Monitor providing cause of trip indication and circuit breaker incorporating the same

A circuit breaker for providing protection in an electric power distribution system, the circuit breaker comprising:

• separable contacts;
• an operating mechanism opening the separable contacts when actuated;
• a trip unit comprising a thermal/magnetic trip device producing a thermal trip by actuating the operating mechanism in response to persistent overload conditions and producing a magnetic trip by actuating the operating mechanism in response to overcurrent conditions;
• and
• a monitor providing a thermal trip indication when the separable contacts are opened by the thermal trip and providing a magnetic trip indication when the separable contacts are opened by the magnetic trip,
• wherein said trip unit produces said thermal trip and said magnetic trip independent of said monitor,
• wherein the trip unit further comprises electronic trip circuitry generating an electronic trip signal indicating at least one of an arc fault and a ground fault in the electric power distribution system and a trip actuator responsive to the electronic trip signal to actuate the operating mechanism, and wherein the monitor provides at least one of an arc fault trip indication and a ground fault trip indication in response to the electronic trip signal,
• wherein the electronic circuitry includes both an arc fault trip circuit and a ground fault trip circuit and the monitor provides both an arc fault trip indication and a ground fault trip indication,
• wherein the monitor comprises a trip sensor sensing opening of the separable contacts, a temperature sensor sensing the temperature of the thermal magnetic trip device, an overcurrent sensor sensing current above a selected value through the separable contacts, a processor generating a thermal trip signal in response to the temperature secured by the temperature sensor above a selected value when the trip sensor senses opening of the separable contacts, generating a magnetic trip indication with the current of the overcurrent sensor above a selected value when the trip sensor senses opening of the separable contacts, generates an arc fault trip signal in response to an arc fault signal from the arc fault circuit when the trip sensor senses opening of the separable contacts, generates a ground fault trip signal in response to a ground fault signal from the ground fault circuit when the trip sensor senses opening of the separable contacts, and output means generating the thermal trip indication in response to the thermal trip signal, the magnetic trip indication in response to the magnetic trip signal, an arc fault trip indication in response to the arc fault trip signal, and a ground fault trip indication in response to the ground fault trip signal.