converting T12 fluorescent fixtures to T8

[Rod Sheridan]

Hi Jim, the neatest way to convert the fixtures is to use a plain metal paperclip to release the wires from the sockets.

Simply unfold one end of the clip and insert it in beside the wire you want to remove from the socket, pull the clip and the wire out.

For T8 lamps the sockets have to have the pins shorted together so cut one old wire about 2 inches long, strip 3/8" of insulation an insert it in the opposite pin to short the socket.

This makes the wiring as neat as the original, with no marrettes everywhere............Regards, Rod.

[Matt Marsh]

Hi Jim, the neatest way to convert the fixtures is to use a plain metal paperclip to release the wires from the sockets.

Simply unfold one end of the clip and insert it in beside the wire you want to remove from the socket, pull the clip and the wire out.

For T8 lamps the sockets have to have the pins shorted together so cut one old wire about 2 inches long, strip 3/8" of insulation an insert it in the opposite pin to short the socket.

This makes the wiring as neat as the original, with no marrettes everywhere............Regards, Rod.

You can do this of course, but it takes a lot more time, and is a lot of extra messing around, all just to save from using a few tiny wirenuts. For most fixtures, it would involve having to remove each socket, which would also normally involve removing the ends of the fixture. The little orange Ideal brand wirenuts work awesome for these retros.

[Jim Andrew]

Rod and Matt, thanks for both those ideas. Matt, according to your wiring diagram, would you just twist all 4 wires on 2 lamps to connect to one wire? And 2 wires on the other end of the lamp? Planning to pick up some small wire nuts.

[Matt Marsh]

Rod and Matt, thanks for both those ideas. Matt, according to your wiring diagram, would you just twist all 4 wires on 2 lamps to connect to one wire? And 2 wires on the other end of the lamp? Planning to pick up some small wire nuts.

Jim, yep, with a 2-lamp ballast, all 4 pins on one end are common, and at the opposite ends, the two pins on each tube are common with one of the blue ballast wires. At work when we're doing a retro, we try to maintain an average of 8 to 12 fixtures an hour, each person. By the end of the day, your shoulders and neck ache pretty good!

[Jim Andrew]

I can imagine how you feel after a day of working on these fixtures. Did the changeover on one of the fixtures, and it actually worked! But I did it upside down on the bench. Plugged the white and black wire into a cord to test it, and it worked great, only it took a little while to warm up and get the tubes to putting out light evenly. The centers took a while. How hot do the electronic ballasts get? They were getting warm after about 15 minutes. Also, do the recycling yards take the old ballasts? And, the wiring diagram on the Sylvania ballasts used all the wires, no need to pull any out.



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[Matt Marsh]

I can imagine how you feel after a day of working on these fixtures. Did the changeover on one of the fixtures, and it actually worked! But I did it upside down on the bench. Plugged the white and black wire into a cord to test it, and it worked great, only it took a little while to warm up and get the tubes to putting out light evenly. The centers took a while. How hot do the electronic ballasts get? They were getting warm after about 15 minutes. Also, do the recycling yards take the old ballasts? And, the wiring diagram on the Sylvania ballasts used all the wires, no need to pull any out.



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They can get very warm, but not as hot as the old ones. Be sure that the new t-8 tubes match the listed specs for that particular ballast. The label on the ballast usually has a list of acceptable tube types printed on it. A standard 2-lamp, 120 volt electronic ballast draws about .5 amps, so the entire amount of heat generated from the bulbs and ballast shouldn't be more than around 60 watts. Also, don't expect to get the long life from the new ballasts as with the old magnetic ones. We've had several go bad after as short as 6 months, and an even larger number of them go out after 2 years. Some of the old magnetic ballasts that we've replaced were installed in the late 1950s, and they were still going strong.