Liebert 1000kVA manual Battery Time Screen Module Only, Battery time screen 15 minute discharge

Operation

To perform the shutdown procedure, transfer the critical load from the UPS system to the bypass line (at the SCC). Then trip open the UPS module output and battery circuit breaker (MBD) and manually open the UPS module input circuit breaker. The Control Power switch may be turned Off if required for maintenance procedures.

Refer to 3.4.5 - Shutdown Procedures for more details, including module shutdowns for service and emergency shutdowns.

3.2.11Battery 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 46). 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 47).

Figure 46 Battery time screen (15 minute discharge)

VDC
500										SELECT : MASTER MENU
480										Low Battery Warning
										Calculated Time (Hrs:Min)
460										Total 00:15 Remain 0:01
440
420
400
380	Battery Shutdown = 384
										Rated Time (Hrs:Min)
360		Battery Charge = 5%
										Total 00:10 Remain 0:00
340
0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15

Time (Minutes)

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.

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 capac- ity presently available based on recharge/discharge activity.

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