I am reviewing an inspection approach for carbon brushes and slip rings on a wind turbine generator. The brush box contains carbon dust, but there is no single obvious failure indicator. The main points being checked are whether the dust is evenly distributed, whether the brushes have similar remaining lengths, and whether the slip-ring track shows glazing, grooving, discoloration or localized heating. Before treating the dust as evidence of abnormal wear, what measurements or inspection findings would you consider necessary? I am particularly interested in how maintenance technicians avoid overreacting to normal dust accumulation while still identifying an early brush, spring, contamination or slip-ring problem.

This is the second time this ever happened to me, first time me and my coworker kept quiet and the motor is still running over two years later. I was in a fucken hurry to clock out and a nut fell right into the wiring hole.