So, I’m now about to wire for combo smoke/co detectors in the upstairs…Q’s:
1. Any recommended brands–I plan on buy a photoelectric sensor.
2. When wiring to have all the alarms interconnected, do you suggest using 3-wire romex with the red wire being used to interconnect all the smoke detectors, or do you run a separate third wire (usually orange or yellow, I believe) individually? Any suggestions.
Thanks!
Replies
Nope, no specific brand recommendation for combo units. I keep the smoke and CO separate.
For wiring, I prefer to have each detector on the circuit of the room that it's in. I just don't like the idea of all the detectors on the same electrical circuit, even with the battery back-up. The detectors I use are battery/hard-wired, so if the power crumps the battery provides back-up.
As such, I use smaller gauge wire to daisy-chain all the detectors in the house together for simulataneous alarm sounding.
The code doesn't say anything about the detectors having to be on the same circuit. It only says that hard-wired units must be interconnected so that they all go off at the same time.
My preference is to put them all on the same circuit along with lights for commonly used rooms (e.g, kitchen) so that if the breaker should go off, it's more likely to be detected.
Rex Cauldwell's book shows an illustration where power is supplied to the first detector via 14-2 and then to the rest of the detectors with 14-3 with the red wire being the interconnect wire.
It would probably be best if the OP contacts his Electrical Inspector and find out what is the preferred approach for his/her town.
In my opinion, don't bother with the combo units - the CO technology in them isn't very sensitive
See msg http://forums.taunton.com/tp-breaktime/messages?msg=31507.7
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Sojourners: Christians for Justice and Peace
Thanks all for the good information--and thanks, Bob, for the useful info on CO detectors.
You need to verify what your local code is.
Many of them are required hardwired interconnected units. And if so they have to be on the same circuit.
And you need to use a 3wire cable. All wires for a circuit need to be in one cable or one conduit. (There is on expection and that is adding grounds to existing circuits).
Also lates codes they need to be in each bedroom (and other places). And the latest codes require ALL circuits in the bedroom to be AFCI protected. But a number of locals have changed that requirement.
Also some places don't allow anything else on the circuit with the smokes.
But where allowed I suggest that you have some commonly used light such as a hall or master bath on it. That way you wll know if the circuit is dead.
Thanks Bill,
My inspector says all smokes on one circuit, so that is what I planned. Smokes don't need to be wired together, but it makes more sense to me (safety wise) so that is what I'm going to do (with battery back up as suggested)...nothing else is allowed on the circuit per the BI. It makes sense to use 3-wire romex (with red being the connecting wire) for all the smokes, but I'll double check with the BI.
Here, all outlets (but not overhead ligt circuits) in the bedrooms must be AFCI, so that is as planned....of course GFCI in the bathroom.
Thanks for the info...
In codess an OUTLET is anyplace that you connect electrial utiilization equipment.That include receptacles, light fixtures, and smokes.An earlier version of the code only required the AFCI on the receptacles.Also I think that you misunderstood if they require all of the smokes on one circuit, but not interconnected. That does not make sense.
Edited 1/12/2005 9:03 pm ET by Bill Hartmann
the local code here is that they must all be on same circuit and a major light must be on the same circuit. I put my kitcern vent fan on it and the inspector had a cow.