the F96T8 ballasts they made were really reliable but ive noticed many of the stores that were 24/7 never shut lights off will often have all original ballasts( one store had most from 1998) and when they went to regular store hours about 15 ballasts failed next time they were powered up. so i replaced all of them that had failed, a week later 10 ,more failed. makes me wonder why an electronic ballast would last over a decade and fail when turned off then on?

It's said that powering off and on stressed electronics more than just staying powered on all of the time. They were probably on the brink of failure, and probably wouldn't have lasted nearly as long if they were switched from the start.

caps were dried out/high esr.
once they cooled they were even worse.
see this with industrial stuff during extended power failures/vacations.

It's said that powering off and on stressed electronics more than just staying powered on all of the time. They were probably on the brink of failure, and probably wouldn't have lasted nearly as long if they were switched from the start.

The frequent switching is not a problem for the electrolytics, but rather for the resonant capacitors generating the ignition voltage: Normally they are operating at about 100V, but during start, there are many 100's of V till the electrodes warm up. And this load difference is, what cause cyclic wear.
But usually these resonant capacitors are not the limiting ballast life factor, that is mainly the electrolytic aging on just plain total burning hours, accelerated by the temperature.

did you save some for autopsy?
still bet the lytics went.

the F96T8 ballasts they made were really reliable but ive noticed many of the stores that were 24/7 never shut lights off will often have all original ballasts( one store had most from 1998) and when they went to regular store hours about 15 ballasts failed next time they were powered up. so i replaced all of them that had failed, a week later 10 ,more failed. makes me wonder why an electronic ballast would last over a decade and fail when turned off then on?

Quote from: TheMaritimeMan on December 18, 2013, 08:23:32 PM

It's said that powering off and on stressed electronics more than just staying powered on all of the time. They were probably on the brink of failure, and probably wouldn't have lasted nearly as long if they were switched from the start.

The frequent switching is not a problem for the electrolytics, but rather for the resonant capacitors generating the ignition voltage: Normally they are operating at about 100V, but during start, there are many 100's of V till the electrodes warm up. And this load difference is, what cause cyclic wear.
But usually these resonant capacitors are not the limiting ballast life factor, that is mainly the electrolytic aging on just plain total burning hours, accelerated by the temperature.

Prob what happened to my 2D kitchen light.   On average was on for about 8-10 hours a day constantly, had no problem with starting however after about 5 years - towards the end of its life it started blinking off every 2-3 seconds.  Eventually it refused to light at all.  When I removed the fitting, the plastics in the fitting had got brittle with heat it crumbled apart in my hand.

In the case of mine the caps had blown, easy enough to repair and it did work until I decided to bin it because it was falling apart.

This is because electronic ballasts are crap. Switch start / pre heat win!

This is because electronic ballasts are crap. Switch start / pre heat win!

The plastic housing get brittle and disintegrated really because of that?
And you think it really won't do that with hotter running and heavier magnetic ballast?
I hope you got the point...

I was surprised on how hot my t12/40 got:o  I assume with on/off heating/cooling over the years iron ballasts start to buzz