What is the reason why the ventilation fan in the bathroom slows down after being turned on for a pe

The solution is to remove the motor, polish the shaft with fine sandpaper, and fill the bearing and linoleum with high-quality lubricating oil with high temperature resistance, and reinstall it to try it.

The speed of the ventilation fan slows down after it is turned on for a while:

1. The motor has been used for a long time, and the shaft end lacks lubrication, so lubricating oil needs to be filled;

2. The motor winding has been burned, the degree of insulation has decreased, and there is a slight short circuit in the winding, and the motor needs to be replaced;

3. Poor starting capacitor;

4. Poor contact between the joints of the wire or the switch.

Explain that the quality of the motor of the exhaust fan is too poor, and the heating is serious after working for a period of time, resulting in the motor holding the shaft, the motor can be disassembled and polished with fine sandpaper to polish the shaft, clean the bearing, and then add high-quality lubricating grease with high temperature resistance, as well as bearing linoleum, and then reinstall, the screws should be slowly tightened diagonally, and at the same time, the motor shaft should be knocked on the motor shaft with the screwdriver handle to make it concentric with the stator, and the shaft must rotate flexibly after fastening.

What brand of ventilation fan are you using? In this case, a two-stage motor is generally used, and there is a resistance booster function. When the air is circulated, the pressure is relatively stable, and the number of revolutions will naturally drop, which is generally a normal phenomenon.

If the temperature of the motor is too high, add some oil to the shaft of the exhaust fan.