Some troubles encountered in the operation of carbon brushes in direct-current generators and motors

This paper deals very briefly with troubles which affect the operation of carbon brushes on motors and generators. It should be of great assistance to the operator in locating various machine troubles and in securing the best service from his brushes. The paper is divided into five sections, based on the location of the cause of trouble: (1) field, (2). armature, (3) commutator, including brush rigging, (4) external electrical, and (5) external mechanical.