The Master Outlet threshold may be incorrectly set.

Solution : Adjust the threshold when the Master
outlet signals the Controlled outlets to
shut down.

1. Ensure a master device is connected to the Master outlet. Put that device
into Sleep or Standby mode, or turn it OFF.
2. Press DISPLAY and MUTE simultaneously and hold for six seconds, until
the leaf icon flashes three times and the Back-UPS beeps three times.
3. The Back-UPS will now recognize the threshold level of the Master
device and save it as the new threshold setting.