Intelligent Motor Control Streamlines Performance

Intelligent motor control centers (MCCs) provide the data to support safe, reliable and more efficient operations, making information available for process monitoring, advanced diagnostics and predictive maintenance. Today’s advanced MCCs provide a scalable solution for motor protection and control and facilitate simple and comprehensive communication choices. Hardwired MCCs can provide back-run status, breaker status, overload status and the status of a local sector switch on their own. A user must install additional components to obtain further information—such as phase voltage and motor current—or other analog signals. Networked MCCs provide real-time diagnostic data that enable proactive and predictive maintenance. MCCs that incorporate smart devices can report on several parameters, including phase voltages, currents, power and fault information. Many types of smart devices are available, including solid-state overloads, variable frequency drives, soft starters and meters. The motor control devices typically support the communication protocols. If a smart device does not natively support the desired protocol, a linking device, such as a bridge, can be added.

Networked MCCs also are more cost-effective to install. Hardwired equipment installation requires more wiring and testing time and can be difficult to troubleshoot when issues arise. Networked solutions have a single pipeline to each node within the MCC and a single pipeline at the output of the MCC. This enables a simplified connection to a distributed control system (DCS), supervisory control and data acquisition (SCADA) system, or programmable logic controller (PLC). A scalable solution for motor protection, including control and monitoring across multiple control device platforms, is critical. An MCC should provide several options so that the user can design the communication protocol. When selecting a network, users must look upstream at the control. For discrete control applications, a PLC typically provides control. Other control systems (such as SCADA and DCS), are more process-driven and are used in continuous process applications. Because most SCADA applications are PC-based, many communicate across network protocols and can operate using an added network card. Serial communication options include Modbus RTU, DeviceNet and PROFIBUS DP. Ethernet communication options include Ethernet/IP and Modbus TCP. Depending on the industrial network selected, the prewired MCC will have a trunk drop configuration (for DeviceNet), a daisy-chain configuration (for PROFIBUS DP and Modbus) or an Ethernet star configuration (Modbus TCP and Ethernet/IP). With any of these options, connecting an MCC can be as simple as plugging in a lamp. Wiring reduction is often limited to network monitoring of simple discrete events, which are associated with a motor controller instead of the data-rich controller parameters. In these cases, run and trip status is monitored by the control, which can provide a run command for auto operation. Because the industrial network interface is a block of inputs and outputs, additional statuses can be brought back. However, the industrial network’s goal is data richness, and today’s motor controllers are blending motor control and metering features. These metering features provide current, voltage, power, current and voltage unbalance, and ground current, as well as advanced protection configurations to meet tough applications. All of these data parameters can be displayed on a user’s human-machine interface (HMI). Taking that information one step further to monitor power and energy parameters, software simplifies viewing information at the device level, managing alarms and comparing trend data. Using a dashboard that displays efficiency, power quality and real-time energy usage, users can easily obtain the daily information they need to make critical operating decisions. The software provides a platform that identifies energy-savings opportunities and reduces wasteful practices.