(1) Remaining voltage is too low ( less than 2% Rated voltage at Rated Speed) can’t exitation, can use 3-6 volt dry cells or batteries and other DC for magnetization , when magnetizing, note that the positive connection L4, the negative pole L2. (2) Wiring erro: Check wiring errors carefully, correct according to wiring diagram (3) Field coil turnoff: Re-connected field coil circuit breaker and solder weld, external insulation wrap. (4) The excitation device terminals loose or poor contact, wipe the lugs after properly connected. (5) Brush and slip ring brush pressure is bad or insufficient, clean collector ring surfaces , grinding brush surface, so that the surface coincide with the collector ring , replace the brush spring constant. (6) Meter incorrect, regularly check meter. (7) The magnetic field coil section short circuit or ground, replace the field coil. (8) The generator armature coil circuit breaker, find where to re- weld dressing. (9) Generator armature short circuit, generator armature coil short circuit can cause severe fever phenomenon, then replace the coils. (10) Silicon Rectifier damaged or silicon element overvoltage protection RC damaged, replace Silicon Rectifier and adjust RC protection rectifiers elment.
(11) Reactor air gap is too small after overhaul reactors, increase the air gap

2. Generator voltage is too high :
(1) Excessive speed, reduce prime Rated Speed.
(2) when re- tuning the excitation device reactors electric reactor has too large gap, reduce the air gap.
(3) Open field rheostat, check the rheostat.

3. Generator voltage is abnormal
(1) Wrong reconnection of main pay winding phase sequence or additional winding, examine and reconnect.
(2) Sparks brush: Brush and brush collector ring connection is bad, brush spring pressure is not enough.

4. Generator overheating
Overload: Pay attention to ammeter at any time, avoid its ampere meter over rated , and pay attention to the load power factor is too low , in order to avoid overheating of the
Magnetic field coils, replace magnetic field coil shorted coil .
Armature coils short, replace the shorted armature coil.

5. Bearings Overheating
(1) Excessive bearing wear, replace the bearings .
(2) Lubricant specification does not match, put too much oil, or oil has impurities, cleaning bearings with kerosene oil, keep fuel tool clean.
(3) Generator Set connection centre is not straight , re- butt joint the correction center axis.