I am new to Home Improvement and recently hear a pop!, then my overhead lighting in my small kitchen stopped working. Lowe's sold me a replacement ballast (good enough to remove the old ballast, and attach the new commercial one which the associate said would work fine), and once reinstalled, the one bulb was killed outright, another flickers nonstop and is very dim, and the third seems okay?

It never did any of this before, and I am concerned. Before getting gouged by an electrician, I was hopeful to ask for insight here.

Thanks enter image description here

enter image description here

  • Commercial ballast are not as good for home usage because they produce more RF noise. As far as lasting longer I have not seen a difference. If the ballast was wired correctly it should not have damaged the lamps but if incorrectly wired it could cause problems. The leading cause of ballast failure I have found with the newer electronic ballast has been weak or old lamps. The lamps will light with a new ballast but I usually relamp when replacing a ballast.
    – Ed Beal
    Commented Mar 14, 2017 at 21:21
  • 1
    lately I have been eliminating ballast all together in office areas and installing double ended LED replacements. 22W LED 500K double ended lamps are much brighter than any t8 or t12 lamp I have found. the ballast is removed 110 on 1 end at the tomb stone and neutral at the other end. Last month greentek had them on sale for 7.99 ea way cheaper than re-ballast and new lamps and so far everyone loves them.
    – Ed Beal
    Commented Mar 14, 2017 at 21:34
  • Don't you need different ballasts depending on the number of tubes served? Can you edit the question to include photos of the markings on old and new ballasts? Commented Mar 15, 2017 at 0:11
  • Hello RedGrittyBrick, I did upload the ballast photos - my apologies that they were not as clear as hoped (as indicated, I am new to all this).
    – SprinKe
    Commented Mar 15, 2017 at 8:42
  • Thank you, Ed Beal, for your insightful words. When I tried to remove the dim bulb this morning, I adjusted it and the light came fully on, so go figure. I am going to buy new light bulbs this morning, and see if that fixes the issue. As evidenced from the photo, I took the assembly and old ballast in so that the associate (30-year-career electrician) could see what it was and offer a correct replacement part. (I had called Keystone Ballast/Lithonia Lighting with no luck.)
    – SprinKe
    Commented Mar 15, 2017 at 8:46

1 Answer 1


Ballast replacement is fairly straightforward. I still prefer fluorescent tubes because I can easily find quality fluorescent tubes in 90+ CRI (in fact Menards stocks them), and I have serious doubts about the real quality and longevity of the LED "cheapie" tubes.

Start with a "ballast disconnect"

enter image description here

For this you need to shut off the circuit breaker supplying power. You then put the ballast disconnect at the point where the power supply (typically 12-14 AWG wire) meets the ballast (18 AWG wire). Some disconnects care which side is the heavier wire, i.e. the yellow Wago types. If there are 2 power cables going in and out, then either use the Wagos (which provide for that) or pigtail it.

Once that's done, you'll be able to service the fixture without turning the breaker off. Just unplug.

Next select the bulbs

Those look like 48" bi-pin tubes (the most common one). From looking at the "old" Keystone ballast, your old ballast was for F32T8 tubes, 1" diameter (T8). Which means it's not that old. Don't use F40T12 tubes, 1-1/2" diameter, they will fit but they are not electrically compatible unless you change to a T12 ballast.

Look at the existing ballast

The big label on the old Keystone ballast says your bulbs are instant-start, with 1 wire per end of the lamp. Gotta watch out for that 2-yellow 2-red 2-blue color scheme as it's also used by 2-lamp rapid-start ballasts. This is an example where the diagram really matters.

Check the new ballast also, the wiring may be subtly different. If the Lowes clerk picked your matching ballast by the same wiring diagram, that's handy, but double-check the type of tube it's made for. Here are generic drawings of ballast wiring; yours may vary. For instance yours wires like two separate 2-tube instant-start ballasts.

enter image description here This is from my big answer here.

Historically 4-lamp fixtures often had 2 ballasts. There is a mounting site in your fixture for a second ballast. Aside from using the more common 2-lamp ballast. it also let you feed them from 2 switches for "high" and "low".

If the ballast is a goner, you'll have no trouble finding 4-lamp ballasts in either instant (1 wire) or rapid-start (2 wires). Rapid-start gives better tube life; a sub-type is programmed-start which gives superb tube life - something to think about if the fixture is hard to access. But if you switch to rapid-start, you'll need to change the lampholders (tombstones) on the end of the tubes to a non-shorting type.

Edited significantly based on updated info

  • Thank you, Harper, for your detailed reply! I am going to study your words in depth, and offer the two ballast photos (before and after - the box in the second shows the diagram).
    – SprinKe
    Commented Mar 15, 2017 at 8:36

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.