Abstract: Implementations include a compartmentalized plug-in load center having connector receptacles for load circuit wiring connection to the load center and a plug-in back plate to connect the plug-in load center to a vertical power busway within a utility wall panel of a building, and a method for installing the load center in a building with a vertical power busway.

Abstract: A low voltage power supply and distribution center comprises a housing (12) having three internal compartments including: a high voltage compartment (17), a low voltage distribution compartment (19), and a transformer compartment (21). The housing (12) is designed for surface or recessed mounting on or in a wall or ceiling. For recessed mounting, with the housing (12) surrounded with 20 cm (8 inches) of insulation, the maximum surface temperature of the housing is less than 90.degree. C. The three compartments (17,19,21) are formed by a removable power tray (15) having a torodial transformer (132) mounted thereon. The low voltage compartment (19) comprises a fuse panel (150) for mounting a plurality of plug-in fuses (153) from which the low voltage power is distributed. The high voltage compartment (17) comprises a switch or a dimmer (131) in a high voltage line between the transformer (132) and the incoming high voltage line, or the dimmer or switch may be remotely installed on a wall.