Vertiv Liebert APM 300, Руководство пользователя

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4 Chapter 1 Overview
APM 300 Integrated UPS Single Module And Parallel System User Manual
the inverter will shut down. Five minutes later, the inverter will start up automatically. If the short circuit is
removed at this point, the load will be transferred back to the inverter. The transfer is determined first of all by
the features of the protective device of the system.
In the above two situations, the UPS operator control and display panel will display alarm messages.
(Parallel System) The control logic system constantly monitors load requirements and controls the power
supplied by the two UPS modules. In the event that an overload condition is sustained for greater than a preset
time, the load will transfer to the bypass, when the number of active modules is unable to satisfy load
requirements. The load returns to the inverter if the power is reduced to a value that can be sustained by the
number of active modules in the system.
Maintenance bypass
The UPS has a second bypass circuit, i.e. maintenance bypass, which provides a safe working environment for
the engineers to provide regular maintenance or repair to the UPS system and at the same time provide
unregulated mains supply to the loads. The maintenance bypass can be manually selected through the
maintenance bypass switch, and it can be disconnected by turning the switch to OFF.
Warning
The internal maintenance bypass must NOT be used when the UPS system is comprised of more than two UPS modules
in parallel.
1.3.4 UPS Power Supply Switch Configuration
Figure 1-3 describes the block diagram of the UPS module. The UPS has split bypass configuration (that is, the
bypass adopts independent mains input) and common source configuration. In split bypass configuration,
the static bypass and maintenance bypass share the same independent bypass power supply. Where a
separate power source is not available, the input supply connections of the bypass input switch (Q2) and
rectifier input switch (Q1) would be linked together (linked before delivery) to make the bypass input and
rectifier input use mains power of the same route.
During the normal operation of the UPS, except for the maintenance bypass switch Q3, other switches shall be
closed.
Bypass input
Shorting copper bar
of common input
configuration
Mains input
Rectifier input
switch Q1
Rectifier Inverter
Automatic
inverter switch
Output
switch Q5 UPS Output
Static switch
Maintenance switch Q3
Battery
charger
BCB Battery
Bypass input switch Q2
Maintenance bypass switch Q3
Figure 1-3 UPS power supply switch configuration