Circuit breaker with instant trip mechanism

A circuit breaker comprising:

• a pair of contact mechanisms that are provided to correspond to a pair of circuits corresponding to a pair of poles and switch the pair of circuits;
• a switching mechanism that is commonly provided in the pair of contact mechanisms and drives the pair of contact mechanisms to a circuit opening position or a circuit closing position;
• a trip bar that is rotatable to a first position for latching the switching mechanism in the circuit closing position or to a second position for releasing the switching mechanism to operate to the circuit opening position;
• and
• an instant trip mechanism that presses the trip bar to rotate to the second position in response to a fault current on the circuit requiring an instant trip,
• wherein the instant trip mechanism comprises:
• a pair of armature assemblies that are provided to correspond to the pair of poles and movable to a position for pressing the trip bar to rotate to the second position;
• and
• a pair of electromagnets that are provided to face the pair of armature assemblies and apply a magnetic attractive force to the pair of armature assemblies in response to the fault current on the circuit requiring an instant trip,
• wherein each of the pair of electromagnets comprises a cutout groove portion that is provided at a side surface corner or an upper surface for guiding a conductive wire electrically connecting a movable contact arm of a corresponding contact mechanism among the pair of contact mechanisms and a terminal.