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

1. A disconnector device for a surge arrester, the disconnector device comprising:

a housing encompassing a cavity;

a disconnector provided inside the cavity, having a first terminal connectable to the surge arrester, a second terminal connectable to ground potential, and a movable member provided at the second terminal and being fitted to the cross section of the cavity, and a disconnector cartridge;

wherein the movable member is movably arranged such in the housing that once the disconnector operates, the movable member is propelled inside the cavity towards an end of the cavity by gas from the disconnector cartridge, and wherein the housing has ventilation openings connecting the cavity to an outside of the disconnector device for releasing gases from the operating disconnector cartridge, the ventilation openings being dimensioned such that no particles harmful size that are potentially capable of igniting a fire can pass the ventilation openings;

wherein the cavity has an elongated shape, and wherein the housing has a retaining section for retaining the movable member at the retaining section once the movable member was propelled towards the end of the cavity; and

wherein the ventilation openings are slits extending along the cavity in a direction of a longitudinal axis defined by the overall shape of the cavity.

2. The disconnector device of claim 1 , wherein the housing has an opening at the end of the cavity, and wherein the movable member and the opening are adjusted to each other such that a portion of the movable member fits into the opening and thereby closes it in an operating state of the disconnector.

3. The disconnector device of claim 2 , wherein the movable member has a tubular section with a diameter fitting to the opening, so that a movement of the movable member during operation of the disconnector is guided by the opening.

4. The disconnector device of claim 2 , wherein after an operation of the disconnector, a portion of the movable member protrudes through the opening such that it is visible from an outside of the housing.

5. The disconnector device of claim 4 , wherein the portion of the movable member that is protruding through the opening is formed by the tubular section.

6. The disconnector device of claim 5 , wherein at least the portion of the movable member protruding through the opening after operation of the disconnector has a signal color for indicating on whether the disconnector already operated or whether it is still in its pristine state.

7. The disconnector device of claim 4 , wherein at least the portion of the movable member protruding through the opening after operation of the disconnector has a signal color for indicating on whether the disconnector already operated or whether it is still in its pristine state.

8. The disconnector device of claim 2 , wherein the ventilation openings are designed for a controlled release of gases from the operating disconnector cartridge.

9. The disconnector device of claim 2 , wherein the ventilation openings are slits extending along the cavity in a direction of a longitudinal axis defined by the overall shape of the cavity.

10. The disconnector device of claim 2 , wherein the cavity has a circular cross section or a polygonal cross section.

11. The disconnector device of claim 2 , wherein at least a part of the movable member has a cup shape, and wherein the cup at least partly encompasses the disconnector cartridge.

12. The disconnector device of claim 2 , wherein the retaining section of the housing has at least one protrusion protruding into the cavity.

13. The disconnector device of claim 2 , wherein the housing is mounted to the first terminal of the disconnector.

14. The disconnector device of claim 1 , wherein the ventilation openings are designed for a controlled release of gases from the operating disconnector cartridge.

15. The disconnector device of claim 1 , wherein the cavity has a circular cross section or a polygonal cross section.

16. The disconnector device of claim 1 , wherein at least a part of the movable member has a cup shape, and wherein the cup at least partly encompasses the disconnector cartridge.

17. The disconnector device of claim 1 , wherein the retaining section of the housing has at least one protrusion protruding into the cavity.

18. The disconnector device of claim 1 , wherein the housing is mounted to the first terminal of the disconnector.

19. An assembly of a high voltage surge arrester and a disconnector device of claim 1 , wherein the first terminal of the disconnector device is electrically connected to the high voltage surge arrester.