To reverse the direction of rotation of a phase motor, what must be done?

To reverse the direction of rotation of a phase motor, reversing the leads is the correct approach. This method works because most phase motors, such as single-phase induction motors, determine their rotational direction based on the phase sequence of the electrical supply. By swapping the connections of the motor leads, you essentially change the phase relationship between the motor windings, which in turn alters the magnetic field orientation. This results in the motor rotating in the opposite direction.

Other options may seem relevant but do not achieve the desired effect. Changing the power supply could affect voltage and current but does not specifically address the direction of rotation. Increasing the voltage might improve performance or speed, but it also does not influence the rotational direction. Similarly, changing the capacitor, which might be applicable in some scenarios (like tuning or improving starting torque), does not inherently reverse the direction of rotation. Therefore, reversing the leads is the clear and effective method for changing the direction of a phase motor.