Open-Wye-Type Phase Conversion Systems

This paper describes the novel open-wye-type phase conversion system which operates three-phase motors on single-phase power. The system is initially depicted in its most basic circuit, with more sophisticated circuits presented as the paper progresses. Circuit voltages and currents are outlined for the basic system. Also presented is the increment (part winding) starting circuit used for large motors, such as a 100-hp 1200-r/min motor driving a rock crusher, operating on single-phase power.