GE 750 UL S2 User manual

GE Digital Energy
Power Quality
SGS_750_UPS_GE_01
User Manual
Uninterruptible Power supply
SG Series 750 UL S2
SG Series 750 T12 UL S2
750 kVA / 480Vac UL / S2
GE Consumer & Industrial SA
General Electric Company
CH – 6595 Riazzino (Locarno)
Switzerland
T +41 (0)91 / 850 51 51
F +41 (0)91 / 850 52 52
www.gepowerquality.com
imagination at work

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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
Model: SG Series 750 UL S2 & SG Series 750 T12 UL S2
Issued by Product Document Department – Riazzino - CH
Date of issue: 10/20/2010
File name: OPM_SGT_USM_M75_M75_2US_V010
Revision: 1.0
Identification No.:
Up-dating
Revision Concerns Date
COPYRIGHT © 2010 by GE Consumer & Industrial SA
All rights reserved.
The information contained in this publication is intended solely for the purposes indicated.
The present publication and any other documentation supplied with the UPS system is not to be
reproduced, either in part or in its entirety, without the prior written consent of GE.
The illustrations and plans describing the equipment are intended as general reference only and are not
necessarily complete in every detail.
The content of this publication may be subject to modification without prior notice.

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Dear Customer,
We thank you for selecting our products and
are pleased to count you amongst our very
valued customers at GE.
We trust that the use of the SG Series 750 &
SG Series 750 T12
Uninterruptible Power
Supply system, developed and produced to
the highest standards of quality, will give you
complete satisfaction.
Please read carefully the User Manual, which
contains all the necessary information and
describes all you need to know about the use
of the UPS.
Thank you for choosing GE !
START UP AND COMMISSIONING
A GE GLOBAL SERVICES FIELD ENGINEER must perform start-up and
commissioning of the UPS.
Please Contact GE. GLOBAL SERVICES at least two weeks prior to schedule
start-up and commissioning at 1-800-637-1738, or by E-mail at
[email protected] .
Distributed in the USA by:
Your service contact:
g
GE Consumer & Industrial SA
General Electric Company
CH – 6595 Riazzino (Locarno)
Switzerland
www.gepowerquality.com
g
GE Digital Energy
Power Quality
2501 Pecan Street
Bonham, TX 75418
T: [phone]
F: [phone]
E: [email protected]om
http://www.gedigitalenergy.com/ups

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Preface
Congratulations on your choice of a SG Series Uninterruptible Power Supply (UPS). It will
help eliminate Load disturbances due to unexpected power problems.
This Manual describes the function of the UPS module, the purpose and location of the
switches, the meaning of the system events related to the front panel indication, and
provides procedures for starting and stopping the equipment.
Please refer to the accompanying Installations Guide, which describes how to prepare the
installation site, and it provides weight, dimensions and procedures for moving, installing
and connecting the UPS.
While every care has been taken to ensure the completeness and accuracy of this manual,
GE assumes no responsibility or liability for any losses or damages resulting from the use
of the information contained in this document.
NOTE !
SG Series 750 &SG Series 750 T12 are a product that needs to be installed by a licensed
and knowledgeable contractor.
We recommend that this manual be kept next to the UPS for future references.
If any problems are encountered with the procedures contained in this manual, please
contact your Service Center before you proceed.
This document shall not be copied or reproduced without the permission of GE.
Some of the information contained in this manual may be changed without notice to
reflect technical improvements.
Safety instructions
Read the safety instructions contained on the following pages carefully before the
installation of the UPS, options and Battery System.
Pay attention to the rectangular boxes included in the text:
They contain important information and warning concerning electrical connections and
personnel safety.
Parallel version secured with RPA
When included in the text, this symbol refers to operation needed
only for parallel system.

