To reduce an equipment cost and a power consumption reducing cost obtained by an energy saving effect and to relieve operation restrictions such as a plant operation stop, etc., caused by a failure of an inverter controller.

This energy saving inverter equipment for large auxiliary apparatuses comprises a commercial power supply, a plurality of motors 8-10 driving large auxiliary apparatuses, a plurality of breakers 1-3 connected with the commercial power supply and the respective motors, a plurality of electromagnetic contactors 11-13 connected between the respective motors and the respective breakers, and one inverter controller 7 connected between the commercial power supply and the electromagnetic contactors. Normally, an inverter control operation, wherein the plurality of breakers are opened and the plurality of electromagnetic contactors are selectively closed to control the inverter controller for driving the respective motors, is carried out. When the inverter controller is failed, the plurality of breakers are selectively closed and the plurality of electromagnetic contactors are opened for the commercial operations of the respective motors.