(1) The wear length of the carbon brush should not exceed 2/3. When the wear length of the carbon brush is more than 2/3 (i.e., the top of the carbon brush is in the same plane as the top of the brush grip), it must be replaced.
(2) There is no spark in the carbon brush. When the carbon brush first starts to spark, it is necessary to find the cause and eliminate it in time.
(3) There is no offset on the outside of the slip ring of the carbon brush, and there is no cracking at the edge of the carbon brush.
(4) The carbon brush braid is well connected with the brush holder and the carbon brush, and there is no heat and touch the brush.
(5) There is no jumping, shaking or jamming of the carbon brush in the brush grip.
(6) Regularly use a DC clamp meter to measure the current sharing of each carbon brush, use an infrared thermometer to measure whether the carbon brush is overheated, and replace it in time if there is any abnormality.
(7) The spring pressure is normal, and there is no deformation and fracture. Under normal circumstances, the pressure of each carbon brush should be uniform and stable, and its unit pressure is usually between 1.1kg~2.5kg, and the uneven pressure difference between each carbon brush should be within 5%.
(8) The distance between the brush grip and the slip ring conforms to the specified value. The distance between the generator brush grip and the slip ring: 2.5~3 mm, the distance between the main excitation brush grip and the slip ring: 2~4 mm
