CBM Economics

Condition Based Maintenance Economics

A New Paradigm Of Condition Based Maintenance

Electrical equipment is generally designed for a certain economic service life. The concept of replacement based on economic service life, considering it as weak or a potential source of trouble is now less supportable in the present reality of financial constraints. Reduction of in operation system failures improves reliability and effectively extends the life of equipment. Electrical infrastructure owners are continuously in search of ways and means other than conventional techniques to efficiently determine the asset condition while in service. In this way remedial measures can be planned and taken in advance of failure thus avoiding disastrous consequences and preventing downtime. The importance of effective maintenance through condition monitoring of electrical equipment is gaining attention in reducing the cost of operating electrical power assets. Computation of "Condition Health Index" is critical to an organized, efficient and effective implementation of condition based maintenance policy.

In practice, the traditional understanding of maintenance is to "fix it when it breaks". This is a good definition for repair, but not maintenance. This style of maintenance is reactive and is usually offset by some manner of time based inspection and testing. In modern and forward thinking utilities and industries, it has been realized that proactive, rather than reactive maintenance management brings improved results. This is promoting exploration of new approaches and techniques of monitoring, diagnosis, life assessment and condition evaluation towards extending the life of critical electrical assets and increasing system reliability. Circuit breakers, cables, transformers and switchgear constitute a significant and critical portion of assets in electrical distribution systems.

Quantification of the risks facing a specific asset population will help owners develop appropriate maintenance plans and replacement strategies as well as the budgets needed to support them. Using risk as the capstone of the Condition Based Maintenance Policy, the potential cost savings of can often be a easily understood by management. Minimization of the service life cycle cost is one of the stated tasks of the electrical power system engineers. The main goal is therefore to reach a cost effective solution for managing critical electrical assets using available resources through A New Paradigm of Condition Based Maintenance Policy.

Though the estimated life of equipment varies between 20-40 years, a large number of equipment is failing much earlier due to poor quality materials, inferior design and inadequate maintenance or poor environmental conditions. Without effective evaluation based on additional knowledge of the "health" condition of the equipment and root cause of the degradation, the equipment reliability and service life will most likely be significantly decreased.

Condition Based Maintenance effectively addresses the above set backs and offers significant positive impact on the economics of operating, maintenance and future system reliability in the following manner:

Operational Benefits

  1. It avoids potential equipment failure by providing early detection of degradation.
  2. It increases the asset availability by reducing the probability of failure to near zero.
  3. It allows the maintenance team to organize activities according to priorities and available human and budget resources.
  4. It provides structured maintenance for equipment that will extend the asset life span and maximize the asset loading capability or capacity.
  5. It provides a measurable and quantifiable means to avoid equipment failure that translates into reduction of insurance premiums.

Maintenance Benefit

  1. It reduces repair costs by giving early warning and indication to avoid more serious damage.
  2. It provides drill down navigation through data integration to confirm the "health" index of equipment.
  3. It assists management in deciding how to plan and utilize maintenance assets.
  4. It reduces overtime and emergency costs related to reactive maintenance.
  5. It minimizes unnecessary production downtime due to scheduled maintenance.
  6. It provides a traceable means to assess the quality of repair work.
  7. It minimizes the inventory of unnecessary spare parts reducing holding inventory costs and allowing for risk based purchasing

Asset Planning Benefit

  1. It improves future equipment specifications and application to maximize asset utilization and performance.
  2. It provides insight into improved system design and configuration.
  3. It enhances equipment utilization and performance

It has been well established that by adopting proper CBM techniques, it is possible to increase the efficiency of a power plant by at least 2% which translates into roughly a 10% energy saving in Power Generation System. Likewise through proper implementation of CBM, the Power Transmission & Distribution System could realize 7% reduction in their losses. At the customer end, it has been well established that the right choice of CBM techniques yield a minimum of 2% savings of energy consumption by abnormal motors operation.