H.T. self-blast circuit breaker having an arc chamber with reduced gas compression.

摘要

A self-blast circuit breaker comprising a movable assembly including an arc chamber in two parts consisting of a blast chamber (17) and of a compression chamber (18). The two chambers are separated from one another by a crown (9). The compression chamber (18) is closed by a semi-movable piston (11). The circuit breaker is characterised by a means for immobilising the piston during a first part of the movement of the movable contact assembly between a closing position and an opening position and by a means for axially displacing the piston with the movable contact assembly during a second part of this displacement. This makes it possible to reduce the quantity of energy necessary for displacing the movable contact assembly during the opening operation. <IMAGE>