Contact system for a short-circuiting device in a medium-voltage or high-voltage switchboard plant

1. A contact system for a short-circuiting device for a switchboard, the contact system comprising:

at least one fixed contact piece connected to a mains voltage source;

at least one moving contact piece connected to ground; and

an insulating screen disposed between the at least one fixed contact piece and the at least one moving contact piece,

wherein the at least one moving contact piece is configured to penetrate the insulation screen when an arcing fault is detected in the switchboard so as to make contact between the at least one moving contact piece and the at least one fixed contact piece and thereby short-circuit the mains voltage source.

2. The contact system as recited in claim 1 , wherein the mains voltage source is a high voltage or medium voltage source.

3. The contact system as recited in claim 1 , wherein the mains voltage source includes at least one phase, wherein the at least one fixed contact piece includes one fixed contact piece for each of the at least one phases.

4. The contact system as recited in claim 1 , wherein at least a part of the screen includes a soft material penetrable by the at least one moving contact piece.

5. The contact system as recited in claim 1 , wherein at least a part the screen includes a hard material having a thickness configured to be pierceable by the at least one moving contact piece.

6. The contact system as recited in claim 1 , wherein at least a part of the screen includes a door or a flap configured to open when pushed by the at least one moving contact piece.

7. The contact system as recited in claim 1 , wherein the at least one moving contact piece has a taper shape toward a free end.

8. The contact system as recited in claim 7 , wherein the taper shape is a cone.

9. The contact system as recited in claim 1 , wherein the at least one moving contact piece includes a tip having a rounded hemispherical shape.

10. The contact system as recited in claim 1 , further comprising a tubular cylinder, wherein the at least one fixed contact piece is surrounded by the tubular cylinder, and wherein the screen is disposed on the tubular cylinder.

11. The contact system as recited in claim 10 , further comprising a rigid conductor, wherein the at least one fixed contact piece is disposed on an end of the rigid conductor, wherein the tubular cylinder extends beyond the end of the rigid conductor and the at least one fixed contact piece and is configured to be closed by the screen on a free end.

12. The contact system as recited in claim 10 , wherein the tubular cylinder includes an inside space filled with an insulating fluid.

13. The contact system as recited in claim 12 , wherein the insulating fluid is a liquid.

14. The contact system as recited in claim 13 , wherein the fluid is an insulating oil.

15. The contact system as recited in claim 1 , wherein the screen includes an electrically conducting coating configured as an electrical screen or an electric field controller.

16. The contact system as recited in claim 15 , further comprising a tubular cylinder, wherein the at least one fixed contact piece is surrounded by the tubular cylinder, and wherein the screen is disposed on the tubular cylinder, wherein the coating is disposed in at least one of an inside of the tubular cylinder and an outside of the tubular cylinder.

17. The contact system as recited in claim 1 , wherein the at least one moving contact piece is disposed on a pivoted lever.

18. The contact system as recited in claim 1 , wherein the at least one fixed contact piece includes three fixed contact pieces and the at least one moving contact piece includes three moving contact pieces respectively for the three fixed contact pieces, and wherein the mains voltage source includes three conductors, each conductor being connected to one of the three fixed contact pieces such that the three moving contact pieces respectively short-circuit individual phases of the mains voltage source at the detection of the arcing fault.