A temporary overvoltage protection assembly for protecting an electrical grid line against temporary overvoltages, comprising a high voltage surge arrester and a disconnector device (10, 100), wherein a first terminal of the surge arrester is electrically connectable to an electrical grid line; the first terminal of the disconnector device is electrically connected to a second terminal of the high voltage surge arrester; the second terminal of the disconnector device is electrically connectable to ground potential; a temporary overvoltage threshold of a disconnector cartridge of the disconnector device (10, 100) is chosen such that the disconnector operates before the surge arrester fails due to a thermal overload of the surge arrester; the disconnector device (10, 100) comprises a housing unit encompassing a cavity and a disconnector unit provided inside the cavity, having a first terminal that is connectable to the surge arrester, a second terminal that is connectable to ground potential, a movable member (40, 41) provided at the second terminal and being fitted to the housing, and said disconnector cartridge provided in the cavity; the housing unit comprises an inner housing encompassing said cavity and an outer housing, the inner housing comprises at least one ventilation opening connecting the cavity to an outside of the inner housing; the outer housing comprises at least one further ventilation opening connecting the outside of the inner housing to an outside of the disconnector device for releasing gases from the operating disconnector cartridge; the at least one ventilation opening and the at least one further ventilation opening are displaced against one another such that a labyrinth with a gas escape path for the gases from the operating disconnector cartridge is formed; and the movable member (40, 41) is arranged in the housing in a movable manner such that it is guided by the inner housing from an initial position to an end position at an end of the cavity by gas from the disconnector cartridge in an operating state of the disconnector unit. the first terminal of the disconnector device is electrically connected to a second terminal of the high voltage surge arrester; the second terminal of the disconnector device is electrically connectable to ground potential; a temporary overvoltage threshold of a disconnector cartridge of the disconnector device (10, 100) is chosen such that the disconnector operates before the surge arrester fails due to a thermal overload of the surge arrester; the disconnector device (10, 100) comprises a housing unit encompassing a cavity and a disconnector unit provided inside the cavity, having a first terminal that is connectable to the surge arrester, a second terminal that is connectable to ground potential, a movable member (40, 41) provided at the second terminal and being fitted to the housing, and said disconnector cartridge provided in the cavity; the housing unit comprises an inner housing encompassing said cavity and an outer housing, the inner housing comprises at least one ventilation opening connecting the cavity to an outside of the inner housing; the outer housing comprises at least one further ventilation opening connecting the outside of the inner housing to an outside of the disconnector device for releasing gases from the operating disconnector cartridge; the at least one ventilation opening and the at least one further ventilation opening are displaced against one another such that a labyrinth with a gas escape path for the gases from the operating disconnector cartridge is formed; and the movable member (40, 41) is arranged in the housing in a movable manner such that it is guided by the inner housing from an initial position to an end position at an end of the cavity by gas from the disconnector cartridge in an operating state of the disconnector unit.