A motor assembly for a switch drive of an electric switch. The motor assembly has a brushless three-phase motor and an electronic control device for controlling the three-phase motor. The control device has a rectifier unit for rectifying a supply voltage of the motor assembly if the supply voltage is an AC voltage, and for reverse polarity protection if the supply voltage is a DC voltage. The control device also has a voltage measuring unit for detecting a rectifier output voltage of the rectifier unit, a switch unit for generating a pulse width-modulated drive AC voltage for the three-phase motor from the rectifier output voltage, and a control unit for actuating the switch unit according to the rectifier output voltage.

A crank arm of an auxiliary rotary switch in a circuit breaker changes electrical connections of contacts in the auxiliary rotary switch when the crank-arm is rotated about its axis. An auxiliary switch actuator decouples abrupt forces from being applied to the crank arm resulting from closing main contacts of the circuit breaker. In response to the main contacts starting to close, the crank arm is set into rotation by motion of a connection-state link that is coupled to the main contacts. The rotation of the crank arm continues up to a point at which the rotation is stopped, while the connection-state link continues its motion without being connected to the crank arm. In this manner, the connection-state link is decoupled from the crank arm, to relieve the crank arm from receiving the abrupt forces conducted by the connection-state link resulting from the main circuit breaker contacts closing.

A crank arm of an auxiliary rotary switch in a circuit breaker changes electrical connections of contacts in the auxiliary rotary switch when the crank-arm is rotated about its axis. An auxiliary switch actuator decouples abrupt forces from being applied to the crank arm resulting from closing main contacts of the circuit breaker. In response to the main contacts starting to close, the crank arm is set into rotation by motion of a connection-state link that is coupled to the main contacts. The rotation of the crank arm continues up to a point at which the rotation is stopped, while the connection-state link continues its motion without being connected to the crank arm. In this manner, the connection-state link is decoupled from the crank arm, to relieve the crank arm from receiving the abrupt forces conducted by the connection-state link resulting from the main circuit breaker contacts closing.

A method of operating a spring-loaded drive of a medium-voltage switchgear system includes at least the following steps: measuring a drive current of an electric auxiliary drive for loading a drive spring of the spring-loaded drive of the medium-voltage switchgear system; loading the drive spring by the electric auxiliary drive; creating an evaluation data set in accordance with the measured drive current; comparing the evaluation data set with an expectation; and outputting a maintenance signal in accordance with a result of the comparison. There is also described a spring-loaded drive and a medium-voltage switchgear system having a spring-loaded drive of this type.

A dual energy storage operating mechanism of an isolating switch is provided. A first energy storage mechanism and a second energy storage mechanism are provided between an input wheel and a housing and between the input wheel and an output wheel or a first output shaft, respectively. The output wheel is provided with a limiting mechanism. The limiting mechanism forms a locking effect on the output wheel when the first energy storage mechanism stores energy, thereby enabling the second energy storage mechanism to store energy at the same time. When the first energy storage mechanism starts to release energy, the locking effect of the limiting mechanism is released, so that the output wheel and the first output shaft can rotate, and the first energy storage mechanism and the second energy storage mechanism release energy at the same time, forming a dual energy storage boosting effect.

A quick-set clevis joint for a three-phase electric disconnect switch linkage includes a clevis housing having a spring chamber axially aligned and disposed around a linkage pipe extending through the clevis housing. A spring positioned within the spring chamber provides play in the linkage. First and second thrust disks compress the spring in a first axial direction with the first thrust disk pushed against a first spring chamber end wall when the linkage pipe moves in the first axial direction while the clevis housing is blocked from moving in the first axial direction. In addition. the first and second thrust disks compress the spring in the second axial direction with the second thrust disk pushed against the second spring chamber end wall when the linkage pipe moves in the second axial direction while the clevis housing is blocked from moving in the second axial direction.

An actuating mechanism for an electrical switching device includes a frame and a driving member. The driving member is rotatably arranged in the frame around an axis and is movable between a first driver position and a second driver position. The driving member is mechanically linkable to the electrical switching device by a first linking member. The movable contacts of the electrical switching device are in a first position in the first driver position of the driving member and are in a second position in the second driver position of the driving member. The actuating mechanism further includes an actuating member. The actuating member is rotatably arranged in the frame around an axis and is movable between a first actuator position and a second actuator position by hand or based on using a motor. The actuating mechanism further includes a load spring.

A key switch including: a support base; a key which is manually operable for being moved, with respect to the support base, between at least a first operating position and a second operating position spaced apart from each other, in order to establish or interrupt at least one electric connection; a leaf spring member operatively interposed between the support base and the key; wherein the first operating position is a stable operating position of the key in which the leaf spring member is deformed between the key and the support base so as to take a first curvilinear configuration.

An actuating mechanism for an electrical switching device includes a frame and a driving member. The driving member is rotatably arranged in the frame around an axis and is movable between a first driver position and a second driver position. The driving member is mechanically linkable to the electrical switching device by a first linking member. The movable contacts of the electrical switching device are in a first position in the first driver position of the driving member and are in a second position in the second driver position of the driving member. The actuating mechanism further includes an actuating member. The actuating member is rotatably arranged in the frame around an axis and is movable between a first actuator position and a second actuator position by hand or based on using a motor. The actuating mechanism further includes a load spring.

A closing spring assembly for an electrical switching device is provided. The closing spring assembly is configured to exert a closing force on a moving contact of the switching device. The closing force helps to maintain physical and electrical contact between the moving contact and an associated stationary contact, so that the moving and stationary contacts form a path for conducing electric current through the switching device. The closing spring assembly is configured so that the closing force remains constant or decreases as the moving contact is driven away from the stationary contact during switching of the current path away from the moving and stationary contacts.