Dr. Prodipto Ghosh, Ph.D. (EE), MBA

Electrical distribution equipment is generally designed for a certain economic service life and it is dependent on operating environment, it’s maintenance program and the quality of the original manufacture and installation. Beyond this service life period the equipment should not expected to function to its original specification with intended reliability. Generally due to poor quality of raw materials, workmanship and manufacturing techniques or due to frequent system faults, over loading, environmental effect, unexpected voltage swings and over voltage stresses on the system during the operation, many equipment failures occur much before their expected economic life span. However, certain equipment is found to operate satisfactorily even after the expected economic life span which may be attributed to good site conditions and good maintenance. On the other hand, the traditional practice of simple replacement of power equipments in the system either before or after their economic service life, considering it as weak or a potential source of trouble is no more valid in today’s business. It is also well known that in the past, environmental concerns and safety issues involved with operation and maintenance of equipment were not addressed with high importance. But as regulations and work standards undergo changes, failure of electrical equipment causing damage or resulting in serious safety consequences for the operator or maintenance crew may have considerable ramifications related to Federal or Provincial Laws in Canada.

So, with the increasing age of the population of equipment in service, it is of paramount importance to assess the internal condition of the equipment while in service before catastrophic failures can take place. At the wake of this avalanche of change, maintenance engineers are continuously in search for a new approach to maintenance to maximize the life of the equipment at a minimal cost and effort is being directed to explore the possibility of extending the life of existing assets. Minimizing the service life cycle cost is one of the challenges of a maintenance engineer. While the pressure to reduce maintenance costs is already being felt, the concept of maintenance is also undergoing change. The consequences of ineffective equipment maintenance can be huge in terms of system reliability indices, revenue loss and organizational image. Therefore, the strategy of effective maintenance is to assess the condition and reduce frequency of failures of equipment, which is a key to improving reliability and also effectively extending the life of equipment. The periodicity of condition-based maintenance tasks is decided based on two factors the frequency of the failure and severity of the failure. Sometimes these two are combined together and expressed as the criticality of the equipment.

In forward thinking industries, it has been realized that proactive, rather than reactive maintenance management brings the best results. Implementing a proactive approach to maintenance will increase maintenance efficiency significantly in an existing reactive maintenance culture of the organizations. Hence industries are continuously in search of proactive maintenance practices to assess the condition of equipment in service so that remedial measures can be taken in advance to avoid catastrophic failures thereby saving lot of valuable resources. Moreover, safety is considered as the capstone of the proactive maintenance program. Proactive maintenance programs are comprised of application of standards and methods, where standards are the measure of performance level of maintenance work and methods are the procedures that need to be practiced to meet the standard. The transformation process from a reactive maintenance culture to a totally proactive maintenance culture is not an overnight project and it will take time, effort and planning to accomplish. The transformation requires commitment from all levels of the organization and will lead to improvements in maintenance through better:

• Engineering Design
• Installation practices
• Maintenance procedures
• Workmanship
• Inventory management

Proactive maintenance is designed to have a feedback system between the maintenance crew and design engineers to prevent recurrence of design mistakes and its main objective is to extend machinery life and to obtain zero breakdowns. The equipment is always viewed from the life-cycle perspective. There are a number of key elements involved in implementing a successful proactive maintenance program:

• Up-to-date single line diagrams
• Availability of equipment manufacturing data
• Safe operating procedures
• Equipment maintenance history
• Failure analysis
• Facilitation and guidance

In today’s context maintenance should be viewed as a business proposition rather than a cost centre.