Talking about the broken electric fan.

1. The rotor shaft of electric fan motor is stuck due to lack of oil;

2. The front and rear end covers of the electric fan motor are offset, resulting in the rotor shaft being stuck;

3. The starting capacitor is disconnected (or the capacity is reduced), resulting in no current (or too small current) in the starting winding coil, and the motor cannot rotate;

4. The coil of the starting winding of the electric fan motor is open. At this time, there is no current flowing through the starting winding, so it will not rotate, just "buzzing, buzzing". You can turn the fan blades slightly hard without electricity to see if the motor can rotate easily. If it can rotate easily, it is generally the fault of starting capacitor and starting winding. If it is difficult to rotate, it is usually the reason why the rotor is stuck. Pay attention to safety when electrifying.

Second, if the electric fan doesn't turn, it depends on the sound.

1. Connect a new capacitor of the same model directly at both ends of the original capacitor to see whether the electric fan rotates (this step is to check whether the fault capacity of the fan capacitor is small, so connect a capacitor in parallel; If the fan is normal, it means that the capacitor fault capacity in the original electric fan is too small. You can delete it and install a new capacitor. Of course, if you can measure with a multimeter, you will soon find out whether the capacitance is leaking or not and whether the capacity is too small. )

2. Check whether the timing switch, gear selector switch and anti-fall switch (some fans have them) are in poor contact or damaged, and replace them. Excluding these peripheral components, if it doesn't turn, the motor must be broken. Go to step 3.

3. Dial R× 100 with a multimeter. First test the motor leads at both ends of the capacitor to see if the multimeter indicates, that is, check whether the main coil of the motor is conductive, if not; Explain that the motor is broken (the coil copper wire is burnt out);

If it is connected but still does not turn, further test the remaining wires to see if there is a local short circuit in the coil of the motor (the specific method is a bit troublesome and will confuse you; You just need to check the first two steps. The fan doesn't work, the motor must be broken);

4. Another common fault of the motor: mechanical fault, such as: the electric fan that has been used for several years is dirty and blocked; In order to show that you can't rotate the shaft by hand, spray "gasoline" or "general lubricating oil" on the motor shaft several times to make the motor shaft rotate flexibly (but it is best to replace the motor.

Because the motor used for several years is blocked by dirt, mostly because the motor shaft and shaft sleeve are worn, refueling can only solve the problem temporarily, and it will be blocked by dirt soon. You can tap the motor shaft gently with a Phillips screwdriver until it rotates very flexibly.