Motor control center houses various starters for the various drives. It is mfg. In compartmentalized and non-compartmentalized constructions. Panels are manufactured in sactions for a big MCC. All sactions are joined together. Copper/Aluminum bus bar is provided with the Panels. In the continuous process industries down time in the starters are critical. In that case draw out type MCC is used. Same is having modules of different ratings and new modules can be plugged by removal of the exciting module.