Abstract: A three phase voltage controller for controlling the voltage applied to a three phase load. The controller includes three autotransformers which have a plurality of output taps for stepping down the output voltage. Contacts to the taps are selected for a high output voltage and a low output voltage with the contacts selected either manually or automatically. In the automatic mode, time delay is provided in switching from a high output voltage to a low output voltage, and a re-cycle timer is provided to re-cycle from a low voltage to the high voltage temporarily. Single phase control contactors are provided to remove voltage from one or more output lines for load shedding. Circuit breakers are provided for removing the controller and for directly applying the input line voltage to the output line.

Abstract: The present invention is a power control unit and method of controlling power particularly for lighting loads such as incandescent lamps and fluorescent lamps. The power control unit is located between the power source and the load, typically between a circuit breaker and the lamps in a single circuit.The power control unit functions to reduce the voltage delivered to the load and thereby to reduce the power consumed by the load. Reductions in power up to 10% or more are possible without any significant loss in lighting usefulness. Savings of up to 40% or more are possible when significant reductions in lighting output are acceptable.