Ceiling fan hum

Would spinning it by hand help narrow things down? Try it both directions.

Seems unlikely that a bearing would cause a hum. IDK how all they use a cap in these, but seems a cap could be used at the higher speed too.

Teach it the lyrics and it will sing instead of hum.

Is the hum speed-dependant? When the fan starts from 0 to final speed, does the hum frequency also increse?

Does your fan go in two directions? Not manually but electrically. What is the hum like in the other direction?

I didn't think ceiling fans spun enough to wear out a bearing. I have table fans that I've used for years and the bearings are fine, and they spin much much faster. Unless ceiling fans allow for this by using cheaper bearings? Seems unlikely since the fans cost so much more.

What happens if you hold the blades while you turn the fan on so that it can't spin. Does it still hum? If so, it's not the bearing. (I wouldn't try catching it once it's already spinning, unless maybe I used a catcher's mitt.)

Humming or vibrating? How to describe the difference? I guess it's the previous paragraph.

Check the spark plug.  Is this a two or four stroke?

Manual Spin: Spinning the fan manually or letting it spin up on its own and cutting power does not produce any hum.

Sound: From the frequency of the hum, its definitely power-supply related.

New Observation: As you watch the blades spin at lower speeds or while they are starting up, you notice the hum becomes louder at one particular location. (watch one blade, and as it passes a particular location the hum increases and then decreases after it passes)

May not be bearing, may be motor or communicator related ? Could be resistance at one location on the bearing or comm' ?

Now Observation: Today it took about 2 min for the hum to start from off on first power on. (fan had been off for a week, couldn't sleep w/noise)

Holding on to the blades: No Hum Hum Both directions: Yes Speed-dependent: No

Thanks

Bad bearings load the motor down and the windings cause vibrations.

Maybe just a slightly tilted blade?

Or maybe a loose winding. Sometimes you need to shim the winding with something as small as a toothpick or two - or tighten a stator bolt

I think we have a winner ;-)

As these things get old and the insulating membranes start to deteriorate the windings can resonate at 60hz. Silly putty or duct seal pushed in at the offending point might stop it. I would still be doing my poking wearing a voltage rated glove or an insulated stick if I was looking for the bad spot