What would be the effect on three-phase equipment if the rotation of a bank is changed?

Changing the rotation of a three-phase electrical bank affects the direction of the electromagnetic field produced by the three-phase supply. As a result, three-phase equipment, particularly motors, will spin in the opposite direction when the phase sequence is altered. This reversal can impact any applications or machinery connected to the three-phase system and may cause mechanical issues, especially if the equipment is not designed for bi-directional operation.

This phenomenon is fundamental in three-phase systems, where the phase sequence determines the direction of rotation for motors. Welding equipment, conveyors, and fans, among others, rely on this consistent rotation direction for proper functioning. If the rotation changes, equipment may become dysfunctional, operate less efficiently, or face damage if the load is incompatible with an opposite direction of rotation. Understanding this concept is crucial for lineman apprentices to ensure safe and effective operation and maintenance of three-phase equipment.