Abstract: An electric switching device has a selector shaft that drives a switching element between a "cut-out" position in which the switch is open and a "cut-in" position in which the switch is closed. In the cut-in position, a set of "movable" electric contacts carried on the switching element each make electrical connection with a corresponding "fixed" contact supported on a housing. A cut-out mechanism automatically opens the switch when the voltage across the switch falls below a predetermined value (an undervoltage condition). The cut-out mechanism includes an electromagnet, wired in series with the switch, which controls the movement of the blocking lever. The blocking lever is movable between a blocking position in which it holds the switching element in its cut-in position, and a release position in which it allows the switching element to move to its cut-out position.