Metal Halide Lamp/ballast

72chevy4x4

if a metal halide 250w lamp is placed in a fixture with a 400w ballast, what would happen?

mdshunk

You'll get sucked into a super massive black hole.

72chevy4x4

I looked at the sticker on the fixture and it's a Cooper MHQF-GS/C73-400. The label is a bit worn, but looks to call for a M59 lamp.

The lamp which was installed (and not working) is a M58 250w...would a smaller lamp typcially damage the ballast?

TrblShooter

Read this about 10 mins ago...and still laughing

Magnettica

I'm not positive, but I believe that a 400 watt ballast would be good enough for a 250 watt bulb. I would install the 400 watt bulb as the ballast indicates.

Do you have enough microfarads?

72chevy4x4

caps were apparently fine-new lamps and everything is operational

didn't hear from anyone who shared knowledge, so here it goes. 8 250w HID's were installed in 400w fixtures. some of the lamps began to fail within 2 weeks; within 3 months 75% of the lamps failed with one of those having a random start issue (not heat related).

Magnetica referenced cap's-not sure if it was a joke or not, but the caps for a 400w fixture are larger than a 250w fixture. looking at a lamp, it appears to have a small inductor inside...can anyone confirm that? If so, the lamp could have altered the load on the ballast and been burned out with too much voltage. Maybe this is a question better suited for an EE.

Eddy Current

Use only the bulb required for the ballast. Type of bulb is printed right on the ballast. Forget about what the fixture says, the ballast may have been changed. Using a different wattage of bulb may work for a short time, but it's not right.

Same deal----> My wife could do the brakes on my car and they might even work for a short time, but it's not right and should be done right the first time!

Magnettica

My comment on microfarads was serious but I could see how u might think I was joking around (capacitance is measured in farads). Have u checked the capacitor to see if it's working correctly? Maybe you have some sort voltage drop issue that hasn't shown up till now.

CNC

Bulbs need to be matched to the ballast, the ballast specs a bulb for a reason, but as magnettica said, do a capacitor test.

this is good material

http://www.advancetransformer.com/up...ting-guide.pdf

SonoranShocker

I thought it opens the doorway to the magical land of Narnia?!

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Electric_Light

MH lamps are expensive, labor is expensive.

Lamp/ballast mismatch is the leading of premature lamp failure not caused by product defect.

Best to do it right the first time at higher cost, than doing it right the second time at the lower cost of hack job + the cost of right job.