I have worked on pole lights before but never before yesterday have seen a pole light fixture lens burst after replacing a lamp. The fixtures in question are about 30 feet up, 1000 watt Metal Halide and the lamps are vertically mounted BT37s. The fixture is the kind that you access by unscrewing four philips head screws holding down the square lit and lifting the lid off. This is a pretty common type of fixture at big box stores. The horizontally square lens fits into the bottom of the fixture and is shaped into a vertically-distended hemisphere.
A few minutes after installing a new lamp into a fixture, turning it on to make sure it was burning normally, and then driving off to the next outage, the fixtuire's lens burst showering cars below with shards of glass about the size and shape of large french fries. The lens didn't fall out in a one or several large pieces and break on the ground, it burst in place with a loud sound, (I was told: I was a couple of minutes away from it when it happened). It scared the Kee-rap out of me because I'm always worried something I work on could fall and hurt someone, as this falling glass could have but luckily did not. The lamp continued to burn, but without a lens, and it seemed to be burning normally so I have no reason to suspect that some malfunction of the lamp caused the lens to break.
Anyway, I can't think of anything I may have done wrong on this job to make that lens burst. The fixture calls for a bt37, and that's what I installed. The only think I can think to suspect is that our hot, very muggy weather allowed moisture to infiltrate the glass of the lens, and the lens burst as the result of the lamp's sudden heat. But, I have worked on plenty of parking lot lights before and nothing like this has ever happened to me. The fixtures are old, I don't know if that matters.
Has anyone here experienced this, or can you suggest to me something I may have done to cause the lens to break?
Tom
A few minutes after installing a new lamp into a fixture, turning it on to make sure it was burning normally, and then driving off to the next outage, the fixtuire's lens burst showering cars below with shards of glass about the size and shape of large french fries. The lens didn't fall out in a one or several large pieces and break on the ground, it burst in place with a loud sound, (I was told: I was a couple of minutes away from it when it happened). It scared the Kee-rap out of me because I'm always worried something I work on could fall and hurt someone, as this falling glass could have but luckily did not. The lamp continued to burn, but without a lens, and it seemed to be burning normally so I have no reason to suspect that some malfunction of the lamp caused the lens to break.
Anyway, I can't think of anything I may have done wrong on this job to make that lens burst. The fixture calls for a bt37, and that's what I installed. The only think I can think to suspect is that our hot, very muggy weather allowed moisture to infiltrate the glass of the lens, and the lens burst as the result of the lamp's sudden heat. But, I have worked on plenty of parking lot lights before and nothing like this has ever happened to me. The fixtures are old, I don't know if that matters.
Has anyone here experienced this, or can you suggest to me something I may have done to cause the lens to break?
Tom