Creating A Safer Work Zone

« Back to Home

How To Replace A Two-Bulb Fluorescent Light Fixture With A Four-Bulb Model

Posted on

If you sometimes feel as if you're living in a cave and your overhead fluorescent light just isn't bright enough, you can always upgrade from a two-bulb model to a four-bulb light. 

A four-bulb fluorescent light doesn't take up any additional space, so it will fit into the same area as your old light. It will,however, use smaller T-8 type light bulbs instead of the larger T-12 bulbs that you may be using in your current light.

Although T-8 bulbs are smaller, they produce the same amount of light per bulb, so a four-bulb light fixture will double your available light.

What you will need

Four-bulb fluorescent light fixture

Four T-8 type bulbs


Wire nuts and electrical tape (Buy an assortment pack of wire nuts to ensure that you have the size that you need)


Removing the old fixture

You will begin by turning off the breaker that controls power to the light fixture. Turning off the light switch will not cut power to the light fixture. You must use the circuit breaker. This is extremely important because you risk electric shock or electrocution if the light fixture is powered when you start to disconnect the wiring.

When the breaker is off, you will remove the outer cover of the fixture by pulling it away from both sides until it comes loose. If the light fixture is recessed inside a suspended ceiling, simply remove the transparent ceiling panel from the ceiling grid.

You will then remove the bulbs from the fixture. If the bulbs have a single prong on each end, hold the light fixture and press the bulb against one side of the fixture until the spring-loaded prong recesses into the bulb and the bulb is released. Two prong bulbs will need to be turned until both prongs are perpendicular to the floor. You will then pull the bulbs down and out of the fixture.

Remove the cover that hides the wiring by removing the single screw on one side of the cover and pulling the cover away from the fixture. You will see black, white and green wires connected to the fixture. The black and white wires from inside the ceiling will be connected to black and white wires from the light fixture, while the green wire from the ceiling will be hooked to a grounding screw on the fixture itself.

To disconnect the wires, loosen the screw that holds the ground wire, then remove the black electrical tape and wire nuts (they resemble the caps from toothpaste tubes) that hold the two black and two white wires together.  

When all wiring is disconnected, loosen the screws that hold the fixture in the ceiling, and set the fixture aside.

Installing the new fixture

Grasp the three wires from inside the ceiling and pull them through the center hole in the new fixture, then place the fixture against the ceiling and secure it with screws. 

Twist the end of the black wire from the ceiling with the end of the black wire of the light fixture in a clockwise direction. Next, you will choose a smaller wire nut from your assortment pack and twist it in a clockwise direction around the connected black wires. When the wire nut is tight, wrap electrical tape around the open end of the wire nut and the wires until the opening is covered and the wires secured.

Repeat the procedure with the two white wires, then wrap the green wire from the ceiling around the green grounding nut on the new fixture and tighten the nut securely.   

Install the four bulbs and the cover, turn on the breaker, and let there be (much brighter) light. 

Contact local professionals, such as those from Chadwick Electric Services, for further assistance.