A circuit breaker comprising: a first contact; a second contact moveable between a closed position relative to the first contact and an open position (200, 300) relative to the first contact, and which is disposed to contact the first contact only in the closed position; a moveable contact arm and lever assembly (120, 175) having a first end on which said second contact is mounted, a second end, and a first pivot point located between the first end and the second end; a circuit breaker linkage mechanism having a tripped state and an untripped state, which is disposed to change the position of the second contact when the circuit breaker linkage mechanism changes state; a trip mechanism connected to said moveable contact arm via said circuit breaker linkage; an actuator having an on state and an off state, which is disposed to change the position of the second contact without changing the state of the circuit breaker linkage mechanism, and of the trip mechanism and its associated components, when the actuator changes state, said actuator having a plunger which is connected to the second end of said moveable contact arm and lever assembly (120, 175) such that said actuator moves said contact arm and lever assembly (120, 175) about the first pivot point when the actuator changes state in order to change the relative position of the contacts (105, 115); characterized in that the moveable contact arm includes an arc-shaped guide channel receiving a second pivot point, wherein when the actuator acts on the second end of the moveable contact arm and lever assembly (120, 175), the second pivot point slides along the arc-shaped guide channel. a first contact; a second contact moveable between a closed position relative to the first contact and an open position (200, 300) relative to the first contact, and which is disposed to contact the first contact only in the closed position; a moveable contact arm and lever assembly (120, 175) having a first end on which said second contact is mounted, a second end, and a first pivot point located between the first end and the second end; a circuit breaker linkage mechanism having a tripped state and an untripped state, which is disposed to change the position of the second contact when the circuit breaker linkage mechanism changes state; a trip mechanism connected to said moveable contact arm via said circuit breaker linkage; an actuator having an on state and an off state, which is disposed to change the position of the second contact without changing the state of the circuit breaker linkage mechanism, and of the trip mechanism and its associated components, when the actuator changes state, said actuator having a plunger which is connected to the second end of said moveable contact arm and lever assembly (120, 175) such that said actuator moves said contact arm and lever assembly (120, 175) about the first pivot point when the actuator changes state in order to change the relative position of the contacts (105, 115); characterized in that the moveable contact arm includes an arc-shaped guide channel receiving a second pivot point, wherein when the actuator acts on the second end of the moveable contact arm and lever assembly (120, 175), the second pivot point slides along the arc-shaped guide channel.