What is Three-Phase Power?
Three-phase electric power is a common method of alternating-current electric power generation, transmission, and distribution. It is the most common method used by electrical grids worldwide to transfer power, power large motors and other heavy loads. A three-phase system is usually more economical than an equivalent single-phase at the same line to ground voltage because it uses less conductor material to transmit electrical power.
Three-phase voltage refers to three voltages that vary by 120 electrical degrees or one third of a cycle from one another. It goes through a phase sequence in a regular order. Voltages can be obtained by using six wires with two wires for each phase. However, three wires are always used to supply three-phase voltages. Each phase voltage is from one of the three possible pairing of three wires. Sometimes, four wires are also used for powering three-phase voltages. The additional wire is used as a grounding or neutral wire.