Abstract: An enclosed high voltage circuit breaker with a sulphur hexafluoride insulating and arc-extinguishing medium includes breaking gaps arranged in a high-pressure chamber which, during breaking is put into communication with a low-pressure chamber through blast valves. A closing resistor is connected in series at each end with a contact device which, upon closing, connects the resistor in parallel with the main breaking gaps before they are closed. The resistor contact device is arranged in the high-pressure chamber while the closing resistor is arranged in a separate tank substantially entirely separated from the low-pressure chamber.

Abstract: For rapid on-off operation of a contact device for a pre-insertion resistor in a high voltage compressed gas circuit breaker, the operating device includes a piston movable in a cylinder and connected to a movable contact. The piston forms two spaces in the cylinder. A quick operating valve connects the first cylinder space alternately to a source of high pressure or to a low pressure space. The space on the other side of the cylinder can be connected through openings to a delay space which surrounds the cylinder in the form of a ring. A spring-mounted slide is provided in the cylinder for normally closing these openings but allowing them to open when the piston moves. The delay space is connected to the source of pressure fluid through a line containing a check valve which prevents outflow from the delay space.

Abstract: An operating device for a high pressure circuit breaker enclosed in an elongated casing filled with compressed gas with a high-pressure chamber and a low-pressure chamber includes a driving arrangement operated by compressed gas. A compressed gas valve is provided for alternatively connecting the driving means to the high-pressure chamber and the low-pressure chamber. The device has openings into the high-pressure space and the low-pressure space respectively communicating with the driving arrangement. There is a valve seat around the first opening and a movable valve member engageable with the valve seat to close this opening. A space is provided on the opposite side of the valve member from the opening which is permanently connected with the high-pressure chamber. An impulse member outside the high-pressurechamber through an operating rod extending perpendicular to the longitudinal axis of the casing engages the valve member for moving the valve member away from the valve seat.