Electronic tripping device for a circuit breaker

An electronic tripping unit for switching on and off a circuit breaker used for a load current circuit, comprising:

• a processing unit configured to compare limit values of a current to a current flowing in the load current circuit, wherein value pairs of limiting values of the current and assigned time delays represent a predetermined, characteristic tripping curve, the processing unit emitting a tripping signal for switching off the circuit breaker when the time delay assigned to the limit value in accordance with the tripping curve, is exceeded;
• a single preset control mechanism;
• and
• a circuit arrangement for forming response characteristics of fuses, the circuit arrangement being provided with characteristic curves that simulate nominal or operating currents, a selection of the simulated characteristic curves being determined exclusively by the single preset control mechanism, a selected nominal or operating current being represented by the single preset control mechanism, the simulated characteristic curve corresponding to the selected nominal or operating current being set as the tripping curve.