A switching apparatus including one or more electric poles. For each electric pole, the switching apparatus includes a first pole terminal, a second pole terminal, a ground terminal, and a plurality of fixed contacts spaced apart one from another. For each electric pole, the switching apparatus further includes a movable contact and a vacuum interrupter. The movable contact is reversibly movable about a corresponding rotation axis. The vacuum interrupter includes a movable arc contact reversibly movable along a corresponding translation axis. For each electric pole, the switching apparatus further includes a motion transmission mechanism operatively coupled to a contact shaft solidly coupled to the movable arc contact. The motion transmission mechanism is actuatable by the movable contact to cause a movement of said movable arc contact along said translation axis, when said movable contact moves about said rotation axis.

A transformer assembly including a transformer that is part of an underground residential power distribution circuit and that provides fault isolation and restoration. The transformer assembly includes an enclosure enclosing a primary winding and a secondary winding. The transformer assembly also includes first and second switching devices mounted to a panel of the enclosure, where each switching device includes an outer housing, a transformer interface electrically coupled to the primary winding, a connector interface electrically coupled to a first connector and a vacuum interrupter having a fixed contact and a movable contact. The fixed contact is electrically coupled to the connector interface or the transformer interface and the movable terminal is electrically coupled to the other connector interface or the transformer interface.

A transformer assembly including a transformer that is part of an underground residential power distribution circuit and that provides fault isolation and restoration. The transformer assembly includes an enclosure enclosing a primary winding and a secondary winding. The transformer assembly also includes first and second switching devices mounted to a panel of the enclosure, where each switching device includes an outer housing, a transformer interface electrically coupled to the primary winding, a connector interface electrically coupled to a first connector and a vacuum interrupter having a fixed contact and a movable contact. The fixed contact is electrically coupled to the connector interface or the transformer interface and the movable terminal is electrically coupled to the other connector interface or the transformer interface.

An arc shield surrounding an outer peripheral side of a fixed electrode and a movable electrode is provided, in addition to a fixed-side insulating unit in which a fixed-side insulator is provided to be connected coaxially with the arc shield on the fixed side in the axial direction of the arc shield, and a movable-side insulating unit in which movable-side insulators are provided to be connected coaxially with the arc shield on the movable side in the axial direction of the arc shield. The movable-side insulating unit has an insulator group in which movable-side insulators are provided to be connected in the axial direction, an insulator-group-side sub shield surrounding the outer peripheral side of a movable-side energizing shaft, and an insulator-group-side sub shield support part which is on the outer peripheral surface of the insulator-group-side sub shield and interposed between two adjacent movable-side insulators of the insulator group.

A circuit breaker includes a frame and first, second and third single-phase vacuum interrupters and first, second and third magnetic actuators connected to respective single-phase vacuum interrupters. Each of said magnetic actuators is configured to receive an open or close signal and in response, actuate the respective vacuum interrupter connected thereto into an open or closed circuit condition. Each magnetic actuator includes a fixed core, a plurality of permanent magnets surrounding the fixed core, and a movable core received within the fixed core. A controller is connected to each of the first, second and third magnetic actuators and generates the open or close signal to a respective magnetic actuator to open or close one or more of the first, second and third single phase interrupters.

A circuit breaker includes a frame having an interior compartment and an outer surface and a bushing opening. A circuit interrupter is mounted within the interior compartment. A terminal bushing is received within the bushing opening and has a lower terminal end extending into the housing and electrically connected to the circuit interrupter. An outer flange forms a bushing seat positioned adjacent the outer surface. An upper gasket is received against the outer flange. A seal pocket is formed by a bushing opening, upper gasket and outer surface of the terminal bushing. A dynamic seal is contained within the seal pocket and compressed an amount sufficient to provide elasticity and a compression height for dynamic loading of the upper gasket.

A switching device that is part of a transformer in an underground residential power distribution circuit and provides fault isolation and restoration. The switching device includes a transformer interface for coupling the device to the transformer and a connector interface for coupling the device to a connector. The device also includes a vacuum interrupter having a fixed terminal and a movable terminal, where the fixed terminal is electrically coupled to the connector interface and the movable terminal is electrically coupled to the transformer interface. A control rod is coupled to the movable terminal, an actuator assembly is coupled to the control rod and is operable to move the control rod to open and close the vacuum interrupter. A capacitor is electrically coupled to the fixed terminal, and provides an interface for power line communications signals, voltage sensing, help determine power flow direction and help determine the distance to a fault.

A switching device that is part of a transformer in an underground residential power distribution circuit and provides fault isolation and restoration. The switching device includes a transformer interface for coupling the device to the transformer and a connector interface for coupling the device to a connector. The device also includes a vacuum interrupter having a fixed terminal and a movable terminal, where the fixed terminal is electrically coupled to the connector interface and the movable terminal is electrically coupled to the transformer interface. A control rod is coupled to the movable terminal, an actuator assembly is coupled to the control rod and is operable to move the control rod to open and close the vacuum interrupter. A capacitor is electrically coupled to the fixed terminal, and provides an interface for power line communications signals, voltage sensing, help determine power flow direction and help determine the distance to a fault.

A switch assembly that is part of a transformer in an underground residential power distribution circuit and that provides fault isolation and restoration. The switch assembly includes first and second switching devices each having an outer housing, a transformer interface electrically coupled to the transformer, a connector interface electrically coupled to a first connector and a first vacuum interrupter having a fixed contact and a movable contact, where the fixed contact is electrically coupled to the connector interface and the movable contact is electrically coupled to the transformer interface. A control board controls the first and second switching devices, where the control board is responsive to voltage signals from capacitors in the first and second switching devices.

A switch assembly that is part of a transformer in an underground residential power distribution circuit and that provides fault isolation and restoration. The switch assembly includes first and second switching devices each having an outer housing, a transformer interface electrically coupled to the transformer, a connector interface electrically coupled to a first connector and a first vacuum interrupter having a fixed contact and a movable contact, where the fixed contact is electrically coupled to the connector interface and the movable contact is electrically coupled to the transformer interface. A control board controls the first and second switching devices, where the control board is responsive to voltage signals from capacitors in the first and second switching devices.