Patent attributes
The heavy-duty circuit breaker contains a first moveable arcing contact piece and a second moveable arcing contact piece as well as an auxiliary drive for driving the second arcing contact piece. An arc may burn between the arcing contact pieces. The heavy-duty circuit breaker has a heating chamber for temporarily storing quenching gas heated by the arc and a throat for guiding a quenching gas flow, which throat is connected to the heating chamber by a channel. The throat can be blocked by one of the two arcing contact pieces, which is the blocking contact piece. The auxiliary drive is designed such that, during an opening operation, a movement direction reversal of the second arcing contact piece from a movement in opposite directions to a movement in the same direction of the two arcing contact pieces takes place, if the throat is no longer blocked by the blocking contact piece.