Abstract: A switching device for the interruption of a fault current includes a housing having first and second electrical connectors for connection in the path of an electrical conductor carrying a single current phase. A vacuum switching chamber is disposed in the housing. A current transformer disposed in the housing includes a primary circuit connected between the first and second terminals for conducting the single current phase and inducing a corresponding current in a secondary winding. A magnet actuator disposed in the housing is electrically coupled to the transformer secondary winding. The magnet actuator is responsive to a fault current in the transformer primary, by way of the corresponding current in the secondary, for changing from an inactive state to an actuated state.

Abstract: A switch chamber for a vacuum switch including a housing having at least one insulating tube with an end face and an axial axis. A contact pin having an exterior surface is arranged for supporting the switch chamber. A stationary contact is held by the contact pin within the housing and has a frontal face. A movable contact contacts the frontal face of the stationary contact in the on-position of the vacuum switch under the force of a contact spring. A seal including a bellows connects the movable contact with the housing in a vacuum-tight manner. A terminating cover is connected to the insulating tube and to the contact pin in a vacuum-tight manner and transfers to the housing impact forces generated when the vacuum switch is switched on. The insulating tube comprises a ceramic tube.

Abstract: A switch chamber for a vacuum switch including a housing composed of a ceramic insulating tube, a contact pin mounting a stationary contact within the housing and a terminating cover connecting the insulating tube with the contact pin in a vacuum-tight manner. Another contact is positioned adjacent the stationary contact and is movable in the axial direction of the insulating tube. A bellows forms a vacuum-tight connection between the movable contact and the housing. In the switched-on position the movable contact contacts the stationary contact under action of a contact spring force and shock stresses are transferred to the housing by the terminating cover which includes an elastically deformable section and a plastically deformable section.

Abstract: An insulating member which functions as a voltage divider in a high voltage system. The insulating member includes an insulating body having a head section and a base section. The insulating body is made of plastic containing conductive fillers to reduce the active resistance of the body. A metal fitting is embedded in the head section for connecting the head section with high voltage carrying components and for supporting such components. A further metal fitting is embedded in the base section for mechanically holding the insulating member at a grounded frame portion of a high voltage system. An electrode is disposed in the region of the further metal fitting and extends over a significant portion of the cross-sectional area of the insulating body. An electrical terminal is connected with the electrode and is insulated against grounded components of the high voltage system.

Abstract: An electrical switching device for switching high voltages in a network having a defined rated voltage. The device includes a series connection of at least first and second current interrupters having control elements across which a load voltage is distributed. Each interrupter operates according to different quenching principles and exhibits different dielectric behavior immediately after a zero passage of load current to be interrupted. The first interrupter comprises a first switch which has an operating voltage that is low relative to a mains voltage of the network and includes means for interrupting, at relatively low switching voltages without participation of the second interrupter, currents having inductive components.

Abstract: A fault protection system for a power circuit composed of a main current path and a plurality of parallel branch paths connected in series with the main current path and each containing a winding of a medium voltage transformer, which system includes: first and second switchable current interrupters for switching the current flowing through the paths and for protecting the paths against fault currents, the first interrupter being connected in one branch path for interrupting fault currents in a first amplitude range and the second interrupter being connected in the main current path for interrupting fault currents in a second amplitude range which is higher than the first range and includes short circuit currents; and current monitoring circuits connected for monitoring the current in the one branch path and for maintaining the first interrupter in the closed state when the current in the one branch is below the first amplitude range, for placing the first interrupter in the open state in response to the pres