Eaton 91PS UPS 8-40 kW Manual

User's and installation
guide
Eaton 91PS/93PS UPS 8–40 kW
P-164000493

Copyright © 2018 Eaton Corporation plc. All rights reserved.
This manual contains important instructions that you should follow during installation and
maintenance of the UPS and batteries. Please read all instructions before operating the
equipment and save this manual for future reference.
This is a product for commercial and industrial application in the second environment.
Installation restrictions or additional measures may be needed to prevent disturbances.
The contents of this manual are the copyright of the publisher and may not be reproduced
(even extracts) without the written approval of Eaton Corporation. Every care has been
taken to ensure the accuracy of the information contained in this manual, but no liability
can be accepted for any errors or omission. The right to make design modifications is
reserved.
Unauthorized copying and lending are prohibited.
Eaton Power Quality Oy
Address: Koskelontie 13
FI-02920 Espoo
FINLAND
Internet: www.eaton.eu
Approvals and version history
Revision Date Description of change Approved by
001 17.04.2015 First issue Otto Asunmaa
002 06.07.2015 Minor updates Otto Asunmaa
003 14.07.2016 Updated to cover 93PS 8–20 kW UPS
C-model
Otto Asunmaa
004 28.05.2018 Minor updates. Recommended secure
hardening guidelines added.
Otto Asunmaa
005 12.09.2018 91PS addition Otto Asunmaa
Original instructions _X_ / Translation of the original instructions __
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
© Eaton Corporation plc 2018. All rights reserved. Revision: 005 Document ID: P-164000493 2 (117)

Contents
1 How to read this manual.......................................................................... 7
1.1 Safety-related signs.................................................................... 7
1.2 Safety symbols............................................................................7
1.2.1 Hazard symbols............................................................. 7
1.2.2 Prohibited action symbols..............................................7
1.2.3 Mandatory action symbols............................................. 8
1.3 Conventions used in this document............................................ 8
1.4 Glossary......................................................................................8
2 Safety instructions..................................................................................10
2.1 Audience................................................................................... 12
2.2 CE marking............................................................................... 12
2.3 User precautions.......................................................................12
2.4 Environment..............................................................................13
2.5 Symbols on the UPS and accessories......................................13
2.6 For more information.................................................................14
3 Introduction to Eaton UPS......................................................................15
3.1 Looking inside the UPS system................................................ 17
3.2 UPS operating modes...............................................................19
3.2.1 Normal operating modes............................................. 20
3.2.2 Stored energy and battery mode................................. 23
3.2.3 Bypass mode............................................................... 25
3.3 UPS features.............................................................................27
3.3.1 Advanced Battery Management.................................. 27
3.3.2 Powerware Hot Sync................................................... 27
3.3.3 Power Conditioner....................................................... 28
3.3.4 Frequency Converter................................................... 28
3.4 Software and connectivity features........................................... 28
3.4.1 User interface.............................................................. 28
3.4.2 Power Management Software..................................... 29
3.5 Options and accessories...........................................................29
3.5.1 Maintenance Bypass Switch (optional)........................29
3.5.2 Field Installed UPM (accessory).................................. 29
3.6 Battery system.......................................................................... 30
3.7 Basic system configurations..................................................... 30
4 UPS installation plan and unpacking......................................................33
4.1 Creating an installation plan......................................................33
4.2 Installation checklist.................................................................. 34
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
© Eaton Corporation plc 2018. All rights reserved. Revision: 005 Document ID: P-164000493 3 (117)