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Table of contents Page
1IMPORTANT SAFETY INSTRUCTIONS ........................................................................................................... 7
2LAYOUT........................................................................................................................................................... 10
2.1 LAYOUT SG Series 750 & SG Series 750 T12 .......................................................................................................................... 10
3INTRODUCTION ............................................................................................................................................ 11
4DESCRIPTION ................................................................................................................................................ 12
4.1 BLOCK DIAGRAM AND MAIN ELEMENTS.................................................................................................................................. 12
4.2 OPERATION MODES........................................................................................................................................................................... 13
4.2.1 Normal operation mode....................................................................................................................................................................... 13
4.2.2 eBoost™ operation mode (option) ................................................................................................................................................... 13
4.2.3 Utility failure operation ......................................................................................................................................................................... 14
4.2.4 Utility recovery operation.................................................................................................................................................................... 14
4.2.5 Automatic Bypass ................................................................................................................................................................................... 15
4.3 PARALLEL SYSTEM OPERATION.................................................................................................................................................... 16
4.3.1 Introduction to the parallel system ................................................................................................................................................. 16
4.3.2 Features of RPA parallel system....................................................................................................................................................... 17
4.3.3 System control.......................................................................................................................................................................................... 17
4.3.4 Synchronization........................................................................................................................................................................................ 17
4.3.5 Load sharing .............................................................................................................................................................................................. 17
4.4 RECTIFIERS PARALLELED ON THE SAME BATTERY .............................................................................................................. 18
4.5 RECYCLING AT THE END OF SERVICE LIFE .............................................................................................................................. 19
5CONTROL PANEL .......................................................................................................................................... 20
5.1 CONTROL PANEL ................................................................................................................................................................................ 20
5.2 TABLE OF FUNCTIONS AND INDICATIONS ON CONTROL PANEL.................................................................................. 21
6LCD SCREEN .................................................................................................................................................. 23
6.1 HOME SCREEN..................................................................................................................................................................................... 23
6.2 METERING.............................................................................................................................................................................................. 25
6.3 ALARMS .................................................................................................................................................................................................. 28
6.3.1 Events (alarms and messages).......................................................................................................................................................... 29
6.3.2 Alarms list.................................................................................................................................................................................................... 29
6.3.3 Messages list.............................................................................................................................................................................................. 33
6.3.4 Event report SG Series 750 & SG Series 750 T12........................................................................................................................ 36
6.4 SETUP ...................................................................................................................................................................................................... 37
6.5 COMMANDS.......................................................................................................................................................................................... 43
7OPERATION.................................................................................................................................................... 44
7.1 PROCEDURES FOR SINGLE SG Series 750 & SG Series 750 T12.................................................................................... 45
7.1.1 Start-up of the SG Series 750 & SG Series 750 T12................................................................................................................... 45
7.1.2 UPS shutdown with Load transfer on External Maintenance Bypass (option)............................................................. 49
7.1.3 From External Maintenance Bypass (option) to normal function VFI............................................................................... 50
7.1.4 Complete UPS shutdown...................................................................................................................................................................... 51
7.1.5 Restore to normal operation after “Load Off”............................................................................................................................. 52
7.1.6 Restore to normal operation after EPO (Emergency Power Off) ........................................................................................ 53
7.2 PROCEDURES FOR SG Series 750 & SG Series 750 T12 PARALLEL SYSTEM............................................................. 54
7.2.1 SG Series 750 & SG Series 750 T12 Parallel System start-up ............................................................................................... 54
7.2.2 Parallel System shutdown with Load transfer on External Maintenance Bypass (option)..................................... 58
7.2.3 From External Maintenance Bypass (option) to normal function VFI............................................................................... 60
7.2.4 Separate a UPS unit from the Parallel System (System Redundancy)............................................................................ 61
7.2.5 Reconnect a UPS unit to a Parallel System.................................................................................................................................. 62
7.2.6 Complete Parallel System shutdown.............................................................................................................................................. 63
7.2.7 Restore to normal operation after “Load Off”............................................................................................................................. 64
7.2.8 Restore to normal operation after EPO (Emergency Power Off) ........................................................................................ 65

