Motor management
November 1st 2008

Motor management plans can increase motor uptimes, reliability and reduce costs says Dave Hawley of Deritend Industries

Electric motors are probably the most widely used equipment type across all sectors of industry, their reliable operation being essential in the production of all product types. Despite this, the needs of electric motors in respect of management and maintenance are little understood.

A Motor Management Programme (MMP) is a coherent structured approach to the purchase, operation, maintenance and repair of a company's electric motors.

It is designed so that the best economic decision is made each time a new piece of plant containing a motor is purchased, and operated, or a when a repair or replacement, is necessary.

The first step of an MMP is to define the objectives of the policy; this means looking at all areas where improvements can be achieved, and are quantifiable to allow measurement or effectiveness. Some typical objectives are extended minimum time between failures (MTBF); reduced product losses from equipment (i.e. motor) failures; reduced motor failures, overall - and the commensurate reductions in downtime; and reduced inventory of spare parts.

The next task is to perform an audit of the company's complete motor stock. If this is too onerous as a start point, then the plant can be divided up into smaller sections, with the section suffering the worst from reliability and downtime problems providing the logical choice to host the pilot MMP. The audit is crucial to the MMP; it gives an up-to-date view of the plant situation, enabling data to be collected regarding the relevant specifications of motors and their operating and maintenance histories. It should also identify the most efficient and energy saving motors in the plant, and reveal any design and engineering problems which militate against reliable operation.

The data gained from the audit should be integrated to form a knowledge database. However, developing such a database from scratch is time consuming and expensive. In addition, the more comprehensive the database is, the more difficult it is to manage.

Deritend has developed its Clearview web portal to address these problems. The online portal and its associated AssetView motor database gives users complete transparency and certainty with regard to their motor assets. It delivers real- time interactive database management, providing key features such as trending and failure mode analysis, identification and search for individual assets; and also key data such as repair history of each asset, work in progress, repair information and completion dates, and cost analysis per plant sector.

Deritend's Portal & Motor asset database really comes into its own where large quantities of motors are concerned. In this case the need for specialist assistance also has implications for another crucial, but later, category of the MMP: namely, skills.

Do existing personnel possess the necessary level of skills to undertake the MMP successfully on a 24/7 basis or should the programme be outsourced? Finding and keeping staff with the necessary electrical and mechanical skills to maintain large and diverse concentrations of motor stock is becoming very difficult. Even if companies are able to harness the skill levels required, they are unlikely to be able to deploy them on a 24/7 basis. These are all issues that must be faced and resolved at an early stage of the MMP to prevent a situation arising that may fatally damage the credibility of the MMP in the eyes of a management that is funding it.

With the key task of the motor asset data accomplished, and the question of skills resolved, the way is now clear to develop the strategy and improvement plan for achieving the objectives of the MMP. The plan must be divided into workable sections to prevent confusion, and it must be boughtinto by, and have the understanding of, all personnel that are concerned with its implementation. In this respect it is better that the team performing the implementation is also the same one that develops the elements of the strategy employed.

An essential tool in support of the small project implementation strategy is a road map. This defines and delineates each task, including assignments, start dates, tasks to be completed, anticipated completion dates and actual completion dates.

Any improvement plan has necessarily to focus on the existing maintenance procedures and rewrite and redefine these in line with the improvement objectives. In contrast to existing instructions, which are often too general and leave the details to the technician, the objective is to get the technician to follow specific methods and procedures to achieve the outcomes that the MMP demands. In order to verify this, the work should be checked and the results reported on every motor assignment. In plants with large numbers of motors this can be a drain of resources, so it is better to rewrite the maintenance procedures progressively, section by section, in order of importance, to prevent data overload and backlogs that could impair the efficiency of the system initially.

What must be appreciated by all the team concerned with the MMP is that it is proactive rather than reactive. This means that the necessary proactive maintenance procedures, static and dynamic, electrical and mechanical, have to be developed and implemented. The success of these procedures can then be measured on a micro scale. They can then be optimised as the MMP is integrated across areas of plant.

Of course, the maintenance measures adopted rely not only on the experience of the maintenance team but also the equipment available. Here again, the question has to be asked as to whether the manufacturer has the right equipment that can provide the necessary functionality to satisfy all the laid-down test and inspection procedures. Increasingly, this is an area for outside specialists like Deritend who invest consistently in the latest condition monitoring, laser alignment, spectroscopic and thermographic equipment.

Finally, measure the performance and results of the MMP at regular intervals: 3- months is not too soon to begin - and benchmark the results against the initial objectives for the programme. The success of the programme depends upon on continuous improvement as to how the work is done and how its results are evaluated.

More articles from The Deritend Group Ltd: