Circuit breaker and method for sensing current indirectly from bimetal voltage and determining bimetal temperature and corrected temperature dependent bimetal resistance

A circuit breaker comprising:

• a housing;
• separable contacts;
• a bimetal electrically connected in series with said separable contacts, said bimetal including a temperature dependent resistance and an output having a voltage representative of current flowing through said separable contacts;
• an operating mechanism structured to open and close said separable contacts;
• a temperature sensor distal from said bimetal, said temperature sensor including an output having a signal representative of ambient temperature;
• and
• a trip circuit cooperating with said operating mechanism to trip open said separable contacts, said trip circuit comprising:
• a first circuit including a first input electrically interconnected with the output of said bimetal to input said voltage representative of current flowing through said separable contacts, a second input electrically interconnected with the output of said temperature sensor to input said signal representative of ambient temperature, a real-time thermal model structured to provide a corrected temperature dependent resistance of said bimetal as a function of said voltage representative of current flowing through said separable contacts and said signal representative of ambient temperature, and an output including a current value which is a function of said voltage representative of current flowing through said separable contacts, and said corrected temperature dependent resistance, and
• a second circuit including an input having said current value and an output structured to actuate said operating mechanism in response to predetermined current conditions.