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8OPTIONS......................................................................................................................................................... 67
8.1 COMMUNICATION OPTIONS.......................................................................................................................................................... 67
8.2 OPTIONS IN UPS CABINET.............................................................................................................................................................. 67
8.3 CONNECTION FOR OPTIONS......................................................................................................................................................... 68
8.3.1 Remote Signaling Box (RSB) ................................................................................................................................................................ 68
9MAINTENANCE.............................................................................................................................................. 69
9.1 MAINTENANCE .................................................................................................................................................................................... 69
9.1.1 Service check............................................................................................................................................................................................. 69
9.1.2 Fans and ventilation............................................................................................................................................................................... 69
9.1.3 Other components with limited lifetime........................................................................................................................................ 69
9.1.4 Battery.......................................................................................................................................................................................................... 70
9.1.5 Long shut-down periods of the UPS-system .............................................................................................................................. 70
9.1.6 UPS room conditions and temperature......................................................................................................................................... 70
9.1.7 Long shut-down periods of the UPS-system .............................................................................................................................. 70
10 NOTES............................................................................................................................................................. 71
10.1 NOTES FORM........................................................................................................................................................................................ 71

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1 IMPORTANT SAFETY INSTRUCTIONS
SAVE THESE INSTRUCTIONS
This manual contains important instructions for models SG Series 750 & SG Series 750 T12 that should
be followed during installation and maintenance of the UPS and battery.
GENERAL
- Move the UPS in an upright position in its original package to the final destination room.
To lift the cabinets, use a forklift or lifting belts with spreader bars.
- Check for sufficient floor and elevator loading capacity.
- Check the integrity of the UPS equipment carefully.
If you notice visible damage, do not install or start the UPS.
Contact your Service Center immediately.
- WARNING! RISK OF ELECTRICAL SHOCK:
Do not remove covers, there are no user serviceable parts inside.
- After switching off takes 5 minutes for the DC capacitors to discharge because a lethally high voltage
remains at the terminals of the electrolytic capacitors.
- All maintenance and service work should be performed by qualified service personnel.
The UPS contains its own energy source (battery).
- The field-wiring outlets may be electrically live, even when the UPS is disconnected from the utility.
- Dangerous voltages may be present during battery operation.
- The battery must be disconnected during maintenance or service work.
- This UPS contains potentially hazardous voltages.
- Be aware that the inverter can restart automatically after the utility voltage is restored.
INSTALLATION
- This UPS must be installed and connected only by trained personnel.
- Verify accurately during Commissioning and Maintenance of the UPS, for the following:
Damaged components, squeezed wires and cables, or not correctly inserted plugs.
- After removing the sidewalls of the UPS, make sure that all earth connections when reassembling, are
correctly reattached.
- This UPS is intended for use in a controlled indoor environment free of conductive contaminants and
protected against animals intrusion.
- WARNING! HIGH EARTH LEAKAGE CURRENT:
Earth connection is essential before connecting to AC input!
- Switching OFF the unit does not isolate the UPS from the utility.
- Do not install the UPS in an excessively humid environment or near water.
- Avoid spilling liquids on or dropping any foreign object into the UPS.
- The unit must be placed in a sufficiently ventilated area; the ambient temperature should not exceed 104°F (40°C).
- Optimal battery life is obtained if the ambient temperature does not exceed 77°F (25°C).
- It is important that air can move freely around and through the unit. Do not block the air vents.
- Avoid locations in direct sunlight or near heat sources.
STORAGE
- Store the UPS in a dry location; storage temperature must be within -13°F (-25°C) to 131°F (+55°C).
- The optimal temperature for Battery storage is 68°F (20°C) to 77°F (25°C) and shall never exceed the range
-4°F (-20°C) to 104°F (40°C).
- If the unit is stored for a period exceeding 3 months, the battery must be recharged periodically (time
depending on storage temperature).
BATTERY
- The battery-voltage is dangerous for person’s safety.
- When replacing the battery, use the same cells number, voltage (V), capacity (Ah).
All the battery used, shall be of the same manufacturer and date of production.
- Proper disposal or recycling of the battery is required.
Refer to your local codes for disposal requirements.
- Never dispose of battery in a fire: they may explode.
- Do not open or mutilate battery: their contents (electrolyte) may be extremely toxic.
If exposed to electrolyte, wash immediately with plenty of water.
- Avoid charging in a sealed container.
- Never short-circuit the batteries.
When working with batteries, remove watches, rings or other metal objects, and only use insulated tools.
- In case of air shipment, the cables +/- going to the battery fuses/terminals shall be disconnected and isolated.

