Insulating oil in electric power generation, transmission and distribution equipment such as circuit breakers, regulators, phase shifters, tank diverter switches and capacitor banks for respectively separated phases of a plural phase transmission or distribution line is filtered for removal of accumulated water, carbon particles and other contaminants by filters in oil circuits respective to each phase in the plurality. Each oil circuit respective to each circuit breaker includes a respective filter and circulation pump. However, all pumps in the plural phase power system, for example, are driven by the same motor and drive line whereby a fluid condition or circulation interruption of one oil circuit that requires termination of pump operation in the one oil circuit terminates the pump operation in all oil circuits. Pump motor power is preferably drawn from an energy source that may be independent of that served by the transmission and/or distribution power source.