Medium voltage circuit breaker with gas filled arc quenching chamber - has tubular stationary contact carrying tubular arcing contact at end protruding into quenching chamber

摘要

The circuit breaker has at least one single-phase switching unit with a cylindrical quenching chamber filled with sulphur hexafluoride. From one face of the chamber protrudes inwards a stationary contact (8) aligned with a moving, axially slidable contact, secured to one end of an actuating rod. The moving contact is surrounded by a blast piston, matching the chamber inner diameter and connected to the moving contact. The stationary contact (8) is formed by a tube whose inner end carries a tubular arcing contact (9). The moving contact consists of a hollow cylindrical support (18) of good conductivity, into which is inserted a multiple contact element (19) which end section, coupled to the actuating rod (21) are provided gas channels (22). the blast piston (15) is extended over the support end facing the stationary contact.