What are the daily inspection items for carbon brushes

The carbon brush and slip ring should be inspected every day, and the main inspection items include:

(1) The wear length of the carbon brush shall not exceed 2/3. When the wear length of the carbon brush exceeds 2/3 (i.e., the top of the carbon brush and the top of the brush holder are in the same plane), it must be replaced.

(2) The carbon brush shall not emit sparks. When the carbon brush starts to spark, it is necessary to find the cause and eliminate it in a timely manner.

(3) The carbon brush shall not deviate from the outer side of the slip ring, and the edge of the carbon brush shall not be cracked.

(4) The connection between the carbon brush braid and the brush holder and carbon brush is good, without heating or touching the brush holder.

(5) The carbon brush does not bounce, shake, or jam in the brush holder.

(6) Regularly use a DC clamp type meter to measure the uniform current sharing of each carbon brush, and use an infrared thermometer to measure whether the carbon brush is overheated. If there is any abnormality, replace it in a timely manner.

(7) The spring pressure is normal, without deformation and fracture. Under normal conditions, the pressure applied to each carbon brush should be uniform and stable, with a unit pressure typically between 1.1kg and 2.5kg, and the uneven pressure difference between carbon brushes should be within 5%.

(8) The distance between the brush holder and the slip ring meets the specified value. The distance between the generator brush holder and the slip ring is 2.5 to 3 mm, and the distance between the main excitation brush holder and the slip ring is 2 to 4 mm.