Hi,

I have a 48" overhead light fixture that uses 2 fluorescent tubes and has been causing me grief. The fixture works well if the temperature is between 85F-95F but does not work well when the temperature falls below 80F.

When it is cooler (There is no flickering of the light bulbs and they are not darkened at the edges. I have also checked the proper voltage is reaching the ballast. After putting up with this for a long time, I could not take it anymore and I opened up the fixture and pulled out the ballast. The ballast is a SunPark SL15T (rapid start) that claims to support T8 and T12 fluorescent tubes. Now, the tubes I am currently using are 30W T5s (F30T55US from a company called Texas Fluorescents) and the manufacturer's catalog says:

T5 lighting and technology in a T8 package. Have a T8 fixture and ballast but need more light. Retrofit with a 30W T55 lamp that provides 3500 lumens or 25% more light than a standard T8 lamp.

If I am to believe the manufacturer, then it appears that this pair of T5 tubes will work with the T8/T12 ballast. I never intended to retrofit anything; the retailer who sold me the light fixture also sold me the T5 tubes and said that these would work.

I am going to try with T8 tubes and see how it works out but I am curious to know if anyone seen such a problem before. Has anyone used T5s with T8/T12 ballasts? Do you think that the tube-ballast mismatch may have ruined the ballast too?

Thanks,

Andy