smoke detector wiring

18 zones for fire? smokes as aux alarm for intrusion? you ever do this before?

What's wrong with 18 zones? I like the idea of one per zone to make it very easy to diagnose. We have a 5000 sqft house and the layout is such that 18 detectors is appropriate using the placement guidelines supplied by System Sensor. Sure, I could zone a few of them in the hallways, but again, each on its own seems much more simple (expansion boards are cheap). Reviewing my post, I guess it is 14 of the detectors listed plus three heat only plus one optical detector (for end-to end coverage along the peak of a 30x60' great room with a 24' high barrel vault ceiling) for a total of 18.

As for the aux alarm - I was just curious... figured the more noise the merrier. Not to mention I suggested that I figured it was a no-no.

Have I ever done this? Nope. I do know that I'll figure things out and the final result will be a quality installation. I'll also run all of my final designs by the home automation and security company I'm working with, but I prefer to do the research on my time since I'm paying them on a consulting basis. They don't normally work this way but I'm "not an average DIY'er" (their words). In our (very small) town, we have electrical inspections only and I've got a friendly relationship with the inspector and working through things with him. I'm also talking to the local fire department about the setup as well.

Having lurked in this group over a year and having read a lot of historical posts, I figured getting a worthwhile response was about

50/50. My worst fear is that Robert Bass will reply, four people will quibble over some local jurisdiction detail and then the whole thing will be derailed with something about Bass being wanted by the FBI, MI-6 and the Florida BBB /sarc.

Constructive feedback appreciated!

I'm assuming the reversing relay is for interconnecting the sounders, in which case you'll need 6 conductors at each detector rather than 4. As far as conductor size, with 18 interconnected sounders, you should consult with the manufacturer for the wire size required for your total wire length and number of detectors. 18 guage fire rated wire is spec for the detectors- I don't know what is spec for your sounders. You're on the right track with EOL resistors and power supervision modules at each detector.

For what it's worth, if you could find Multiplex addressable detectors (instead of 4-wire) that work with your system, it would be SO much easier to configure and install, and probably cheaper. That way, you retain the ability to know exactly which smoke tripped, but eliminate a great deal of extra home-run wiring, relays, zone expanders, and power supv modules, and probably the need to physically interconnect the sounders. Multiplex wiring is a wonderful thing for any large alarm installation, for both fire and burg devices.

No, you shouldn't use the smoke sounders as aux signaling devices- use your smoke sounders as they are intended- fire alarm only. For a house that big, I would use an supervised Aux power supply, triggered from the alarm panel output, driving 1 or 2 "talking" siren drivers, which in turn drive 2 to 4 siren-speakers each in appropriate places throughout the home.

Here's a link to a good "talking" siren driver-

And some siren-speakers-

The reversing relay changes the polarity of the power causing all smokes to sound. I know that for the 2WTA-B we use an RRS-Mod since that smoke gets its coded sound from the relay.

We don't install too many 4wires but I think one relay would do it.

As far as using the smokes as an aux... there needs to a definite difference in sound between a fire alarm and a burglar alarm since, in the middle of the night, the two events require quite different responses.

You wouldn't want your 13 year old daughter climb> I'm assuming the reversing relay is for interconnecting the sounders, in

OR

You only need one RRS module on the smoke detector power wires. Even though you have zoned out the smokes they will all use the same power source so 1 relay is good. You will need one end of line supervision relay for each zone (18) of them. The reversal relay should be wired to a fire alarm bell/siren output. I would not use the sounders in the smoke detectors for burglary, although it is possible.

James B

Nothing wrong with 18 zones, just a bit of an overkill. No, I would not use the sounders in the smokes as aux burg sounder.

A big thanks to all of you for all the very helpful information.

Using 1 power supervision module at the control will only supervise the power supply itself- it will do nothing to supervise the wiring. The proper way to supervise power on 4 wire smokes is an EOL power supv relay. In this case, 18 of them...

You took part of James response out of context, while he stated that you would only need one reversing relay to activate the sounders, he also clearly stated that you would still need a supervision relay for each zone.

The complete text of his reponse is quoted below

"You only need one RRS module on the smoke detector power wires. Even though you have zoned out the smokes they will all use the same power source so 1 relay is good. You will need one end of line supervision relay for each zone (18) of them. The reversal relay should be wired to a fire alarm bell/siren output. I would not use the sounders in the smoke detectors for burglary, although it is possible. James B"

Doug L

I'm coming into this thread a bit late so pardon me if I missed something but you shouldn't ordinarily need 6 wires for the smokes.

Run smoke power for all smokes through a single reversing relay. Run the zone wire pairs to the detectors individually. When the panel goes into alarm from any smoke detector all detectors will sound.

Don't use the smoke sounders for anything but fire. You want their sound to mean one thing and one thing only -- fire.

I see that the "Winfixer" pop-up ad you're using has been modified to identify the viewers home country. There's a Canadian Flag in the upper right corner. You still haven't changed the "contact us" address information though... It still comes up as your old Pine View Circle addy.