Re: 2 wire vs 4 wire Smoke allarms

[Frank Olson <Use_the_email_links@xxxxxxxxxxxxxxxxxxxxxx>]

Kurt Delaney wrote:

>>110V are different from 4 wire which are 12V or 24V.  you can hook up
>>relay from 110V to OMNI but that is against code.  The relay is not listed
>>for connection to alarm system. It appears condo has you in  a Catch 22

What's the difference between the relay in a 110VAC smoke alarm and a
24VDC smoke alarm?  Nothing.  There is no "code violation" as long as
you maintain a clear physical separation between the 110 and the low
voltage connections to the panel.  The only thing you might wind up with
is an alarm every time you have a power failure because in most 110VAC
smoke alarms the relay activates for a few seconds when power is
reapplied.  I do agree that the *best* method involves the installation
of 12 VDC smoke alarms (which means you'll wind up with two units next
to each other in most applications).  On my own system I've run 18AWG to
all the 110VAC smoke alarm locations, and after the final electrical
inspection, replaced all of them with two wire smoke alarms connected to
the alarm panel.  The 110VAC wires were marretted off and stuffed into
the back of the box.