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.
How to deal with sparking in the generator carbon brush
1. Check if the broom length is too short and reaches the lifeline, resulting in too much pressure. too small and the brush contacts and does not slide up;
2. Check if the finger pressure is too small, it will cause brush discharge;
3. Check the surface finish of the slip ring. If it is too hairy, it will increase the electric current. The contact resistance of the brush will cause large sparks.
4. make sure the resistance is normal and there is no short circuit between turns;
5. Check if the oil gap in the bearing is too large, causing the rotor to rotate on the slip ring. large Check whether the radial runout on the slip ring surface is too large. The brush rbounces and causes sparks;
6. In addition, if the brush is consistent with the one used previously. The brush has requirements for conductive current and friction speed.
Methods to prevent sparking from generator carbon brushes: Check carbon brushes and slip rings daily
1. The wear length of the carbon brushes should not exceed 2/3. When the wear length of the carbon brush exceeds 2/3 (that is, the top of the carbon brush and the top of the brush holder are on the same plane), it should be replaced.
2. There is no spark from the carbon brush. When the carbon brush just begins to spark, it is necessary to find the cause and eliminate it in time.
3. There is no deviation of the carbon brush from the outside of the slip ring, and there is no crack on the edge of the carbon brush.
4. LThe braid of the carbon brush is well connected to the brush holder and the carbon brush, and there is no heat or contact with the brush holder.
5. The carbon brush does not jump, shake or get stuck in the brush holder.