An electronic circuit breaker includes controllable contacts adapted to connect a power source to at least one load, and a microcontroller for monitoring the flow of power to the load, detecting different types of fault conditions and automatically opening the contacts in response to a fault. A primary power supply of the breaker receives power from the line source when the contacts are closed, and supplies power to the control circuitry. Fault indicators in the microcontroller indicate the type of fault that caused the contacts to open. A secondary power supply provides power to the control circuitry when the contacts are open and a switch is closed.