Vertiv Liebert EXM2 User manual

Liebert® EXM2
User Manual
100kVA to 250kVA UPS

Proprietary and Confidential ©2023 Vertiv Group Corp.
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If you encounter any installation or operational issues with your product, check the pertinent section of this
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Visit https://www.vertiv.com/en-us/support/ for additional assistance.
The information contained in this document is subject to change without notice
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Refer to local regulations and building codes relating to the application,
installation, and operation of this product. The consulting engineer, installer,
and/or end user is responsible for compliance with all applicable laws and
regulations relation to the application, installation, and operation of this product.
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Vertiv™ Liebert® EXM2 UPS User Manual

TABLE OF CONTENTS
1 Important Safety Instructions 1
2 Overview 5
2.1 Features 5
2.2 Design Concept 5
2.2.1 System Design 5
2.2.2 Bypass 7
2.2.3 System Control Principle 7
2.2.4 UPS Power Supply Switch Configuration 8
2.2.5 Battery Circuit Breaker (BCB) 9
2.3 Parallel System 10
2.3.1 Parallel System Features 10
2.3.2 Parallel System Requirements 10
2.4 Operation Modes 10
2.5 Battery Management 15
2.5.1 Normal Function 16
2.5.2 Advanced Function 16
2.5.3 Battery Temperature Compensation 17
2.6 Battery Protection 17
3 Mechanical Installation 19
3.1 Precautions 19
3.2 Transportation 20
3.3 Tools 20
3.4 Unpacking 22
3.5 Initial Inspection 24
3.6 Environmental Requirement 24
3.6.1 UPS Location Selection 24
3.6.2 Battery Location Selection 25
3.6.3 Storage 25
3.7 Mechanical Requirement 25
3.7.1 Composition 25
3.7.2 Moving Cabinet 25
3.7.3 Clearance 26
3.7.4 Cable Access Mode 26
3.8 Installation Drawings 27
4 Electrical Installation 29
4.1 Wiring of Power Cable 29
4.1.1 System Configuration 29
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4.1.2 Maximum Steady State AC and DC Currents 29
4.1.3 Recommended CSA of UPS Cable 30
4.1.4 Selection of UPS I/O and Battery Switch 30
4.1.5 Distance Between the UPS Connection Point and The Floor 31
4.1.6 Notes 31
4.1.7 Power Cable Connecting Terminal 31
4.1.8 Protection Ground 31
4.1.9 External Protective Device 31
4.1.10 Power Cable Connection Steps 33
4.2 Wiring of Signal Cable 38
4.2.1 Overview 38
4.2.2 Dry Contact Port J6 39
4.2.3 Dry Contact Port J7 40
4.2.4 Programmable Dry Contact Port J8 43
4.2.5 REPO Port 44
4.2.6 Host Communication Port 45
4.2.7 Parallel and LBS Communication Ports 45
4.2.8 Intellislot Port 45
4.2.9 Signal Cable Connection Steps 45
5 Operator Control and Display Panel 49
5.1 Introduction 49
5.2 Navigating through the Vertiv™ Liebert® EXM2 Touchscreen Control Panel 50
5.2.1 Access Level Log-In 50
5.2.2 Vertiv™ Liebert® EXM2 Touchscreen Control Panel Components 51
5.3 Operation 57
5.3.1 Log In to the Vertiv™ Liebert® EXM2 Touchscreen Control Panel 57
5.3.2 Customizing the Display 57
5.3.3 Operator Controls 64
5.4 Viewing UPS Status 71
5.4.1 Viewing UPS Data with the Status Gauge 71
5.4.2 Viewing UPS Data with the Status Panel 75
5.4.3 Logs-Alarms and Events 80
5.5 Viewing UPS Component Status 81
5.6 Status Bar Component 84
5.6.1 Status Bar Messages 84
5.7 Alarm List 87
6 Single UPS Operation Introduction 93
6.1 Brief Introduction 93
6.1.1 Precautions 93
6.1.2 Power Switch 93
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6.2 UPS Startup Procedures 95
6.2.1 Startup Procedures in Normal Mode 95
6.2.2 Startup Procedures in ECO Mode 98
6.2.3 Startup Procedures in Battery Mode (Battery Cold Start) 99
6.3 Procedures for Transfer between Operation Modes 100
6.3.1 Transfer from Normal Mode to Battery Mode 100
6.3.2 Transfer from Normal Mode to Bypass Mode 100
6.3.3 Transfer from Bypass Mode to Normal Mode 101
6.3.4 Transfer from Normal Mode to Maintenance Mode 101
6.3.5 Transfer from Maintenance Mode to Normal Mode 102
6.4 Battery Test Procedures 102
6.5 UPS Shutdown Procedures 104
6.5.1 Procedures for Completely Powering Down UPS 104
6.5.2 Procedures for Completely Powering Down UPS while Maintaining Power to Load 105
