1. Modern box fan the motor is not lubricated: The first thing to think about is that the motor is not lubricated. The shaft part should be lubricated. The fan blade is installed on it and the motor cannot be dragged. After removal, the shaft can still run normally, which means the motor is not broken. How to judge the lack of oil? That is, after disconnecting the power, gently flip the fan blades, and found that the rotation is a bit stiff, indicating that the oil is gone, and it turns easily, indicating that the lubrication is good, and this is not due to other reasons.
2. Modern box fan fan Excessive motor loss: Secondly, you have to consider how long the electric fan has been used, the motor will be worn out, and the shaft sleeve of the motor will easily burn out. If the motor is used for a long time, the internal resistance of the motor will also increase, and the load capacity will be reduced, resulting in the inability to drive the blades to rotate.
3. Motor overheating: Overheating of the motor will also cause the load capacity of the motor to deteriorate, and the active power of the motor will decrease, resulting in the inability to drive the load.
4. Partial short circuit of the coil winding: From the inside of the motor, there is a protection device inside it, and there is an overheating circuit breaker, that is, the coil winding part is short-circuited, which causes the heat generation to rise sharply and the circuit breaker opens. In this case, the motor is generally It went on strike. This rarely happens.
5. Capacitor capacity reduction: There is also a decrease in the starting capacitor capacity. Although those parameters are written on the nameplate, the capacitor capacity will decrease after a long period of time, which will cause the motor’s starting torque to become smaller and fail to drive the load. This is simple. Remove the capacitor and replace it with a new one. The same model should be no problem. But it is best to change to a 20% larger than the original one, and you will get better results.
6. The axial clearance of the motor shaft is too large: If the motor is disassembled, the axial clearance of the shaft is too large and should be adjusted by adjusting the gasket. When installing the motor, the rotor must be concentric with the bearing, and the screws should be slowly tightened diagonally, and then knock the shaft with a screwdriver to make it concentric. It’s easy to disassemble the motor, but you don’t just put it back in and put it back in again. Don’t happen to the above situation, otherwise, just repair the “broken”. There are many types of electric fans and their sizes are also different.