Vacuum circuit breaker contact set - has one internally chamfered contact ring on pot-shaped contacts, reducing wear

摘要

A set of contacts for vacuum switches for use in electric networks of 7 to 37 kV and for currents of a few thousand A, consists of two pot-shpaed contacts (2 4). Each is equipped with a closed ring (16) of a material with a high burn up resistance such as a chrome-copper sinter metal, while the contact carriers (6 8) are made of copper. One copper ring has a chamfer (40) with the result that the arc (24) is formed away from the edge of the central recess and cannot be forced inside it. The slots (20) in the recess wall are so arranged that the slot (120) for example starts on the top face (S1) at a point where another slot (122) exists below it (dotted line). It ends at the bottom face (S2) where another slot (124) has started (dotted line). This ensures that a current entering a segment receives an azimuthal component.