I am working on a job where I have several 4' fluorescent lamps (F40T12) and 8' fluorescent lamps (F96T12/DX) all from Phillips and the owners are wanting LED replacements for them. We don't know what ballasts are present in the 4' or 8' fixtures. My solution was going to be replacing the 4' fluorescents with 4' LED's that are both ballast compatible and can be tied to line voltage if needed. For the 8' fixtures I was going to remove the existing ballasts completely and have the new LED lamps directly to the line voltage. Does anyone have experience with this such work? This is my first re-lamping exercise, want to be sure to get it right.

  • 3
    Replacing the light bulbs, you can probably do. Since this not your place that you own, you probably are not legal to do anything else, like modifying the lights. You and/or the owners probably need a electrician to legally work on the lights to remove the ballast/change to line voltage.
    – crip659
    Commented Dec 7, 2021 at 23:25
  • I have successfully replaced 4' fluorescents with 4' LEDs that were sold as direct replacements. ( no ballast changes needed).
    – Barry
    Commented Dec 7, 2021 at 23:27
  • 2
    I’m voting to close this question because this is not HOME IMPROVEMENT.. Commented Dec 8, 2021 at 0:50

1 Answer 1


On both it should be fairly straightforward, as long as the 8’ fluorescents are 1-pin (nub on end, tubes spin freely). If they are funny 2-pin sockets, you have High Output or Very High Output 8’ fluorescents, and the owner will Not be happy with the light output of LED replacements.

With 1-pin, Nothing to mess up, power goes to opposite ends of the tube. Reuse the existing wires.

On the 4 foot tubes, if you are going with universal types, again not much to screw up.

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