Robert11 wrote:
Hello:

About to buy a few Kidde P12000 Smoke alarms.
The AC wired type, with both ionization and photocell.

Looked at their on-line instructions, and was surprised
to see that they say to install on circuits that are NOT
GFCI protected.

Seems surprising.

Anyone know the reason why ?

Thanks,
Bob
-----------------
" Make certain all alarms are wired to a single, continuous (non-switched)
power
line, which is not protected by a ground fault interrupter. "


One reason that I can think of is that their products work better when
they have power and GFCI-protected circuits are more likely than ones
that are not to be continuously powered. A minute circuit fault that
will never be noticed in a regular circuit may well kill one with a GFCI
-- exactly what you want most of the time but not so with an alarm.
--
John McGaw
[Knoxville, TN, USA]
http://johnmcgaw.com