Patent ID: 8796980

Claim:
A fault detection system for an over-speed protection system of a rotating machine including a first speed sensor, second speed sensor, and third speed sensor sensing a speed of a shaft of the rotating machine, the system comprising: a first input configured to receive a first pulse train from the first speed sensor; a second input configured to receive a second pulse train from the second speed sensor; a third input configured to receive a third pulse train from the third speed sensor; and a processor configured to generate a shutdown signal for the rotating machine based on the first pulse train, the second pulse train, and the third pulse train; a first error integrator configured to process the first pulse train and the second pulse train and output a first fault signal; a second error integrator configured to process the first pulse train and the third pulse train and output a second fault signal; and a third error integrator configured to process the second pulse train and the third pulse train and output a third fault signal, wherein the processor generates the shutdown signal for the rotating machine based on the first fault signal, the second fault signal, and the third fault signal.