The common types of faults occurring in synchronous generators are:
Stator winding faults (phase to phase faults, phase to earth faults, inter turn faults),
Rotor winding faults (conductor to earth faults, open circuit faults, inter turn faults),
failure of prime mover, failure of the field, unbalanced loading, over loading, over-voltage at generator terminals, over-speed, ventilation failure, loss of excitation.