Description; Block Diagram And Main Elements - GE SG 225 User Manual

4

DESCRIPTION

4.1

BLOCK DIAGRAM AND MAIN ELEMENTS

The SG Series 225 & 300 system can be divided into the following main elements:
Control System
SG Series 225 & 300 is 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
The standard Rectifier consists of a 6-pulse SCR-bridge, which converts the three-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
All SG Series 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 Manual Bypass Q2 (option).
Manual Bypass (option)
The Manual Bypass consists of a pair of manual switches (Q1 and Q2), which removes the UPS from the
Load for maintenance, while still supplying the Load with power directly from the Utility.
Battery
The Battery supplies the DC power to the Inverter when the Utility is out of accepted tolerances.
Modifications reserved
OPM_SGS_USM_M22_M30_2US_V010.doc
Fig. 4.1-1 Block diagram
Page 12/79
User Manual SG Series 225 & 300 UL S2