Abstract: The sectionalizer comprises a means that automatically sections a circuit under preset conditions, for the purpose of insulating and signaling the line defect, when said sectionalizer is mounted between some contacts fixed to an insulating support.The sectionalizer consists of a conductor tube which, independently of other elements, includes an electromagnetic triggering mechanism or device formed by an electromagnet functionally associated to a mechanical multiplier which is comprised by two arms that, in the inoperative position of the electromagnet, sustains a triggering rod maintaining the contact of the sectionalizer, while the activation of the electromagnet entails liberation by the arms of the multiplier, of the triggering rod, producing the opening of the circuit.