By-pass of an electrical component

A modular by-pass device of an electrical component comprising a housing possessing a movable means of sealing and equipped with conducting terminals, one of whose ends is connected to one of the terminals of the electrical component circuit, the other end being fastened to the wall of the housing projecting into the interior of the housing and constituting a contact post, an actuator providing transposition between two positions of a control device consisting of a plunger shaft and comprising a spring arranged in the space formed between the plunger shaft and the internal wall of the housing, a trigger comprising a retention device of the plunger shaft held in place by a fusible material, a reversing switch comprising a contact zone providing electrical continuity between two contact posts of the terminals carried by the housing, wherein the plunger shaft of the actuator is a one-piece shaft equipped with a shoulder which comprises at one of its ends a cylindrical part in the form of a barrel provided with a central bore providing a seating making possible an easy replacement and fastening of the trigger.