Vertiv Liebert PEX3 DX Series User manual

Liebert® PEX3TM DX Series
User Manual
Precision Air Conditioning

Copyright by Vertiv Co. Ltd.
The content in this document is subject to change without notice. All rights, including rights of translation,
reproduced by printing, copying or similar methods, and even of parts, are reserved. Violators will be liable for
damages. All rights, including rights deriving from patent license or registration of a utility model or design,
are reserved. No part of this document may be reproduced or transmitted in any form or by any means
without the prior written consent of Vertiv Co. Ltd.
Notice
The purchased products, services, and features are stipulated by the contract made between Vertiv Co.,
and the customer. All or part of the products, services, and features described in this document may not be
within the purchasing scope or the usage scope. Unless otherwise specied in the contract, all statements,
information, and recommendations in this document are provided “AS IS” without warranties, guarantees or
representations of any kind, either express or implied. The information in this document is subject to change
without notice. Every eort has been made in the preparation of this document to ensure the accuracy of
the contents, but all statements, information, and recommendations in this document do not constitute a
warranty of any kind, express or implied.
Vertiv Co., Ltd.
China
Homepage: www.vertiv.com
E-mail: [e-mail]
Customer service hotline: [phone]
Asia Pacic
Homepage: www.vertiv.com.
E-mail: [e-mail]
Australia
Customer service hotline: [phone]
New-Zealand
Customer service hotline: [phone]
For Technical Support, users may contact the nearest Vertiv Co. local sales oice or service centre.

Purpose of the Document
This document applies to the series of precision air conditioners and cooling solutions which maintain optimal
environmental control of technological ecosystems at minimal operating costs. This document gives an
overview of the specications, installation, commissioning, and maintenance procedures with troubleshooting
from the user perspective. The gures used in this document are for reference only.
Please read this manual carefully before installing, maintaining, and troubleshooting.
Liebert PEX3 DX series precision CRAC is a professional device, only professionals are permitted to access the
unit and is kept in a place where access is restricted to common people.
Styling used in this Guide
The styles used in the manual will be dened as mentioned in the following table:
Situation Description
Warning/Danger/Caution • The Warning/Danger/Caution note indicates a hazardous or potentially
harmful situation that can result in death or injury. It also indicates
instructions that need to be adhered to, failing which may result in
danger and safety issues thereby having an adverse eect on the
reliability of the device and security. Even for practices not related to
physical injury, to avoid equipment damage, performance degradation,
or interruption in service, follow the warning instruction.
Note
• The Note section indicates additional and useful information. It also calls
attention to best practices and industry-best protocols that are
standardized and help make maximum utilization of the resources at
hand. Helpful information related to the product also comes under the
Note heading, helping the users with the denitions, concepts, and
terminologies used in the manual.
Version History
Version Revision Date Issue Changes
1.0 25.08.2019 ---

Safety Precautions and Measures
The important safety precautions and measures that should be followed during the installation and
maintenance are described in the following sections.
Read the manual prior to installation and operation of the unit. Only qualied personnel should move, install,
or service this equipment.
Before working on the equipment, the user reads and considers all precautions, compliance and safety
measures. The unit control must be used exclusively for the purpose which it is intended for; the
manufacturer takes no liability for incorrect use or a modication to the unit control.
Adhere to all the Warnings and Cautionary measures included in the manual.
Please read this manual carefully before installing, maintaining and troubleshooting; especially the
Warning/Danger/Caution information in the User Guide. Apart from the User Guide, also pay attention
to the warning labels on the unit and its components.
This manual is retained for the entire service life of the unit. The user must read all the precautions, danger,
warnings, and cautionary measures mentioned in the manual prior to carrying out any operations on the unit.
Each unit is equipped with an electric insulation which allows the users to work in safe conditions. The main
switch is positioned on the electrical panel cover; to access it, open the right door. Before any maintenance
operation, switch o the unit with this electrical insulation device to eliminate risks such as electrical shocks,
burns, automatic restarting, moving parts, and remote control. The panel key, supplied along with the unit,
must be kept by the personnel responsible for the maintenance. The protective covers can be removed after
the electric power has been cut o by opening the main switch.
In the following sections, notice the various cautionary measures and warnings that need to be read carefully
prior to installing or operating the system.
Disconnect the local and remote power supplies prior to working with the unit.
Prior to the installation process, read all the instructions, verify if all the parts are in place, and check the
nameplate to ensure the voltage matches the available utility power for the unit.
The controller doesn’t isolate power from the unit even in the O mode, and some internal components still
require and receive power during the O mode.
If the unit door is open while the fans are operating, the airow may result in abrupt slamming of the door
resulting in injury. Another aspect is the presence of small objects in the fans bay that can result in object
ejection during the fan start-up and there is a probable risk of being hit by these objects resulting in grievous
injury and causing equipment damage.
The unit contains uids and gases under high pressure. Therefore, the pressure should be relieved before
working with the piping.

