Desludging of energized power transformers

A method has been developed whereby the life of power transformers (those 500 KVA and greater) can be extended through a unique process of removing sludge from energized transformers. This paper zeroes in on the fundamental problem of power transformers-oil deterioration and its destructive effect on the cellulose insulating system. The discussion considers seven (7) alternatives to service transformers concluding with the unique DeSludging treatment. The key to Preventative Maintenance lies in annual oil testing. Its primary purposes are to pinpoint the condition of a transformer's insulating system and to determine the work necessary to correct the situation. Twelve years experience has shown that even the worst cases have responded to this unique desludging process. In most instances these transformers have been completely desludged after one treatment. Equally bad transformers have required one additional treatment, and in rare cases, a third treatment was necessary to finish the desludging procedure. Annual transformer oil tests have verified these findings.