6.6 EPO Procedures 105
6.7 UPS Reset Procedures after EPO 105
6.8 Automatic Restart 106
6.9 Selecting Language 106
6.10 Changing Current Date and Time 108
6.11 Control Password 108
7 Battery 111
7.1 Introduction 111
7.2 Safety 111
7.3 UPS Battery 113
7.4 Precautions for Installation Design 113
7.5 Battery Installation Environment and Number of Batteries 115
7.5.1 Installation Environment 115
7.5.2 Number of Batteries 116
7.6 Battery Protection 116
7.7 Battery Installation 117
7.8 Design of Battery Room 117
7.9 Common Battery String 118
7.10 Connections between Battery Compartments and UPS 119
7.11 BCB Box (Optional) 120
7.12 Battery Ground Fault Detector (Optional) 123
7.13 BCB Reference Current and Connection 124
7.14 Battery Maintenance 126
7.15 Disposal of Used Battery 126
8 Parallel System and LBS System 127
8.1 General 127
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8.2 System Installation Procedures 127
8.2.1 Preliminary Checks 127
8.2.2 Cabinet Installation 127
8.2.3 External Protective Device 129
8.2.4 Power Cable 129
8.2.5 Parallel Cable 129
8.2.6 Remote EPO 130
8.3 Operation Procedures for Parallel System 131
8.3.1 Startup Procedures in Normal Mode 131
8.3.2 Maintenance Bypass Procedures 132
8.3.3 Procedures for Isolating One UPS Module from Parallel System 133
8.3.4 Procedures for Inserting One Isolated UPS Module in Parallel System 133
8.3.5 Procedures for Completely Powering Down UPS 134
8.3.6 Procedures for Complete UPS Shutdown while Maintaining Power to Load 134
8.4 LBS System 134
8.4.1 Cabinet Installation 134
8.4.2 External Protective Device 136
8.4.3 Power Cable 136
8.4.4 LBS Cable 136
9 Options 139
9.1 Option List 139
9.2 Option Introduction 140
9.2.1 Optional Side Cabinet 140
9.2.2 Bypass Short-circuit Withstand Option 142
9.2.3 Battery Temperature Sensor 143
9.2.4 Battery Ground Fault Kit 144
9.2.5 Seismic Anchor Kit 144
9.2.6 IS-UNITY-DP Card 147
9.2.7 IS-UNITY-LIFE Card (Available in Specific Regions only) 148
9.2.8 SIC Card (Available in Specific Regions only) 148
9.2.9 UF-RS485 Card 149
9.2.10 IS-Relay Card 150
9.2.11 BCB Box 151
9.2.12 Parallel Cable 151
9.2.13 LBS Cable 151
9.2.14 Back-feed Contactor Option 151
9.2.15 Top Fan Kit 152
9.2.16 Input/Output Switch Kit 153
9.2.17 IP21 Option 154
9.2.18 IP31 Option 155
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Vertiv™ Liebert® EXM2 UPS User Manual

9.2.19 Transformer 155
9.2.20 C2 Electromagnetic Shielding Option 157
9.2.21 CPSS Model Option 157
9.2.22 LBS Adapter 157
10 Communication 159
10.1 SNMP Protocol Communication 159
10.2 Modbus Protocol Communication 159
10.3 Dry Contact Communication 159
10.3.1 Communication through IS-Relay Card 160
10.3.2 Communication through Dry Contact Port 160
11 Service and Maintenance 161
11.1 Safety 161
11.2 Service Procedures of Power Module and Bypass Module 161
11.2.1 Service Procedures of Power Module 161
11.2.2 Service Procedures of Bypass Module 162
11.3 Key Components and Service Life of UPS 163
11.3.1 Life Parameters and the Proposed Replacement Time of Key Components 163
11.3.2 Replacement of Air Filter 164
11.4 Maintenance of UPS and Options 165
12 Specifications 167
12.1 Conformance and Standards 167
12.2 Environmental Characteristics 167
12.3 Mechanical Characteristics 168
12.4 Electrical Characteristics (Input Rectifier) 168
12.5 Electrical Characteristics (Intermediate DC Circuit) 169
12.6 Electrical Characteristics (Inverter Output) 169
12.7 Electrical Characteristics (Bypass Input) 170
12.8 Efficiency and Loss 171
Appendices 173
Appendix A: Technical Support and Contacts 173
Appendix B: Glossary 174
Appendix C: Hazardous Substances and Content 175
Appendix D: Declaration of Materials and Components 176
Appendix E: Disposal after End of Product (Applicable for India) 177
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Vertiv™ Liebert® EXM2 UPS User Manual

1 Important Safety Instructions
Personnel Safety
1. This product must be installed and commissioned by professional engineers of the manufacturer or its
authorized agent. Failure to observe could result in product malfunction or personal safety risk.
