Three phase power:In electrical engineering, three-phase electric power systems have three conductors carrying alternating current voltages that are offset in time by one-third of the period. A three-phase system may be arranged in either a “delta” or “star” (Y) configuration. A wye system allows the use of two different voltages from each phase, such as a 240 V line-to-line voltage and a 120 V line-to-neutral voltage. Star or Y configurations are generally used when there is a need for multiple voltages, such as in an industrial facility where 240 V three-phase is used for large motors and other equipment, while 120 V three-phase and single-phase are used for lighting, office equipment, and smaller motors.
