Abstract: Employee #1, a cogeneration mechanic, was assigned to clean the electrical contact surface of the turbine exciter. The outer surfaces were readily accessible but he asked the assistant plant manager if the upper collector brush assembly could be removed to facilitate access to the rear surface. His request was denied, and he was not given any directions on how to access the rear surface. With the collector moving at 1 to 3 rpm, Employee #1 attempted to clean the rear surface with a rag. His hand became caught by the rotating collector head and he suffered a severed nerve and a broken knuckle. Employee #1 was hospitalized for 16 days for corrective surgery and skin grafts.