Miniature circuit breaker

A miniature circuit breaker, comprising:

• a tripping mechanism comprising:
• a moving contact support,
• at least one moving contact disposed on the moving contact support, and
• a first actuation input part and a second actuation input part which are respectively operatively connected to the moving contact support, wherein when any of the first actuation input part and the second actuation input part is actuated by an external force, the moving contact support is driven to move, so that the at least one moving contact is separated from a corresponding fixed contact;
• a magnetic trip assembly comprising:
• a coil, and
• an actuation part, wherein the coil is electrically connected to the fixed contact, and when a main circuit current flowing through the miniature circuit breaker is greater than a first predetermined short-circuit current threshold, the actuation part acts under the action of an electromagnetic field generated by the coil so as to apply the external force to the first actuation input part;
• and
• an electronic trip unit comprising:
• a current sensor,
• a controller, and
• an action actuator, wherein the current sensor is configured to measure a magnitude of the main circuit current, and the controller is configured to control the action actuator to act in response to the main circuit current being greater than a predetermined overload current threshold and less than a second predetermined short-circuit current threshold, so that the action actuator applies the external force to the second actuation input part, wherein the first predetermined short-circuit current threshold is greater than the second predetermined short-circuit current threshold.