Re: Smoke alarms (was Re: For Graham, Rober, and Coppernob)

[robertlbass@xxxxxxxxxxx]

> do you mean resi burg / fire panel?  because
> that is what we are talking about.

That is exactly what we're speaking of.  You might want to take note
that combination fire/burglar alarm control panels used for fire
detection in private residences within the USA are required to carry a
UL listing.  Specifically, they carry the UL 985, "Household
Fire-warning System Unit" listing.  Most control panels actually carry
more than one listing.  That is why manufacturers spend tens of
thousands of dollars getting them listed.  Without that listing the
local inspector will reject the panel and no alarm company would buy or
install it.

Note: Not all inspectors care a hoot about burglar alarms.  However,
the vast majority will insist upon code compliance when it comes to
fire detection.  While interconnected 110VAC detectors can and do meet
the code requirements if properly located and wired, once they are
connected to an alarm control panel they become part of a fire alarm
system.  Do so using a non-listed panel and you have a non-compliant
fire alarm system.

This is somewhat analagous to DOT requirements for automobiles.  You
are required to have (among other things) operable brakes and a
regulated exhaust system on passenger vehicles driven upon public
highways.  Now suppose you decide to build a four-wheeled, engine
driven vehicle without submitting it for DOT testing.  The thing has no
brakes and the exhaust pipe spews clouds of gray smoke.  When the
police pull you over will you claim that your car is exempt from the
state vehicular code because it's home-made and it doesn't have brakes,
a muffler or a catalytic converter?  Of course not.  That would be as
ludicrous as claiming that a fire alarm system doesn't have to comply
with NFPA72 because you built it yourself and you connected non-listed
stuff to it.  It's still a fire alarm system -- an illegal one.

By the way, the listing for residential burglar alarm control panels is
UL 1023, "Household Burglar Alarm System Units".  Even these should be
listed units though some inspectore don't care.  Insurers often ask if
the components are all UL listed when considering a premium reduction.
They don't want to know it the unit complies as a UL listed toaster.
They're asking for UL listed alarm components.  For clarity, this is
not the same as requiring a UL *certificated* installation.  That's
another matter entirely.

There is another issue with connecting 110VAC smoke detectors to an
alarm control panel.  Code requires that all parts of the system be
connected according to the manufacturer's instructions.  Every listed
panel sold in the USA requires that smoke detection circuits be
supervised.  There can be no "T-taps" in the wiring.  There must be a
supervisory device connected to the last smoke detector (the one
farthest from the panel).  If the detectors are not 2-wire, the power
to the detectors must also be supervised so that no detector can be
disconnected without the control panel sensing and indicating a
"trouble" condition.  With these relays there is no way to comply with
these requirements.  You cannot supervise 110VAC wiring to the smoke
detectors.  If one becomes disconnected the others -- and the relay--
will not know it and will not indicate it to the control panel.

Furthermore, because the relay relies on 110VAC to operate, the panel
will not sense a fire if the power goes out.  Unfortunately, the
electrical system is often one of the first things to fail during a
fire.

Regards,
Robert L Bass
Bass Home Electronics
www.BassBurglarAlarms.com