 4 wire smoke or burglar zone.

If you need more fire zones, you will have to use 4 wire smoke detectors on any of the M1 or EZ8 zones. The downside is that there is no "Clean Me" on a 4 wire smoke zone.
 

bfisher

Active Member
I noticed the recommendation of wiring with Cat5... I thought there was a requirement they were wired with special fireproof wire (sorry - don't know the specifics, but saw this somewhere). Is this not true? (this is a future project, so I haven't researched it much yet)
 

upstatemike

Senior Member
I don't know about fireproof but most jurisdictions require that fire alarm wires have a red jacket to distinguish them from other wires. Also all fire wire I have ever seen is solid conductor rather than stranded but I don't know if that is a requirement.

Because fire alarm wire is most commonly available as 4 conductor it works best with 2 wire smoke detectors because you can use 2 conductors as the zone feed and 2 conductors as zone return. This prevents you from having to fish 2 seperate wires up a wall to a detector.
 
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