High-voltage power circuit breaker

摘要

A high-voltage power circuit breaker has a moving (3) and a stationary (5) eroding contact. The moving eroding contact (3) is constructed as a nozzle having a nozzle constriction (7) and is rigidly connected to an insulating material nozzle (9) and to the compression piston (11) of a device for producing a compressed extinguishing gas. In the switched-on position, the stationary eroding contact (5) passes through the insulating material nozzle (9) in its constriction (10) and engages into the interior of the first eroding contact (3). The compression space of the compression device is connected to a volume (13) which, during switching off, contains compressed extinguishing gas before the separation of the two eroding contacts (3, 5). In such a circuit breaker, it is now intended to increase the switching off performance, using simple means, by means of intensive blowing and improved gas interchange between the switching-off arc and the surrounding extinguishing gas. This is achieved in that the diameter of the second eroding contact (5) and the diameter of the nozzle constriction (10) of the insulating material nozzle (9) are dimensioned in such a manner that an annular surface (F2), which is bounded during switching off after separation of the contacts by the nozzle constriction (10) of the insulating material nozzle (9) and the second eroding contact (5), is at least 30% of the size of the passage area (F1) of the nozzle constriction (7) of the first eroding contact (3). As a result of these measures, the switching-off arc (14) is blown twice as much at the start of contact separation, and the switching-off performance is hence increased. <IMAGE>