We have a small parking area with metal halide light fixtures. They are 175 watt med base, GE brand "Garage Gard". They are on and running 24/7. The mounting is surface on the ceiling which is about 30 feet high. To high if you ask me for 175 watt.

There is no maintenace of any type done except changing bulbs when they burn out. Last change out there were 3 exploded out of 5 changed. One melted the plastic diffuser leading to a fire department call.

The boss wants me to drop them somehow to improve air circulation so they will not overheat.

Based on info that I have read the best way to stop explosions is to cycle them an hour a week and to change them out around end of life.

Anyone else have trouble with exploding bulbs?

To sum up, how important is it to cycle the bulbs if they burn 24/7? Also how important is it to change the bulbs at the published end of life?

My biggest fear is that we will do all the above and they will still explode and I will look stupid.

I have tried to find something in writing on the net preferbly by NEMA or something offical like with no luck.

drillman —

That is a very good question that we all should be reminded of. See moderator Don’s comments with OSHA & NEMA links at: exploding metal halide lamps and Hot Lamp!

{Be careful out there.}




[This message has been edited by Bjarney (edited 07-10-2004).]

HID's aren't my pet area, so it's probably a stoopid question; but any chance the bulbs were "bare handed" during purchase / storage / installation? I've heard of similar failures if the bulbs weren't clean before being heated...

I always assumed that barehanding was to be avoided w/ halogen lamps not hid lamps.

I've seen some with warnings not to touch with bare hands, most don't have the warning. I don't make it a pratice to touch them anyway. The smaller ones, and Zenon ones definately don't touch! Some will pop after five minutes... And your fingerprint is burned into the glass next to the cracks.

I bare hand HID bulbs all the time and rarely see a blow up. I do believe the warnings posted on the packaging that says the bulbs have a lifespan and that they have to be cycled off for a period of time if left on 24/7.

I wonder if a change in brands(GE to whatever) would make any difference?

The larger mogal HID's seem to be OK, no warnings... The smaller they are it seems to be more of an issue. Just got done with some Lightoiler track with HID fixures.

Had to rubber glove all of them, or clean with alcohol. Still had a few of the 150 of them pop.
http://www.lighting.philips.com/nam/products/hid/p5575.php
Read the bottom of this page...

Another story about HID's, this good! We do showrooms for furnature and antique dealers, and for some reason the lighting designers haven't figured out that this type of lighting isn't Kosher for items that color fade. We've done a bunch of showrooms with them recently, all complain that it "burns" the furnature. One place had a $50,000 table, with a perminent place setting burned into it from these!

The UV is sooo high, I would imagine, that prolonged exposed could lead to skin cancer...

[This message has been edited by e57 (edited 07-12-2004).]

Re: http://www.lighting.philips.com/nam/products/hid/p5575.php


If this weren't included as an operating instruction I would have got a zero on that test.