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 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.