22 Jul 2024


Smart motor control centres eliminate the usual wiring

Eaton has developed a drawer-based motor control centre (MCC) technology in which the conventional control wiring and wiring to higher-level controllers are replaced by its SmartWire-DT communication and wiring system. The motor control system, called iMCC, can transfer detailed information from the drawers to the controllers, thus increasing the reliability and availability of motors, as well as cutting wiring efforts.

The system, designed for use with Eaton’s xEnergy switchboards, is aimed at industrial production processes that need high levels of machine and system availability. It was unveiled at the recent Hannover Fair in Germany.

SmartWire-DT is used for communications within the switchboards. It replaces the previously required control wiring in the drawers, as well as cabling for control and status information in the switch cabinet. Standard fieldbuses such as Profibus-DP, CANopen, Modbus-TCP or Ethernet/IP transfer data from the switch cabinet to higher-level PLCs.

The iMCC system can be used with Eaton’s PKE electronic motor-protection circuit-breakers to provide detailed operating and diagnostic information that would not be available using conventional control wiring. As well as digital signals to switch or detect switch positions or status information, it can also handle analogue values such as for the thermal load of the motor and actual motor currents. This data can be used to implement predictive maintenance (condition monitoring) functions to detect faults in advance, to improve reliability and to minimise downtime.

If an iMCC drawer needs to be exchanged, maintenance personnel can simply pull it out of the MCC section and replace it with a preconfigured alternative. The interrupted communications of the removed drawer are restored automatically. To ensure safety during maintenance, there are three switch positions – operational, test and de-energised.

The SmartWire-DT system simplifies mounting as well as reducing wiring and saving space in the drawers. Because it replaces both the control wiring inside the drawers (to operating elements, switchgear, circuit-breakers and I/O modules) and in the cable connection compartment to the PLC, considerable savings can be made in installation and commissioning.

The use of space inside the drawers is optimised and material costs are reduced. Unnecessary hardware components are eliminated, and the engineering and commissioning of switchboards are simplified. Eaton’s SWD-Assist planning and commissioning software allows users to test individual drawers, without needing a PLC.

There are two versions of the iMCC: a basic model with a PKZ thermomagnetic circuit-breaker which indicates the state of the circuit-breaker; and an enhanced version with the communication-enabled PKE motor-protection breaker. The system can be extended at any time by adding drawers without needing to change the infrastructure. The data from these drawers is also transferred easily via SmartWire-DT.

iMCC drawers currently available include: DOL starters from 0.06–160kW; reversing starters from 0.06–110kW; star-delta starters from 5.5–75kW); and 3/4p power outgoers from 16/20–400A.