Abstract: A safety shield assembly for insertion within a drawout circuit breaker compartment between the load and line receivers in the compartment and the power stabs on the circuit breaker. The shield assembly utilizes a moveable shield, a pair of spring motors and a pair of actuating probes to operate the shield. One spring motor and one actuating probe are attached on either side of the circuit breaker compartment and both probes must be actuated before the spring motors can draw the moveable shield into an open position to expose the line and load receivers. The probes include a compression spring at its point of contact with the circuit breaker to compensate for overtravel.

Abstract: A barrier system includes elongated, insulative, high impact resistant isolating barrier members clamped in semi-embracing relation with the horizontal bus runs in an electrical switchboard and the like. These horizontal bus runs are interrupted by bus joints electrically connecting them with riser bus; these joints being isolated by an enclosure comprising an insulative collar and a removable, insulative cover. The barrier members, joint enclosures, and insulative barrier panels and support bases isolating the riser bus all cooperate to afford an essentially impenetrable barrier protecting the buswork and preventing inadvertent human contact therewith.

Abstract: In an electrical switchboard vertical section, vertically adjacent pairs of cubicle doors are mounted by common hinge blocks located adjacent door corners and releaseably, latchingly retained in their closed positions by common latch blocks located adjacent opposed door corners. Horizontally aligned pairs of hinge and latch blocks additionally serve as mounts for instrument compartments located in the spaces available between vertically adjacent doors; these compartments slidingly accomodating drawout instrument drawers.

Abstract: A copper busbar is created in H-shaped cross-section by assembling a pair of elongated copper bars of rectangular cross-section to one or more conjoining copper webs of U-shaped cross-section. The bars and web legs are pre-punched with series of holes accommodating bolts clamping the bars to the web in parallel spaced relation. The bridging portion of the web is also pre-punched with a series of bolt holes facilitating the implementation of the busbar as a riser bus in electrical distribution equipment, such as switchboards, switchgear, and the like.

Abstract: A switchgear construction utilizes improved modular bases to serve as individual, insulative backwalls for the stacked array of cubicles in a vertical switchgear section. The back sides of the bases, assembled to the switchgear frame in end-to-end vertical relation, are channelled to receive and mount H-shaped vertical busbars in electrically isolated, side-by-side relation. Apertures in the bases accommodate electrical connections of device line terminal run-in straps with the vertical bus, and the rearward extension of device load terminal runbacks which isolatively pass through openings in the vertical bus. The vertical bus, the horizontal bus, and the bus joints therebetween are completely isolated from external contact.

Abstract: Elongated width, depth and vertical posts of a structural metal frame are joined in mutually perpendicular relationship at the frame corners by a gusset sub-assembly consisting of a right angle brace reinforced by a gusset plate. The posts are each of C-shaped cross-section to provide a coextensive slot flanked by flanges having preformed therein corresponding hole patterns utilized by self-tapping screws to secure the gusset sub-assembly thereto. Integral fingers bent back from the terminations of the brace penetrate the slots to resiliently engage the width and depth posts and impart tension to the corner assembly joint.

Abstract: An electrical device is supported on rails for racking movement between disengaged and engaged positions through an intermediate test position. The device mounts a single lead screw centrally located between the rearwardly extending device line and load terminal disconnects for threaded engagement with a caged nut fixedly mounted at a central location between the switchboard line and load terminal disconnects. A chain and sprocket drive train mounted by the device communicates rotational drive to the lead screw from a manual drive input applied at the front of the device to motivate racking movement between the disengaged and engaged positions. Interlocks are included to insure the device is off while the device and switchboard disconnects are being mated and unmated incident with this racking movement.

Abstract: In an electrical switchboard, the body of an aluminum connector is welded to a riser bus. Bolts clamp a horizontal busbar in electrical connection with the connector body and, at the same time, fixture the horizontal busbar with a projection of the connector body protruding through an opening in the horizontal busbar. The projection is then welded to the horizontal busbar along the edges of the opening therein to create a bolted/welded joint electrically connecting the horizontal busbar to the riser bus. The projection is of sufficient height to accommodate plural coextensive horizontal busbars of a multiple bar bus run, common, bolted/welded electrical connection with the riser bus.

Abstract: In an electrical switchboard, an aluminum run-in connector is formed in an L-shaped configuration having a vertically oriented segment and a horizontally oriented segment extending inwardly to a termination where electrical connection to a device terminal can be made. A bolt clamps the vertical segment in electrical connection with an aluminum riser bus and, at the same time, fixtures the connector with a horizontal projection of the vertical segment protruding through an opening in the riser bus. The projection is then welded to the riser bus along the edges of the opening therein to complete a bolted/welded joint between the connector and the riser bus.

Abstract: An aluminum insert, friction welded to a copper plate, is projected through a close-fitting aperture in an aluminum busbar and joined to the busbar by a circumferential weld at the exit end of the aperture, using conventional arc welding techniques, to complete a high ampacity, aluminum-copper electrical joint. The copper plate is then bolted to a copper strap in conventional high ampacity, bolted electrical joint fashion.

Abstract: A mechanical assist, incorporated in each of one line and one load terminal electric connection of a multi-pole device to a switchboard, comprises a bolted joint wherein the bolt, carried by the device, is constrained against endwise movement relative thereto. The other line and load terminal connections are plug-in types. Rotation of the bolt in each assist produces movement of the device relative to the switchboard, thereby facilitating electrical connection and disconnection, as well as mounting and dismounting thereof. An insulative torque coupler is incorporated in the line terminal assist to facilitate connection and disconnection while the switchboard is live.