Motor Control Centre (MCC)
A motor control centre (MCC) is an assembly of one or more enclosed sections with a common power busbar, housing motor starters and feeders that control and protect multiple motors from a central location. Each unit typically contains a circuit breaker or fuse switch, a contactor, an overload or motor-protection relay and control circuitry; units may be fixed, plug-in or withdrawable. Starters can be direct-on-line, star-delta, soft starter or VFD feeders. MCCs are used in water treatment, oil and gas, mining and manufacturing plants. Selection parameters include rated voltage and busbar current, short-circuit withstand rating, form of internal separation, IP rating, unit type and communication with PLC or SCADA systems. Low-voltage MCCs are designed and verified to IEC 61439-1 and IEC 61439-2; internal arc performance may be tested to IEC TR 61641.
Examples
- Withdrawable MCC for a water pumping station
- Intelligent MCC with networked motor-protection relays
- MCC lineup feeding process pumps and fans