Abstract: The lightning arrester device comprises an external metal casing (1) defining an enclosure (2) containing a neutral gas, and at least one metal rod (3a, 3b) forming an electrode and penetrating into the interior of the casing, insulating sealing means (4) being provided between the rod and the casing in order to close said casing, and comprising, moreover, at least one fusible element (5) adapted to create a short circuit between the electrode (3a, 3b) and the casing (1) when the quantity of energy to be diverted by the lightning arrester device exceeds a specified threshold.

Abstract: The surge protection element comprises an inert gas-filled protective device with electrodes inserted between two line input terminals, these terminals being connected respectively to branch terminals of an installation to be protected. The surge protection element also comprises initial protection apparatus, intended to be inserted between the terminals of the installation to be protected, and having a response time and a voltage threshold below that of said protective device, and also decoupling apparatus connected in series between the terminals of the protective device and those of the initial protection apparatus. The decoupling apparatus are capable of causing the voltage to rise at the terminals of the protective device when the current strength passing through the initial protection means increases, whereby the protective device can be tripped and can take over from the initial protection apparatus.