Ballast replacement

For starters, I have been replacing ballasts in fluorescent fixtures since 1968 before I retired and now still do some at my church. I don't recall ever doing one with an 8 foot fixture. My friend asked me to help her with one in her garage and of course it's an 8 footer. I thought, no problem, how difficult can it be. I tried to do the job yesterday and it didn't work. She took the old one out and took it to an electrical supply house for a replacement and they gave her the newer, smaller, and lighter type to replace the one that has been in since 1982. The fixture has a red wire and a blue wire on the one side that connects to the tube holders. On the other side all that comes from there is a black wire and a white wire. It looks like the hot (black) and the neutral (white) from the main feed connects right to the black and white wires at the tube holders and then come down and connect to the black and white on the ballast. That's fine except the new ballast has TWO blue wires and one red wire. I tried all kinds of combinations with the red and blue wires but nothing worked. I suggested to my friend that it might be easier if she (or I) just took down the 8 foot fixtures (she has 3) and replaced them with some shop lights from Home Depot or Lowes. That still wouldn't allow me to know why I couldn't get that ballast to work. Any suggestions would be greatly appreciated.

Thanks.

Go Cubs!

Rich

 

You should be able to simply cap the unneeded blue wire. Check the label of the ballast to confirm 1-lamp operation is supported. It probably is. Here is a wiring diagram.

This is F96T12 slimline (single-pin), not F96T12 high output (RDC), right? See a comparison of bipin, slimline, and RDC. It sounds like single-pin slimline from the number of colored leads. I'm a little confused about your description regarding hot and neutral. Normally they connect directly to the black and white leads of the ballast. Then it's red to one socket, and blue to the other.

 

Two blue wires and one red suggest a two tube ballast.

However.... the system you're describing is fairly old. At one time they ran the ballast power wiring thru the sockets. The circuit only worked with both tubes in place. The sockets were actually like switches.

 

Thanks for the info, Pete. First of all I live in SE Pennsylvania. After looking more closely at that ballast setup I saw the black hot lead and the white neutral from the romex went to the black and white on the ballast but also to the tube holders on the one end of the fixture. The electronic ballast I replaced it with didn't show that so I just capped off the two wires from the tube ends and connected the (2) blue wires from the ballast to the red and blue at the other end of the fixture. The black hot and the white neutral I ran to the black and white on the ballast and the red wire from the ballast I ran to the two tube ends. My friend is very happy with the outcome. Thanks again.

Rich

 

That's right, I should have checked the old 8' ballast I have. It does indeed wire in series as in the diagram shown by PJmax. I had forgotten about the difference. A magnetic single-lamp slimline ballast would have only had a red lead.