Patent ID: 8837103

Claim:
A circuit breaker electronic trip unit, comprising: an input section for receiving a phase current level signal; a processor in communication with the input section, wherein the processor generates a first circuit breaker trip signal based on the phase current level signal and user-adjustable trip settings, the user-adjustable trip settings including: a long time current pickup setting; a long time delay setting; a short time current pickup setting; and a short time delay setting; and an analog instantaneous trip circuit in communication with both of the input section and the processor, wherein the analog instantaneous trip circuit includes a digital potentiometer having a non-volatile memory, the digital potentiometer providing a reference signal corresponding to a resistance setting stored in the non-volatile memory, wherein the analog instantaneous trip circuit compares the phase current level signal to the reference signal and generates a second circuit breaker trip signal based on a result of comparing the phase current level signal to the reference signal, and wherein the processor programs the resistance setting stored in the non-volatile memory of the digital potentiometer according to a user-adjustable instantaneous current pickup setting.