An installation switching device which rapidly disconnects short-circuit currents is provided. A contact lever is arranged at least partially in an air gap in a magnetic circuit such that, in case of a short circuit, the interaction between current flow and magnetic flux within the air gap can result in an electrodynamic force effect, which leads to rapid opening of at least one contact point. A switching mechanism acts via a first operating connecting line on the contact lever to open the contact point and/or to keep it open. In case of overcurrent tripping, an overcurrent release acts, by a switching mechanism and via a second operating connecting line, on the switching mechanism to open the contact point and keep it open. In case of short-circuit tripping, the contact lever acts via a third operating connecting line on the switching mechanism to keep the contact point open.