There may be four reasons why the generator brush sparks:
The carbon brush pressure is uneven or does not meet technical requirements. According to practical experience, the minimum pressure of non-sparking commutator ring carbon brush is 200C300g/cm2, and the pressure of each carbon brush should be uniform.
The material of the carbon brush does not meet the requirements. The carbon brush material is incompatible with the slip ring material, resulting in an increase in the coefficient of friction and the formation of sparks.
The carbon brushes are poorly sharpened. If the carbon brush is poorly ground and the surface roughness is too large, the contact surface between the carbon brush and the slip ring will be in poor contact, resulting in sparking.
Voltage fluctuation or overload. Excessive voltage fluctuation or overloadthe generator output will cause sparks in the brushes.