Re: Far Side Chat -- Fire Alarm Code Issue

["Frank Olson" <feolson@xxxxxxxxxx>]

"Frank Olson" <feolson@xxxxxxxxxx> wrote in message
news:xe0ce.1147651$6l.1023901@xxxxxxxxxxx

> No Robert.  And I know where you're "steering" the discussion too.  There
> is no connection to any low voltage equipment at the time the building is
> inspected for occupancy so your next "argument" won't work, but even if
> there was there wouldn't be a problem.  There are many instances where low
> voltage and 110VAC cables are in the same electrical box (most FACP's are
> good examples).  There's no way for you to connect a 24VDC door strike or
> strobe light (or your residential security panel) to a smoke alarm with a
> built-in relay (or compatible relay module) for instance, without "mixing
> voltages in the same box".  There is no US Code prohibiting such a
> connection (or situation).  The only proviso is that the high voltage and
> low voltage cables have to have a "physical separation" and/or be clearly
> marked as such to prevent confusion.  Usually the "separation" is just a
> small piece of "Bakelite", but I've seen examples where there is nothing
> and the wires are just individually tagged.


Addendum:

Another good example is the System Sensor 1451A smoke detector and 406B
relay base we just installed that's part of a Notifier 5000 system.  The
relay's hooked up to the elevator alternate floor recall.  When activated
(main floor lobby), it sends the elevator to the second floor (so that
anyone riding the elevator when the fire alarm is activated won't come down
into an area filled with smoke).  The terminal strip for the relay has a
hard plastic barrier with the words "high voltage" on it.  The relay itself
is rated at 120VAC and 1.0 Amp.  For some reason I can't fathom the contact
rating in the instructions is different for Canada, so after we consulted
with the electrical inspector, we installed a 24VDC "ice cube" relay in a
separate enclosure (with contacts rated at 120VAC 5.0 Amps) and brought the
110VAC into that.  The relay base on the detector trips the ice-cube through
the 24 VDC aux power from the panel which activates the elevator recall.  It
would have been much easier to simply wire the 110 straight to the relay
base but for the quirky change in contact ratings that happened when the
base crossed the border from the US to Canada.  Weird, huh??

Which brings up another one.  On the Mircom 1000 series FACP's, the 8-relay
module has contacts rated at 24VDC.  When you have to wire 110VAC door
holders up to the fire panel (so they release on an alarm), you also need to
use a separate ice-cube relay with the proper contact ratings which means
you have to find room somewhere in the enclosure (or use a separate box
again).  Why the heck can't they come up with a relay board with the
appropriate voltage ratings.   I miss the old Mirtone 790 and Edwards 6500
panels.  They didn't have this problem.