Patent ID: 8786131

Claim:
An uninterruptible power supply having a standby mode and a backup mode, the uninterruptible power supply comprising: an input unit configured to receive AC input power from an AC source; a control unit coupled to the input unit; and an output unit coupled to the control unit and configured to supply AC output power to a load; wherein the control unit is configured to: automatically detect a load level measurement; determine whether the uninterruptible power supply is operating in the backup mode or the standby mode based on whether power is being supplied to a load from the uninterruptible power supply, wherein the backup mode is determined when the uninterruptible power supply supplies power to the load and the standby mode is determined when the uninterruptable power supply does not supply the power to the load; automatically power off to disable the power supplies to the load when operating in the backup mode and when the detected load level measurement is less than a predetermined value; and automatically power on and start supplying power to the load according to the detected load level measurement.