Re: Can't Mix Smoke Models....really?

[Nomen Nescio <nobody@xxxxxxxxx>]

Mike said:

>The literal intent here is that the test only includes one make and
>model at a time.  No one has paid UL to test different combinations of
>devices on the same control.

I suspect this is a non-issue, since I haven't seen control panel
instructions that say, "Use up to 7 Brand A two-wire smokes per zone, but
you can use 15 Brand B two-wire smokes per zone."  It's always "Use any of
the following smokes, and use a maximum of X per zone."  Which leads me to
believe the specs have to be pretty much identical.

I remember that UL has "compatibility identifiers" for two-wire smokes; the
usual ESL/System Sensor two-wire smokes are compatibility identifier A, as
I recall.  I don't have a copy of UL 268, but perhaps the answer lies
there.

In any case, I still don't see where it says we can't mix and match smokes
that are all on the approved list for a particular control panel.  The 268
and 864 standards don't require a single brand of smoke, as far as I know.
NFPA 72 doesn't require it either.  The panel manufacturer's instructions
don't prohibit mixing and matching either.  And as others have pointed out,
it is necessary during the life of a system to replace older smokes with
newer models, unless you're going to claim that all the smokes have to be
replaced whenever one goes bad.

You may consider it to be the "literal intent" of the standard, but I think
that's guesswork on your part.

If you know any engineers at the panel manufacturers or smoke detector
manufacturers, it would be interesting to hear their views on this subject.

>Before using common sense in this case, buy errors and ommission
>insurance.

Don't leave home without it!

- badenov