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.

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

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?



"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

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

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.

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.


Reply to
Bruce L. Bergman

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