# New T8 bulbs flickering during start up in older fixtures



## cichlid_baby (Jan 28, 2003)

Okay.. so I have found out through some trial and error and some discussions with others locally who have experienced the same problem with the newer T8 bulbs which are fastly replacing all the older T12 style bulbs.

Problem so far seems to be related somehow to the ballasts in the older fixtures being designed to operate a higher wattage tube...

for example... my older oceanic flourescent fixture uses a T12 40watt 48 inch tube.. when that bulb went kaput... I replaced it with a newer style T8 32watt 48 inch tube. Had all kinds of flickering.. on and off.. on and off.. strobe effect for hours before the bulb would eventually stay on... but it would still ficker occasionally during the day a few times. I thought it was the new bulb being defective.. went and got another bulb with the same T8 32watt 48 inch tube rating... had the same problem with that bulb too. Put those new bulbs in the newer fixtures and they worked just fine without any more than normal flickering at start up.

Then went and got some old school T12 40watt 48 inch tubes from a local shop that still had the old T12 style bulbs and popped them in.. bamm... light works perfectly again.. just like it did on day one years ago.

So in conclusion.. it appears anyway that there may be some thing to these newer T8 bulbs not being ideal replacements for any of the older ballast equipped lighting fixtures.

Any one else have this similar problem? If you could share your experience and how you resolved it?


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## Number6 (Mar 13, 2003)

ballasts are not all created equally... an Icecap ballast will run T12, T8, PC, T5, HOT12, HOT5, etc. Other ballasts might be tar filled hunks of junk that will only run one of the above mentioned bulbs. Forcing a T8 into some old T12 fixtures could easily just fry the ballast. I should know ;-)


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## cichlid_baby (Jan 28, 2003)

This is an interesting read regarding the older T12 ballasts and the newer T8 electronic ballasts.

http://www.gelighting.com/na/business_l ... olders.pdf

http://www.chameleonforums.com/diy-t12- ... nge-31490/

http://www.ace-ballast.com/articles/?id ... _Questions


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