Intelligent motor control centers help drive energy, productivity savings

Manufacturers are continuously seeking new ways to increase productivity, streamline processes and boost their profit margins. Plant engineers can play an important role in this effort by helping to select and implement control solutions that reduce costs, save time and increase the flow of information within automation systems.

08/01/2009


Manufacturers are continuously seeking new ways to increase productivity, streamline processes and boost their profit margins. Plant engineers can play an important role in this effort by helping to select and implement control solutions that reduce costs, save time and increase the flow of information within automation systems. But with myriad choices available, it’s easy for engineers to overlook one of the keys to success: leveraging technological advances to integrate smart devices, device-level networks and software into motor control systems.

Traditionally, motor control centers (MCCs) contained only electromechanical components with hardwired connections. While these components remain the workhorses of MCCs, advances in solid-state technology have resulted in more intelligent, programmable devices that do more than just turn on and off a motor. Today’s MCCs monitor motor current and thermal capacity, perform protective troubleshooting functions and provide detailed diagnostics to help avert downtime.

These intelligent MCC designs also address some of the configuration and data-management inefficiencies that device-level networks can create, which include:

  • Reliability and flexibility shortcomings associated with typical daisy-chain architectures such as adding new units or accidental breaks in the chain that can affect downstream units in that connection, potentially shutting down equipment

  • Potential damage to exposed trunk-line and drop-line network cables in the wireways when pulling and installing other power cables

  • Integrating motor control data into the plant control system, and sorting through the enormous data available on the network to find needed information.

    • Complete integration

      The intelligent MCC integrates three major system components %%MDASSML%% communications, hardware and software %%MDASSML%% to address these issues. While early versions of MCCs with communication networks contained variations of these elements, today’s solutions leverage a harmonized design that deliberately integrates these elements into a unified solution.

      A standard MCC installation requires extensive interwiring, documenting and testing in the field. Pretested and pre-configured, the intelligent MCC arrives ready to install. Communication cables are installed and tested at the MCC factory, while software screens come pre-configured for the specific MCC. Additionally, intelligent devices are preprogrammed with baud rate, node number, trip current and other settings.

      Communication network capability lies at the heart of an intelligent MCC. The network replaces the traditional control interwiring with a single communication wire. Ideally, all the units have input points to monitor devices such as the disconnect switch, contactor, overload relay or pilot devices. In addition, a network scanner module or network linking device connects the MCC to the plant control network, and collects and distributes the device data in the MCC.

      The type of MCC you select for your application can have a significant impact on overall cost, installation time and monitoring capabilities. Therefore, it’s important that engineers carefully evaluate the core components of an intelligent MCC system.

      Proven, open communication network %%MDASSML%% The trend toward open networks (as opposed to proprietary networks) has clear and well-documented advantages. The network should provide proven performance, offer a low cost per node and be accepted by a wide range of suppliers and users.

      Optimized physical construction %%MDASSML%% The traditional approach for routing network cables in MCCs is through horizontal and vertical wireways. Although this method works, consider these more optimized approaches:

      • Trunk lines and drop lines isolated behind barriers %%MDASSML%% This design helps users avoid potential damage to communication cables during installation and maintenance

      • Independent, easy-connect ports on drop lines %%MDASSML%% This configuration provides independent, readily accessible ports to simplify installing, withdrawing, relocating and adding plug-in units. The configuration is preferable to a daisy-chain architecture, in which moving or adding an MCC unit requires interrupting the chain and disabling downstream units.

        • Pre-configured software %%MDASSML%% To integrate the intelligent MCC hardware elements and deliver useful real-time information with minimal expense and effort, intelligent MCCs should come equipped with a pre-configured monitoring software package. The software delivers a window into the MCC and related equipment. It also eliminates the need to create costly customized MCC screens within operator interface software, yielding a true plug-and-play solution.

          Easy installation

          Traditionally, MCCs were provided without inter-wiring and required extensive field wiring, documenting, testing and system integration. Because the intelligent MCC arrives ready to install, pretested and pre-configured, it significantly reduces startup time.

