I agree with all waross said and add the following:
The sparking and burning on the commutator of the DC Exciters is most likely the cause of the subsequent sparking on the slip-ring brushes.
DC Exciters operating correctly will provide a smooth DC current to the excitation slip-rings of the...
Sounds like the fans high inertia is prolonging the startup. At startup with a direct on line starter the inrush current is about 6 x that of full load. If your run up time is longer than say 3-4 seconds this could trip the breaker. Remember the run up time is dependant upon the difference...
Ahmed,
Looks to me like you have two problems, the mounting of the brush holders is not correctly set up. The brushes need to be radial to the commutator. If they run slightly reaction or stubbing (into the toe) vibration and chattering will occur with subsequent breakage. Second problem the...