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Safety instructions when working with battery
EXTERNAL BATTERY MUST BE INSTALLED AND CONNECTED TO THE UPS BY
QUALIFIED SERVICE PERSONNEL.
INSTALLATION PERSONNEL MUST READ THIS ENTIRE SECTION BEFORE HANDLING
THE UPS AND BATTERY.
DANGER!
Full voltage and current are always present at the battery terminals.
The battery used in this system can provide dangerous voltages, extremely high currents and a
risk of electric shock.
If the terminals are shorted together or to ground they may cause severe injury.
You must be extremely careful to avoid electric shock and burns caused by contacting battery
terminals or shorting terminals during battery installation.
Do not touch un-insulated battery terminals.
A qualified service person, who is familiar with battery systems and required precautions, must
install and service the battery.
The installation must conform to national and local codes.
Keep unauthorized personnel away from the battery.
The qualified service person must take these precautions:
1 Wear protective clothing, such as rubber gloves and boots and protective eye wear.
Batteries contain caustic acids and toxic materials and can rupture or leak if mistreated.
Remove rings and metal wristwatches or other metal objects and jewellery.
Do not carry metal objects in your pockets where the objects can fall into the battery
cabinet.
2 Tools must have insulated handles and must be insulated so that they will not short battery
terminals.
Do not allow a tool to short between individual or separate battery terminals or to the
cabinet or rack.
Do not lay tools or metal parts on top of the battery, and do not lay them where they could
fall onto the battery or into the cabinet.
3 Install the battery as shown on the drawing provided with the battery.
When connecting cables, never allow a cable to short across a battery’s terminals, the
string of battery, or to the cabinet or rack.
4 Align the cables on the battery terminals so that the cable lug will not contact any part of
the cabinet or rack, even if the battery is moved.
Keep the cable away from any sharp metal edges.
5 Install the battery cables in such a way that the UPS or battery cabinet doors cannot pinch
them.
6 Do not connect the battery terminal to Ground.
If any battery terminal is inadvertently grounded, remove the source of the ground.
Contacting any part of a grounded battery can cause a risk of electric shock.
7 To reduce the risk of fire or electric shock, install the battery in a temperature and humidity
controlled indoor area, free of contaminants.
8 Battery system chassis ground (earth) must be connected to the UPS chassis ground (earth).
If you use conduits, this ground conductor must be routed in the same conduit as the
battery conductors.
9 Where conductors may be exposed to physical damage, protect the conductors in
accordance with all applicable codes.
10 If you are replacing the battery or repairing battery connections, shut OFF the UPS and
remove the battery fuses.

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Safety symbols and warnings
Safety warnings
The text of this manual contains some warnings to avoid risk to the persons and to avoid damages to
the UPS system and the supplied critical loads.
The non-observance of the warnings reminding hazardous situations could result in human injury and
equipment damages.
Please pay attention to the meaning of the following warnings and symbols.
Throughout this manual the following symbols are defined:
WARNING, if instruction is not followed injury or serious equipment damage may
occur!
CAUTION, internal parts have dangerous voltage present.
Risk of electric shock!
PE (Earth) – GND (Ground)
PROTECTIVE GROUNDING TERMINAL:
A terminal which must be connected to earth ground prior to making any other
connection to the equipment.
A terminal to which or from which an alternating (sine wave) current or voltage
may be applied or supplied.
A terminal to which or from which a direct current or voltage may be applied or
supplied.
This symbol indicated the word “phase”.
This symbol indicates the principal on/off switch in the on position.
This symbol indicates the principal on/off switch in the off position.

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2 LAYOUT
2.1 LAYOUT SG Series 750 & SG Series 750 T12
Fig. 2.1-3 Control Panel
SGS_750_UPS_GE_01
Fig. 2.1-1 SG Series 750 & SG Series 750 T12 general view
SGS_750_Switch Q1_01
Q1
Fig. 2.1-4 Q1 UPS Output Switch
SGS_750_S2_UPS_GE_02
Q1
4
1
3
2
4
1
3
2
2
1
12
1
1415
34
1617
56
1920
89
18
7
22
11
21
10
2
13
Fig. 2.1-2 SG Series 750 & SG Series 750 T12 general view with open door

