Large industrial or manufacturing facilities have hundreds of various size motors all requiring specialized control and protection. Rather than scatter them throughout the facility, they are grouped together into motor control centers (MCC.)
The MCC itself is simply a sheet metal cabinet with a front panel containing operator controls and indicators. The interior of the MCC contains plug-in units such as starters, controls, and specialized units. This combination of a central location and simplified plug-in units makes the MCC an economical, space-saving approach to controlling and protecting several motors.
The Article 430H of NEC covers the rules governing the requirements of Motor Control Centers.
