Vertiv EXM 0080kTK16FN01000, Руководство пользователя

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2 Chapter 1 Overview
Liebert EXM 80kVA ~ 200kVA UPS User Manual
When the mains is normal, the rectifier and inverter work together to supply the loads and charge the
battery.
When the mains is abnormal, the rectifier stops working, and the battery supplies power to the loads
through the inverter. If the battery voltage falls to end of discharge (EOD) voltage and the mains still has
not been recovered, the UPS will shut down (if the system uses split bypass configuration and the bypass
is normal, the system will transfer to bypass). The battery EOD voltage is preset. When the mains is
abnormal, the battery maintains the UPS operation till the battery voltage is reduced to EOD voltage and
the UPS shuts down, this time is called 'Backup Time'. The length of backup time depends on the battery
capacity and the loads.
1.2.2 Bypass
Through the intelligent control of the 'Static Switch' module (as shown in Figure 1-1) containing the
controllable electronic switch, the loads can be supplied by the inverter or the bypass. In normal situation,
the loads are supplied by the inverter, in which case the automatic inverter switch at inverter side is
closed. In the case of overload (the overload delay time expires) or inverter failure, the automatic inverter
switch is opened, and the 'Static Switch' module will automatically transfer the loads to the bypass.
In normal operating state, to realize the uninterrupted transfer between inverter and bypass, the inverter
output must be synchronized with the bypass.
Therefore, when the bypass frequency is within the synchronization range, the inverter control circuit will
synchronize the inverter output frequency with the bypass frequency and phase.
Besides, the UPS has a manual maintenance bypass switch for shutdown of the UPS upon maintenance. In
this situation, the bypass will directly supply the critical loads through the maintenance bypass.
Note
When the load is supplied by the bypass or maintenance bypass, the power supply quality will be uncertain.
1.2.3 System Control Principle
Normal operation
Normal mode: It means that the UPS has normal input mains, the rectifier and inverter operate normally,
the load is supplied by the inverter, the battery circuit breaker is closed, and the battery is in stable
floating charge state.
(Parallel System) Note: As the UPS single module outputs are connected in parallel, the system checks
that the inverter control circuits are perfectly synchronized with one another and with the bypass in terms
of both frequency and phase, and that they have the same output voltages. Current supplied to the load is
automatically divided among UPSs. A warning message appears while synchronization is in progress.
Mains abnormal
When the mains fails or is abnormal, the rectifier will stop working automatically, and the system will
transfer to battery output (through inverter). The length of the operation time in battery mode depends
on the load and the battery capacity. During this period, if the battery voltage falls to the EOD voltage and
the mains still has not been recovered, the inverter will stop working automatically, and the UPS operator
control and display panel will display corresponding alarm messages. If the system uses split bypass
configuration and the bypass is normal, the system will transfer to bypass.