Circuit breaker (1; 20), such as a vacuum interrupter, for use in medium voltage applications, which circuit breaker (1; 20) comprises: - a housing; - a first contact arranged on an end of a first contact stem, which first contact stem extends fixedly through the housing; - a second contact arranged on an end of a second contact stem, which second contact stem extends axially movable through the housing; - moving means (9, 10) for moving the second contact between a closed position in contact with the first contact and an open position spaced apart from the first contact, wherein the first contact is the cathode and the second contact is the anode, wherein the mass of the second contact is less than the mass of the first contact, and wherein, the moving means (9, 10) comprises a separate closing mechanism for urging the second contact to the closed position and a separate opening mechanism for urging the second contact to the open position, characterized in that, the circuit breaker (1; 20) further comprising a reconditioning power source, such as a low voltage capacitor bank, and a controller for providing, in a reconditioning mode of the circuit breaker, a reconditioning current from the reconditioning power source to the first and second contact, wherein in the reconditioning mode the current direction is reversed such that the first contact is the anode and the second contact is the cathode. - a housing; - a first contact arranged on an end of a first contact stem, which first contact stem extends fixedly through the housing; - a second contact arranged on an end of a second contact stem, which second contact stem extends axially movable through the housing; - moving means (9, 10) for moving the second contact between a closed position in contact with the first contact and an open position spaced apart from the first contact, wherein the first contact is the cathode and the second contact is the anode, wherein the mass of the second contact is less than the mass of the first contact, and wherein, the moving means (9, 10) comprises a separate closing mechanism for urging the second contact to the closed position and a separate opening mechanism for urging the second contact to the open position, characterized in that, the circuit breaker (1; 20) further comprising a reconditioning power source, such as a low voltage capacitor bank, and a controller for providing, in a reconditioning mode of the circuit breaker, a reconditioning current from the reconditioning power source to the first and second contact, wherein in the reconditioning mode the current direction is reversed such that the first contact is the anode and the second contact is the cathode. wherein the mass of the second contact is less than the mass of the first contact, and wherein, the moving means (9, 10) comprises a separate closing mechanism for urging the second contact to the closed position and a separate opening mechanism for urging the second contact to the open position, characterized in that, the circuit breaker (1; 20) further comprising a reconditioning power source, such as a low voltage capacitor bank, and a controller for providing, in a reconditioning mode of the circuit breaker, a reconditioning current from the reconditioning power source to the first and second contact, wherein in the reconditioning mode the current direction is reversed such that the first contact is the anode and the second contact is the cathode.