metal halide lamp life

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nizak

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Has anyone here ever taken the time to record or chart bulb life? I am reading on the manufacturers specs that 100 and 175W medium base MH lamps have 8,000-10,000hrs life expectancy. This seems like a long time, anybody ever looked into this? Thanks.
 
I believe the manufacturers for MH and sodiums,

of course, if they are used for temp const. lights or some other hard use, expect 1/4 to 1/2 of the life (if that).

As far as what manufacturers write on incandescent bulbs ? Well, they are a bunch of big fat liars.


10000 hrs isnt that much for, say, a parking lot bulb though (3 years or so at 8 +/- hrs/day) (IMO)
 
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CFL's and MH lamps are great, and with a few exceptions thats all I use in my house. Well Ok the other one is Halogen, not MH, but their life span is also up there.

Whats wrong with considering an average of 12 hours a day of lamp useage againest your numbers gives 1.8 years and 2.2 years respectfully.

8000 hr ? 12 hr /day = 666 days

666 days ? 365 days / yr = 1.82 yr.

And I'm only running 25 Watt CFL's, 60 watt Halogens...

I bought in a long time ago in the lamp techno craze, I've bought the multi packs but the lamp will sometimes get broken before being used... :rolleyes:
 
nizak said:
Has anyone here ever taken the time to record or chart bulb life? I am reading on the manufacturers specs that 100 and 175W medium base MH lamps have 8,000-10,000hrs life expectancy. This seems like a long time, anybody ever looked into this? Thanks.
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The lamp life of MH is relatively short compared to HPS which is 24,000 hours.

One thing to keep in mind with MH and any HID light source is that the lumen output gradually decreases over time, primarily due to electrode deterioration in the arc tube. This problem is particularly bad with typical probe-start metal halide. New pulse start and ceramic metal halide have made great strides in overcoming the problem of lumen depreciation.
 
Osram 70 watt single ended metal halide lamps last a year and a bit at work, lit 24/7 which is about 10,000 hours.
I change them when they start to change color, if run until electrical burnout they would last longer.
These are the lamps with a 2 pin ceramic base, not the screw base ones.
 
nizak said:
Has anyone here ever taken the time to record or chart bulb life? I am reading on the manufacturers specs that 100 and 175W medium base MH lamps have 8,000-10,000hrs life expectancy. This seems like a long time, anybody ever looked into this? Thanks.
Click to expand...

There is probably also a life expectancy chart that shows lumen maintenance over the projected life expectancy. Even though they claim the bulb will last 10,000 hours, they probably only claim it will have 60-70% of its original light output toward the end of its life.

I attached the spec sheet for the bulbs we use in our warehouse as an example. They are 400 W metal halide with a 20,000 hour expectancy. Check out the graph on the front page.
 
lamp life depends very much on the voltage supplied for them.

a 120V lamp running on 119V will last a wee bit longer than the same lamp running at 125V
 
All published Lamp Life values indicate the point at which 50% of a large sample of lamps will still work.
Most Group Re-lamping efforts try to replace all the lamps well within that timeframe.
Mark the date of installation on the lamp base with a sharpie.
db
 
A couple of manufacturers are now making LED parking lot lights. I think the life is rated at 100,000 hours.

And I think there is very little depreciation in the lumen output.

But, I haven't priced these. I'm sure they are a premium price. And I think they are more for the cooler climates (Midwest and above). I think they have shorter life in warmer climates like Texas and Floridia.

Steve
 
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