4.3 Site preparations.......................................................................34
4.3.1 Environmental and installation considerations.............35
4.3.2 UPS system power wiring preparations.......................39
4.4 Unpack and unload the UPS.....................................................50
5 UPS system installation......................................................................... 55
5.1 Steps to install the UPS............................................................ 55
5.2 Battery system installation........................................................ 58
5.2.1 Battery trip wiring......................................................... 58
5.3 Installing UPS external battery cabinet and battery power
cabling............................................................................................. 59
5.4 Installing a remote EPO switch ................................................ 60
5.5 Installing interface connections.................................................61
5.5.1 Installing customer input signals interface................... 61
5.5.2 Battery breaker wiring interface................................... 61
5.5.3 Relay output interface connections..............................62
5.5.4 Industrial Relay Card interface connections................ 62
5.5.5 MiniSlot interface connections..................................... 63
5.5.6 Installing signal interface connections in a parallel
system................................................................................ 63
5.6 Wiring parallel 91PS/93PS UPS systems................................. 64
5.6.1 Power wiring overview................................................. 64
5.6.2 Control signals overview..............................................66
5.6.3 Installing parallel control wiring....................................67
5.7 UPS system interface wiring preparation..................................70
6 Communication interfaces......................................................................71
6.1 Native signal terminals..............................................................73
6.2 MiniSlot cards........................................................................... 74
6.3 Intelligent Power Software........................................................ 76
6.4 Signal input monitoring............................................................. 76
6.5 General purpose relay contact..................................................76
6.6 Configuring relays..................................................................... 77
7 UPS operating instructions.....................................................................81
7.1 UPS controls and indicators......................................................81
7.1.1 Control panel............................................................... 81
7.1.2 Status indicators.......................................................... 82
7.1.3 System events............................................................. 84
7.1.4 Menu structure of the 91PS/93PS UPS.......................84
7.2 Signing in.................................................................................. 88
7.3 System control instructions....................................................... 88
7.3.1 Starting the UPS system in the double conversion
mode...................................................................................88
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
© Eaton Corporation plc 2018. All rights reserved. Revision: 005 Document ID: P-164000493 4 (117)

7.3.2 Starting the UPS system in the bypass mode............. 89
7.3.3 Transferring from the double conversion mode to
the bypass mode................................................................ 90
7.3.4 Transferring from the bypass mode to the double
conversion mode................................................................ 90
7.3.5 Transferring from the double conversion mode to
the Energy Saver System mode.........................................91
7.3.6 Transferring from the Energy Saver System mode
to the double conversion mode.......................................... 91
7.3.7 Transferring from the double conversion mode to
the Variable Module Management System mode...............91
7.3.8 Transferring from the Variable Module
Management System mode to the double conversion
mode...................................................................................92
7.3.9 Shutting down the UPS system and critical load......... 92
7.3.10 De-energizing the critical load..................................... 93
7.4 UPS control instructions............................................................93
7.4.1 Starting a single UPS...................................................93
7.4.2 Shutting down a single UPS........................................ 94
7.4.3 Enabling and disabling the battery charger................. 94
7.5 UPM control instructions........................................................... 95
7.5.1 Starting the UPMs........................................................95
7.5.2 Shutting down the UPMs............................................. 95
7.6 Using the Remote Emergency Power-off switch.......................96
7.7 Turning the UPS from the double conversion mode to the
maintenance bypass mode..............................................................96
7.8 Turning the UPS from the maintenance bypass mode to
the double conversion mode............................................................98
8 UPS maintenance................................................................................ 100
8.1 Important safety instructions................................................... 100
8.2 Preventive maintenance......................................................... 101
8.2.1 Daily maintenance..................................................... 101
8.2.2 Monthly maintenance.................................................102
8.2.3 Periodic maintenance................................................ 102
8.2.4 Annual maintenance.................................................. 102
8.2.5 Battery maintenance..................................................102
8.3 Recycling the used UPS or batteries...................................... 103
8.4 Maintenance training...............................................................105
9 Technical data......................................................................................106
9.1 Directives and standards........................................................ 106
9.2 UPS system input................................................................... 106
9.3 UPS system output................................................................. 107
9.4 UPS environmental specifications.......................................... 108
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
© Eaton Corporation plc 2018. All rights reserved. Revision: 005 Document ID: P-164000493 5 (117)

9.5 Battery specification................................................................108
10 Warranty...............................................................................................110
10.1 General................................................................................... 110
10.2 Whom to contact in case of Warranty..................................... 111
11 Appendix A: Recommended secure hardening guidelines.................. 112
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
© Eaton Corporation plc 2018. All rights reserved. Revision: 005 Document ID: P-164000493 6 (117)

1 How to read this manual
1.1 Safety-related signs
The following table explains the safety-related signs used in this document.
DANGER DANGER indicates a hazard with a high level of risk which, if
not avoided, will result in serious injury or death.
WARNING
WARNING indicates a hazard with a medium level of risk which,
if not avoided, could result in serious injury or death, or damage
to your machine.
CAUTION
CAUTION indicates a hazard with a low level of risk which, if not
avoided, could result in minor or moderate injury, or damage to
your machine.
Note: Notes are used to indicate important information and useful tips.
1.2 Safety symbols
1.2.1 Hazard symbols
These symbols indicate a hazardous situation or action. Symbols are used to
warn of situations, which may cause environmental damage and personal injury.
General warning sign Explosion and fire hazard
Electrical hazard Corrosive hazard
Battery hazard
1.2.2 Prohibited action symbols
These symbols are used to indicate an action that should not be taken.
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
© Eaton Corporation plc 2018. All rights reserved. Revision: 005 Document ID: P-164000493 7 (117)

