UNINTERRUPTIVE POWER SUPPLY UNIT

PROBLEM TO BE SOLVED: To solve a conventional technical problem that necessity of power supply to a load side was controlled by providing a special additional function for detecting the power condition on the load side, and detecting the power condition of the load for the purpose of detecting the power condition of a control device at the time of occurrence of power failure or the like, and that eliminating wasteful back-up power supply, however, power control for wasteful commercial input to a system including uninterruptive power supply unit during normal operation is not considered. SOLUTION: This power supply system comprises a power condition detecting means of the control device using a general-purpose interface, a means for monitoring the power condition of the control device, and a means for receiving the monitor result and controlling the commercial input from facility as an internal circuit of the uninterruptive power supply unit. Thus, standby power control of the control device which is in a power supply stop condition as well as the prevention of energy loss can be attained. COPYRIGHT: (C)2003,JPO