2. Take the time to read this product manual and the safety precaution thoroughly before installing and
commissioning this product. Failure to observe could result in product malfunction or personnel safety risk.
3. This product is not intended for life support equipment application.
4. Never dispose of the internal or external battery of this product in fire, as it may explode and jeopardize
personnel safety when exposed to flame.
Product Safety
1. If this product will be stored or remain de-energized for a long period, it must be placed in a dry and clean
environment within specified temperature range.
2. This product should be used in an appropriate operating environment. For details, refer to the section on the
environmental requirement in this manual.
3. This product is not designed for application in an environment:
•Where the temperature and relative humidity are outside the specifications
•Subjected to vibrations or shocks
•Where conductive dusts, corrosive gases, salts, or flammable gases are present
•Near heat sources or strong electromagnetic interferences.
Disclaimer
Vertiv disclaims any and all responsibility or liability for the defects or malfunction caused by:
•Application range or operating environment outside the specifications.
•Unauthorized modification, improper installation or operation.
•Force majeure.
•Other actions not in compliance with the instructions in this manual.
Safety Precaution
This manual contains information concerning the installation and operation of the Vertiv™ Liebert® EXM2 100kVA to 250kVA
UPS.
Read this manual thoroughly before installing, using and servicing the UPS.
IMPORTANT! The UPS with standard configuration is a category C3 product for commercial and industrial application
in the second environment. Installation restrictions or additional measures may be needed to prevent disturbances.
IMPORTANT! The UPS adding C2 EMC option based on the standard configuration is a category C2 product for a
residential environment or commercial and industrial application in the second environment.
Conformity and standards
This product conforms to the following European directives and UK Regulations:
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Vertiv™ Liebert® EXM2 UPS User Manual

2014/35/EU
Directive of the council for adapting the legal regulations of member states on electrical equipment for use within specific
voltage limits.
Electrical Equipment (Safety) Regulations: 2016
Regulations implemented according to EU Directive (2014/35/EU) on electrical equipment designed for use within specific
voltage limits approved on the GB market.
2014/30/EU
Directive of the council for adapting the legal regulations of member states on electromagnetic compatibility.
Electromagnetic Compatibility Regulations: 2016
Regulations concerning the aspects on electromagnetic compatibility approved on the GB market.
Conformity is established through compliance with the following standards:
•IEC/EN/BS 62040-1:2008+A1:2013
•IEC/EN/BS 62040-2:2018
Additional information regarding adherence to these directives and regulations is included in the appendices NSR and EMC
to the Declarations of Conformity. If needed, the Declarations of Conformity can be requested to Vertiv.
2011/65/EU
Directive of the council for adapting the legal regulations of member states on the restriction of the use of certain hazardous
substances that can be used in the manufacture of electrical and electronic equipment.
The Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment Regulations 2012.
The restriction of the use of certain hazardous substances that can be used in the manufacture of electrical and electronic
equipment approved on the GB market.
WARNING! High earth leakage current: Earth connection is critical before connecting the input supply
(including both mains supply and battery).
This equipment is installed with an EMC filter.
Earth leakage current is less than 3000 mA.
