So in my apartment, tenants aren't allowed to drill holes in the ceiling (it's concrete), but there are junction boxes available where lighting/fans can be installed.

I thought it might be a good idea to repurpose these junction boxes to mount my projector.

To start, I bought a junction box cover, drilled holes in it, and bolted in a projector mount.

I also drilled an additional hole for the power line. My projector uses a typical pc power cable, so I cut off the end that normally plugs into the wall and ran it through the hole in the junction box cover. The colors of the wires from the power cable were a little unfamiliar, but I mapped them brown to black, blue to white, and green to green.

So two things:

1) Is this a good idea as far as weight/support? I was told it was ok to mount a ceiling fan and the projector should be on the lower end of what a ceiling fan might weigh.

2) On my initial test run everything worked as far as the mounting went, but my projector didn't operate normally. It's fans made an unusual noise, the picture flickered, and after a minute or so it would turn itself off. This leads me to believe there might be something wrong with the power supply, but as far as I know, power supplied to the ceiling should be the same as that supplied to the outlets. Is there something I might have done wrong in wiring, or could this be an issue somewhere else?


  • your wiring sounds correct. try a different cable connected to a regular outlet just to see if that makes any diference.
    – Jasen
    Commented Nov 22, 2019 at 23:33
  • Can you post photos of the inside of the ceiling box please? Commented Nov 23, 2019 at 0:39
  • 1
    For part 2: If the "switch" on this circuit is really a fan control, you could get odd power issues from that.
    – Ecnerwal
    Commented Nov 23, 2019 at 0:43

1 Answer 1


Your cord penetration needs to either be grommeted, or use a proper cable clamp in a standard knockout hole. They sell junction box covers with standard knockout holes.

Mechanically, what you did is fine as long as the projector weighs less than 4 pounds. If it weighs more, you need to properly tie into the fan support structure in the way that you might for a chandelier.

The data cable cannot run in the same in-wall conduit or raceway as the power cables. You might consider stick-on surface mount wire loom for the low-voltage cables. Alternately, you could remove all mains voltage wires from the conduit, and replace them with signal cables and 12/18/24VDC to power the projector, e.g. Extend the wires on the projector's wall wart.

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