General symbol for pro-
hibited action
No smoking
Limited or restricted ac-
cess
1.2.3 Mandatory action symbols
These symbols are used to indicate an action that must be taken.
General symbol for man-
datory action
Disconnect from power
source
Read the manual or in-
structions
1.3 Conventions used in this document
This document uses the following type conventions:
•Bold type highlights important concepts in discussions, key terms in
procedures and menu options, or represents a command or option that you
type or enter at a prompt.
•
Italic type highlights notes and new terms when they are defined.
•Screen type represents information that appears on the screen or LCD.
1.4 Glossary
Eaton documentation uses these acronyms to refer to Eaton UPS products or
their parts:
Table 1: Glossary of acronyms
ABM Advanced Battery Management
BIS Bypass Input Switch
EAA Energy Advanced Architecture
EBC External Battery Cabinet
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
© Eaton Corporation plc 2018. All rights reserved. Revision: 005 Document ID: P-164000493 8 (117)

EMBS External Maintenance Bypass Switch
EPO Emergency Power-off
ESS Energy Saver System
FI-UPM Field Installed UPM
IPM Intelligent Power Manager
IPP Intelligent Power Protector
MBP Maintenance Bypass
MBS Maintenance Bypass Switch
MCB Miniature Circuit Breaker
MIS Maintenance Isolation Switch
MOB Module Output Breaker
REPO Remote Emergency Power-off
RIS Rectifier Input Switch
SCR Silicon-controlled Rectifier
SNMP Simple Network Management Protocol
STSW Static (bypass) Switch
UPM Uninterruptible Power Module
UPS Uninterruptible Power Supply
VMMS Variable Module Management System
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
© Eaton Corporation plc 2018. All rights reserved. Revision: 005 Document ID: P-164000493 9 (117)

2 Safety instructions
DANGER
Important safety instructions!
Keep these instructions!
This document contains important instructions that must be obeyed during the
installation, operation and maintenance of the UPS and the batteries. Read all of
the instructions before operating the equipment. Keep this manual for future
reference. These instructions are also available for download at www.eaton.eu/
91psand93ps.
DANGER
Operations in the UPS must be done by an authorized Eaton Customer
Service Engineer or by other qualified service personnel authorized by Eaton.
There are no user-serviceable parts inside the UPS.
The UPS operates with mains, battery or bypass power. It contains components
that carry high currents and voltage. A properly installed enclosure is earthed
and IP20 rated against electrical shock and foreign objects. However, the UPS
is a sophisticated power system and only qualified personnel can install and
service it.
DANGER
This UPS carries lethal voltages. All repairs and service must be done by
authorized personnel only. There are no user-serviceable parts inside the
UPS.
WARNING
The UPS is powered by its own energy source (batteries). The output
terminals may be energized even when the UPS is disconnected from an AC
source. To reduce the risk of fire or electric shock, install this UPS in a
temperature and humidity controlled, indoor environment that is free of
conductive contaminants.
The ambient temperature must not exceed 40 °C (104 °F). Do not operate the
UPS near water or excessive humidity (95% maximum). The system is not
intended for outdoor use.
Before you start any installation or service work, make sure that all AC and
DC power sources are disconnected. Power may come from multiple sources.
Also ensure system grounding / PE continuity.
In a parallel system, the output terminals may be energized even when the
UPS is turned off.
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
© Eaton Corporation plc 2018. All rights reserved. Revision: 005 Document ID: P-164000493 10 (117)

