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46
5.3.1 OFF Mode
When the Liebert FS is initially powered on, it enters the OFF mode and magnetically levitates its
rotating group. A manual user command will make the system transition from OFF mode to STAR-
TUP mode if all startup conditions are met.
The Liebert FS also will enter OFF mode at the end of a shutdown and will transition automatically
from SHUTDOWN mode to OFF mode.
5.3.2 STANDBY Mode
In STANDBY Mode, the Liebert FS will be ready for Startup but be in a STANDBY Mode waiting for
user initiation of STARTUP Mode (State of Charge = 0%). By pressing the STARTUP button “F1” at
that point the Liebert FS will automatically transition into STARTUP Mode.
Figure 46 STANDBY mode diagram
The Liebert FS will be in STANDBY Mode as long as:
• Liebert FS’s SOC is less than 0%; and
• UPS DC Bus Voltage = Vcharge
• STARTUP has not been initiated
5.3.3 STARTUP Mode
In STARTUP mode, the Liebert FS will charge (increase flywheel speed) up to the minimum operat-
ing speed (State of Charge = 0%). At that point the Liebert FS will automatically transition into
CHARGE mode.
Figure 47 Startup mode diagram
The Liebert FS will be in STARTUP mode as long as:
• Liebert FS’s SOC is less than 0% and
• UPS DC Bus Voltage ≥ Vcharge.
In case the UPS DC bus voltage drops below Vcharge while in STARTUP mode, the Liebert FS will
transition automatically into COAST mode. As soon as the UPS DC bus voltage rises above Vcharge,
the Liebert FS automatically exits COAST mode and resumes STARTUP mode.
NOTE
Startup conditions are:
• UPS DC bus voltage
≥
Vcharge and
• Status is “OK”.
NOTE
In STARTUP mode, the Liebert FS will not be capable of supporting the UPS DC bus.
State of Charge < 0 State of Charge > 0
0%
10
0
%
9
9.
5
%
UPS DC Bus Voltage = Vcharge
State of Charge < 0 State of Charge > 0
0%
1
00%
99.5%
Note: UPS DC Bus Voltage ≥ Vcharge