CO Detector wiring

[chrisexv6]

One of the last steps in my install is to add CO detectors. I know which ones Ill be using (System Sensor), but I havent seen an answer to what wire to use.

Do they need to be on fire wire (red, 18/4 or even 18/6 if I make it one loop) or can it be non-fire wire. System Sensor specs gauges from 22 to 14 so if it doesnt need to be fire-wire, it looks like standard 22 ga. contact wire would suffice.

Thanks.

-Chris

 

[gizzmo]

I would recommend 18 gauge on any life safety circuits. Squirrels can go through 22 like butter.

Sent from my Galaxy Nexus

 

[cooljoe04]

I would use 22/4 for runs less than 100', more than that I would run an 18/4 but thats personal preference. It doesn't need to be solid or fire wire. I agree that 18ga would give a better protection from animals than 22ga, but I also presume this is inside your house and that you don't have a problem with squirrels getting into your walls or attic. lol

 

[newalarm]

In the city, we don't have squirrels, we have rats... and they eat everything.

 

[Del91574]

No mandates for wire AWG, construction or color, and actually the same goes for fire wire, it's not necessary to be red.

Personally, I prefer my life safety devices, strobes and speakers to be solid if at all possible. I've seen way too many people break off many strands of stranded wire under terminals and wire nuts, but that's me.

I think 18 AWG is somewhat overkill, most CO's draw trivial current, and wire distance and voltage drop isn't a huge factor in most installs.

 

[gatchel]

100mA on 22 awg wire at 100 feet is around .2 to .3 volts at 12vdc, IIRC.

The CO1224T draws 20 mA in standby and a max of 75 mA in test mode.

Run them at 24vdc and the drop will be less.

22 should be fine.

 

[chrisexv6]

Thanks for the input.

I was asking more along the lines of code (not knowing that red isnt REQUIRED, and there is no AWG specified for code either)

It will be solid 22/4 and 22/2, as thats what ive used for all of my alarm contacts and have plenty left over. What I *didnt* have a lot left over of is 18/4 which is why I asked.

22 ga it is! Now just gotta get the detectors and some motivation to run more wires.

Thanks again.

-Chris

 

[Del91574]

All you really need is a 22/4 to the detector, assuming a single detector/zone.

If you daisy, then more wires are needed to maintain the supervisory contacts.

The CO1224's documentation spells it all out, but if possible, I would drop each CO on it's own zone.

 

[chrisexv6]

All you really need is a 22/4 to the detector, assuming a single detector/zone.

If you daisy, then more wires are needed to maintain the supervisory contacts.

The CO1224's documentation spells it all out, but if possible, I would drop each CO on it's own zone.

Thanks.

I was planning on daisy chaining them, but will look at a detector per zone. Im running low on zones, though, so daisy chaining would have helped with that.

 

[mwheeler42]

Thanks.
I was planning on daisy chaining them, but will look at a detector per zone. Im running low on zones, though, so daisy chaining would have helped with that.

You can daisy without issue, but as DEL said, you need 4 wire to the first detector and then 6 wire to all subsequent detectors on the chain for power supervision.

 

[gizzmo]

Don't forget you have a five year end of life relay that opens the circuit. I can't remember if it opens for power loss but I'll bet it does. I would pull 6 cond for the loop if more than one device.

Sent from my Galaxy Nexus

 

[chrisexv6]

Yep, understood I need 4 wires to the first and then 6 to the rest (read it in the System Sensor manual)

I also have leftover 22/2, so Id go 22/4 to the first detector, then 22/4 + 22/2 to the second, then third, etc.

Trying to figure out what the loop will be, since its less complicated than my smoke loop being that there will probably be only 3 detectors vs 8 or 9. That may determine if I go ahead and just use one detector per zone.

 

[Del91574]

I try to go individual on the CO's because of a bad experience myself and a bunch of other installers had with the ESL CO's and faulty sensing elements and no-alarm issues....had to replace tons of them (recalled) and trying to narrow down an intermittent chirp on the affected units or in a house with a lot of detectors with the same basic type of sounder is a nightmare, since they don't necessarily latch in alarm like a smoke.