① The rotating shaft is stuck, and the fan blades are difficult to start after being electrified, and the operation is weak and there is abnormal noise. This situation is mostly caused by poor use environment (oil smoke, dust, high temperature).
Inspection: When power is cut off, you can find that the rotating resistance is large by pulling the rotating shaft.
Treatment method: clean the motor shaft. Without disassembling the machine, the rotating shaft can be decontaminated and cleaned with carburetor cleaning spray while rotating the blades, and then lubricating oil is added. The best way is to disassemble the motor, thoroughly clean the shaft and bearing, and then add lubricating oil. After reassembly, tap the shaft with a wooden stick for concentric correction to make the shaft flexible and free.
(2) The capacitor is damaged, and the capacitor is nonpolar, which is used to convert single-phase alternating current into two phases to generate a two-phase rotating magnetic field, increase the starting torque and make the rotor rotate.
Inspection: When testing with general ammeter R× 1K or R× 10K, there is obvious needle jumping reaction, and its resistance should be infinite after needle return.
Treatment: For breakdown (path) and capacitance reduction, replace the capacitance. Non-polar capacitor can be used instead, with the withstand voltage of 400V,1.2 ~1.8 μ f.
(3) After the reasons of 1 and 2 are eliminated, if the motor winding still can't rotate, it will cause serious fever, which is often a partial short circuit.
Inspection: Take the 5-wire fan motor as an example, and test it with multimeter R× 100 or R× 10. The black line is the male * * terminal, which is red, white and blue. (The resistance difference of each speed regulator is about100Ω) and the resistance of yellow (capacitor) should be between 600 and 900Ω. The resistance of the shell should be infinite.
Treatment: If an open circuit or short circuit is found (the resistance value is obviously reduced), it cannot be repaired by itself, so the motor can only be replaced.
(2) There is no response after power-on, and the plug resistance is infinite when power is off (the electric fan is placed vertically, and the timing and speed control switches are turned on).
This situation is that the circuit is open. If the timer, speed regulating switch, safety anti-dumping power-off switch and thermal protector (some fans have them) on the motor are detected step by step with an electric meter, the fault position can be found quickly, and the corresponding treatment such as maintenance and replacement can be carried out.