Important Note:

 
> Ensure that the Back-UPS is Off but connected to utility power.
> Ensure that the Load's are not connected with the Back-UPS.


Follow the below steps:

Press the front panel push button fully inward for 10 seconds. All indicators on the Back-UPS will flash to acknowledge going into Programming Mode ,The Back-UPS will then indicate its current Sensitivity Setting
 

• To select the Low Sensitivity setting, press the push button until the yellow,indicator is flashing.
• To select the Medium Sensitivity setting, press the pushbutton until the yellow and red indicators (second and third from the top) are flashing.
• To select the High Sensitivity setting, press the pushbutton until yellow and both red indicators (bottom three) are flashing.
• To exit without changing the Sensitivity Setting, press the pushbutton until the green indicator is flashing.
• Once in Programming Mode, if the pushbutton is not pressed within 5 seconds, the Back-UPS will exit Programming Mode; all indicators will extinguish.

Please find the video below which will help you to  understand the steps easily.