Blueline Ballast too bright?

[Cnidariaus]

I recently replaced a 4 year old blueline 250 watt ballast. The old one started blowing the GFI circuit breaker. I have two 250 watt ballasts now driving two 250 watt XM bulbs (20,000K). The bulbs are both new and the reflectors are also new. I noticed that one bulb looked biighter than the other so I switched ballasts. The result is that the ballast seems to drive one bulb brighter than the other. I don't know if one ballast is too bright ( if too bright is possible) or the year old ballast is too dim. I checked with a lux meter at constant distance and the bright one is approx. 1900 and the dimmer one is 1100. Champion was very nice and said they would be glad to replace it. But which one should I replace? My gut says the dim one but could I be overdriving with the bright one? Any ee's out there that can comment?

 

[Arik]

That's tough to answer, because we don't have a baseline number to compare it to. I would use a amperage meter to see how much each ballast is drawing, and then compare the results to Blueline's specs on the ballast. That way you know for sure which one isn't performing correctly.

 

[chrisguy]

If you check out some of Sanjay's ballast reviews, I believe he has data that points out that different ballasts do infact drive a bulb different, creating brighter (or dimmer) light.

Sounds to me like it's normal based on the fact that you have 2 different ballasts. I'm assuming they are different makes. Might not be true.

 

[Arik]

There should be some variance between the same ballasts, but the numbers you posted are REALLY different.

 

[Cnidariaus]

Thanks for the input. I will have access to a 3rd newish 250 watt ballast and I will test its output with both lamps and see which one the 3rd one conforms to. I'll try this tomorrow and will report back.

 

[Gary Majchrzak]

OK. Ballast wattage and make is the same: Blueline 250w electronic ballast.
Are both wiring harnesses the same length?
I'd allow both new halide lamps to burn in and/or hook up an amp meter to both ballasts before sending one back to Champion.

 

[Cnidariaus]

Both wiring harnesses the same. I ran all 3 ballasts tonight into the same bulb pendant housing and measured lux in air at water level. Newest ballast April 06 = 1780, Ballast from Nov 05 = 1819, oldest ballast about 15 months old (the dim one) =1120 The lesson here for me is how useful a light meter is to evaluate ballasts and bulb aging. I am going to send the dim one back.