Re: 24VAC UL FIRE Powersupply

[Frank Olson <use_the_email_links@xxxxxxxxxxxxxxxxxxxxxx>]

jewellfish wrote:
> On Dec 27, 6:28 am, Frank Olson
> <use_the_email_li...@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>> Duncan wrote:
>>> Does anyone know where to track down a 24VAC UL Fire power supply?  At
>>> this poin, I don't care how many amps it has.  None of the "big names"
>>> have them...
>>> Thanks
>> If all you're looking for is 24VAC, I would imagine any UL Listed
>> Transformer will do.  I do know that a large number of "24VAC" fire
>> alarm systems are out there.  Most I've seen use a standard
>> off-the-shelf transformer in whatever flavor best suits the installation
>> (current wise, etc.).
>
> I just have to ask, "what are you going to do with this 24 volt ac
> transformer that you need it to be UL listed for ( I assume
> commercial) Fire use?
>
> Regards,
>
> Bill

There are a number of older non-coded fire alarm systems out there.
Edwards made more than a few.  They use 24VAC (or 12VAC) with a 12VDC
non-rechargeable (and unsupervised) battery.  They also used a three
wire system with the "common" for both the bells and pull stations/heat
detectors.  Another well known manufacturer (at least here in Vancouver)
was Pacific Protective Systems.  The units fulfilled a basic need but
advances in technology made them all obsolete pretty quickly.
Now-a-days unless the AHJ absolutely insists on replacing the units with
a supervised fire alarm system, the "old workhorses" stay pretty much
where they are.  As long as they pass the annual inspection (ring the
bells when required) all we can do is recommend the customer consider
upgrading.  We recently had to replace an annunciator on one of the
Edwards units we service.  Parts are no longer available and there's
nothing "off the shelf" that will work, so we had to build one
ourselves.  We made it as a ladder graphic (which is far better than the
"presentation" they had originally).  We also used LED's instead of the
incandescents (each of which was individually fused) and prone to
failure due to weather (unit was mounted outside and we're living on the
"wet coast").  The only things the AHJ insisted on (in addition to
identifying the individual floors) was an "AC Power" LED and a "lamp
test" button (which the old annunciator didn't have).  Took a bit of
"doing" but we used the schematic Edwards provided to design the circuitry.