Multi-pole and single-pole circuit breakers include a housing and a reset lockout mechanism disposed within the housing. The reset lockout mechanism disables electrical communication between line and load terminals of the circuit breaker if a predefined condition exists. Some circuit breakers include a single actuator, transition between ON and OFF states, and are capable of performing test functions. The test functions may involve testing AFCI and/or GFCI functions of the circuit breakers. The test functions may be performed when the circuit breaker transitions from an OFF state to an ON state. Some circuit breakers including a reset lockout mechanism may be powered only on its line side. Some circuit breakers provide an electrical indication when they are in the OFF state.

Multi-pole and single-pole circuit breakers include a housing and a reset lockout mechanism disposed within the housing. The reset lockout mechanism disables electrical communication between line and load terminals of the circuit breaker if a predefined condition exists. Some circuit breakers include a single actuator, transition between ON and OFF states, and are capable of performing test functions. The test functions may involve testing AFCI and/or GFCI functions of the circuit breakers. The test functions may be performed when the circuit breaker transitions from an OFF state to an ON state. Some circuit breakers including a reset lockout mechanism may be powered only on its line side. Some circuit breakers provide an electrical indication when they are in the OFF state.

An operating mechanism of a circuit breaker, wherein two ends of a first spring are rotationally connected to a rocker arm assembly and a first crank through a first spring shaft and a second spring shaft respectively, and one end of a jump buckle is rotationally connected to a bracket and is a jump buckle pivoting end; a jump buckle hole of the jump buckle is aligned with a bracket hole of the bracket; the first spring shaft is in limiting fit with the jump buckle; and one end of the first crank swings in a direction away from the jump buckle pivoting end, such that a spacing between the first spring shaft and the second spring shaft is smaller than or equal to the length of the first spring, and a first assembly state is formed.

An operating mechanism of a circuit breaker, wherein two ends of a first spring are rotationally connected to a rocker arm assembly and a first crank through a first spring shaft and a second spring shaft respectively, and one end of a jump buckle is rotationally connected to a bracket and is a jump buckle pivoting end; a jump buckle hole of the jump buckle is aligned with a bracket hole of the bracket; the first spring shaft is in limiting fit with the jump buckle; and one end of the first crank swings in a direction away from the jump buckle pivoting end, such that a spacing between the first spring shaft and the second spring shaft is smaller than or equal to the length of the first spring, and a first assembly state is formed.