Factors affecting life cycle of motor control centers

This is part two of a two-part series. The first part appeared in the February issue. Maintaining electrical infrastructure in the manufacturing plant is a challenge. In this environment, electrical gear is subjected to every extreme of heat, dirt, chemicals, misuse, abuse, and good old-fashioned hard use.

By Douglas H. Sandberg March 10, 2005

This is part two of a two-part series. The first part appeared in the February issue.

Maintaining electrical infrastructure in the manufacturing plant is a challenge. In this environment, electrical gear is subjected to every extreme of heat, dirt, chemicals, misuse, abuse, and good old-fashioned hard use. The old axiom, “If it ain’t broke, don’t fix it” clearly no longer has a place in this world.

The advent of new streamlined manufacturing systems, highly sophisticated electronic controls, and “just-in-time” inventory supply has added complexity and criticality to once fairly simple systems.

Document control

Each piece of gear has documentation. The system or manufacturing line also has documentation associated with it. This body of information includes operator’s manuals, bills of material, one-line schematic diagrams, detailed control and power schematics, mechanical details, maintenance records, software, and test results. I vividly recall troubleshooting a master MCC in a can manufacturing plant and spreading out a mosaic of drawings on the floor. It reminded me of an old war movie where the map is spread out in the bunker while the various commanders draw proposed tactics in the sand. Our system drawings certainly looked as though they had survived bombardment. You may not be ducking live rounds, but you are fighting a war against time, and the production superintendent is surely trying to outflank you. Information is power; it must be properly maintained, organized, and protected. Good documentation is a valuable as full ammo cans in your war against time.

  • Maintaining this information is paramount. It is your only reference in an emergency. Benchmark control settings provide a default reference

  • Protect yourself against the “tweeker.” This is a person who may not understand the big picture but is compelled to “fine tune” control setpoints and then deny any involvement

  • Pay attention to the type of media containing your backup program. I learned the hard way in the early days of the programmable logic control that control transformers make excellent degaussing devices for programs stored on cassette tape. While this is no longer the technology of the day, there are other pitfalls awaiting you. Be aware

  • A master one-line diagram on the wall under glass or plastic and adjacent to switchgear is a quick reference point in an emergency or when operating the system. The motors controlled, branch circuits, individual controllers, intermediate disconnects, and overcurrent protection should be clearly identified on this diagram, as well as the device. Just as there’s “no crying in baseball,” there’s no excuse for shutting down an adjacent manufacturing line due to mismarked components or devices

  • Revision control cannot be stressed too strongly. Have in place a system governing how revisions are made, who can make them, how they are documented, and how schematics and software are revised to reflect the latest “as built” information

  • Personnel should drill on system operational knowledge so that it becomes second nature in an emergency situation

  • Contact information for all key service providers and manufacturer’s representatives is critical and must be maintained and updated as changes occur.

    • Routine (scheduled) maintenance

      The point to be made here is, while maintenance according to the manufacturer’s recommendations is essential, it does not totally preclude a problem. The realities of the potential of a failure must be understood and planned for. If the MCC in question is critical to your operation, consider redundancy. The word “preventive” can be misleading. Regular scheduled maintenance will increase the odds in your favor.

      Maintenance is one of the most neglected aspects of the critical system. Neglected can mean that maintenance is simply not done on a routine basis, may not be able to be done properly due to improper physical or electrical design, or may be simply put off due to the demands of production.

      Electrical maintenance in a manufacturing plant is a serious consideration. It is typically part of a much larger event requiring a lot of planning and an all-out effort. Personnel must understand individual roles in a successful maintenance event.

      I have attended many such events. In one case, after receiving three different sets of directions from three different individuals, I managed to get them together face to face in the sincere hope they would eliminate one another. The point here is situations like this are counter productive. Planning sessions should include the mechanics responsible for doing the work. Review the master schedule, contingencies, each craft’s responsibility, etc., and who’s in charge.

      Plant engineering, production control, and operations are part of an essential maintenance team. Failure of any team member may result in mistakes or incomplete maintenance, which, in turn, may impact reliability. It is essential that all parties understand their unique responsibilities to the other team members. Engineering may have the responsibility to maintain a specific piece of system equipment. However, they cannot be effective without the cooperation and understanding of production control and operations.

      Cost approach

      Sometimes the decision on the breath and depth of a maintenance procedure is based on cost alone. On more than one occasion, this approach has been proven to be shortsighted. The old saying “pay me now or pay me later” rings a familiar bell. As a plant engineer, you should include the risks involved and the results of not addressing recommended maintenance procedures. Qualify and quantify the issue, risk, and result.

