Circuit breaker

A circuit breaker device for protecting an electrical low-voltage circuit, the circuit breaker device comprising:

• a housing having network-side connections and load-side connections for the low-voltage circuit;
• an electronic interruption unit associated with said network-side connections, said electronic interruption unit having semiconductor-based switching elements;
• a mechanical isolating contact unit connected in series with said electronic interruption unit, said mechanical isolating contact unit being associated with said load-side connections, and said mechanical isolating contact unit having at least one contact;
• a handle configured to operate said mechanical isolating contact unit for switching opening of said at least one contact to avoid a current flow or closing of said at least one contact for a current flow in the low-voltage circuit;
• said semiconductor-based switching elements configured to be switched to a high-impedance state to avoid a current flow or a low-impedance state for a current flow in the low-voltage circuit;
• a current sensor unit for determining a current level of the low-voltage circuit;
• a control unit connected to said current sensor unit, to said mechanical isolating contact unit and to said electronic interruption unit, for initiating avoidance of a current flow in the low-voltage circuit upon exceeding at least one of current limit values or current-time limit values;
• and
• said mechanical isolating contact unit having a handle sensor for determining position information relating to said handle.