Re: 120 to 12v conversion



--
Regards,

PopRivet

Nope, not going to Vista. Why?
Simple: It offers me nothing I need nor
even want that I don't already have.
So, why switch? NOT gonna happen.
"Jimmie D" <GFENDER@xxxxxxxxxxxxxxx> wrote in message
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"Twayne" <nodoby@xxxxxxxxxxxxxxxxxxx> wrote in message
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"Twayne" <nodoby@xxxxxxxxxxxxxxxxxxx> wrote in message
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I have 4 flourescent stairwell lights I would like to convert to
low
voltage LED.
The existing lights are on a dedicated circuit. What I would like
to
do is mount the low voltages power supply at the breaker panel and
use the existing wiring and 3 way switching to distribute the
12VDC
to the LED lights. The circuit draws olny about 400ma of current
on
the 12v side so I intend to place a cartridge fuse on that side.
Also I would like to place a fuse on the 120VAC side of the power
supply as I have seen these power supplies smoke without tripping
a
15 amp breaker. Are their any code problems with doing this

Jimmie

To actually answer your question which all but one of the
blatherskites seem to have not been able to comprehend, YES, there
could be code problems. The best thing to do is figure out just
how
you want to do the installation, and then call your local Code
Enforcement Office to see whether it would meet code or not. You
don't have to give them name & address; just tell them it's
something your'e considering and you want to know if it'd pass
codes. Keep a record of the call also. Forget all the mA figures
etc. you see in the posts so far; they're
only based on guesses. Check the fixtures for the specific
voltages and current each needs. Then go to RS or someplace and
find a regulated power supply for that voltage with the full rated
current output. You don't want just a wall wart as someone
mentioned because if you disconnect one lite to work on it, or it
goes bad somehow, the output voltage rises, probably to too high a
value, depending, and possibley ruining the remaining light. If
you
can't figure it out, then you might have to look for someone with
the background and experience to assist you; so far it sure doesn't
look like it's this group! --

Regards,

Twayne

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www.openoffice.org

Please respond to the newsgroup, not to
my e-mail, so that all may benefit. I do not
always respond to newsgroup e-mails.



I guess I failed to mention the LED lights came with a wall wart
rated to supply all 4 of them. I am not crazy about this type of
supply. I have given some thought to replacing it with a regulated
supply something like a SOLA 12 volt supply. We use these at work
and
many of them are well over 20 years old. I am thinking powersupply
in
a metal box, box fastened to my entrance panel with a couple of
close
nipples and nuts

If it came with a wall wart new, then that wart is designed for the
application and shouldn't be any problem, really. Replacement may be
a problem if it ever goes out on you, but ... it's probably fine to
use.
I guess the main thing would be that whatever gets used has UL or
CSA approvals/numbers and if it's a digital switching supply, FCC
Part 15. Theoretically you shouldn't be able to buy anything that's
not rated thus, but ... anything is possible.
The other aspect is the the UL/CSA/EU ratings are for the
application you have in mind. Modifying it in any way removes the
safety assurance (fire/personal) aspects of the markings regardless
of what they are.
The metal enclosure might be a bit of overkill, and could be real
bad it if restricts air flow from a cooling viewpoint. Some supplies
must not be encolsed, some can be; it will be part of their specs.
I do mount my battery chargers, things like that which might run
unattended with a metal place between them and any flammable mounting
surface and sometimes an "L" overhead if there are flammables within
a few inches of it. Obviously it's located where looks aren't a
concern.

Again, the main thing to do is probably check with local code
enforcement to see just what your own local codes say specifically.
Purchase what you need so you won't have to modify it.
--

Regards,

Twayne

Thanks Twayne, I did check with them today, and they said my
installation plan would meet code. They even said the added fuse on
the 120vac side was overkill but a good idea as well as the output
fuse. The one thing I added later was a low voltage transorb
downstream of the 12v side fuse. If it ever conducts the fuse will
instantly blow.

Jimmie


Sounds great; good thinking.



.

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