flourescent tubes

[dick621]

What would cause an f96t12 tube, in a two tube fixture to turn black about two inches in 48 hours?

 

[frenchelectrican]

most common way is incorrect wiring on slimline ballast

somecase you may got a bad batch of bulbs as well.

check the ballast connection to make sure it is correct.

Merci, Marc

 

[stickboy1375]

Ballast trying to start a bad bulb?

 

[dick621]

Thanks Guys, I'll check the connections out tomorrow.
Dick

 

[quogueelectric]

Bad tombstone or bad connection to tombstone.

 

[wireman71]

T12? Is this a old ballast. I'd suspect that ballast is shot if tombstones looked good.

 

[LarryFine]

My first suspicion would be a bad ballast ruining new tubes.

 

[SmithBuilt]

Is there a way to check the ballast out? Other than installing new bulbs. I normally recommend replacing the ballast and the bulbs. Mainly because a ballast that is going bad can light new bulbs for a while.

 

[LarryFine]

Mainly because a ballast that is going bad can light new bulbs for a while.

True, but it might cause the ends of the tube "to turn black about two inches in 48 hours."

 

[The Iceman]

I just had the same problem with T12 lamps. The ballast instructions required the lamps to burn in for 100 hours. I replaced the lamps in all three fixtures, left them on for 100 hours, and had no problems. It has been two weeks and still no problems.

 

[dnem]

I just had the same problem with T12 lamps. The ballast instructions required the lamps to burn in for 100 hours. I replaced the lamps in all three fixtures, left them on for 100 hours, and had no problems. It has been two weeks and still no problems.

I agree with Iceman, I've heard that new fluorescents shouldn't be turned off and on when they're new. . You should turn them on and leave them on overnight [at least] before you turn them off for the first time.

David

 

[mivey]

I thought the burn-in was for dimming.

We always shook the lamps before installing to reduce "rolling"

 

[dick621]

After changeing the blackend tube the 27th, I checked the new one last night and it appears ok. Could still be a ballast going bad, but owner doesn't want to change it.
Has anyone heard anything about doing away with T12 lamps and ballasts completly and going to T8s? I've heard this a couple of times, but don't know if they knew what they were talking about.
Dick

 

[dnem]

After changeing the blackend tube the 27th, .....

Did you let that one burn for awhile ?

When you first lit the one that eventually got a blacked end, did you burn it nonstop overnight ?

 

[dick621]

I can't really say. I think it burned all night and the next day, but i'm not sure.