A three-phase power supply is a special method to alternate power generation, transmission and distribution. This method establishes power supply delivery in three lines, and each line is a phase that carries equal voltage at equal frequency.
Generally, a three-phase power supply may or may not have the neutral wire. The exact method involved in this procedure is for the use of higher voltage at the same time as support for lower voltage situations with single-phase supply. Also, this three-phase system requires less conductor material for transmitting power than the equivalent single-phase, double-phase or direct-current system at a similar voltage.