      Modifications and upgrades

      Replace or upgrade? Upgrading systems is a viable alternative to replacement. Depending on the equipment or system, the manufacturer may be able to provide a range of services from a simple control replacement to a complete rebuild and modernization. The cost involved may be considerably lower than the total cost of replacement. This is especially true when you consider the collateral costs associated with de-installation, rigging, and re-installation.

      Still not convinced? Take a long, hard look at your equipment/systems. Ask the manufacturer if all components and parts are readily available.

      Manufacturers strive to produce a better product for the market while reducing or containing cost. When a redesign takes place, the manufacturer must decide how long the prior model will be supported with parts and maintenance. Some manufacturers are better than others, and there is usually a limited quantity of new old stock or obsolete parts. The point is you need to understand the degree of support available for the systems your plant depends upon.

      When it becomes clear that older equipment may lack support, it’s time to consider replacement or upgrade. Upgrading or modernization provides a cost-effective alternative to replacement. The cost must be weighed against the degree of disruption, which may be caused if a failure occurs and parts are not available or the cost of replacement.


      Periodic testing is very important to the health and life expectancy of your production equipment. It allows you to determine if the system is fully operational following maintenance, track performance degradation, and monitor performance set points. The benchmarks established during initial installation are the standard used for comparison.

      Results often tip you off to problems, which if left unaddressed will lead to unplanned failure. Normally, as we said, testing is part and parcel of a well-designed maintenance program. If not, it should be.

      Testing is also recommended following major maintenance to help ensure that everything is ready to for the re-start of production.


      Manufacturing facilities are becoming more complex and automated every day, as are the systems they depend on. The evolution of technology, coupled with the convergence of the truly connected environment, indicates this trend will only continue. Manufacturing systems must remain reliable.

      Your role as a plant engineer is to provide uptime to your customer. Maintaining a top-notch maintenance organization is not easy, but it is achievable.

      Questions and answers

      There are so many things that we can think of, which when discussed, elicit the reply “everybody knows that.” If it’s been some time since you went through your records, you may want to ask yourself some probing questions:

      Q. How are your plant maintenance people selected, trained, and qualified to work on critical equipment?

      A. This varies from organization to organization. I’ve been in organizations where selection and training were highly organized and managed. Unfortunately, I’ve also been in those organizations that were simply happy to have a warm body (obviously why I got the job).

      The tendency here is to place our total trust in the capabilities of the folks who work for us. That’s not bad.

      Q. Can you provide training for the operations staff?

      A. Think about it; you’re asking for time and money from people who probably are concerned with doing the most for the least. A well-designed overview of a system, the maintenance required, and the risks of doing less may go a long way to get you the time and resources you need. Who knows, you may even get a new multimeter out of the deal?

      Q. When you have a problem, how do you process it?

      A. A good escalation plan provides for uniform steps and involvement and notification of escalating levels of management. Each level of supervision must also understand unique responsibilities when called.

      Q. How does your company become aware of product changes, technical bulletins, etc. from the manufacturer?

      A. It is important to maintain a relationship with the OEM so that you will be aware of service bulletins, etc. A maintenance window is your opportunity to install upgrades or recommended changes. If the equipment was purchased via a supply house or sales rep, they may receive notification; you may not. How well connected you are makes a difference. Major OEMs are ready willing and able to provide you with information and training. You have a mutual interest; it’s your plant that could suffer an unplanned outage, and it’s their equipment, which will surely suffer a bad reputation.

      Q. What type of extended protection can you get from the manufacturer?

      A. Take the time to understand what types of agreements are available and which one best fits the requirements of the system and facility. Some equipment is relatively simple and very dependable. Some is complex and expensive. It may pay to have extended protection in place.

      Q. What spare parts do you carry?

      A. You will find that many companies do not invest in spares. They may bank on the manufacturer having spares available in an emergency. The bottom line is that if you’re in the maintenance business, spare parts are a cost of doing business. Will they have the parts you need in an emergency? Can you afford to wait and find out? It is mandatory to assess your spares prior to maintenance.

      Author Information
      Doug Sandberg serves as Director of Operations for ASCO Services, the OEM service provider for ASCO Technologies. His prior positions include plant electrician, field service technician, senior field service technician, and national service manager. He can be reached at 973-966-2079 or Dsandberg@ASCO.com .