S&C Electric Company

A system and method for providing fault isolation in a power distribution network. The network includes a power line, a recloser coupled to the power line and a plurality of switching devices coupled to the power line downstream of the recloser, where each switching device is capable of detecting fault current in response to the fault and detecting presence of voltage. In one non-limiting embodiment, the method includes detecting overcurrent, loss of voltage and return of voltage by the switching devices and includes sequentially opening and closing switching devices from the recloser to a switching device immediately upstream of the fault in response to detecting overcurrent, loss of voltage and return of voltage.

Dead-front air insulated switchgear that includes switches and fuses that are mounted to a top panel of the switchgear housing so as to lower the cable connection location of the switches and fuses. More specifically, when the switch and the fuse are mounted to the top panel, the switch bushing and fuse bushing well to which the cables are attached end up being located closer to a base of the switchgear.

A fuse assembly for switchgear including a fuse, a first coupling assembly coupled to the fuse, and a second coupling assembly coupled to the fuse opposite to the first coupling assembly. The switchgear also includes an extension component extending parallel to the fuse and being coupled to the first and second coupling assemblies. The extension component includes an internal conductor electrically coupled to the second coupling assembly and a single piece insulating member molded around the conductor. The single piece insulating member includes a first cylindrical portion coupled to the first coupling assembly, a second cylindrical portion coupled to the second coupling assembly and a vertical portion coupled to the first and second cylindrical portions and being perpendicular thereto, where the conductor runs through the second cylindrical portion and the vertical portion.

A detection system including a first module, a second module and an interface configured to allow the first module and the second module to be detachably coupled to each other. The first module includes a first detection circuit and the second module includes a second detection circuit coupled together on a single detection line. The first detection circuit measures voltage on the single detection line to determine if the second detection circuit is connected thereto and if so, whether the second detection circuit is being powered, and the second detection circuit measures voltage on the single detection line to determine if the first detection circuit is connected thereto and if so, whether the first detection circuit is being powered.

A system and method for operating a vacuum interrupter in a self-resetting interrupter. The method includes detecting fault current, opening the vacuum interrupter a first time using power harvested from the current transformer when the fault current is detected, and storing a polarity of the detected fault current when the vacuum interrupter is opened. The method then determines a close time to close the vacuum interrupter so that the current has the same polarity that was stored when the vacuum interrupter was opened and that actuation of closing the vacuum interrupter ends at a current zero crossing, closes the vacuum interrupter at the close time, and opens the vacuum interrupter a second time after the vacuum interrupter is closed using power harvested from the current transformer.

A system and method for isolating a fault in a power distribution network. The network includes a power line, a plurality of transformers electrically coupled to and positioned along the power line, and a recloser coupled to the power line. Each transformer has a unique address identifying the transformer and includes a source side switching device at an upstream side of the transformer and a load side switching device at a downstream side of the transformer. The method includes learning the address by each transformer of its immediate neighbor transformers, detecting overcurrent by some of the switching devices as a result of the fault, detecting loss of voltage by some of the switching devices and sending clear to close messages to selectively open and close certain ones of the switching devices using the transformer addresses to limit the number of switching devices that are operated and to isolate the fault.

An actuation assembly that is part of and operates to open and close a cut-out mounted switching device. The actuation assembly includes components that cause the switching device to be released from an upper coupling assembly when the actuation assembly opens the switching device and causes the switching device to be closed when the switching device is dropping out of the coupling assembly.

A switch assembly including a switch and an interface physically coupled to the switch and configured to be physically coupled to an electrical component, such as a transformer. The switch assembly also includes an interface having electrical hardware electrically coupled to the switch and configured to be electrically coupled to the component. The switch assembly further includes a surge arrester having an insulation member, a grounding jacket formed over a portion of the insulation member and a conductor extending through the insulation member and being electrically coupled to the hardware and the grounding jacket. The interface further includes a releasable connector that is electrically coupled to the conductor and allows the surge arrester to be disconnected from the interface.

An electrical device including a first cylindrical capacitor, a first terminal electrically coupled to one end of the first capacitor, a first electrical line electrically coupled to the first terminal and a first annular conductive end shield formed over the first terminal and being electrically coupled to the first terminal and the one end of the first capacitor, where the first end shield has a greater diameter than the diameter of the first capacitor. The device also includes a second cylindrical capacitor, a second terminal electrically coupled to one end of the second capacitor, a second electrical line electrically coupled to the second terminal and a second annular conductive end shield formed over the second terminal and being electrically coupled to the second terminal and the one end of the second capacitor, where the second end shield has a greater diameter than the diameter of the second capacitor.

A system and method for operating a vacuum interrupter in a self-resetting interrupter. The method includes detecting fault current, opening the vacuum interrupter a first time using power harvested from the current transformer when the fault current is detected, and storing a polarity of the detected fault current when the vacuum interrupter is opened. The method then determines a close time to close the vacuum interrupter so that the current has the same polarity that was stored when the vacuum interrupter was opened and that actuation of closing the vacuum interrupter ends at a current zero crossing, closes the vacuum interrupter at the close time, and opens the vacuum interrupter a second time after the vacuum interrupter is closed using power harvested from the current transformer.