Abstract: Method and apparatus for sealing an air vent in a switchgear cabinet provide a vent seal assembly having a vent seal cover and a set of linear guides on which the vent seal cover may be mounted. The vent seal cover and linear guides are housed within a casing attachable to an interior surface of the switchgear cabinet and directly over an air vent. Within the casing, the vent seal cover may slide freely along the linear guides toward the air vent, with no spring or other mechanical biasing mechanism to oppose the sliding of the cover. A catch on the casing releasably holds the vent seal cover to keep the air vent open during normal operating conditions. When an arc event occurs, pressure from the arc event knocks the vent seal cover free of the catch and propels it toward the air vent, quickly slamming the air vent shut.

Abstract: Method and apparatus for sealing an air vent in a switchgear cabinet provide a vent seal assembly having a vent seal cover and a set of linear guides on which the vent seal cover may be mounted. The vent seal cover and linear guides are housed within a casing attachable to an interior surface of the switchgear cabinet and directly over an air vent. Within the casing, the vent seal cover may slide freely along the linear guides toward the air vent, with no spring or other mechanical biasing mechanism to oppose the sliding of the cover. A catch on the casing releasably holds the vent seal cover to keep the air vent open during normal operating conditions. When an arc event occurs, pressure from the arc event knocks the vent seal cover free of the catch and propels it toward the air vent, quickly slamming the air vent shut.

Abstract: Method and apparatus for sealing an air vent in a switchgear cabinet provide a vent seal assembly having a vent seal cover and a set of linear guides on which the vent seal cover may be mounted. The vent seal cover and linear guides are housed within a casing attachable to an interior surface of the switchgear cabinet and directly over an air vent. Within the casing, the vent seal cover may slide freely along the linear guides toward the air vent, with no spring or other mechanical biasing mechanism to oppose the sliding of the cover. A catch on the casing releasably holds the vent seal cover to keep the air vent open during normal operating conditions. When an arc event occurs, pressure from the arc event knocks the vent seal cover free of the catch and propels it toward the air vent, quickly slamming the air vent shut.

Abstract: Method and apparatus for mounting fuses in switchgear and similar electrical isolation equipment provide a nonconductive fuse support that allows the fuses to be mounted separately from the transformers. Two such fuse supports may be used to support a fuse, one fuse support for each fuse terminal. Each fuse support may support two fuse terminals so dual fuses may be supported by the same pair of fuse supports. The fuse supports substantially surround the fuse terminals to provide an insulating barrier that helps prevent electrical discharge and also ensure sufficient spacing between the fuse terminals and ground or other conductors in the switchgear. Such an arrangement allows the fuses and transformers to fit within a reduced space in the switchgear and similar electrical isolation equipment while complying with industry-standard performance requirements. The fuse supports are preferably noncontiguous, thereby leaving the nonconductive portion of the fuse physically unsurrounded.

Abstract: Method and apparatus for reducing the minimum clearance needed between an electrical conductor and ground in switchgear and similar electrical isolation equipment provide a bus-connector having an extended toroidal shape that is designed to allow the size of the switchgear cabinet to be reduced while complying with industry-standard performance requirements. The toroidal shaped bus-connector has mostly or only smooth and rounded surfaces so there are no hard or sharp edges or corners from which electrical discharge from/to ground or other conductors may occur. The shaped bus-connector also has an elongated body that produces an offset connection resembling a “Z,” which allows power buses and breaker terminals that do not vertically line up to connect.

Abstract: A compact electrical bushing has a separate insulating end cap removably attached to the shaft of the bushing at an end used for mounting a current transformer. The removably attached insulating end cap has a large outer diameter that increases the linear surface distance of the bushing. The outer diameter may be determined in a predefined manner based on the desired length of the shaft, and vice versa, with a larger outer diameter corresponding to a shorter shaft. The increased linear surface distance allows the bushing to meet minimum tracking distance with a shorter shaft relative to existing bushings. The shorter shaft reduces the footprint of switchgear and other electrical isolation equipment to which the bushing may be connected. The insulating end cap may be removed from the bushing as needed to allow the current transformer to be slid onto the bushing without having to pass over the end cap.

Abstract: Method and apparatus for mounting fuses in switchgear and similar electrical isolation equipment provide a nonconductive fuse support that allows the fuses to be mounted separately from the transformers. Two such fuse supports may be used to support a fuse, one fuse support for each fuse terminal. Each fuse support may support two fuse terminals so dual fuses may be supported by the same pair of fuse supports. The fuse supports substantially surround the fuse terminals to provide an insulating barrier that helps prevent electrical discharge and also ensure sufficient spacing between the fuse terminals and ground or other conductors in the switchgear. Such an arrangement allows the fuses and transformers to fit within a reduced space in the switchgear and similar electrical isolation equipment while complying with industry-standard performance requirements. The fuse supports are preferably noncontiguous, thereby leaving the nonconductive portion of the fuse physically unsurrounded.

Abstract: Method and apparatus for reducing the minimum clearance needed between an electrical conductor and ground in switchgear and similar electrical isolation equipment provide a bus-connector having an extended toroidal shape that is designed to allow the size of the switchgear cabinet to be reduced while complying with industry-standard performance requirements. The toroidal shaped bus-connector has mostly or only smooth and rounded surfaces so there are no hard or sharp edges or corners from which electrical discharge from/to ground or other conductors may occur. The shaped bus-connector also has an elongated body that produces an offset connection resembling a “Z,” which allows power buses and breaker terminals that do not vertically line up to connect.

Abstract: Method and apparatus for sealing an air vent in a switchgear cabinet provide a vent seal assembly having a vent seal cover and a set of linear guides on which the vent seal cover may be mounted. The vent seal cover and linear guides are housed within a casing attachable to an interior surface of the switchgear cabinet and directly over an air vent. Within the casing, the vent seal cover may slide freely along the linear guides toward the air vent, with no spring or other mechanical biasing mechanism to oppose the sliding of the cover. A catch on the casing releasably holds the vent seal cover to keep the air vent open during normal operating conditions. When an arc event occurs, pressure from the arc event knocks the vent seal cover free of the catch and propels it toward the air vent, quickly slamming the air vent shut.

Abstract: A compact electrical bushing has a separate insulating end cap removably attached to the shaft of the bushing at an end used for mounting a current transformer. The removably attached insulating end cap has a large outer diameter that increases the linear surface distance of the bushing. The outer diameter may be determined in a predefined manner based on the desired length of the shaft, and vice versa, with a larger outer diameter corresponding to a shorter shaft. The increased linear surface distance allows the bushing to meet minimum tracking distance with a shorter shaft relative to existing bushings. The shorter shaft reduces the footprint of switchgear and other electrical isolation equipment to which the bushing may be connected. The insulating end cap may be removed from the bushing as needed to allow the current transformer to be slid onto the bushing without having to pass over the end cap.