DIYbanter - Ping-Bruce

On Sun, 13 Nov 2005 12:41:05 GMT, Gunner Asch
wrote:

Earlier in this week, I picked up a couple apparently new outdoor
lighting fixtures. The old standby yardlight, with the photocell on
top. A UL sticker on the aluminum housing said HID..which I assume
means High Intensity Discharge.

They are all HID - you need to figure out what flavor and wattage.

The only markings are a UL sticker, and the photocell on top is a
Fisher-Pierce

The UL sticker code might be traceable back to a manufacturer, but
good luck prying the info out of UL. Fisher-Pierce is no help - they
sell photocells to anyone.

The only similar lights Ive ever had exerience with were mercury
vapor, years ago.

These are missing the bulbs, unfortunately. So what do I use for
bulbs? Id like to put up one of these in the back lot for when I need
some area lighting.

Got any suggestions on type, etc etc?

Need more information - you probably will have to take it apart to
figure out what lamp type and size it takes. Or stop by a local
outlet of The Borg and see if you can get clues.

Open the access plate under the lamp socket, pop the ballast
mounting bar out, and note any numbers or letters printed on the
ballast in white paint - they often don't put the entire part number,
just the significant digits and the maker's name.

If all else fails, the ANSI Ballast Code is a reliable clue - H38 is
100W Mercury, M47 is 1000W Metal, H36 is 1000W Mercury, etc. AIUI the
letter is the type lamp, and the numbers are the lamp operating
voltage. And since they sell the same ballast for H36/M47, the lamp
type affects the voltage needed.

If there's an ignitor on a bare circuit board or in a small
encapsulated 35-mm film can along with the ballast core it's probably
HPS, though there are newer (last 5 years or so) Pulse Start Metal
Halide lamps that you won't find in a cheap barn light. The PSMH
takes a different lamp base with the same screw shell and an extended
center tit, so they won't fit in regular mogul sockets and vice versa.

If it has just the ballast core and that's it, it's probably Mercury
Vapor, the old standby. If there's the ballast core and a series
capacitor with the lamp socket, it's almost certainly a newer Metal
Halide, though Mercury should work.

(Any fixture maker can add a power factor correction capacitor
across the incoming power line, but the cheap ones don't.)

You can often stick Metal Halide lamps in a fixture rated for the
same wattage Mercury lamp, but not always the opposite. Gotta check
the labels - newer MH fixtures are usually back-rated for Merc if
they'll do it, but they never marked old Merc ballasts for a lamp that
wasn't in wide use yet...

Mercury has a nasty habit, they burn for decades, but they fade out.
During their useful life of ~15,000 hours they lose about 25% of their
output and after that they just start getting dimmer, and dimmer, and
dimmer.... (Maybe 5W worth of light after 15 years - But it's still
out there sucking down 100W of power.)

Metal Halide hits ~15,000 hours and the inner arc tube pops.
"Replace Me." This is why you absolutely HAVE to run the dual-shield
lamps (with an inner Pyrex tube around the arc capsule) in open bottom
high-bay or barn light fixtures - if the outer envelope ruptures when
the inner does (and that's maybe 5% of failures) whoever is standing
there is going to get a red hot glass fragment shower.

-- Bruce --

--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
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