... harmonic excitation system, easy operation and maintenance.The generators are three-phase, four-wire type, adopting star connection with neutral point. ... The rated line voltage is 400V, phase voltage is 230V, frequency is 50Hz. power factor 0. ... 1000m Cooling air temperature: 258~313K(-15 oC ~ 40 oC) Relative air damping: not exceed 90% STC Series Three Phase Synchronous Generator,