A low-voltage circuit breaker device includes: at least one external conductor section from an external conductor supply connection of the low-voltage circuit breaker device to an external conductor load connection of the low-voltage circuit breaker device; a mechanical bypass switch arranged in the external conductor section; a first semiconductor circuit arrangement connected in parallel to the mechanical bypass switch; an electronic control unit; a current measuring arrangement arranged in the external conductor section, which current measuring arrangement is connected to the electronic control unit, the electronic control unit controlling the mechanical bypass switch and the first semiconductor circuit arrangement when a given overcurrent, namely a short-circuit current, is detected by the current measuring arrangement; and a second semiconductor circuit arrangement arranged in the external conductor section in series with the mechanical bypass switch and in parallel to the first semiconductor circuit arrangement.