What causes the fan reversal?

Detailed reasons for fan inversion:
1. If the fan motor starting winding is reversed, the fan will reverse, and the two joints of the starting winding can be switched to solve the problem;
2, there are two winding inside the fan, a main winding and a secondary winding, the main winding plays a running role, the secondary winding plays a starting auxiliary role. Capacitance is to change the degree of the magnetic field, so that the phase difference between the main winding and the secondary winding. If the main winding is ahead of the secondary winding degree, the motor is turning, otherwise, the main winding lags the secondary winding degree, the motor will reverse;
3, therefore, as long as the capacitor wiring is changed, it is easy to achieve positive and negative rotation. You can also find a double control switch, the terminals of both ends are connected to one end of the main winding and one end of the secondary winding, and the central contact of the double control switch is connected to the power line. Then connect the two terminals at the other end of the main winding and the secondary winding together, connect them to the neutral line of the power supply, press the switch to turn the fan motor in the positive direction, turn off the switch, and the fan motor will reverse;
4, general electric fan production, the motor is only designed to turn forward, there is no positive and negative rotation, because the main winding and secondary winding coil turns are different, and some wire diameters are different, so the positive and negative operation of the output power, speed and other working conditions are not the same.