WARNING
Batteries present a risk of electrical shock or burn from high short-circuit
current. Obey the precautions.
Electric energy hazard. Do not attempt to alter any battery wiring or
connectors. Attempting to alter wiring can cause injury.
Do not open or mutilate batteries. Released electrolyte may be toxic and is
harmful to the skin and eyes.
Batteries may contain HIGH VOLTAGES, and CORROSIVE, TOXIC and
EXPLOSIVE substances. Because of the battery string the output receptacles
may carry high voltage even when the AC supply is not connected to the
UPS. Read the shutdown instructions carefully.
IMPORTANT: The battery may consist of multiple parallel strings. Make sure
that you disconnect all strings before installation.
CAUTION
Only qualified service personnel knowledgeable of batteries and the required
precautions can do installation or service work on batteries. Keep
unauthorized personnel away from the batteries. Before you install or replace
batteries, obey all the warnings, cautions, and notes concerning appropriate
handling. Do not disconnect the batteries when the UPS is in the Battery
mode.
Make sure that your replacement batteries are of the same number and type
as the battery that was originally installed in the UPS. See more accurate
instructions on the UPS.
Before you connect or disconnect battery terminals, disconnect the charging
source by opening the corresponding battery circuit breaker.
Examine if the battery is inadvertently grounded. If it is, remove the source of
the ground. Contacting any part of a grounded battery can cause a risk of
electric shock. If you disconnect the grounding connection before you work on
the batteries, the risk of an electric shock is less likely.
Discard batteries according to your local disposal requirements. Do not
dispose of batteries in a fire. When exposed to flame, batteries may explode.
To ensure proper cooling airflow and to protect personnel from dangerous
voltages inside the unit, keep the UPS door closed and the front panels
installed.
Do not install or operate the UPS system close to gas or electric heat
sources. Keep the operating environment within the parameters stated in this
document.
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
© Eaton Corporation plc 2018. All rights reserved. Revision: 005 Document ID: P-164000493 11 (117)

CAUTION
Keep the surroundings of the UPS uncluttered, clean, and free from excess
moisture.
Obey all DANGER, CAUTION, and WARNING notices affixed to the
equipment.
2.1 Audience
The intended audience of this document are as follows:
• People who plan and perform the installation of the UPS
• People who use the UPS
This document provides guidelines for how to check the UPS delivery and how
install and operate the UPS.
The reader is expected to know the fundamentals of electricity, wiring, electrical
components and electrical schematic symbols. This document is written for a
global reader.
CAUTION
Read this document before you start to operate or perform work on the UPS.
2.2 CE marking
The product has a CE marking in compliance with the following European
directives:
• LVD Directive (Safety) 2014/35/EU
• EMC Directive 2014/30/EU
• RoHS Directive 2011/65/EU
Declarations of conformity with UPS harmonized standards and directives EN
62040-1 (Safety), EN 62040-2 (EMC) and EN 50581 (RoHS) are available at
www.eaton.eu or by contacting your nearest Eaton office or authorized partner.
2.3 User precautions
The only permitted user operations are as follows:
• Startup and shutdown of the UPS, excluding the commissioning startup.
• Use of the LCD control panel and the Maintenance Bypass Switch (MBS).
• Use of optional connectivity modules and their software.
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
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Follow the precautions and only perform the described operations. Any deviation
from the instructions can be dangerous to the user or cause accidental load
loss.
DANGER
Do not open any other screws in the unit than those holding the cover plates
of the MiniSlots and the MBS locking plate. Failure to recognize the electrical
hazards can prove fatal.
CAUTION
The 8-40 kW models are available as a C2 UPS product in regard to
emissions and a C3 UPS product in regard to immunity. The UPS can be
placed both in residential and commercial or industrial environments. When
included in a residential environment, this product may cause radio
interference, in which case you may have to take additional preventive
measures.
2.4 Environment
The UPS must be installed according to the recommendations in this document.
Never install the UPS in an airtight room, in the presence of flammable gases, or
in an environment exceeding the specifications.
Excessive amount of dust in the operating environment of the UPS may cause
damage or lead to malfunction. Always protect the UPS from the outside
weather and sunshine. In order to maximize internal battery service life time, the
recommended operating temperature range is from +20 ºC to +25 ºC.
WARNING
During charge, float charge, heavy discharge, and overcharge, hydrogen and
oxygen gases are emitted from lead-acid and NiCd batteries into the
surrounding atmosphere. Explosive gas mixture may be created if the
hydrogen concentration exceeds 4% by volume in air. Ensure the necessary
air flow rate for the ventilation of the UPS location.
2.5 Symbols on the UPS and accessories
The following are examples of symbols used on the UPS or its accessories. The
symbols are used to alert you of important information.
RISK OF ELECTRIC SHOCK
Indicates that a risk of electric shock is present and the associated
warning should be observed.
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
© Eaton Corporation plc 2018. All rights reserved. Revision: 005 Document ID: P-164000493 13 (117)