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3 INTRODUCTION
An Uninterruptible Power Supply (UPS) provides the power for critical loads that need a reliable,
continuous, disturbance free supply.
In case the power provided by the Utility fails, or exceeds the permitted tolerances, the power to supply
the Load is provided by the Battery for the specified time at the rated Load (or longer at a reduced Load)
or until the Utility power returns.
SG Series 750 & SG Series 750 T12 are a true double conversion VFI (Voltage Frequency Independent)
UPS system where the Load is continuously supplied by the Inverter through the Rectifier.
In case of trouble on the Inverter Output Voltage, or when overload or short-circuit on the output occur,
the Load is instantly transferred to the Utility via the Automatic Bypass.
The UPS automatically returns to normal mode when the failure condition is restored.
Key features:
• More Critical equipment supported
Rated at 0.9 Power Factor for SG Series 750 & SG Series 750 T12 deliver more real power than other
UPS in the market.
With today’s trend toward power factor corrected loads, SG Series 750 & SG Series 750 T12 can
support more total Load than any other UPS available, allowing you to support a greater number of
today’s enterprise computing Power Factor Corrected (PFC) equipment.
• No single point of failure
Redundant Parallel Architecture (RPA) is an exclusive GE technology.
With RPA, SG Series 750 & SG Series 750 T12 UPS are controlled in a true peer-to-peer configuration
where all critical elements and functions (including Bypass) are redundant.
SG Series 750 & SG Series 750 T12 are designed to be the most reliable power protection system
available on the market today.
• High Efficiency
Using IGBT technology and Space Vector Modulation (SVM) strategy, SG Series 750 & SG Series 750
T12 offer low output voltage distortion and provides efficiencies up to 93%.
• Fully digital
Digital Signal Processor (DSP), Flash memory and SVM strategy, are the technology corner stones
of new age of power quality and power reliability.
• Extremely flexible
Tailor made power protection to meet your individual installation requirements; SG Series 750 & SG
Series 750 T12 offer various options like input harmonic filters and our comprehensive GE Power
Diagnostic software suite for mission control and data protection to cover all your application
needs.

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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.

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4.2 OPERATION MODES
4.2.1 Normal operation mode
During normal operation, the Rectifier converts
input AC power to DC.
The DC power provides input power for the
Inverter and charging power for the Battery.
The Inverter converts the DC power to continuous
and regulated AC power, which supplies the
critical load.
The control panel reports the Battery charge
status and the expected backup time with the
actual load.
Fig. 4.2.1-1 Block diagram normal operation mode
4.2.2 eBoost™ operation mode (option)
eBoost™
ehigh efficiency (up to 99%)
Boost fast power transfer (< 4ms)
When the eBoost™ Operation Mode is selected,
and the Utility Power is available, the Load is
normally powered through the Automatic
Bypass.
When the Utility Voltage is detected out of the
prescribed tolerances, the Load is automatically
transferred to the Inverter.
Fig. 4.2.2-1 Energy flow in eBoost™ Operation Mode
When the Utility recovers, the Load returns to the Automatic Bypass after a variable time defined by the
control unit.
The eBoost™ Operation Mode can be configured directly by the user for scheduled activation,
considering the Utility reliability and criticality of the Load.
The selection between the two operation modes “VFI Mode and eBoost™ Operation Mode”, or switching
between operation modes at required time, can be done through the UPS control panel (see Section 7.4
/
eBoost).
NOTE !
The eBoost™ Operation Mode is available only if enabled at the factory or by a GE
GLOBAL SERVICES FIELD ENGINEER.

