Liebert 350-500 VA - Manual (Page 16)

12
M
ODES OF
O
PERATION
Normal Mode
During Normal mode operation, the Power-
Sure PST supplies conditioned, computer-
grade power to the connected equipment: util-
ity power passes through the TVSS circuitry,
EMI/RFI filters and then through the Trans-
fer Switch to the connected equipment.
When the UPS is in Normal mode, the
Utility/Battery Indicator illuminates green.
The PowerSure PST continuously monitors the batteries to maintain
them in a fully charged state. The battery charger operates whenever
AC power is present, even if the UPS is switched off. The UPS per-
forms an automatic battery test after it has been operating continu-
ously for two (2) weeks.
Battery Mode
The UPS switches to Battery mode in the
event of an extreme voltage/frequency condi-
tion or complete utility failure. The battery
system supplies power through the Inverter to
generate power for connected equipment.
When the UPS is in Battery mode, the Utility/
Battery Indicator flashes green and an alarm
sounds every 5 seconds.
When a low battery condition occurs, the Battery Indicator continues
to flash green and the alarm sounds every half-second. Low battery
warning is initiated when approximately two (2) minutes of battery
run time are remaining. For more information, refer to Trouble-
shooting section.
!
CAUTION
Turning off the UPS while in either Normal mode or Battery
mode will result in the loss of output power.
NOTE
Once utility power is restored, the UPS resumes normal
operation. At this time, the battery charger begins recharging
the battery. The UPS is capable of OFF-State charging, i.e.,
with utility power, the UPS will charge the batteries as long
as it is plugged in.
+ -
Continuous LED
illumination denotes
Normal Mode
Flashing LED
illumination denotes
Battery Mode
+ -