I have a very old 2 bulb T12 fixture that the ballast went bad on. The old fixture has 1-white 1-black 2-yellow 2-red and 2-blue wires. The old ballast had all matching wires to go along with the wires in the fixture. The person at the light store told me they do not make the same ballast anymore but gave me a newer ballast that he said would work.
The new ballast has 1-black 1-white 1-yellow 1-red and \1-blue. Could someone please tell me how to wire this new ballast to the existing wires in the fixture? Thank you for any assistance you can provide
elhigh2020-06-24T12:50:17Z
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Well, the salesman did you a disservice.
With a dead ballast, this is an opportunity to seriously upgrade your fixture to not just a new ballast, but also new lights. The old T12 tubes are nowhere near as efficient as T8s. If your T12s use the typical "medium bipin" spacing (they usually do but check to be sure) then getting T8 tubes to replace them is easy.
I install low-wattage T8 tubes in my fixtures and get about 100 lumens per watt, which is about twice as efficient as even a good T12. If you can live with a slightly lower light output, you could upgrade to LED and save even more, and maybe skip the ballast entirely for even greater efficiency.
Anyway. On to your question.
A new ballast will almost always have a wiring diagram right on it. In my 30+ years of pro handyman work replacing every kind of lighting device, I have never encountered a ballast that had only one wire of each color. Single yellow sometimes yes, single red and dual blue sometimes yes, one of each? No. So congrats, you threw a curve and I can't hit it.
But I can figure it out. Please follow up by including a picture of your new ballast. I really need to see the label in order to be able to help you properly.
[edit] I see, an HO ballast. For eight-foot tubes, no less. Ugh. I've not had to mess with any of those except in fixtures I was replacing, in which case the ballast went away with the fixture. It was obviated.
Okay. It's like I expected: yellow wire to the near side of the fixture - Y'd in this case so one wire hits both tubes - and red to the far end of one tube, blue wire to the far end of the other tube.
NOTE: I think this means your tubes are single-pin tubes, big heavy pins about the size of a pencil eraser. So you don't need to worry about whether your tombstones are shunted or not, you just make your connection and go on. Take your yellow wire and a couple of short pieces of yellow wire, twist together stripped ends of all three into a single wire nut, and the two short wire ends go on to the tombstones.
At the far ends, just poke the red wire into one lampholder, blue into the other, and you're done.
the ballast came with a wiring diagram and, after you open up the fixture to get at it, you'll be able to see the wires to the various parts. just follow the diagram and you'll be ok