Abstract: An improved electric control center comprising a plurality of drawout type switchgear units housed in a cabinet having incorporated therein an integral air-ventilation duct system of modular snap-fitting construction having at least one air intake opening located at the bottom of the cabinet, one air exhaust opening at the top of the cabinet, and a plurality of branch ducts that communicate with a plurality of tandem compartments that are in stacked relationship and contain the respective switchgear units. The heat generated by the switchgear units and associated bus bars is thus removed from the cabinet by the air flow through the ventilator duct system.

Abstract: A shipping cover for a motor control center characterized by a motor control center having a panel surface from which projects a handle and a handle knotting frame, and a shipping cover therefor characterized by spaced walls forming cavity means for enclosing the assembly of the handle and frame which walls engage the surfaces of the handle and frame to effect a friction fit between the cover and the assembly.

Abstract: A control center for distributing electric power from a power supply source to power consuming devices characterized by a plurality of parallel bus bars covered on each side with dielectric barriers in surface-to-surface contact with the bus bars, the barriers comprising a plurality of sheet-like barrier members in end-to-end abutment which members include cooperating first interfitting portion and extending between each pair of adjacent bus bars, the abutting ends of the barriers having cooperating second interfitting end portions to provide a labyrinth-like structure between adjacent bus bars to maintain insulating and isolating properties between adjacent bus bars.

Abstract: A control center characterized by horizontal bus bars having electrically insulating covers thereon which covers are in surface-to-surface contact with the surfaces of the bus bars except for removable surface portions for providing electrical connection with vertical bus bars, the removable surface portions being disposed in a pattern to enable alignment of said removable portions with the vertical bus bars when the barriers are assembled with the horizontal bus bars in either upright or inverted positions.

Abstract: A control center characterized by vertical bus bars supported by dielectric insulators which are disposed in vertically spaced pairs along the bus bars and which are molded with a configuration to accommodate bus bars of various shapes and sizes.

Abstract: A control center with insulated bus bars characterized by a cabinet having a plurality of spaced vertical bus bars, each bus bar comprising an intermediate portion and a leg extending toward the front side of the cabinet and another leg extending toward the back side of the cabinet, a barrier encasing the bus bars and being substantially coextensive therewith, the barrier and the bus bars being in complete surface-to-surface contact with the bus bars without air space between them, the barrier having spaced openings for exposure of the legs of the bus bar for connection by detachable conductor members of a circuit interrupter, and the barriers also having breakaway surface portions for exposure of the intermediate portion of a bus bar to provide access for connection of a conductor to the bus bar.

Abstract: A control center characterized by vertical bus bars having bent-over portions forming a U-shaped cross section adapted for engagement by clip-on contacts of a circuit interrupter.

Abstract: A stab assembly for a circuit interrupter for use in drawout switchgear characterized by a circuit breaker movable into and out of contact with bus bars and having spaced terminals in substantial alignment with the bus bars, each terminal comprising a base and a pair of flexible contacts disposed on opposite sides of an axis and engageable with opposite sides of a bus bar, the base comprising lateral portions extending from the sides of the axis corresponding to the flexible contacts, a dielectric housing in which the base is pivotally mounted to affect rotation laterally of said axis, and the housing having a projection spaced from each lateral portion for limiting rotation therein.

Abstract: A control center characterized by a metal enclosed upright cabinet having a plurality of vertical bus bars therein, which bus bars are separately insulated and isolated from each other. The assembly of the bus bar and insulation barriers is supported and reinforced by a plurality of vertically spaced braces to prevent lateral movement of the bus bars as well as to hold the insulating barriers in tight surface-to-surface contact with the bus bars.

Abstract: A control center characterized by vertical bus bars having electrically insulating covers thereon which covers are in surface-to-surface contact with all surfaces of the bus bars except for spaced areas where connection is made by conductors for load distributions. In addition, each pair of spaced bus bars are isolated from each other by interfitting portions of the covers which portions are coextensive with the bus bars so that resistance to tracking and arcing between the bus bars is maximized.