I have standing fan, it has a simple 0-1-2-3 pushbutton switch system with a timer.
A few days ago it stopped working. If I try pushing the blade (with an insulated screwdriver, of course, not with my fingers) there's clear resistance before it spins for roughly one rotation then seizing up again.
If I power the fan down (pressing 0 or unplugging it or turning the timer to "off"), the blades can rotate freely. No resistance (aside from initial inertia), no seizing up. Pushing the blades hard will cause it to rotate several times before stopping due to (seemingly normal) friction.
What could be the problem with this fan? And how do you suggest I fix it?
Best Answer
I'm going to suggest that this fan has reached the end of its useful life. It sounds like there is a bearing problem that is impeding the rotation.
This is almost certainly an induction motor and one characteristic of these is that once power is applied, the magnetic field from the stator not only tries to rotate the rotor but also pushes is axially forward or backward. So when you turn the fan ON, there is a force on the shaft that is not present when the power is off. That's putting pressure on the bad bearing and stopping it from turning.