Transformer Explosion Breaking News Transformers are among the most expensive assets in the power network, representing over half of substation capital cost. In that extremely valuable transformer the cellulose insulation is the one component that will degrade with age and cannot be replaced without considerable cost and loss of service. Of the factors that can degrade the cellulose insulation – moisture, temperature, and oxygen – moisture is the most aggressive combatant. Excessive moisture and other impurities in the paper and oil can significantly reduce the dielectric strength and the partial discharge inception levels; therefore, it has a profound effect on the aging rate. Transformer Insulation Paper To put it simply, moisture and contamination in the transformer’s insulation system cause the molecular chains of the cellulose to decompose, in turn accelerating the aging process of the cellulose and adversely affecting the tensile strength and dielectric properti...