4'- T12's not starting quickly?

[ritelec]

I replaced a ballast and two lamps.. electronic ballast for 2-40w T12, two T-12 40w bulbs.. (one of two fixtures)

These two fixtures next to each other, the older existing one (not ballast changed) lights immediately and the one with the new ballast and bulbs lights like this......
one one thousand then light.

Do you think it's a bad ballast? Supply house gave me another to swap out but don't want to especially if it's going to light the same way.

I also installed a new 4' T-8 two bulb fixture in a different room that lights immediately .

Thoughts?

Thank you

 

[mbrooke]

How are the tomb stones? I almost want to say on of the filaments isn't heating, but its just a wild guess.

 

[ritelec]

How are the tomb stones? I almost want to say on of the filaments isn't heating, but its just a wild guess.

Tomb stones???

are you saying try replacing new bulbs with different new bulbs??

( i did notice when I first turned it on one bulb didn't seem as bright, but it was lit???)

 

[mbrooke]

Tomb stones???

are you saying try replacing new bulbs with different new bulbs??

( i did notice when I first turned it on one bulb didn't seem as bright, but it was lit???)

This creature:

Sometimes they can fail and only make contact with one set of pins. Also make sure it isn't shunted for a rapid start ballasts. If the previous ballast was rapid start and the new one instant start, make both pins are externally shorted.

 

[ritelec]

Tomb stone, got it thanks .....
lol..You lost me on the rest of it ..lol

I may just take out the fixture and install a new 2 bulb t-8...???

 

[mbrooke]

Tomb stone, got it thanks .....
lol..You lost me on the rest of it ..lol

I may just take out the fixture and install a new 2 bulb t-8...???

Do this: change out everything including the tombstones. Something has failed.

 

[LarryFine]

If I were going to re-ballast a light, and I have, I would use a T-8 ballast and tubes, re-wiring the tombstones accordingly.

 

[ritelec]

Do this: change out everything including the tombstones. Something has failed.

Yes.... I was thinking to do that but the existing fixture which looks like and older Rickels or some other outlets tomb stone are little weird, not typical and I may be spinning my wheels to install a differently designed standard one.. (I'll bring 4 with me and see)

Maybe I'll look closer into them that theres continuity between the the point of wire insertion and internal clip areas....

Maybe best to just swap the fixture out.. ?? We'll see.

Thank you

 

[ritelec]

If I were going to re-ballast a light, and I have, I would use a T-8 ballast and tubes, re-wiring the tombstones accordingly.

the two fixtures were 40w t-12...... was hoping to match the light....... but, your probably right.

 

[mbrooke]

Yes.... I was thinking to do that but the existing fixture which looks like and older Rickels or some other outlets tomb stone are little weird, not typical and I may be spinning my wheels to install a differently designed standard one.. (I'll bring 4 with me and see)

Maybe I'll look closer into them that theres continuity between the the point of wire insertion and internal clip areas....

Maybe best to just swap the fixture out.. ?? We'll see.

Thank you

the two fixtures were 40w t-12...... was hoping to match the light....... but, your probably right.

T-12 is no longer standard- its all T-8 now. Soon to be phased out by LED. A high output electronic ballast and a GE/Phillips Alto/Sylvania T-8 should equal old T-12s.

 

[MAC702]

Even when staying with the same lamps, a new ballast may have a different wiring scheme. Don't just hook it up based on the existing one. Follow the wiring diagram on the ballast itself. This is PROBABLY not the issue here, but it's the best I can do for brainstorming at the moment.

 

[Little Bill]

Personally, I wouldn't fool with repairing/replacing a T12 with T12, I would make it T8. If you (OP) are concerned about the lights matching, I would change both over to T8. It would probably even save the customer money since the other T12 will soon need servicing soon anyway.

Having said that, if you do stick with T12, make sure you ground the fixture in the plane where it states on the fixture or ballast. These lights use the ground to help ignite/fire the bulb. If the ground is not in the right place, or nonexistent, then the bulbs won't light correctly.

 

[kwired]

Personally, I wouldn't fool with repairing/replacing a T12 with T12, I would make it T8. If you (OP) are concerned about the lights matching, I would change both over to T8. It would probably even save the customer money since the other T12 will soon need servicing soon anyway.

Having said that, if you do stick with T12, make sure you ground the fixture in the plane where it states on the fixture or ballast. These lights use the ground to help ignite/fire the bulb. If the ground is not in the right place, or nonexistent, then the bulbs won't light correctly.

Sometimes the problem is you need to change out many lamps/ballasts or put in same thing that was there to still match. You might get away with slight color/intensity changes in one fixture in a room with several troffers, but maybe in an end to end row setup, and worse yet if it is an indirect light scheme, that one lamp that is different color/intensity can stand out pretty well.

 

[junkhound]

I replaced a ballast and two lamps.. electronic ballast for 2-40w T12, two T-12 40w bulbs.. (one of two fixtures)

These two fixtures next to each other, the older existing one (not ballast changed) lights immediately and the one with the new ballast and bulbs lights like this......
one one thousand then light.

Do you think it's a bad ballast? Supply house gave me another to swap out but don't want to especially if it's going to light the same way.

I also installed a new 4' T-8 two bulb fixture in a different room that lights immediately .

Thoughts?

Thank you

Not a bad ballast, simplyone that has a slow 'soft start'.. Most only take a few dozen milliseconds though. The PWM in electronic ballasts has a ramp that gradually widens the pulse width from zero to perating mode to decrease inrush. My guess is that the delay you are seeing is the 'soft start' feature of the electronic ballast.

Look at a data sheet on Infineon or TI web site application note to get a full description of soft start features.

 

[ritelec]

make sure you ground the fixture in the plane where it states on the fixture or ballast. These lights use the ground to help ignite/fire the bulb. If the ground is not in the right place, or nonexistent, then the bulbs won't light correctly.

I replaced it with a new fixture (T8'S)
The plane? Interesting. There's a ground pigtail on the fixture but the fixtures fed with bx.

ground plane ? interesting.

Thank you all