Sorry for the delayed response but I don't normally browse this forum. The UPS can be configured several ways. One way is after a loss of power the UPS shuts off in xx minutes. This is how your UPS must be set. Other settings allow you to shut down when there is xx minutes of battery power remaining. Are you using the LCD display to set the UPS, or are you using the software ULNM to set the device. Also do you have a NMC (Network Management Card) installed or not?