The voltage of the alternator is 230V or 431V( the frequency is 50Hz or 60Hz Its operation mode is of continuous duty. The alternator can be coupled with a prime mover directly or thorough a V-belt. with 5% change of speed the prime mover under load variation of 0-100% at a voltage of 230V or 400V 50Hz or 60Hz to get a satisfactory constant-Voltage performance.