I have photos of the brush holders, but they're on a different computer. Will upload them tomorrow.
Geometry of the brushes & holders has been verified correct. Mass-loss of the brushes is also monitored closely and plotted over time with no outrageous degredation of the brushes. Spring...
One of my clients has experienced failures on a Toshiba 6500kW, 11kV WRIM where a phase-to-phase arc destroys the slip rings during start-up. After the 1st failure, the mfg suggested that poor housekeeping (carbon dust build-up) and excessive start events contributed to the failure...
