Installing a Ceiling Fan Using Existing Wiring

Dear Mr. Electrician: I’d like to install a ceiling paddle fan in the bedroom.  The house was built in the 70’s.  The fan would be mounted onto an existing ceiling light fixture box on the 1st floor.  The electrical box in the ceiling is metal, but I’m not sure how it is attached to the joists.  The box is round and has 2 metal arms extending out.  I saw the house being built back then but I don’t remember if it’s nailed or just tacked with metal type prongs.

Answer: You will have to remove the old ceiling light electrical box as it is not approved for ceiling fan support.  Shut off the circuit breaker for this particular lighting circuit.  Start the removal process by disconnecting and separating the wires and identifying them with colored tape or numbers.  This will help when you put them back together.

Loosen the screw for the wire clamp or unscrew the locknut on the cable connector.  Remove the center screw(s) that holds the box to the support brace and carefully pull the box down while removing the wire from the box.  Do not cut or damage the wires.

Removing the old ceiling box support bracket that is up inside the ceiling can be difficult.  I usually just use my 24″ bolt cutter’s to cut it in half.  Then I swing the cut pieces forth and back to see if they loosen from the ceiling.  Most of the time they are nailed in and the longer the nail, the more difficulty there is in removing the bracket.
I have some mini pry bars for just such an occasion.  I can get a short pry bar up in the ceiling and reach over and get it behind the nailed-in bracket and give it a few tugs to get it loose enough for removal.  Persistence is the key.  If you get frustrated with the old box removal, take a short break and then get right back at it.

Once the old box and support has been removed you are free to install a new ceiling fan brace and fan rated box as per article 314.27(2)(C) in the National Electrical Code (NFPA 70).  Also read article 422.18.  The new ceiling fan braces are relatively easy to install.   The ends of the brace are made in such a way that they will position the box at the correct height as they rest on top of the drywall ceiling.  Just line the brace up with the center of the hole and tighten it according to the manufacturers instructions.  The fan brace will expand as you turn it and will bite into the joists.  The brace should be straight and level as it goes from joist to joist and should be centered on the existing hole in the ceiling.  Confirm that the fan brace is solid by giving it a strong tug.  Bring the wire into the fan box using a cable connector or clamp before attaching the box to the fan brace.

Occasionally I have an installation that is not so typical and requires some thought and ingenuity to get a ceiling fan box installed.  One of the most common out-of-the-ordinary installations is when double drywall is used on the ceiling.  Sometimes I also encounter resilient channel.  My simple fix is to buy a regular fan brace kit and also buy a separate 2-1/8″ deep fan box to use instead of the 1 1/2″ box that normally comes with the fan brace.  It is possible to buy a fan brace with a deep box, however the legs on the brace are longer, therefore the deep box will not sit lower.  I have heard of other electricians cutting the legs a little to bring the box down.  That works as long as the fan bracket is able to engage into the ceiling joist.

Ceiling fan manufacturers usually furnish installation instructions and many have simplified the process by the addition of a hook or hole to hold the fan motor up on the ceiling while you splice the wires together.  Ceiling fan installations vary slightly by manufacturer and even from low end models to high end models.  If installing a ceiling fan is new to you, I suggest that you read the instructions and also plan it out on the floor how the ceiling fan needs to be assembled.  Do not try to assemble the fan on the floor and mount it on the ceiling as a whole unit.  It is not made to be done that way.
Start by grounding the new fan box with the existing bare or green ground wire and a green ground screw.  Leave a grounding pigtail long enough to extend past the box a few inches.

Next mount the bracket that came with the fan using the screws and hardware that came with the fan brace and box kit.

You may find my post about repairing loose ceiling electrical boxes helpful.