Issues w/ fluorenscent lights. Dim T12's

[The Lazy Destroyer]

I have four 4-bulb recessed lighting in our finished basement. These use the 48" T12 bulbs. Two ballasts each.
Over the past year sometimes I will get one or two fail to turn on, sometimes they will, sometimes they won't. Typically have that "hum" usual with older ballasts. These have original ballasts, they look... old
So I replaced all the ballasts with electronic T12 ballasts.Everything was going fine.

The last one I worked on lately has always been dim. After replacing the ballast the lights are still dim. **** Their bulbs looked pretty new but replaced them anyways... still dim By dim I mean like 25% light output if that. Sometimes they show visible light rings on some of the bulbs.

Temperature is not a problem, probably 65° or so.

This fixture is the last on the electrical run, I'm not sure if this is just a coincidence or not.

I checked for proper voltage and they are getting 120vAC.

Some of the sockets on this particular unit are a little beat up. Some cracked plastic and such. I had other units have sockets like this and they were working fine. But I am thinking my next step is to replace the sockets (at least the ones that look sketchy).

But wanted to check if there is anything else I could look for. The sockets look a bit old so I am kind of taking a stab that they should be replaced, but I have no for sure proof they are bad. Thoughts?

What confuses me is both pairs of lights look about the same so it is odd to get the same problem on a pair that is in the same housing...

 

[cybrdyke]

Done correctly, the electronic ballast should work fine.
Be advised that new T12 lamps are not as bright as the old ones were, but the old ones got banned by the gub'ment for energy reasons.
First, verify that those lamps WILL come on full bright by trying them in another set of sockets that are working. If so, then you either have a wiring issue or a socket issue. Sockets can be easy to replace and for safety reasons, you might as well go ahead and do that. Take one out and take it with you to the local electrical supply store. You will be asking for Rapid Start sockets.
Those lamps use both pins to operate, which means that there needs to be connectivity between each pin and each piece of brass in the socket. Old sockets can be failing at this.
Finally, check that the wiring diagram on the new ballast is the same as the old one. Or at least verify that you got all the connections correct.
Let me know how it goes.
CD

 

[CGT80]

cybrdyke basically covered what I was going to say.

t12 lamps ****. I always retrofit with T8 ballasts and lamps. The t8 lamps do put out more light. Home Depot and lowes have the common sockets, or any other big home center should have them. I needed some old school sockets last month and found them on 1000bulbs.com for a much better price than anyone else.

 

[The Lazy Destroyer]

Ya after going through some stuff afterwards I didn't realize T8's have the same socket as the T12's. Had I known that I would have checked out swapping to T8's but I didn't really know when I was buying the ballasts... live and learn.

I'll verify the wiring again... but I'm thinking more and more the sockets (or their pigtails) are toast. This was also the only one that had discoloration on the yellow wires. Both the insulation and also oxidation on the copper. I see the sockets are avail on Amazon pretty cheap. Might try this and just swap all the sockets on this figure and see how it works.

 

[Charles (in GA)]

Did you wire the new ballast according to the diagram on the ballast? It will be different than the way the old ballast was wired to the tombstones.

Most electronic ballast that handle T12 bulbs also will power T8 lamps. Read the label on the ballast and see. If so, install T8's, which is what you should have done to begin with.

Make sure the fixtures are well grounded. Where the ground wire screws on, scrap the paint away, and also scrap the paint on the ballast and the fixture at the point where the Ballast attaches to the housing with a screw.

Poor grounds, for what reasons I do not know, make fluorescent lights do strange things.

Charles

 

[cybrdyke]

Most electronic ballast that handle T12 bulbs also will power T8 lamps.

these 2 lamp types have vastly different starting and operating requirements from a ballast.
Advance/Sylvania/GE dont make such a thing.
CD

 

[The Lazy Destroyer]

Well, I hate to post this but I checked the wiring (including ensuring all sockets had continuity between pins and wire leads) and only then realized I cross wired the ballasts

Rewired and they work great

It was the last one I did, so I guess I went into autopilot and didn't pay as close attention as I should.

 

[cybrdyke]

Well, I hate to post this but I checked the wiring (including ensuring all sockets had continuity between pins and wire leads) and only then realized I cross wired the ballasts

Rewired and they work great

It was the last one I did, so I guess I went into autopilot and didn't pay as close attention as I should.

Glad you found it!
CD

 

[Norcal]

Might have been better off to convert to T8, more common today, the only downside is w/ a four lamp ballast the whole fixture goes dark when they fail.