Abstract: A control system for automatically adding and subtracting capacitors to and from an electrical supply line for regulating the power factor of the supply line. A three-phase transducer is connected to the supply line and supplies a signal in direct proportion to the VARs of the supply line to a double setpoint meter relay. The meter relay is connected to a pair of timing relays which are selectively energized in response to a capacitor "add" or "subtract" signal from the transducer. If the signal is maintained for a predetermined period of time on one of the timing relays, a motor of a respective "add" or "subtract" cam-actuated switch is activated. The cam switches are programmed to energize or deenergize control relays, which in turn actuate capacitor contactors to add or subtract the next available capacitor.