How to Replace T12 With T8 Ballasts

Replacing T12 ballasts with T8s gives you better light and greater efficiency.

Fluorescent lights have undergone huge changes in the past few years, though few people know it. Fluorescent lights are still commonly thought of as humming fixtures in office buildings giving off sickly, dim light. However, this is no longer the case. The new T8 lighting system, which replaces the antiquated T12 system, promises quiet, efficient operation and brighter lights. The two systems are designed to be compatible, so swapping them only takes a small effort.

Instructions

1. Turn off the circuit the light is connected to at the circuit breaker.

2. Remove the plastic diffusion shield around the bulbs and set it aside. This piece will snap out; be careful not to damage it.

3. Twist the existing T12 bulbs a quarter-turn to the right and pull down to release them. Dispose of these bulbs according to your local regulations.

4. Clip the wires attached to the ballast as closely as you can. The ballast is the large black box with wires running from it.

5. Unscrew the bolts holding the ballast in place. Support the ballast with one hand to keep it from falling.

6. Screw the new T8 ballast into the same place the old T12 ballast was mounted.

7. Wire the new ballast to the existing circuit. Connect the two blue wires to the pairs of blue and red wires at the opposite end of the fixture. Connect one of the red wires to the yellow wire on the other side of the lamp. There will be one remaining red wire.

8. Wrap all the new connections in electrician's tape to protect them. Also, wrap the end of the extra red wire to prevent it from interfering with the ballast's operation.

9. Install the new T8 bulbs and replace the plastic diffusion cover.

References

• Merchant Circle: T12 to T8 Retrofits
• T8 Bulbs.net
• Express Lightbulbs: Fluorescent Electronic Ballast T8