Inhibited oils for transformers

ALLOWABLE AND actual loadings of transformers of the Commonwealth Edison Company have increased considerably in the past 15 years with consequent rises in transformer temperatures. Oils with improved oxidation stability have gained increased importance, especially for older type transformers in service. An immediate interest developed in inhibited oil when it became commercially available in 1946, and a program of tests was initiated at that time to determine the extent of its superiority.