Disconnector device for surge arrester and a protection assembly comprising a surge arrester connected to such a disconnector device

A disconnector device for a surge arrester is provided. The disconnector device (10) comprises: a housing (15) encompassing a cavity (20); a disconnector (25) provided inside the cavity (20), having a first terminal (30) connectable to the surge arrester, a second terminal (35) connectable to ground, a movable member (40, 41) provided at the second terminal (35) and being fitted to the cross section of the cavity (20), and a disconnector cartridge 26. The member (40, 41) is movably arranged such in the housing (15) that once the disconnector (25) operates, the movable member (40, 41) is propelled inside the cavity (20) towards an end (45) of the cavity (20). The housing (15) has ventilation openings (65) connecting the cavity (20) to an outside of the disconnector device for releasing gases from the operating disconnector cartridge (26). These ventilation openings (65) are dimensioned such that no particles of harmful size that are potentially capable of igniting a fire can pass the ventilation openings (65).