A differential cylinder for a hydromechanical drive for actuating an electrical switch, for example a high-voltage switch, is disclosed which includes a first pressure region for applying a working pressure, a second pressure region, and a piston which is capable of moving in a movement region and which is movable depending on a pressure difference between the first and second pressure region. A damping device is provided which, in the event of a movement of the piston in the direction of the second pressure region, provides damping with respect to the movement of the piston in a section of the movement region, wherein the damping is adjustable.

An on-load tap changer is provided having a plurality of modules, each of which is operable to change taps in a transformer winding. The tap changer includes a motor connected to rotate at least one shaft. The at least one shaft is connected to the tap change modules and is operable upon rotation to cause the tap change modules to each perform a sequence of operations that effectuate a tap change. A multi-turn absolute encoder is connected to the at least one shaft. A monitoring system is connected to the encoder and is operable to determine from the position of the at least one shaft where the tap change modules are in the sequence of operations.

A differential cylinder for a hydro-mechanical drive for actuating an electric switch, for example, a high-voltage switch, can include a first pressure area to be loaded with an operating pressure, a second pressure area, and a piston which can be moved in a movement range as a function of the pressure difference between the first and second pressure area. A damping device is provided which, during a movement of the piston in the direction of the second pressure area in one section of the movement range, provides damping against the movement of the piston, wherein the damping is adjustable.

An on-load tap changer is provided having a plurality of modules, each of which is operable to change taps in a transformer winding. The tap changer includes a motor connected to rotate at least one shaft. The at least one shaft is connected to the tap change modules and is operable upon rotation to cause the tap change modules to each perform a sequence of operations that effectuate a tap change. A multi-turn absolute encoder is connected to the at least one shaft. A monitoring system is connected to the encoder and is operable to determine from the position of the at least one shaft where the tap change modules are in the sequence of operations.

An electrical switching apparatus including a housing, a circuit interrupter mechanism movably disposed in the housing, and a damper assembly. The damper assembly includes a bracket that secures the damper assembly to the housing. A damper body is adjustably secured to the bracket. A stopper is coupled to the damper body and arranged to limit relative movement of the circuit interrupter mechanism with respect to the damper assembly. A damper rod extends through an opening in the stopper and has a surface that is arranged to interact with the circuit interrupter mechanism. The damper rod is arranged to damp movement of the circuit interrupter mechanism with respect to the damper body when the circuit interrupter mechanism is in contact with the surface of the damper rod.

The disclosure relates to a fast earthing switch including

two contacts of which at least one contact is movable in relation to the other contact between a closed position, in which the contacts are connected, and an open position, in which the contacts are unconnected,

a cylinder-like guiding tube in which the at least one movable contact forming a piston is slidably arranged for linearly moving between the closed position and the open position, whereby

the guiding tube is closed at an upper end and/or at a thereto opposite lower end so that that the piston defines a first compression chamber with the upper end and/or a second compression chamber with the lower end for thereby decelerating movement of the piston when moving into the open position and/or into the closed position.

A piston rod (15) and a first piston (13) are arranged in the interior of an external cylinder (11) and internal cylinder (12); a second piston for absorbing the change of volume of operating fluid (24) is also arranged therein. Also, a first return spring (18) for returning the piston rod (15) to the interruption position is provided and a second return spring (20) for returning the operating fluid 24 into the high-pressure chamber (25) by pressurizing the second piston (14) is provided. In addition, the air in the interior of the buffering device (10) is withdrawn by a vacuum pump (38), and operating fluid (24) is thus introduced in a degassed condition.

A high voltage circuit-breaker comprising a housing defining a volume for an insulating gas, at least two making and breaking (M&B) units arranged therein, each M&B unit comprising a first and second contact element for forming an electrically conductive connection, at least the first contact element is movable along an axially extending switching axis of the high voltage circuit-breaker, and the first contact elements of the at least two M&B units are motion-coupled; a drive device connected to the first contact element of at least one M&B unit and configured for moving the first contact element along the switching axis over a moving distance for separating conductive connections; and a gas damper connected to the first contact element of the at least one M&B unit and configured for damping movement of the first contact element with a damping force increasing in relation to the moving distance.

Examples of an operating mechanism of a circuit breaker are described. The operating mechanism includes a housing, a cam element installed on a mechanically driven first shaft, a transmission lever installed on a second shaft parallel to the first shaft, and a support assembly. The transmission lever is provided with a first roller element. The support assembly includes a fork joint that is to support a second roller element and a damper element coupled to the fork joint. During a closing operation of the circuit breaker, the cam element rotates to interact with the first roller element to cause rotation of the transmission lever to close the circuit breaker and rotates further to engage with the second roller element on the fork joint to initiate a closing damper stroke.