CAUTION: REFER TO OPERATOR'S MANUAL
Refer to your operator's manual for additional information, such as
important operating and maintenance instructions.
This symbol indicates that you may not discard the UPS or the UPS
batteries in the trash. This product involves sealed, lead-acid batter-
ies and they must be disposed of properly. For more information,
contact your local recycling / reuse or hazardous waste center.
This symbol indicates that you may not discard waste electrical or
electronic equipment (WEEE) in the trash. For proper disposal, con-
tact your local recycling / reuse or hazardous waste center.
2.6 For more information
Address any inquiries about the UPS and the battery cabinet to the local office
or an agent authorized by the manufacturer. Quote the type code and the serial
number of the equipment.
Call your local service representative if you need help with any of the following:
• scheduling initial startup
• regional locations and telephone numbers
• a question about any of the information in this manual
• a question that this manual does not answer
Note: For more information about the installation space, safe operation and
working, see IEC 62485-2: Safety requirements for secondary batteries and
battery installations.
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
© Eaton Corporation plc 2018. All rights reserved. Revision: 005 Document ID: P-164000493 14 (117)

3 Introduction to Eaton UPS
Figure 1. 15/20 kW C-model frame, 15/20 kW standard frame and 30/40 kW frame
The Eaton® 91PS/93PS uninterruptible power supply (UPS) is a true online,
continuous-duty, transformerless, double-conversion, solid-state single-phase
(91PS) or three-phase (93PS) system. It supplies conditioned and
uninterruptible AC power to critical load and protects it from power failures.
The UPS is used to prevent loss of valuable electronic information, minimize
equipment downtime, and minimize the adverse effect on production equipment
due to unexpected power problems.
The Eaton UPS continually monitors incoming electrical power and removes the
surges, spikes, sags, and other irregularities that are inherent in commercial
utility power. Working with a building’s electrical system, the UPS system
supplies clean, consistent power that sensitive electronic equipment require for
reliable operation. During brownouts, blackouts, and other power interruptions,
batteries provide emergency power to safeguard operation.
The UPS system is housed in a single, free-standing cabinet with safety shields
behind the door for protection against hazardous voltage. Each UPS cabinet has
a centralized system static bypass. The available static bypass ratings are 15
and 30 kW for 91PS and 20 kW and 40 kW for 93PS. The static bypass size is
chosen according to UPS system power. For example, if a future requirement is
to upgrade the UPS capacity, the UPS bypass rating has to be selected
accordingly. In addition, the bypass ratings of all the UPS cabinets in a parallel
system need to be matched.
Eaton 91PS/93PS output power ratings are based on 15 kW or 20 kW rated
uninterruptible power modules (UPMs).
91PS/93PS is also available as a C-model, which consists of the electrical part
of the 91PS/93PS UPS 15/20 kW frame without the battery compartment.
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
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UPS frame Position in Figure 9 Number of UPMs Ratings
91PS 15 kW A and B 1 8, 10, 15 kW
91PS 30 kW C 1 or 2 8, 10, 15, 20, 30 kW
93PS 20 kW A and B 1 8, 10, 15 or 20 kW
93PS 40 kW C 1 or 2 8, 10, 15, 20, 30 or
40 kW
A UPM includes a rectifier, inverter, battery converter, and independent controls.
Each UPM is able to operate independently from the other power modules.
Note: Startup and operational checks must be done by an authorized Eaton
Customer Service Engineer or by other qualified service personnel authorized
by Eaton, or the terms specified in the Warranty (see Chapter 10 ) become
void. This service is offered as part of the sales contract for the UPS. Contact
service in advance (usually a two-week notice is required) to reserve a
preferred startup date.
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
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3.1 Looking inside the UPS system
Figure 2. Looking inside the 15/20 kW standard and C-model frames
Figure 3. Looking inside the 30/40 kW frame
1. Control panel 6. Input switch (optional in some regions)
2. Door latch 7. Battery breaker for internal batteries *
3. Power module (UPM) 8. Maintenance bypass switch (optional)
4. Internal battery (not included in the C-
model)
*In the C-model for external batteries
5. Communications area
The system level static bypass in the UPS cabinet determines the attainable
output power of the UPS. The static bypass line consists of a static switch and a
backfeed protection isolation device connected in series. In addition, there is a
system level control unit that constantly monitors the power delivered through
the bypass line or to the input of the UPS. Transfers to static bypass are
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
© Eaton Corporation plc 2018. All rights reserved. Revision: 005 Document ID: P-164000493 17 (117)