Transient and steady state earth leakage currents, which may occur when the equipment is started, should be
taken into account in the selection of instantaneous RCCBs or RCD devices.
RCCB which is sensitive to unidirectional DC pulse (class A) and insensitive to transient state current pulse
must be selected.
Note also that the earth leakage currents of the load will be carried by the RCCBs or RCDs.
The equipment must be earthed in accordance with the local electrical code of practice.
WARNING! The selection of the upstream distribution protection equipment of the UPS shall be selected in
accordance with the details and shall comply with the local electrical regulations.
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WARNING! Backfeeding protection.
This UPS is fitted with a dry contact closure signal for use with an external automatic disconnect device
(supplied by others) to protect against backfeeding voltage into the incoming terminal through the rectifier or
bypass static switch circuit. A label must be added at all external incoming primary supply disconnect device
to warn service personnel that the circuit is connected to a UPS. The text of the label has the following
meaning: Risk of voltage backfeed! Isolate the UPS, then check for hazardous voltage between all terminals
including the protective earth before working on this circuit.
User serviceable components (For service personnel)
All equipment maintenance and servicing procedures involving internal access requires the use of a tool and should be
carried out only by trained personnel. There are no user-serviceable parts behind covers requiring a tool/key for removal.
Battery voltage exceeds 400 VDC (For service personnel)
All physical battery maintenance and servicing procedures requires the use of a tool/key and should be carried out only by
trained personnel.
Take special care when working with the batteries associated with this UPS. When connected, the battery terminal voltage will
exceed 400 VDC and is potentially lethal.
Battery manufacturers supply details of the necessary precautions to be observed in working on, or in the vicinity of, a large
bank of battery cells. These precautions should always be followed implicitly. Particular attention should be paid to the
recommendations concerning local environmental conditions and the provision of protective clothing, first aid and fire-
fighting facilities.
General safety (For users)
Like other types of large power equipment, the UPS and battery circuit breaker box/battery cabinet have high voltage inside.
Because the components with high voltage can be accessed only when the front door is opened, the risk of contacting high
voltage has been minimized. This equipment meets the IP20 standard, and other safety shields are provided inside the
equipment.
There will not be any risk when operating this equipment according to the general instructions and the steps recommended
in this manual.
Multiple power inputs (For users)
This UPS system receives power from more than one source. Disconnection of all AC source and the DC source is required
before servicing.
This UPS has several circuits that are energized with high AC as well as DC voltages. Check for voltage with both AC and DC
voltmeters before working within the UPS.
WARNING! When the internal fuse of the UPS is damaged, it must be replaced with fuse of the same electric
parameters by qualified personnel.
IMPORTANT! Beside the communication board is a static sensitive area, an ESD-proof action is critical before
contacting with this area.
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Vertiv™ Liebert® EXM2 UPS User Manual

WARNING! The user must select an appropriate MCCB to protect against short circuit and overload for the
battery. It is recommended to adopt Vertiv BCB to provide a better solution.
NOTE: The UPS meets the standard requirement of short time with stand current of 10 kA when external upstream
distribution is equipped with adequate capacity of fuses/circuit breaker for fault clearance. The specified upstream
fuses are required to obtain the conditional short circuit current rating, Icc at 65 kA symmetrical rms. It is
recommended to select the fuses in compliance with voltage of 690 V, current of 800 A and breaking of 200 kA. The
specified upstream breakers should comply with an IEC 60269 series standard.
NOTE: Bypass SCR is only protected against short circuit when adequate capacity of fuses/circuit breaker are present
in the upstream distribution.
The Manual Describes the Following Equipment
Product Model
100kVA EXM 0100kTG16FN02000
120kVA EXM 0120kTG16FN02000
150kVA EXM 0150kTG16FN02000
160kVA EXM 0160kTG16FN02000
200kVA EXM 0200kTG16FN02000
250kVA EXM 0250kTG16FN02000
Revision Information
V1.0 (November 11, 2020)
Initial release.
V1.1 (October 20, 2022)
Updated the manual for GHMI images in Chapter 5 Operator Control and Display Panel. Added 28-block battery in Table 7.4
on page124 . Added LBS Adapter on page157 . Updated Table 12.1 on page167 , Table 12.2 on page167 , Table 12.3 on
page168 , Table 12.5 on page169 , Table 12.6 on page169 , Table 12.7 on page170 , and Table 12.8 on page171 .
