# metal halide question



## hojimoe (Mar 7, 2008)

Just wondering if MH ballasts are backwards compatible? it would make sense, but wanted to double check - google didn't give me a good answer lol..

Can I use a 175W bulb in a 400W ballast/fixture? that's what I want to know

thanks gals and guys!


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## moon (Mar 11, 2006)

The short answer is NO. Ballasts are designed as current limiting devices. a 400W ballast will draw a higher current with a 175W lamp and possibly shorten the life of the lamp.


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## hojimoe (Mar 7, 2008)

moon said:


> The short answer is NO. Ballasts are designed as current limiting devices. a 400W ballast will draw a higher current with a 175W lamp and possibly shorten the life of the lamp.


perfect, the type of answer I WANTED!  thanks moon


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## hojimoe (Mar 7, 2008)

can you put a lower wattage PC lamp into a higher wattage PC fixture? i know you can with flourescents but with power compact flourescents?


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## moon (Mar 11, 2006)

CF lamps operate on electronic ballasts. These are quite flexible in their operating characteristics. Might work.


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## KevD (Mar 2, 2008)

It's always recommended to use the proper wattage lamp/bulb with the appropriate ballast. Otherwise, make sure your fire insurance coverage is up to date


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## hojimoe (Mar 7, 2008)

oh well, doesn't matter I picked up a different PC fixture today used, but the right size and perfect for what I need


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