seamless and performed automatically by the system as needed, for example,
in case of an extended system overload.
Each UPM includes a rectifier, battery converter, inverter and independent
controls. Each UPM is able to operate and share the load independently,
despite the status of the other UPMs.
In addition, the system can have a UPS-internal maintenance bypass switch as
a factory-installed option.
Table 2: UPS configurations
UPS frame Number of UPMs Static switch [kW] Internal battery
93PS 20 kW 1 20 Yes
93PS 20 kW
C-model
1 20 No
93PS 40 kW 1 or 2 40 Yes
91PS 15 kW 1 15 Yes
91PS 15 kW
C-model
1 15 No
91PS 30 kW 1 or 2 30 Yes
WARNING
Hazardous voltage can exist in the battery circuit until disconnected from
external battery source.
In the 30/40 kW frame, the two UPMs are paralleled internally.
The rectifier input switch and battery breaker are available as standard for all the
models. The internal MBS is available as option for all the models.
If utility power is interrupted or falls outside the parameters specified in Chapter
9 , the UPS uses a backup battery supply to maintain power to the critical load
for a specified period of time or until the utility power returns. For extended
power outages, the UPS allows you to either transfer to an alternative power
system (such as a generator) or shut down your critical load in an orderly
manner. The UPS bypass consists of a continuous-duty static switch and a
backfeed protection isolation device. All the models also include an internal fuse
in the bypass line. The backfeed protection and bypass fuse are located in
series with the static switch.
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
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3.2 UPS operating modes
Table 3: UPS operating modes
UPS operating mode Description
Normal operating modes:
Double conversion mode Critical load is supplied by the inverter,
which derives its power from rectified utility
AC power. In this mode, the battery charg-
er also provides charging current for the
battery, if needed.
Variable Module Management System
(VMMS) mode
Critical load is supplied by the inverter. The
inverter derives its power from rectified util-
ity AC power, identically to double conver-
sion mode. In the VMMS mode, the UPS
system is able to optimise the load level
per power module: the operating efficiency
is significantly improved when operating
load is below 50% of UPS capacity. The
UPS system will automatically place the re-
dundant power modules to suspended
mode. In case of any anomalies in utility or
a sudden load increase, the suspended
power modules are able to transfer to on-
line mode with less than 2 ms transition
time.
Energy Saver System (ESS mode) Critical load is supported securely by utility
power through the static bypass switch with
double conversion available on-demand
with typically less than a 2 ms transition
time, should any abnormal condition be de-
tected in the utility. When operating in the
ESS mode, the load is protected with inher-
ent surge suppression. Operating the UPS
in the ESS mode increases system effi-
ciency up to 99%, allowing significant sav-
ings in energy losses without compromis-
ing system reliability.
Other operating modes:
Stored energy mode Energy is drawn from a DC backup power
source and converted to AC power by the
UPS inverter. Most commonly VRLA bat-
teries are introduced to the system for this
purpose, and the mode of operation is
called the battery mode.
Bypass mode Critical load is supported directly by utility
power through the UPS static switch.
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
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3.2.1 Normal operating modes
During normal UPS operation, power for the system is derived from a utility input
source. Unit Online is displayed on the front panel, indicating that the
incoming power is within voltage and frequency acceptance windows.
3.2.1.1 Double conversion mode
Figure 4 shows the path of electrical power through the UPS system when the
UPS is operating in the double conversion mode.
Figure 4. Path of current through the UPS in the double conversion mode
A Static
switch
1 Bypass in-
put
Main power flow
B Rectifier 2 Rectifier in-
put
Energized
C Inverter 3 Output De-energized
D Battery con-
verter
4 Battery
breaker
Trickle current
E Battery Closed Open
Three-phase AC input power is converted to DC using a multilevel converter
with IGBT devices to produce a regulated DC voltage to the inverter. The UPS
status indicated on the display is Unit Online and the UPM status is Active.
The battery converter derives its input from the regulated DC output of the
rectifier and provides regulated charge current to the battery. The battery is
Eaton 91PS/93PS UPS 8–40 kW User's and installation guide
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