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Vertiv™ Liebert® EXM2 UPS User Manual

2 Overview
This chapter briefly introduces the features, design concept, parallel system, operation mode, battery management, and
battery protection of the Vertiv™ Liebert® EXM2 UPS 100kVA to 250kVA (UPS for short).
2.1 Features
The UPS is connected between a critical load (e.g. a computer) and mains power to provide high quality power for the loads.
The UPS has the following advantages:
Augment power quality
The UPS protects its output against the input power change through the intelligent controller.
Provide mains failure protection
If the input power fails, the UPS will work in battery mode, and the power supply to the loads will not be interrupted.
2.2 Design Concept
2.2.1 System Design
This section introduces the working principle of the UPS single module. The UPS adopts AC-DC-AC converter (as shown in
Figure 2.1 on the next page ). The first stage conversion (AC-DC) adopts three-phase high frequency rectifier to convert the
three-phase input voltage into stable DC bus voltage.
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Figure 2.1 Block Diagram for Working Principle of UPS Single Module
Item Description Item Description
1 Input 9 Rectifier input switch
2 Output 10 Rectifier
3 Bypass input 11 Inverter
4 Maintenance bypass switch 12 Inverter switch
5 Maintenance bypass 13 Output
6 Static switch 14 UPS Battery
7 Bypass input switch 15 Battery charger
8 Mains input 16 Output switch
The UPS has its own battery charger and adopts advanced temperature compensation technology to effectively prolong the
battery service life. The inverter adopts three level T-type IGBT topology and uses advanced SVPWM control technology to
derive the stable AC voltage from the DC bus voltage. When the mains is normal, the rectifier and inverter work together to
supply the loads and charge the battery.
When the mains is abnormal, the rectifier stops working, and the battery supplies power to the loads through the inverter. If
the battery voltage falls to End of discharge (EOD) voltage and the mains still has not been recovered, the UPS will shut down
(if the system uses split bypass configuration and the bypass is normal, the system will transfer to bypass). The battery EOD
voltage is preset.
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When the mains is abnormal, the rectifier stops working, and the battery supplies power to the loads through the inverter. If
the battery voltage falls to End of discharge (EOD) voltage and the mains still has not been recovered, the UPS will shut down
(if the system uses split bypass configuration and the bypass is normal, the system will transfer to bypass). The battery EOD
voltage is preset. When the mains is abnormal, the battery maintains the UPS operation till the battery voltage is reduced to
EOD voltage and the UPS shuts down, this time is called 'Backup Time'. The length of backup time depends on the battery
capacity and the loads.
2.2.2 Bypass
Through the intelligent control of the 'Static Switch' module (as shown in Figure 2.1 on the previous page ) containing the
controllable electronic switch, the loads can be supplied by the inverter or the bypass. In normal situation, the loads are
supplied by the inverter, in this case the automatic inverter switch at inverter side is closed. In the case of overload (the
overload delay time expires) or inverter failure, the automatic inverter switch is opened, and the 'Static Switch' module will
automatically transfer the loads to the bypass.
In normal operating state, to realize the uninterrupted transfer between inverter and bypass, the inverter output must be
synchronized with the bypass.
Therefore, when the bypass frequency is within the synchronization range, the inverter control circuit will synchronize the
inverter output frequency with the bypass frequency and phase.
Besides, the UPS has a manual maintenance bypass switch for shutdown of the UPS upon maintenance. In this situation, the
bypass will directly supply the critical loads through the maintenance bypass.
NOTE: When the load is supplied by the bypass or maintenance bypass, the power supply quality will be uncertain.
2.2.3 System Control Principle
Normal operation
Normal mode: It means that the UPS has normal input mains, the rectifier and inverter operate normally, the load is supplied
by the inverter, the battery circuit breaker is closed, and the battery is in stable floating charge state.
Parallel System As the UPS single module outputs are connected in parallel, the system checks that the inverter control
circuits are perfectly synchronized with one another and with the bypass in terms of both frequency and phase, and that they
have the same output voltages. Current supplied to the load is automatically divided among UPSs. A warning message
appears while synchronization is in progress.
Mains abnormal
When the mains fails or is abnormal, the rectifier will stop working automatically, and the load will be catered by the battery
output (through inverter). The length of the operation time in battery mode depends on the load and the battery capacity.
