... easy operation and maintenance. The alternators are three-phase, four-wire type, adopting star connection with neutral ... point. The rated line voltage is 400V, phase voltage 230V, frequency 50Hz. power factor 0.8( ... range of 0~100% cos j 0.8~1.0, the alternators offer constant voltage, when sudden ... excitation system, easy operation and maintenance. STC Three-Phase A.C, Synchronous Alternators