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: 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.