How can the direction of a three-phase delta connected AC induction motor be changed?

The direction of a three-phase delta connected AC induction motor can be changed by interchanging any two supply connections. This is due to the way three-phase systems work: the rotation of the magnetic field generated by the motor is determined by the sequence of the phases.

In a three-phase system, the phases can be labeled as A, B, and C. When the connections of two phases are swapped, the sequence that drives the rotating magnetic field also changes. For example, if the original sequence is A-B-C, interchanging A and B will change the sequence to B-A-C, which effectively reverses the direction of the magnetic field and hence the motor's rotation.

This method is straightforward and does not require mechanical alterations or extensive rewiring of the motor itself. Other options, such as reversing the motor load, changing the supply voltage, or rewinding the motor, do not affect the fundamental operation of the motor's direction in the way that altering the phase connections does. Changing the supply voltage, for instance, can affect the torque and speed of the motor but will not change its rotational direction.