OVERVIEW
User Manual 10H52246UM60 - Rev. 1 - 01/2017
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4. For parallel system consisting of two or more UPS modules, the bypass load sharing inductors (optional) should
be selected.
1.4
Operating Modes
The UPS operating modes are as follows:
Normal mode
Battery mode
Automatic restart mode
Bypass mode
Maintenance mode
ECO mode
Parallel redundancy mode (system expansion)
LBS system mode
Common battery string mode
Frequency converter mode
Normal mode
As can be seen in Figure 1-3, the mains is rectified by the UPS rectifier and then inverted by the inverter to supply
uninterrupted AC power to the loads. At the same time, the charger will charge the battery.
Rectifier input switch
Mains input
Battery charger
Output switch
Inverter
Rectifier
UPS output
Battery
Automatic inverter switch
Figure 1-3
Schematic diagram of normal mode
Battery mode
Figure 1-4 illustrates battery mode, where the battery provides backup power supply to the loads through the
rectifier and inverter. Upon failure of the main input, the UPS will transfer automatically to battery mode without
interrupting the power supply to the loads. When the main input is restored, the UPS will automatically re-transfer to
normal mode without the need for any manual intervention, and without interrupting the power supply to the loads.
Output switch
Inverter
Rectifier
UPS output
Battery
Automatic inverter switch
Figure 1-4
Schematic diagram of battery mode
Note: The battery cold start function can be used to switch the UPS on directly in Battery mode (provided the battery is
charged) during a mains failure. Thus, the battery power supply can be used independently to improve the availability of
the UPS.
Automatic restart mode
The UPS is equipped with an automatic restart function. When the inverter shuts down due to a mains failure, and
the battery reaches the EOD voltage, when the mains is restored, the UPS will restart automatically after a certain
delay. This function, and the automatic restart type, can be set-up by Vertiv authorized service engineers.
During the automatic restart delay period, the UPS will charge the battery to protect the load against the risk of
power interruptions in the event of a new mains failure.
If the automatic restart function has not been set, the user can restart the UPS manually by pressing the FAULT
CLEAR key followed by the ON key.
Bypass mode
As can be seen in Figure 1-5, in the event of an inverter failure, an inverter overload or a manual inverter shutdown,
when the UPS is in normal operating mode the static switch will transfer the load from the inverter to the bypass
line, without interrupting the power supply to the loads. At this point, if the inverter and bypass are not
synchronized, the load power supply will be interrupted momentarily (< 20 ms).
