Drives & MCC Control Systems. A motor controller is a device that controls the performance of an electric motor. It might include a manual or automatic means for starting and stopping the motor, selecting forward or reverse rotation, selecting and regulating the speed, regulating or limiting the torque, and protecting against overloads and faults. A motor control center (MCC) groups these motor controllers and related devices in one compact structure. A motor control center consists of one or more enclosed vertical sections mounted on the floor. It contains incoming line facilities, a common horizontal bus, wireway trough, and conduit facilities for incoming and outgoing wires. Each vertical section typically contains a vertical bus connected to the power bus, a vertical wireway, one or more combination motor control units, and various related devices, including push buttons, selector switches, etc.