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OPM_SGS_USM_M75_M75_2US_V010.doc
User Manual
SG Series 750 UL S2 & SG Series 750 T12 UL S2
4 DESCRIPTION
4.1 BLOCK DIAGRAM AND MAIN ELEMENTS
Fig. 4.1-1 SG Series 750 & SG Series 750 T12 Block diagram
The
SG Series 750
&
SG Series 750 T12
UPS can be divided into the following main elements:
Control System
SG Series 750
&
SG Series 750 T12
are designed with microprocessor-controlled signal processing
circuits.
The interface between the operator and the unit is provided by the monitoring system on the front panel.
This monitoring system consists of an active mimic diagram, a keyboard and a backlit display.
Rectifier
SG Series 750
Rectifier
consists of a
6-pulse SCR-bridge
,
12-pulse SCR-bridge
for
SG Series 750 T12,
which
converts the 3-phase
Utility Voltage
into a controlled and regulated DC-voltage.
This regulated DC-voltage is used to supply power to the
Inverter
, and to provide charging power to the
Battery
.
Inverter
The
Inverter
converts the DC voltage into a three-phase AC-voltage with constant amplitude and
frequency, which is completely independent and isolated from the AC-input voltage.
Automatic Bypass
The
Automatic Bypass
consists of a static semiconductor-switch
(SSM: Static Switch Module)
, used to
provide an uninterrupted transfer of the Load from
Inverter
to
Utility
.
Back-feed Protection
SG Series 750
&
SG Series 750 T12
UPS's are equipped with an automatic system for the protection
against voltage back feeding towards
Utility
, through the
Bypass
(Applied Standard IEC 62040-1).
This protection works automatically by opening
contactor K6
and eventually
K7
, and acts in case of
internal defects of the system, or due to wrong manipulations on the
External Maintenance Bypass
(option)
.
Battery
The
Battery
supplies the DC power to the
Inverter
when the
Utility
is out of accepted tolerances.