Abstract: A method for recognizing a valid change of state in a communication signal including capacitively coupled signals received by an input contact includes maintaining the input contact in a first state and an impedance of the first contact input in a first impedance level, validating that the communication signal sent from to the input contact is a valid change of state, and changing the input contact to a second state and the impedance of the first input contact input to a second impedance level when the voltage signal is validated. An input contact circuit is also disclosed.

Abstract: The measurement of analog coil voltage and coil current during the energizing of the circuit breaker coil that is connected to the output contact of a protective circuit breaker relay in order to detect an incipient failure of the circuit breaker mechanism.

Abstract: A monitor circuit is provided which detects various incipient failure modes of a circuit breaker. The monitor circuit includes a processor and a primary circuit connected in circuit with the processor. The primary circuit may be configured for preventing transients and high currents associated with the operation of the circuit breaker from damaging the processor. A secondary circuit may be connected in circuit with the processor and the primary circuit. The secondary circuit provides an analog voltage input and a current input to the processor that is representative of an aspect of the circuit breaker and wherein the processor is configured to detect at least one failure mode of at least one circuit breaker from the analog voltage and current input.

Abstract: The measurement of analog coil voltage and coil current during the energizing of the circuit breaker coil that is connected to the output contact of a protective circuit breaker relay in order to detect an incipient failure of the circuit breaker mechanism

Abstract: A method for recognizing a valid change of state in a communication signal including capacitively coupled signals received by an input contact includes maintaining the input contact in a first state and an impedance of the first contact input in a first impedance level, validating that the communication signal sent from to the input contact is a valid change of state, and changing the input contact to a second state and the impedance of the first input contact input to a second impedance level when the voltage signal is validated. An input contact circuit is also disclosed.