STC series are to be used in town ,the countryside ,worksites,mountain districts and pastrue lands as a electric power source for lighting purpose.It can also be used as a reserved power source for emergent case.The alternator are of dripproof with rotary field type and with the adoption of harmonic excitation system,that allow your easy operation and simple maintenance.The generators are of three-phase four-wire type,making use of star connection with meutral point.The rated line voltage is 400V ,phase voltage 230V frequency 50Hz,power factor 0.8(lag).It can provide 60Hz and the other voltage's alternator according to necessery. They can be coupled with a prime mover directly or through V-belt ,   making right or reverse continous rotation at the rated speed.When the revolution slip of prime mover is 3% and load varies in the range of 0→100% and 100%→0,cosΦ1.0→0.8 and cosΦ0.8→1.0 ,they give good constant voltage.After sudden change(increase or decrease) of load ,the alternator will soon return to their normal working state.Without any stating devices the alternator can directly start an unloaded squirrelcage includtion motor.