          Another critical aspect for efficient startup and troubleshooting is detailed documentation, which all too often is incomplete or misplaced altogether. In the case of the intelligent MCC, users can access electronic documentation on the same PC running the monitoring software. This allows users to view the real-time status of the MCC, as well as view CAD drawings, user manuals and spare parts information applicable to specific MCC units.

          An intelligent MCC provides users with critical information needed to help minimize or prevent downtime. Remote access to motor-control data also affords an opportunity for reduced exposure to hazardous voltages and improved personnel safety during startup and troubleshooting. This information includes warnings of abnormal operation, identification of trip causes, automated logging of events and electronic documentation.

          Reaping the rewards

          Intelligent MCCs can deliver considerable cost savings in the form of reduced design, installation, commissioning and documentation time. Savings occur as a result of the significant reduction in cabling requirements. Specifically, users require fewer cables and conduit, and less interface equipment such as terminal boxes, control system I/O modules and interposing relays.

          Other benefits include reduced engineering, planning and commissioning times. Intelligent MCC users report installation cost reductions of up to 15%, compared to a conventional MCC installation. In addition, users can achieve operational cost savings through improved diagnostics, which result in faster troubleshooting and, therefore, less downtime.

          As the capabilities of intelligent devices continue to increase, intelligent MCCs offer plant engineers an excellent opportunity to benefit from the advanced technology of these control systems. Plant engineers reap the rewards of reduced total cost of ownership through improved diagnostics, increased system reliability, design flexibility and simplified wiring.

          Networked motor control centers optimize performance, improve energy efficiency and protect assets.

          Motor control centers manage motor functions and connect equipment throughout the facility for centralized, intelligent motor control.




          Top Plant
          The Top Plant program honors outstanding manufacturing facilities in North America. View the 2017 Top Plant.
          Product of the Year
          The Product of the Year program recognizes products newly released in the manufacturing industries.
          System Integrator of the Year
          Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
          May 2018
          Electrical standards, robots and Lean manufacturing, and how an aluminum packaging plant is helping community growth.
          April 2018
          2017 Product of the Year winners, retrofitting a press, IMTS and Hannover Messe preview, natural refrigerants, testing steam traps
          March 2018
          SCCR, 2018 Maintenance study, and VFDs in a washdown environment.
          April 2018
          ROVs, rigs, and the real time; wellsite valve manifolds; AI on a chip; analytics use for pipelines
          February 2018
          Focus on power systems, process safety, electrical and power systems, edge computing in the oil & gas industry
          December 2017
          Product of the Year winners, Pattern recognition, Engineering analytics, Revitalize older pump installations
          Spring 2018
          Burners for heat-treating furnaces, CHP, dryers, gas humidification, and more
          April 2018
          Implementing a DCS, stepper motors, intelligent motion control, remote monitoring of irrigation systems
          February 2018
          Setting internal automation standards

          Annual Salary Survey

          Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

          There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

          But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

          Read more: 2015 Salary Survey

          The Maintenance and Reliability Coach's blog
          Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
          One Voice for Manufacturing
          The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
          The Maintenance and Reliability Professionals Blog
          The Society for Maintenance and Reliability Professionals an organization devoted...
          Machine Safety
          Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
          Research Analyst Blog
          IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
          Marshall on Maintenance
          Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
          Lachance on CMMS
          The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
          Maintenance & Safety
          The maintenance journey has been a long, slow trek for most manufacturers and has gone from preventive maintenance to predictive maintenance.
          Industrial Analytics
          This digital report explains how plant engineers and subject matter experts (SME) need support for time series data and its many challenges.
          IIoT: Operations & IT
          This digital report will explore several aspects of how IIoT will transform manufacturing in the coming years.
          Randy Steele
          Maintenance Manager; California Oils Corp.
          Matthew J. Woo, PE, RCDD, LEED AP BD+C
          Associate, Electrical Engineering; Wood Harbinger
          Randy Oliver
          Control Systems Engineer; Robert Bosch Corp.
          Data Centers: Impacts of Climate and Cooling Technology
          This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
          Safety First: Arc Flash 101
          This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
          Critical Power: Hospital Electrical Systems
          This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
          Author Information
          Keith Blodorn is a product manager at Rockwell Automation.