Converted T12 fixture to T8

[Jeff May]

OK,
I'm currently using 8' T12 fixtures in my shop.
The ballast seem to die after about a year or so.
I just had another shut off the other night.
Visited my local electrical supply house today and bought a T8 ballast and 2, T8 bulbs.
They assured me all I had to do was just wire it like the old and set the new T8 bulbs in the fixture.
Sounds easy enough, so I change things out and turned things on expecting to be blinded with my new light bulbs.
Nope, they came on nice and bright on each end about a foot in, the centers are a nice shade of violet.
As I type this the light has been on for about 10 minutes, there is now about 2' of white light from each end, but the center is still a violet color.
What the heck is going on?
It appears that its getting better, it may actually be totally lit up in about 30 minutes.
Is this something I'm gonna have to deal with everytime I turn them on?
Also, the temp in here is about 60 degrees. Granted I did have them in the back of my truck bringing them home, its about 40 or so degrees outside today.
Any thoughts???
Thanks
Jeff

 

[6t7gto]

http://nemesis.lonestar.org/reference/electricity/fluorescent/trouble.html

read about your bulb situation

 

[pattenp]

It just takes some time on the first start up. Should be okay after that. Are the fixtures 4 4' lamps or 2 8' lamps?

 

[tfi racing]

Your new ballast's wiring may be just slightly different than your old T12's,check the diagram on the ballast.

 

[EOC_Jason]

I would double check the wiring diagram on the ballast itself, there's usually only 2 ways they are wired up.

It's more than likely a combination that the tubes were cold (you said they were in 40F temps) and that they are brand new. Leave them on for a while and they should brighten up.

 

[Jeff May]

OK,
Well, good news.
After about 20 minutes it was all the same brightness.
I turned off and came inside for several hours. When I returned to shop and turned on the lights it came on instantly and bright.
I'm guessing it was cold from being in the back of my truck and coupled with the fact they were brand new tubes could have caused this initial condition.
So far it appears to be working ok now.
Thanks to all the above posts for the help.
Jeff

 

[NUTTSGT]

I doubt it had anything to do with the bulbs being new. I know GE runs their fluorescent bulbs on an "ager" wheel before they are packed and shipped as part of the production line.

On the other hand, I'm not sure if everybody else does this.


Glad to hear you got the problem solved. What ballast did you use ? A commercial or residential, any radio interference ?

 

[Random Guy]

If these are 8' normal output lamps, each end only has one pin.