Proposed is an automatic transfer switch with an N-phase overlapping structure, the switch including: a driving unit including a drive shaft provided to generate power; a three-contact switching unit including a normal power shaft and an emergency power shaft provided to be rotated by the drive shaft, and a normal power terminal and an emergency power terminal for inputting/releasing normal power and emergency power; and an N-phase overlapping unit including a first insertion part having a first insertion hole, an N-phase normal contact terminal provided to input/release an N-phase normal power, a second insertion part having a second insertion hole, an N-phase emergency contact terminal provided to input/release an N-phase emergency power, and a connection bar connected between the first insertion part and the second insertion part so as to be interlocked with each other.

An on-load tap changer is for uninterrupted diverter switch operation. The on-load tap changer includes: a first module having a first module shaft; and a second module having a second module shaft. The first module shaft is configured to actuate the first module. The second module shaft is configured to actuate the second module. The first module shaft and the second module shaft are mechanically coupled to one another in such a way that the first module shaft is configured to drive the second module shaft and the second module is configured to be actuated with a time delay with respect to the first module.

An on-load tap changer uninterruptedly switches between winding taps of a tap-changing transformer. The on-load tap changer includes: at least one selector configured to preselect, in a powerless manner, a selected winding tap of the winding taps; at least one diverter switch configured to actually switch loads from a previous winding tap to a preselected winding tap of the winding taps; at least one toothed gearing comprising a first gearwheel and a second gearwheel, the first gearwheel being assigned to the selector, and the second gearwheel being assigned to the diverter switch; and a drive shaft, which is configured to be actuated by a motor drive. The first gearwheel and the second gearwheel are directly interconnected mechanically in such a way that the first gearwheel and the second gearwheel are simultaneously actuatable. The drive shaft is configured to drive either the first gearwheel or the second gearwheel.

Embodiments of a disconnector and a switchgear, wherein the disconnector comprises a contact assembly operable to change a status of a circuit, the disconnector arranged in the circuit; shafts adapted to be driven to rotate to operate the contact assembly; and a transmission unit arranged between the shafts and comprising: a plurality of gears coupled to the shafts to enable the shafts to rotate with a mutual engagement of the plurality of gears; and a holding assembly adapted to hold radial positions of the plurality of gears to ensure the mutual engagement of the plurality of gears. By arranging the holding assembly to hold the radial positions of the gears to ensure the mutual engagement of the plurality of gears, only one input shaft and one transmission unit are enough to transmit large torques sufficient to operate the contact assembly.

An arc quenching device for a three-phase electrical switchgear. The device includes a first busbar, a second busbar and a third busbar, each of a respective phase of the three-phase switchgear. The device also includes at least one piston of an electrically conductive material and having a tapered shape, tapering towards its front end. The device also includes only one pyrotechnical actuator arranged to, when the pyrotechnical actuator is fired, axially move each of the at least one piston until all of the first, second and third busbars are short-circuited to each other via the at least one piston.

An arc quenching device for a three-phase electrical switchgear. The device includes a first busbar, a second busbar and a third busbar, each of a respective phase of the three-phase switchgear. The device also includes a first piston and a second piston, each of an electrically conductive material. The device also includes at least one pyrotechnical actuator arranged with the first and second pistons to axially move each of the first and second pistons if the at least one pyrotechnical actuator is fired. The first and second pistons are arranged in relation to the first, second and third busbars such that said axial movement brings the first piston into contact with both the first busbar and the second busbar, and the second piston into contact with both the first busbar and the third busbar.

A protection unit, including a power switching device, with a mechanical switch. To improve the multipurpose nature of the power switching while making lockout easier and more reliable, provision is made for the power switching device to include an electrical actuator actuating the mechanical switch and being controlled by an electronic control unit, which is itself powered via an auxiliary switching device. A lockout system with a lock is provided, which, in a lockout configuration, mechanically keeps the mechanical switch and the auxiliary switching device in an isolation configuration, and, in operating configuration, allows the mechanical switch and the auxiliary switching device to move between the conduction configuration and the isolation configuration.

An automatic transfer switch includes a first phase switch component having a first plurality of cassettes, and at least one outer bus component disposed at an outer side of the first phase switch component. The automatic transfer switch additionally includes a first plate which is disposed on the outer side of the first phase switch component at a terminal end of the first phase switch component. The first plate is structured to increase impedance on an outer bus component of the first phase switch component to rebalance current along the first phase switch component.

An automatic transfer switch includes a first phase switch component having a first plurality of cassettes, and at least one outer bus component disposed at an outer side of the first phase switch component. The automatic transfer switch additionally includes a first plate which is disposed on the outer side of the first phase switch component at a terminal end of the first phase switch component. The first plate is structured to increase impedance on an outer bus component of the first phase switch component to rebalance current along the first phase switch component.

A central module for a three-phase electrical switching device, comprising a central plinth intended to bear a central switch module and a front face comprising control/command members for the switching device. The central plinth comprises rear fixing means capable of fixing a rear plinth intended to bear two rear switch modules, lateral fixing means capable of fixing two lateral plinths intended to each bear a lateral switch module, an actuation mechanism intended to actuate a central switch module, and means for transmitting movements of the actuation mechanism toward the rear plinth and the lateral plinths to be able to actuate the rear and lateral switch modules. A three-phase electrical switching device comprising such a central module is also disclosed.