Carbon brush collector maintenance on turbine-generators

Carbon-brush collectors have historically been an operations/maintenance concern on turbine-generators. This is understandable in that this relatively small component is one of the most frequent causes of generator forced outages. The root cause of collector service problems is lack of performing the required on-going inspection and maintenance. While this inspection/maintenance effort is relatively minor, it is sometimes overlooked or done inadequately. This paper will discuss collector performance and root causes of collector forced outages, and will provide guidance on identifying and correcting collector operating conditions before serious problems develop. In addition, information is included on retrofit of fixed brush holders with removable brush holders. Performing of the items in the maintenance checklist at the end of the paper, Table 1, should greatly reduce or eliminate exposure to carbon-brush collector service problems.