Abstract: In order visually to indicate the existence of a "continuation" current through a lightning arrester, an indicator is associated therewith, which is formed by an elastically deformable strip maintained retracted against capsule electrode by a retention mechanism which is associated with an electrical filter which causes fusion of a fusible wire under the effect of a "continuation" current. Once its end is released, the strip projects outwardly of the lightning arrester and marks the location of the defective insulation.

Abstract: In order positively to ground a structure such as a pole carrying an electric line, which is not sufficiently grounded and therefore presents risks of electrocution in the event of untimely connection with the line, a voltage detector is provided, interposed between the structure and the ground, a fuse cartridge is connected to the voltage detector, said cartridge comprising a plunger which, when the cartridge is functioning, triggers a short-circuit switch grounding the structure via large-section conductors. A surge arrester is associated with the system which, during the very short instant necessary for the assembly constituted by the voltage detector and fuse cartridge and switch to function, maintains the voltage of the structure at a limited value not presenting any risk of instantaneous electrocution.

Abstract: A pyrotechnical cartridge or motor (5) is actuated by electric firing from its head (5c), and pushes the insulating piston (3) which separates by shearing the intermediate connecting portion (1b) of the destructible conductor (1) and pushes it into the bore (1e) together with the rod (9), the conical end (9a) of which becomes wedged within the plug (10) so as to form a brake. The fuse cartridges (13) then open the circuit in a fully safe manner.The present invention is useful for instance under the control of overcurrent detectors.