62 Operation
3.1.10 Battery Time Screen (Module Only)Atthe Master Menu, move the highlighted cursor to BATTERYTIME. Press the Select pad and the Battery
Time screen is displayed.
WhenAC power is not available to the UPS module, the UPS inverter uses DC power from the battery to supply
thecritical load. This screen helps the operator assess his power resourcesto determine if and when the critical
loadshutdown procedures need to be started.
TheBattery Time screen is a line graph that tracks thepresent battery voltage versus the elapsed time that the
batteryhas been discharging (Figure 4 1). As the batteryvoltage decreases, the linerepresenting it moves closer
tointersecting the line that represents the battery shutdownvoltage. When the battery starts to discharge, the
screendisplays a 15-minute graph. If the battery has been providing power for more than15 m inutes,the screen
displaysa 30-minute graph. If battery power is still availableafter 30 minutes, a 60-minute graph is displayed
(Figure 42).
Figure 41 Battery Time Screen Example - 15 Minute Discharge
Thescreen also displays alarm messages (Battery Discharging, LowB atteryWarning, and Battery Shutdown)
anda set of five parametersthat inform the operator of batterycondition and time remaining. Thefive parameters
describingbattery resources are:
• Rated TotalTime, in hours and minutes, is theamount of battery backup time that shouldbe available under
fullrated load, based on system design.
• Rated Time Remainingis the Rated Total Time lessthe duration of the present dischargeevent.
• Calculated TotalTime is an estimate of the total batterybackup time available, based on the initialbattery
conditionand actual performance while powering the connected load during the dischargeevent.
• Calculated TimeRemaining is a real-time estimation of batterytime remaining— with the actual connected
load—beforebattery voltage drops to the Battery Shutdown setpoint.
• Battery Charge is theapproximate percentage of total designed ampere hours of batterycapacity presently
availablebased on recharge/dischargeactivity.
Valuesfor C alculated Total Time and Calcula ted Time Remaining will appe ar on the screen approxima tely two
minutesafter the beginning of the dischargeevent. Calculated Time Remaining alsoappears on the Present Sta-
tusReport screen. Both Calculated TotalTime and Calculated TimeRemaining will be updated every six sec-
onds,reflecting actual load changes and battery condition.When the Calculated Times become available, they
willbe displayed in place of the Battery Dischargingmessage on this screen.
NOTE
Ifthe UPS modules connect to independent battery plants, consultall the individual
modulescreens to get the complete picture.If the modules share a common battery,
selectone module to do the monitoring and disregardthe 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
BatteryShutdown = 384 RatedTime (Hrs:Min)
Total00:10 Remain0:00
BatteryCharge = 5%
SELECT: MAST ER MENU
LowBattery Warning
CalculatedTime (Hrs:Min)
Total00:15 Remain0:01
DISCONTINUED
PROD U C T