Chapter 6 Operating Instructions
MUST400_User manual_EN_REV02 User Manual
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5.1.1 Split-Bypass Input
Fig. 5-1 illustrates the Modular UPS in dual input configuration (the bypass line uses a separate AC source).
In this configuration, the static bypass and maintenance bypass share the same independent bypass power
supply and connect to the power supply through a separate switch.
In single input version bypass line and rectifier input are supplied from the same source..
Note
Split-Bypass Input function is optional.
5.1.2 Static Transfer Switch
The circuit blocks labeled Static Switch in fig.5-1 contain electronically controlled switching circuits that enable
the critical load to be connected to either the inverter output or to a bypass line. During normal functioning the
load is connected to the inverter; but in the event of a UPS overload or inverter failure, the load is automatically
transferred to the static bypass line. To provide a clean (no-break) load transfer between the inverter output
and static bypass line, the inverter output and bypass supply must be fully synchronized during normal
operating conditions. This is achieved through the inverter control electronics, which makes the inverter
frequency track that of the static bypass supply, provided that the bypass remains within an acceptable
frequency window.
A manually controlled maintenance bypass supply is incorporated into the UPS design. It enables to supply
the load directly from the bypass line while the UPS is shut down for routine maintenance.
Note
When the UPS is operating in bypass mode or on maintenance bypass, the connected equipment is not
protected from mains failures or surges and sags.
Note
Optional isolation transformers are available for applications where sources do not share the same neutral reference
or where the neutral is not available.
5.2 Operating Mode
The Modular UPS is an on-line, double-conversion, reverse-transfer UPS that permits operation in these
modes:
Normal mode
Battery Mode
Auto-restart mode
Bypass mode
Cold start mode
Maintenance mode (manual bypass)
Parallel redundancy mode
Eco Mode
Soft start mode
警告
危 险
警告
危 险
警告
危 险
