Rick asks: I've been doing a lot of research about changing from T12s to T8 or T5's but haven't run across any solutions for the 8' one pin tubes. I have at least 150 2 tube arrangements and another 50 4 tube jobs. Anything out there?
As you probably already know, most retrofits of existing T12 lighting can happen with a retrofit kit where the installer basically pulls the guts of the existing light fixture out, and re-uses the shell of the existing fixture with new brackets, and sometimes a new reflector...
For your 8' T12 tubes, the installer would replace your T12s with a 8-2 REB (8' reflector 2 4' T8 lamps, w/electronic ballast), or an 8-4 kit (8' reflector, 4 lamp T8 w/ electronic ballast). The choice would depend on the height of the fixtures off the floor and work tasks being done on site by the occupants... (normally the 8-2 works great).
One Pin T12 Fluorescent Tubes
For the 50 4 tube fluorescent lights that are one pin types... the answer depends on whether the lights are high output (HO) or not.
The pin sockets cannot be reused, so a kit would be used, either a 4-1 kit, or a 4-2 kit (again depending on height and tasks). When using a kit, the guts are pulled out, and a new reflector, brackets, T8 lamps, and electronic ballast are installed.
If the lamps are HO, the fixture may need to be replaced, a HO lamp is slightly shorter (between 2-4 inches shorter than a 4' T8).
T8 as stated would be the most practical. T5s can be done as well, however they are less common.