To change the rotation of a 3-phase motor, what must be done?

To change the rotation of a 3-phase motor, swapping any two of the three phase supply leads (often referred to as T leads) is the appropriate method. In a 3-phase motor, the motor's direction is determined by the sequence of the electrical phases. When two of these leads are swapped, the phase sequence is altered, which effectively reverses the magnetic field direction within the motor. This, in turn, reverses the direction of the motor's rotation.

This technique is widely used in industrial and commercial environments where the speed and direction of motors need to be controlled efficiently. It’s also essential to ensure that the motor is not under load when making this change to prevent potential damage or operational hazards.

The other choices provided do not change the motor's rotation in the correct manner. For instance, changing the power supply would not influence the phase sequence. Simply reversing the motor direction is not a feasible approach, as the motor’s mechanical structure does not allow for that. Adjusting the load could impact performance but does not influence rotation. Thus, swapping two phase leads is the only method to achieve the desired outcome effectively.