a circuit breaker includes a switching contact arrangement and a drive apparatus which operates it , with the connection between the switching contact arrangement and the drive apparatus being designed such that it is detachable . for this purpose , a contact support of the switching contact arrangement contains a coupling bolt , which produces a hinged connection to a lever arrangement for the drive apparatus . a holding piece allows a actuating shaft of the drive apparatus to be rotated to a position , and to be fixed in this position . this allows the switching contact arrangement to be removed without any problem , and subsequently to be replaced by another switching contact arrangement . once the control panel for the circuit breaker has been removed , the holding piece can be placed on the actuating shaft and can be attached to a front housing body of the circuit breaker where the control panel would otherwise be located .