Installing Fluorescent Lights


Fluorescent lighting is inexpensive to run, but the light from standard tubes is cold and industrial. Replace them with tubes labeled "warm" or "full spectrum," which produce light that is more suitable for a home. Adding a translucent cover diffuses the light and reduces the glare.

Replacing an incandescent fixture with a fluorescent one is relatively easy. If your goal is simply to save energy costs, simply install a fluorescent bulb in an incandescent fixture.

An existing fluorescent light might have cable running directly into it with no electrical junction box. That's OK -- usually the fixture's housing is considered adequate for protecting spliced wires.

Because some fluorescent fixtures are heavy and bulky, enlist a helper when removing or installing one.


About 1 hour to remove a fixture and install a new fluorescent

Screwdriver, drill, strippers, side cutters, voltage tester, lineman's pliers, ladder

Stripping and splicing wires, driving screws

Spread a drop cloth on the floor beneath the light; set up a stable ladder

New fluorescent fixture, wire nuts, screws, electrician's tape

Step 1

Shut off power to the circuit. Remove the wire nuts and disconnect the house wires from the fixture wires. Or snip and restrip them. Loosen and remove the locknut that holds the cable clamp to the fixture.

Step 2

Remove the screws holding the fixture in place -- usually there are several driven into ceiling joists. Support the fixture as it comes loose and guide the wires out through the hole. Note the locations of the ceiling joists. Mark the new fixture to line up screws with joists.

Step 3

With a hammer and screwdriver, open a precut knockout hole in the top of the fixture, then twist off the piece with pliers. Thread the wires through the hole and attach the cable clamp to the fixture with a locknut.

Step 4

Have a helper hold the fixture against the ceiling. Drive the mounting screws into joists.

Step 5

Wire the fixture. Connect the ground wires together and to a grounding screw on the fixture. Splice white fixture wire to white house wire and black to black. Install the fixture tubes and cover.

Replacing a Fluorescent Fixture in a Suspended Ceiling: Step 1

To replace a fluorescent fixture in a suspended ceiling, shut off power to the circuit. Remove the ceiling panels around the fixture. Remove the diffuser, disconnect the wires, unscrew the locknut, and pull out the cable. With a helper lift the old fixture out and set the new fixture in place in the ceiling frame.

Installing a Fluorescent Fixture in a Suspended Ceiling: Step 2

Clamp the cable and splice the wires, as in Steps 3 and 5 above. Replace the ceiling panels, install tubes, and slip on the diffuser.

Circular Fixture

A round fluorescent fixture usually mounts to a box. Thread the house wires through the hole in the middle and splice them to the fixture wires. Start driving both mounting screws into the electrical box, then tighten.

Fluorescent Fixture mounted to Electrical Box

Sometimes fluorescent fixtures are mounted to an electrical box. In this common arrangement a nipple (short threaded pipe) and the wires poke through a hole in the middle of the fixture.

Comments (3)
Add your comment

You must be logged in to leave a comment. Register | Log In
One Hour or Less

Three simple projects to cross off of your to-do list -- just print these instructions and begin!