Abstract: A busway system having several parallel bus bars arranged in a housing with a plug-in opening in a front wall of the housing employs a cover assembly with a plug-in unit over the plug-in opening. The cover assembly has a brick mounted onto the front wall of the housing, and a shutter attached to the brick. The brick has a plurality of cavities each of which receive a stab of one of the bus bars, and has a guide opening along its bottom wall on opposed ends. The shutter extends across the front of the brick, is positionable over the several cavities of the brick, and has a configuration corresponding to the arrangement of the cavities. A cam-linkage assembly located on opposed sidewalls of the brick is spring biased and allows the shutter to be moved along tracks of the brick for opening and closing the cavities. The plug-in unit has guide probes which enter the guide openings along the bottom of the brick as the plug-in unit is being installed onto the busway system.

Abstract: A drawout switchgear apparatus is characterized by a cell having a front opening through which a circuit breaker is movable on tracks into and out of the cell for engagement and disengagement with electrical terminals within the cell. A cell frame includes formed columns at outside corners members, cross-strut members, and formed horizontal members which members are of similar cross-section of a substantially U-shape with U-legs and a bight and with a laterally extending flange. Each member converges to form junction corners where they are fastened together. A track extension and interlock cooperate to facilitate removal and retention of the unit into and out of the cell.

Abstract: An enclosure structure for housing switchgear apparatus (such as circuit breakers) is fabricated from a pair of sheet metal panels that are held in precisely-spaced upstanding relationship by a plurality of metal cross-struts of U-shaped cross-section which mechanically interlock with apertured portions of the panels and are held in such position by triangular-shaped metal gussets which overlap and are bolted to adjacent portions of the cross-struts and panels. The cross-struts are provided with longitudinally protruding tangs at each end that are slip-fitted into and interlock with slot apertures in the panels. The width dimension of the finished enclosure structure is precisely controlled by positioning tabs on the ends of the cross-struts that are offset from the associated tangs and are drawn into abutting relationship with the inner surfaces of the respective panels when the structure is bolted together.