Maintenance -> Status -> Equipment Status -> 1. UPS 
Set the UPS Battery Level, that 
when reached, will cause the 
PBX to Shutdown 
UPS Status can be seen here 
1.1 UPS Connection and setting (2) 
1. Connect the UPS as described in the Installation manual
2.
S
et the NS1000 Shutdown threshold via the WebMC
NB: UPS Status alerts can also be sent via email.