Dr B Pahlavanpour
Dr H Habibollahi

While transformer manufacturers prepare elaborate insulation and maintenance manuals regarding their product, and give specific and generalized information for the transformer user, they approach the problem from a client customer background. Day to day decisions need to be made that will result in extending the life of the transformer beyond the twenty to thirty years of normal life expectancy. Therefore, we will approach this problem from a fundamental and elementary basis, and establish guidelines for the transformer maintenance engineer to follow.many of the materials used in the manufauring of the transformer are detrimental to many of the other materials. The result of this is that the transformer is designed to "self destruct for example,oil impregnated paper is the basic insulation system. Mineral transformer oil is used to protect the paper and enhance its mechanical and dielectric strength. However the Kraft paper acts as a catalyst to from acids in the oil. these attacking and destroying the paper. it is clear that the objective of a maintenance program for the transfromer should be to control the rate of "self destruction" since this phenomenon cannot be eliminated, but controlled.