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4.2.3 Utility failure operation
When the Utility is no longer within acceptable
tolerances, the Battery will provide the DC power to the
Inverter.
The Inverter will maintain continuous AC power to the
Load until the Battery Voltage reaches the lower limit of
the Inverter operation capability.
During the discharge, the LCD screen displays the
estimated time the Battery can support the critical Load.
Prior to the Battery completely discharging, the "stop
operation"alarm (shutdown imminent) warns the
operator that the Battery is almost discharged and the
UPS is about to shut down.
Fig. 4.2.3-1 Block diagram Utility Failure operation
In case of parallel operation
With a parallel system for power capacity (see Section 4.3)
• With the Bypass Utility power available, a low Battery warning on any unit will cause the Load to
be transferred to Utility (after a selectable time delay).
• With Bypass Utility power not available, a low Battery warning on any unit will start the “stop
operation” timer (adjustable). The Load will shut down at the end of the “stop operation” time period.
With a parallel system for redundancy (see Section 4.3)
• When a Battery low warning occurs on a unit not necessary to support the present load, this unit
will shut down after a timeout period (selectable). The Load is shared between the other units.
As the warning occurs on one unit necessary to support the present load, the system starts the
"stop operation" timeout (selectable).
The Load will shut down at the end of the “stop operation” time period.
4.2.4 Utility recovery operation
As soon as the AC input power recovers, the Rectifier will
start automatically, supplying DC power to the Inverter
and recharging the Battery.
If the Inverter was previously shut down due to low
Battery, the Load will be initially powered by Utility
through the Automatic Bypass.
When the Battery is recharged enough to ensure a
minimum time of operation with the present load, the
Inverter will start automatically and the Load will be
transferred back to the Inverter.
Fig. 4.2.4-1 Block diagram Utility recovery operation
In case of parallel operation
When the AC input power recovers, the Rectifiers will start up sequentially, according to their
number in the parallel system. This minimizes the initial inrush current.
The Inverters will start up automatically, but only when the Battery has recharged enough for a
minimum runtime with the present load.
When enough Inverters to supply the Load have been restarted, the Load will be transferred from
the Automatic Bypass back to the Inverter output.

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4.2.5 Automatic Bypass
In normal operation, the Load is supplied by the
Inverter.
When the control system detects a fault in the
Inverter, an overload condition or a short-circuit
condition, the Automatic Bypass will transfer the
critical Load to the Utility without interruption.
Fig. 4.2.5-1 Block diagram Automatic Bypass
When the Inverter recovers, or the overload or short-circuit condition is corrected, the Load will be
automatically transferred back to the Inverter.
If the UPS is unable to return to normal mode following an automatic transfer to Bypass mode, an
alarm condition will be initiated.
A Manual Bypass (operator initiated) will not be considered as an alarm condition.
In case of parallel operation
Each unit has its own internal Bypass.
These units are continuously exchanging information, enabling all of the internal Bypass circuits in a
parallel system to operate simultaneously.
If the Inverter of a unit fails, its Bypass circuit remains available to the Parallel System.
It is excluded only if the unit is separated from the common bus by opening its output switch Q1.

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4.3 PARALLEL SYSTEM OPERATION
4.3.1 Introduction to the parallel system
Fig. 4.3.1-1 SG Series 750 & SG Series 750 T12 block diagram parallel system operation
Two or more equal power units can be paralleled to increase the output power (paralleling for capacity)
or to improve the overall reliability of an UPS system (paralleling for redundancy).
The outputs of parallel units are connected to a common power bus, and in normal operation the units
connected on the parallel bus share the Load equally.
The modular concept of SG Series allows parallel operation of up to 6 units, without using paralleling
switchgear, external bypass circuits or common control circuitry (see Fig. 4.3.1-1).
Parallel units for power capacity
Several units can be paralleled in order to achieve output power greater than the maximum power of a
single unit.
The maximum total power shared between the paralleled units is equal to the total installed nominal
power.
In the event of a failure of one unit, the power supplied by the UPS system becomes insufficient and the
Load will be transferred to the Utility Bypass source.
Parallel units for redundancy
The nominal power rating of the nout of n+1 redundant paralleled modules must be equal to or greater
than the required Load power.
The Load will be equally shared by the nunits connected on the output bus.
Should one of the n+1 paralleled units trip Off-line, the remaining n modules will supply the load,
maintaining conditioned power to the critical load. This results higher reliability and security for the
Load plus a higher MTBF (Mean Time Between Failures).

