Positioning device for positioning, in a manner straddling an electrical conductor of an overhead electrical line, a placement means for placing, on this electrical conductor, a system for grounding this electrical conductor, this positioning device comprising: - a distal part, a proximal part, and a middle part arranged between the distal part and the proximal part; - a placement means which at least the distal part and the middle part of the positioning device comprises and which is designed to place the grounding system on the electrical conductor; - a ballast which the distal part of the positioning device comprises and which is associated with the placement means; - a retaining means which the distal part of the positioning device comprises, which is designed to retain the ballast within the positioning device, and which can move between an active position for retaining this ballast and an inactive position for retaining this ballast; - a return means which the distal part and/or the middle part of the positioning device comprises and which is designed to return the means for retaining the ballast from the active position for retaining the ballast and towards the inactive position for retaining the ballast; - a holding means which the distal part and/or the middle part of the positioning device comprises, which is designed to hold the retaining means in the active position for retaining the ballast, counter to the action of the return means, and which can move between an active position for holding the retaining means in its active position for retaining the ballast and an inactive position for holding this retaining means; - a control means which the middle part of the positioning device comprises and which is designed to control the movement of the holding means from the active position for holding the retaining means in the active position for retaining the ballast towards the inactive position for holding the retaining means, under the influence of interaction with the electrical conductor. - a distal part, a proximal part, and a middle part arranged between the distal part and the proximal part; - a placement means which at least the distal part and the middle part of the positioning device comprises and which is designed to place the grounding system on the electrical conductor; - a ballast which the distal part of the positioning device comprises and which is associated with the placement means; - a retaining means which the distal part of the positioning device comprises, which is designed to retain the ballast within the positioning device, and which can move between an active position for retaining this ballast and an inactive position for retaining this ballast; - a return means which the distal part and/or the middle part of the positioning device comprises and which is designed to return the means for retaining the ballast from the active position for retaining the ballast and towards the inactive position for retaining the ballast; - a holding means which the distal part and/or the middle part of the positioning device comprises, which is designed to hold the retaining means in the active position for retaining the ballast, counter to the action of the return means, and which can move between an active position for holding the retaining means in its active position for retaining the ballast and an inactive position for holding this retaining means; - a control means which the middle part of the positioning device comprises and which is designed to control the movement of the holding means from the active position for holding the retaining means in the active position for retaining the ballast towards the inactive position for holding the retaining means, under the influence of interaction with the electrical conductor.