Stability of DBPC inhibited oil

WHILE 2,6-di-tertiary-butyl-para-cresol (DBPC) has been established as a suitable oxidation inhibitor for transformer oil, its use in oil for reclosers has not been evaluated. A number of persons have raised the questions of the effect of DBPC on rate of settling, particle size, and quantity of carbon formed by an arc, and the effect of an arc on the inhibitor itself. In the present investigation, the operation and stability of DBPC inhibited oil was studied to determine if the inhibited oil showed any undesirable characteristics which would make it unsuitable for use in oil circuit reclosers.