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4.3.2 Features of RPA parallel system
The SG Series 750 & SG Series 750 T12 Parallel System are designed to provide a complete Redundant
Parallel Architecture and is free from common equipment.
Not only the Inverters are redundant, but also the Bypass functions are designed with redundant
modular concept.
When one UPS needs maintenance or service, the Load is powered by the other units supplying the
Load bus.
The redundant communication bus to which all units are connected keeps each unit informed about the
status of all the other units.
The control panel located on each unit allows controlling and monitoring the status of this unit.
4.3.3 System control
A high-speed redundant, serial communication bus guarantees the exchange of data and thus the
communication between the CPU's of each unit.
Each module controls it's own function and operational status and communicates with all other
modules, in order to act or react if necessary, adapting it to the new conditions.
4.3.4 Synchronization
All units are identical, but one unit is arbitrarily selected as the reference and all the other units
synchronize to this unit, which in turn, synchronizes to the Utility Bypass voltage, as long as the later is
within tolerances.
In case of reference failure, another unit in the parallel system is automatically chosen to take over the
reference role.
The Bypass Input for all the units of the parallel system must be supplied from the same AC source (no
phase shift allowed between them).
4.3.5 Load sharing
On each unit of the parallel system, Inverter Output Voltage and Current are measured and applied to a
Load sharing bus.
An eventual difference between the units is therefore automatically equalized.
NOTE !
It is strongly recommended that no transformers, automatic circuit breakers or
fuses should be inserted between the unit’s output and the Load common bus bars.
However, it is recommended that a disconnect or isolation switch be inserted.

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4.4 RECTIFIERS PARALLELED ON THE SAME BATTERY
NOTE !
A parallel system with a Common Battery for two or more Rectifiers, requires
a particular installation and adequate setting of some parameters,
(accessible only through password), and can therefore only be done by a
QUALIFIED SERVICE ENGINEER GE.
Usually each Rectifier-Inverter Unit runs with its own Battery.
In case of parallel units are running with a Common Battery (max. 4 UPS - in SG Series 750 & SG Series
750 T12 we already have two rectifiers in parallel - see Fig 4.4-1), the sharing circuit between individual
Rectifier is integrated in the communication bus of the system in order to assure an equal sharing of the
Rectifiers output currents.
Fig. 4.4-1 Diagram RPA system with Rectifiers on Common Battery
1 –
2 –
3 –
4 –
Utility input
External Battery Fuse
Battery
Load Bus Bar
Pay attention to the following recommendations:
• The units delivered for this functioning mode needs a special parameters setting, so they must be
prepared in advance before the installation.
• The installation must be performed only with the UPS system completely shut down.
• The AC Rectifiers input power (1) must be the same, with clockwise phase rotation for each unit.
• Each Rectifier must be set for the same floating DC voltage and the same Battery current limitation.
• It is recommended to install the fuses / MCCB (2) on each line connecting the Rectifiers to the
common Battery for maintenance / safety reasons.
• In case one must be powered down for maintenance, switch-OFF the concerned unit before open
the DC fuses / MCCB on the Battery line (2).
• It is recommended to connect an external NO free contact “Battery Fuses” to the UPS and to enable
the function by setting the parameter (see Section 4.1 of the “Installation Guide”).
• If an emergency generator set supply the UPS, and the free contact “Generator ON” is connected to
the Customer interface, connect a separate NO free contact on each parallel unit.
• The parameters enabling the Battery test, both manual and automatic, must be set in the same
mode on all the units having the Rectifiers on Common Battery.
• Do not connect the temperature sensor for automatic battery floating voltage compensation.
• Do not enable the function Boost charge (parameter 87).

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4.5 RECYCLING AT THE END OF SERVICE LIFE
NOTE !
This product has been designed to respect the environment, using
materials and components respecting eco-design rules.
It does not contain CFCs (chlorofluorocarbons) or HCFCs
(hydrochlorofluorocarbons).
GE, in compliance with environment protection recommends to the
User that the UPS equipment, at the end of its service life, must be
recovered conforming to the local applicable regulations.
WARNING !
Leads contained in the batteries is a dangerous substance for the
environment, therefore it must be correctly recycled by specialized
companies!

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5 CONTROL PANEL
5.1 CONTROL PANEL
Fig. 5.1-1 Control panel
The control panel, positioned on the UPS front door, acts as the UPS user interface and comprises of the
following elements:
• Back lit Graphic Display (LCD) with the following characteristics:
− Multilanguage communication interface:
English, German, Italian, Spanish, French, Finnish, Polish, Portuguese, Czech, Slovakian, Chinese,
Swedish, Russian and Dutch;
− Synoptic diagram indicating UPS status.
• Command pushbuttons and parameters setting.
• UPS status control LED.