Motor Control Centres are used where a central control point is needed to remotely operate multiple loads. In industrial applications, the loads being controlled are usually conveyors, pumps, fans and mixers. These loads often require coordinated control and can be the source of important process or diagnostic information. Programmable logic controllers (PLCs) are used normally to provide control and data acquisition functionality.

Traditional MCCs

Traditional MCCs are often designed with the input/output (I/O) structure centrally located near the point of control, or directly into the MCC, with individual cables connecting between each input/output and the starters. This wiring is expensive, limiting the amount of information and control points that can economically be incorporated. Often, only the run command and running signal is connected for a given unit connected to the control system. Where the wiring crosses shipping splits, the connections have to be broken, or the cables rolled back into the I/O enclosure before delivery.

Intelligent MCCs

Intelligent MCCs are characterized by simplicity and usually deliver the lowest installed cost. They usually provide additional functionality, that is not feasable with hard wired systems.

The network used usually only consists of between four and six cores so the installation and commissioning time is significantly improved over traditional MCCs. The electronic components fitted into solid state overloads, drives and soft starts offer additional functionality and protective features.

Typically, intelligent systems have three things in common:

• Control is achieved via a microprocessor-based system
• Network technology is used to replace hardwiring
• Some degree of enhanced diagnostic or protective functionality is included.