Liebert Series 600T - Manual (Page 68)

62 Operation
3.1.10 Battery Time Screen (Module Only)
At the Master Menu, move the highlighted cursor to BATTERY TIME. Press the Select pad and the Battery
Time screen is displayed.
When AC power is not available to the UPS module, the UPS inverter uses DC power from the battery to supply
the critical load. This screen helps the operator assess his power resources to determine if and when the critical
load shutdown procedures need to be started.
The Battery Time screen is a line graph that tracks the present battery voltage versus the elapsed time that the
battery has been discharging (Figure 41). As the battery voltage decreases, the line representing it moves closer
to intersecting the line that represents the battery shutdown voltage. When the battery starts to discharge, the
screen displays a 15-minute graph. If the battery has been providing power for more than 15 minutes, the screen
displays a 30-minute graph. If battery power is still available after 30 minutes, a 60-minute graph is displayed
(Figure 42).
Figure 41 Battery Time Screen Example - 15 Minute Discharge
The screen also displays alarm messages (Battery Discharging, Low Battery Warning, and Battery Shutdown)
and a set of five parameters that inform the operator of battery condition and time remaining. The five parameters
describing battery resources are:
• Rated Total Time, in hours and minutes, is the amount of battery backup time that should be available under
full rated load, based on system design.
• Rated Time Remaining is the Rated Total Time less the duration of the present discharge event.
• Calculated Total Time is an estimate of the total battery backup time available, based on the initial battery
condition and actual performance while powering the connected load during the discharge event.
• Calculated Time Remaining is a real-time estimation of battery time remaining— with the actual connected
load—before battery voltage drops to the Battery Shutdown setpoint.
• Battery Charge is the approximate percentage of total designed ampere hours of battery capacity presently
available based on recharge/discharge activity.
Values for Calculated Total Time and Calculated Time Remaining will appear on the screen approximately two
minutes after the beginning of the discharge event. Calculated Time Remaining also appears on the Present Sta-
tus Report screen. Both Calculated Total Time and Calculated Time Remaining will be updated every six sec-
onds, reflecting actual load changes and battery condition. When the Calculated Times become available, they
will be displayed in place of the Battery Discharging message on this screen.
NOTE
If the UPS modules connect to independent battery plants, consult all the individual
module screens to get the complete picture. If the modules share a common battery,
select one module to do the monitoring and disregard the others.
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Time (Minutes)
340
360
380
400
420
440
460
480
500
VDC
Battery Shutdown = 384
Rated Time (Hrs:Min)
Total 00:10 Remain 0:00 Battery Charge = 5%
SELECT : MASTER MENU
Low Battery Warning
Calculated Time (Hrs:Min)
Total 00:15 Remain 0:01