To reverse it, we need to change the direction of the rotating magnetic field produced by the main and starter windings. And this can be accomplished by reversing the polarity of the starter winding. If you were to switch the main and starter windings, as one does with a split phase motor, the motor will also reverse.
How do you change the direction of rotation of a split phase induction motor?
You have to stop the motor before you can reverse it. That lets the starter winding establish the new direction (and if the starter winding is disconnected by a centrifugal switch, it lets the switch turn on again. Capacitor and split phase start induction motors don't need the start winding to run.
Can I reverse the direction of any motor?
In order to reverse the direction of an AC motor, the magnetic fields must be altered to provoke movement in the opposite direction. ... This easy switching of wires works because the polarity of the magnetic field is reversed, thus reversing the motor.