CIRCUIT BREAKER FOR AN ELECTRICAL CIRCUIT

A circuit breaker is disclosed, including a series circuit including a measuring unit for determining the electrical current or/and voltage of the electrical circuit, an exchangeable trip unit for determining when current limit values are exceeded, and a switching unit for interrupting the electrical circuit if current limit values are exceeded. A switch characteristic module is connected to the trip unit and stores characteristic data relating to the circuit breaker. If a trip unit used is at least exchanged for a new trip unit, the characteristic data are transmitted to the new trip unit. Data specific to the trip unit are transmitted from the trip unit and are stored in the further memory area of the switch characteristic module. If a new trip unit is used, the characteristic data and the data specific to the trip unit are transmitted to the new trip unit.