Surge Protection Device

A method for assembling a protection device (1) comprising:

• making a first sub-assembly comprising:
• at least a first connection terminal (13, 47) and a second connection terminal (14) which are respectively intended to be connected to a first line and a second line of an electrical installation to be protected;
• a first set of protection components comprising at least a first varistor (6) and a gas discharge tube (8), the first varistor (6) comprising a first varistor electrode (16) and a second varistor electrode (17), the first varistor electrode (16) being electrically connected to the first connection terminal (13, 47), the gas discharge tube (8) comprising a first discharge tube electrode and a second discharge tube electrode;
• the first discharge tube electrode being electrically connected to the second varistor electrode (17) by a thermofusible connection (21) which is capable of passing, when said thermofusible connection (21) is subjected to a temperature exceeding a threshold, from a connected state to a disconnected state in which the second varistor electrode (17) and the first discharge tube electrode are disconnected from each other;
• the first set of protection components comprising a flexible braid (23) which is soldered to the second discharge tube electrode and electrically connected to a connection piece (22), said connection piece (22) being electrically connected to the second connection terminal (14), said flexible braid (23) being able to deform so as to allow the gas discharge tube (8) to move away from the first varistor (6) and the insulating flap (26) to move into the cut-off position when the thermofusible connection (21) passes into the disconnected state;
• mounting the first sub-assembly in a base (11) of a housing (10);
• mounting a first arc-breaking device in the housing (10), the first arc-breaking device comprising an insulating flap (26) which is configured to move, upon a transition of the thermofusible connection (21) from the connected state to the disconnected state, from an original position to a cut-off position in which said insulating flap (26) is interposed between the second varistor electrode (17) and the first discharge tube electrode;
• and
• closing the housing (10) by securing the base (11) to a cover (12) of the housing (10).