Abstract: In a motor control center of the present invention, a plurality of units are mounted on a frame. Each of these units has an appliance mounting plate with two walls which extend transversely from the floor plate in stepped form. A first group of electrical appliances which requires relatively frequent maintenance and inspection among the electrical appliances to be mounted in the unit is mounted at the front sides of said two walls and a second group of electrical appliances which requires less frequent maintenance and inspection is mounted on the back side of the wall nearest the front.

Abstract: In an enclosed switchboard, each of side plates is provided, along both edges thereof, with vertically extending ribs having a U-shaped cross section protruding toward the confronting side plate. Connecting members for connecting the side plates are formed to fit in U-shaped cutaway portions provided at the upper and the lower ends of the ribs. A vertically extending opening is provided in the side plate to permit ventilation and wirings through the side plate.