Fluorescent lights can give you years of dependable service, but sometimes with age a fixture will fail because the ballast gives out. The ballast is the long, rectangular metal part inside a fixture. Usually 6 to 8 inches long and painted black, it controls the amount of electric current that reaches the fluorescent bulbs. Fortunately, replacing a ballast is a simple procedure that you can usually do in 30 minutes or less.
Caution: Sometimes when a ballast fails it will become very hot; test the unit with a light touch before grabbing hold of the part. If it's hot, use gloves to hold it as you remove it.
Symptoms of ballast failure:
* Buzzing sound
* Leaks a black, tar-like substance
* Light seems only half bright or doesn't stay on
1.
Turn Off Power
Turn off the power to the circuit before you start.
2.
Remove Diffuser Shield and Tubes
If the fixture has a plastic diffuser shield over the fluorescent bulbs, remove it; then take out the tubes.
3.
Note Code on Old Ballast
Remove the panel that covers the wires and the ballast. Jot down the number codes on the old ballast and take them to the store with you, just to make sure you buy the right replacement.
4.
Disconnect Wires
Once you have the new ballast, disconnect the old one. Remove the wire connectors to disconnect the ballast from the house power. Also, you will need to cut the wires leading from the ballast to the fixture's sockets. Notice that the ballast wires are color-coded (Fig.1). The new ballast must be connected in the same way. If you find the wiring confusing, make a simple color-coded diagram before you disconnect any wires.
5.
Remove the Old Ballast
Remove the old ballast. The ballast you are removing is heavier than you might think. Be careful. Have a helper hold the ballast while you remove the fasteners that attach it to the fixture. Note carefully which direction the different color wires on the ballast face. You want to install the new ballast so that its wires face the same direction. Otherwise, the wires may not be long enough to reach the same colored wires in the fixture (Fig.2).
6.
Attach New Ballast
Have your helper hold the new ballast as you position it in the fixture. Screw the new ballast to the fixture.
7.
Wire New Ballast
Strip the insulation from the ends of the cut socket wires and connect these wires to the appropriate wires on the new ballast. Also connect the appropriate ballast wires to the house power. Splice the appropriate wires together using your fingers or pliers; then cover them with wire connectors and wrap the wire connectors with plastic electrical tape (Fig. 3).
8.
Replace Tubes
Replace the tubes.
9.
Turn On Power and Test
As a final step, turn on the power and test the light. If everything works, re-install the rest of the fixture's components.
