Vertiv Liebert PSI XR 1000, User Manual

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5 OPERATIONAL MODES
5.1 Normal Mode
When the UPS is in Normal Mode, the Normal Mode Indicator illuminates green.
5.2 Buck/Boost Mode
The Automatic Voltage Regulator (AVR) circuitry compensates for fluctuations in mains power, such as
voltage surges and sags. The Liebert PSI XR compensates for these by raising the undervoltage (boost)
or lowering the overvoltage (buck). The AVR operates automatically and maintains the output voltage to
the connected equipment without utilizing the batteries.
5.3 Battery Mode
The UPS switches to Battery Mode in the event of an extreme input voltage/frequency condition or mains
failure.
When the UPS is in Battery Mode, the Battery Indicator illuminates amber and an alarm sounds at
2-second intervals. As capacity decreases, fewer indicators remain illuminated.
When a Low Battery condition occurs, the Battery Indicator flashes amber and an alarm sounds at one-
second intervals. For approximate battery run times, refer to Table 8.3 on page 29.
5.4 Battery Recharge Operation
Once mains power is restored, the UPS resumes normal operation, and the Battery Charger begins
recharging the batteries.
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