During this period, if the battery voltage falls to the EOD voltage and the mains still has not been recovered, the inverter will
stop working automatically, and the UPS operator control and display panel will display corresponding alarm messages. If the
system uses split bypass configuration and the bypass is normal, the system will transfer to bypass.
Mains recovery
When the mains resumes normal within allowable time, the rectifier will start automatically and supply the load and charge the
battery again. Therefore, the power supply to the load will not be interrupted.
Battery disconnection
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Vertiv™ Liebert® EXM2 UPS User Manual

To disconnect the external battery from the UPS system for maintenance, use the external isolating switch. At this time,
except for the battery backup function upon mains failure, other functions and all the steady state performance of the UPS
will not be affected.
UPS module failure
In case of inverter failure and output fuse blowout, the load will automatically transfer to the bypass, and the output power
supply will not be interrupted. In this situation, please contact the local customer service center of Vertiv for technical support.
Parallel System In the event of a fault in a UPS module, it will automatically exit from the parallel system. If the system is still
capable of providing the required load, the remaining modules will continue to supply the load with no interruption. If the
remaining modules are no longer capable of fulfilling the power requirements, the load will automatically transfer to the
bypass.
Overload
If the inverter is overloaded or the inverter current remains outside the specifications (refer to Table 12.6 on page169 ) longer
than the specified time, the load will automatically transfer to the bypass without power interruption. If both the overload and
the current are reduced to a level within the specified range, then the load will be transferred back to the inverter. In case of
output short circuit, the load will be transferred to the bypass, and the inverter will shut down. Five minutes later, the inverter
will start up automatically. If the short circuit is removed at this point, the load will be transferred back to the inverter. The
transfer is determined first of all by the features of the protective device of the system.
In the above two situations, the UPS operator control and display panel will display alarm messages.
Parallel SystemThe control logic system constantly monitors load requirements and controls the power supplied by each
UPS module. In the event that an overload condition is sustained for greater than a preset time, the load will transfer to the
bypass, when the number of active modules is unable to satisfy load requirements. The load returns to the inverter if the
power is reduced to a value that can be sustained by the number of active modules in the system.
Maintenance bypass
The UPS has a second bypass circuit, i.e. maintenance bypass, which provides a safe working environment for the engineers
to provide regular maintenance or repair to the UPS system and at the same time provide unregulated mains supply to the
loads. The maintenance bypass can be manually selected through the maintenance bypass switch, and it can be
disconnected by turning the switch to OFF.
WARNING! If the UPS system is composed of two or more UPS modules and when the load capacity exceeds
the single module capacity, do not use the internal maintenance bypass switch.
2.2.4 UPS Power Supply Switch Configuration
The UPS has four switches: rectifier input switch Q1, bypass input switch Q2, maintenance bypass switch Q3, and output
switch Q5.
Figure 2.2 on the facing page describes the block diagram of the UPS module. The UPS has split bypass configuration (i.e.,
the bypass adopts independent mains input) and common input configuration. If the system adopts common input
configuration, the UPS has shorting copper bar of common input configuration, and the bypass input switch (Q2), and rectifier
input switch (Q1) would be linked together. If the system adopts split bypass configuration, just remove the shorting copper
bar of common input configuration of the UPS.
During the normal operation of the UPS, except for the maintenance bypass switch Q3, other switches shall be closed.
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Figure 2.2 UPS Power Supply Switch Configuration
Item Description Item Description
1 Bypass input 10 DC bus
2 UPS 11 Inverter
3 Maintenance bypass switch Q3 12 Inverter switch
4 Static switch 13 Output switch Q5
5 Shorting copper bar of common input configuration 14 Charger
6 Bypass input switch Q2 15 UPS output
7 Mains input 16 Neutral line input
8 Rectifier input switch Q1 17 Battery
9 Rectifier 18 BCB
NOTE: Q1, Q2, and Q5 are optional while Q3 is standard.
NOTE: The mains input and bypass input share the same neutral line.
2.2.5 Battery Circuit Breaker (BCB)
The external battery shall be connected to the UPS through the BCB. The BCB box is optional, which shall be installed near
the battery. The BCB is closed manually. The BCB has a shunt tripping coil. When the system is faulty and the BCB needs to be
disconnected, the UPS control circuit will send a signal to the shunt tripping coil so as to trip the BCB. It also has a magnetic
trip facility for overload protection and short circuit protection.
