How to Replace a Light Ballast

by | Apr 24, 2020

Hold up! Do not get rid of your fluorescent fixture! Try a fluorescent light ballast upgrade! A ballast is needed to produce light. Replacing this will return your lights back to full operation! A ballast upgrade only takes around 10 minutes and if you would like to know how to do it, look no further. Kalahari Electrical of Atlanta, Georgia has you covered.

How to Replace a Ballast in a Fluorescent Light

Gather Tools
  • Smartphone/camera
  • Voltage tester (non-contact)
  • Wire nuts
  • Wire cutter/stripper
  • Socket wrench
Turn the power off

Always remember to turn off the power to the light at the breaker box.
Make sure the light is unplugged as well.

Remove the Fluorescent Light Tubes

Twist the bulbs about 90-degrees. When you see the metal contact located at the ends of the bulb, tug down until the contacts slide out of the socket and remove the bulbs. While you’re in there, check the sockets holding the bulbs, tightening/replacing as necessary..

Take Off the Cover Plate

The wiring cover plate in the center of the fixture must be removed to expose the wires. Visually locate the tabs that hold the cover in place, then squeeze the sides of the cover in to release the tabs from the slots, pulling down to remove

Check for Voltage

Before you touch and connections/wires, check the power with a voltage tester (Non-contact)

Take A Picture

You should take a picture of the wires, for when hooking up the new ballast!

Disconnect the Ballast Wires

Disconnect each ballast wire, removing the connectors or cutting the wires as close to the ballast as possible.

Remove the Ballast

Support the ballast with your hand to keep it from falling while using your socket wrench to remove the nuts/bolts. Remove ballast from the fixture.

Replacement Ballast

Get a new replacement ballast. Take down the code of the current ballast and order online or visit your local store. Make sure the new ballast matches the wiring diagram, voltage, and current of the old one

Prepare The Wires For The Brand New Ballast

Removed damaged/crimped portions of ballast wires, stripping half inch insulation from ends using wire strippers.

Install the New Ballast!

Mount the new ballast to the fixture using mounting nuts/bolts and your socket wrench. Connect the new ballast wires to the fixture with wire nuts, referencing your photo an ensuring a match to the original wiring.

Reinstall Light Components

Put the wiring cover plate back in, followed by the bulbs and the fixture lens.

Restore Power

Flick the circuit breaker back on and plug-in the light, testing for proper operation.

Get Rid Of The Old Ballast

Older ballasts (made before 1979) often contain PCBs, a known environmental toxin. If your old ballast is leaking a black, tar-like substance, handle it carefully, avoiding skin contact and taking it to the nearest hazardous waste disposal site.