On line monitoring of bushings on large power transformers

Industry statistics suggest that 80% of all plant and equipment failures occur on a random basis and only 20% of the failures are age related. This means that 80% of failures have not been detected with common test and maintenance practices and therefore these failures have not been prevented. Based on different sources up to 30-35% of large power transformer failures are attributed to bushing insulation failures. About half of these bushing failures result in an explosion and fire. In today´s competitive environment, increasing demands are being placed on the management of physical assets. Advances in technology are allowing new approaches to maintenance. These include reliability-centered maintenance, predictive maintenance, condition monitoring, and expert systems. Trend setting organizations are increasingly taking advantage of the convergence of these new technologies to implement proactive maintenance programs