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2.3 Parallel System
Up to six UPS modules can be parallel-connected to form a parallel system to increase the system capacity and reliability. The
load is equally shared between the paralleled UPS modules.
Moreover, two UPS modules or parallel system can comprise a dual bus system. Each parallel system has independent output.
Output synchronization is achieved through the LBS cable or LBS device, thus enabling seamless load transfer between the
two parallel systems or single modules through the STS device.
2.3.1 Parallel System Features
1. The hardware and software of parallel system are completely the same as those of the single module. The
parallel system configuration is achieved through settings in configuration software.
2. Parallel cables are connected in a ring, providing both system reliability and redundancy.
3. The total load of the parallel system can be queried from each UPS module's TOUCHSCREEN.
2.3.2 Parallel System Requirements
A group of paralleled modules behave as if it were one large UPS with the advantage of presenting higher reliability. To ensure
that all modules are equally utilized and to comply with relevant wiring rules, the following requirements apply:
1. All UPS modules must be the same series, and connect to the same bypass source.
2. The N line of bypass and rectifier input sources must be connected to the same neutral line terminal.
3. Any RCD, if installed, must be of an appropriate setting and located upstream of the common neutral line input
terminal. Alternatively, the device must monitor the protective earth current of the system.
WARNING! High earth leakage current: Earth connection is critical before connecting the input supply
(including both mains supply and battery).
2.4 Operation Modes
The UPS has the following operation modes:
•Normal mode.
•Battery mode.
•Automatic restart mode.
•Bypass mode.
•Maintenance mode.
•ECO mode.
•Parallel redundancy mode (system expansion).
•Frequency converter mode.
•LBS mode.
•Dynamic online mode.
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Normal mode
As shown in Figure 2.3 below , the UPS inverter continuously supplies the critical AC load. The rectifier draws power from the
commercial AC source and converts it into DC power for the inverter and the battery charger. The battery charger maintains
the battery in a fully charged and optimum operational condition. The inverter converts the DC power into clean and
regulated AC power which is supplied to the critical load (conditioned line).
Figure 2.3 Schematic Diagram of Normal Mode
Item Description Item Description
1 Mains input 6 UPS output
2 Rectifier 7 Rectifier input switch
3 Inverter 8 Battery
4 Inverter switch 9 Battery charger
5 Output switch
Battery mode
As shown in Figure 2.4 on the next page , the operation mode in which the battery provides backup power supply to the
loads through the rectifier and inverter is called battery mode. Upon mains failure, the system will automatically transfer to the
battery mode with no load power interruption. When the mains is recovered, the system will automatically transfer back to the
normal mode without any manual intervention, and the power to the load will not be interrupted.
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Vertiv™ Liebert® EXM2 UPS User Manual

Figure 2.4 Schematic Diagram of Battery Mode
Item Description Item Description
1 Rectifier 4 Output switch
2 Inverter 5 UPS output
3 Inverter switch 6 Battery
NOTE: Battery cold start function is available for switching the UPS on from Battery (charged) mode directly during
mains failure. Therefore, the battery power supply can be used independently to improve the availability of the UPS.
Automatic restart mode
The UPS has automatic restart function. When the inverter shuts down because of the mains failure and battery discharges to
EOD voltage, if the mains is recovered, the UPS will restart automatically after a certain time of delay. This function restart
delay time can be set by the service engineer authorized by Vertiv.
During the process of automatic restart time of delay, the UPS will charge the battery to protect against the power-off risk to
the load device caused by mains power failure.
If the automatic restart function has not been set, the user can manually start the UPS through Reset Fault function.
Bypass mode
As shown in Figure 2.5 on the facing page , in normal mode, in case of an inverter failure, an inverter overload or an inverter
manual shutdown, the static switch will transfer the load from the inverter side to bypass side, with no interruption in
supplying the power to the load. At this time, if the inverter and bypass are not synchronized, power supply to the load has
transitory interruption, with time of less than 20ms.
12 Proprietary and Confidential ©2023 Vertiv Group Corp. 2 Overview
Vertiv™ Liebert® EXM2 UPS User Manual