| Jeff Miller 2007-04-12, 3:25 am |
| Hi, I'd like to retrofit my duplex with AC powered smoke detectors, the kind
with common signal wires. I'd like to wire them together both within and
between my two flats (renters upstairs).
Now I know that, for example, you cannot run a separate ground wire to a
two-pronged outlet in an attempt to retrofit it with a three pronged outlet
because all of the conductors to the outlet must be bundled or run together.
That's why replacing a two-pronged outlet with a GFCI outlet is the only
technique permitted by code.
But I wonder if the smoke alarm common signal wire counts as a conductor in
the same respect. Can I run that wire along the ceilings and walls to make
the interconnects? If so, are there any requirments for protecting the
signal wire from impact/abrasion? Deos the wiring I use for the interconnect
have to be insulated to the same voltage standard as the supply wires to the
smoke detector, or can I use LV (even telephone) wiring? I have heard that
if LV and HV conductors are mixed in the same box, the LV wires must be
insulated to the same standard as the HV wires.
Is there any gaurantee the signal wires are LV, in the first place? I
suppose probably, since the system is designed to work on backup batteries
if AC power fails.
Is it possible some of the answers to my questions vary by manufacturer,
ultimately resting on following the manufacturer's instructions?
X10's site (www.homecontrols.com) has a suggestion for using X10 to achieve
much the same end. I would imagine this solution relies on X10 plug-in alarm
annunciator modules, which I've seen used for security. In any case I'd be
hesitant to use X10 for the purpose due to the possibility of false alarms
across premises. I've had problems with X10 in the past due to this issue.
Of course in theory if you get false alarms you can just switch channels,
but there's no guarantee you'll switch to a free one. I think there are
things you can do to isolate but, well, I'm just not that into X10.
Thank you in advance for your advice!
-Jeff
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