20
3 Description
The pin (moving) 22.9 is moved against the direction of movement of the tube contact 22.11 by the connected
components of heating cylinder 22.41, nozzle 22.11.1, connecting rod 22.51, pin 22.52, control lever 22.46
(circuit-breaker opening movement).
The moved electrode 22.45 is also pushed in the direction of the heating cylinder 22.41.
During the continued course of the opening operation, the arcing contact opens, creating an arc (Fig. 6c). At the
same time, the heat cylinder 22.41 moves to the left and compresses the quenching gas between piston 22.11.17
and valve group 22.11.19. This causes the quenching gas to be forced in the direction opposite to the movement
of the moving contact components through the non-return valve, consisting of piston 22.11.17 and valve plate
22.11.18, into the heat cylinder and through the gap between the tube contact 22.11 and the arc quenching
nozzle, thus quenching the arc.
With large short-circuit currents the quenching gas surrounding pin 22.9 in the arcing chamber is heated by the
arc's energy and driven into the heat cylinder 22.41 at high pressure. When the current passes through zero, the
gas flows back from the heat cylinder into the nozzle and quenches the arc. When this happens, the valve plate
22.11.18 in the heat cylinder 22.41 prevents the high pressure from entering the compression chamber between
piston 22.11.17 and the valve group 22.11.19.
