Switching device and method

A switching device for a low-voltage circuit including a plurality of conductors, the switching device comprising:

• a housing, connection contacts being arranged on the housing to connect conductors of the low-voltage circuit;
• a mechanical unit, located in the housing, including an isolating function, an OFF or ON position and isolating contacts for galvanically interrupting the conductors of the low-voltage circuit;
• an electronic unit, connected to the mechanical unit in series on a current flow side;
• and
• an auxiliary switch, connected to the mechanical unit and connected to the electronic unit via the mechanical unit, the auxiliary switch and the electronic unit being configured such that during an opening process of the mechanical unit, the electronic unit has high impedance, wherein the isolating function includes a minimum clearance of opened isolating contacts in the OFF position as a function of rated surge voltage impedance and a degree of soiling, the minimum clearance being between 0.01 mm at 0.33 kV and 14 mm at 12 kV and including a degree of soiling 1 for nonhomogeneous fields.