What is the method to reverse a three-phase motor?

To reverse a three-phase motor, the method involves swapping any two of the three phase leads connected to the motor. This effectively changes the direction of the magnetic field produced by the motor, which in turn causes the rotor to spin in the opposite direction. This is a well-established and straightforward technique used in three-phase systems due to the symmetrical nature of the three-phase electrical supply.

The other methods mentioned are not suitable for reversing the direction of a three-phase motor. Changing the electrical connections to a higher voltage does not impact the direction of rotation; it would only increase the voltage supplied, which could potentially damage the motor. Altering the output frequency from the motor controller can affect the speed of the motor but does not inherently reverse the direction unless specifically programmed to do so. Lastly, swapping field or armature leads pertains more to DC motors or specific types of configurations and is not applicable for the three-phase AC motors in question. Thus, the correct method for reversing a three-phase motor remains the swapping of any two of its phase leads.