Various components such as compressors, refrigerant discharge lines, and humidiers are extremely hot during
the unit operation. Therefore, allow suicient time for the unit to cool down before working with the unit cabinet.
Handle the unit with extreme caution and wear safety equipment such as protective gloves, safety shoes, and
arm protection while working with the hot compressors, discharge lines, and reheats.
There is a risk of water leaking that can damage both the equipment and the building. Eective water drain
connection and facilities should be available. Installation should be precise. Implementation of the application
and service practices should be appropriate and fault-free. Failure to comply with these norms will result in
water leakage from the unit. Water leakage can lead to massive damage and loss of critical equipment in the
hosting ecosystem. Therefore, care should be taken to ensure that the unit is not located directly above any
equipment that could sustain damage due to water and excessive moisture. Use of a leak detection system for
the unit and system supply lines are recommended by Vertiv Co.

Vertiv | Liebert® PEX3™ Series Precision Air Conditioner | User Manual i
Table of Contents
Table of Contents
Chapter 1: Product Overview................................................................................................................................................................................1
1.1. Product Introduction................................................................................................................................................................................................1
1.2. Model Description....................................................................................................................................................................................................2
1.3. Model Nomenclature..............................................................................................................................................................................................3
1.4. Components of PEX3 Model..........................................................................................................................................................................4
1.4.1. Indoor Unit Parts........................................................................................................................................................................................... 5
1.4.2. 9-Inch Color Display..................................................................................................................................................................................7
1.4.3. Condenser..........................................................................................................................................................................................................8
1.4.4. Remote Monitoring Software..........................................................................................................................................................8
1.5. Optional Components...........................................................................................................................................................................................8
1.5.1. Electrode Humidier .................................................................................................................................................................................8
1.5.2. 2-stage Electrical Heating..................................................................................................................................................................8
1.5.3. Dual Power Supply- ATS...................................................................................................................................................................... 8
1.5.4. Dual Power Supply- Parallel..............................................................................................................................................................8
1.5.5. Plenum Conguration.............................................................................................................................................................................9
1.5.6. Dual Power (Interlocked Contactors)......................................................................................................................................9
1.5.7. Large & Small Display..............................................................................................................................................................................9
1.5.8. IS-UNITY-DP Card Assembly..........................................................................................................................................................9
1.5.9. Smoke Detectors.......................................................................................................................................................................................10
1.5.10. Fire Detectors.............................................................................................................................................................................................10
1.5.11. Supply Air Pressure Sensor............................................................................................................................................................10
1.5.12. Supply Air Temperature Sensor ...............................................................................................................................................10
1.6. Refrigerant Requirement.................................................................................................................................................................................10
1.6.1. Charging Refrigerant................................................................................................................................................................................11
1.7. Storage & Operating Environment Requirements...................................................................................................................12

Vertiv | Liebert® PEX3™ Series Precision Air Conditioner | User Manual ii
Table of Contents
Chapter 2: Installation................................................................................................................................................................................................13
2.1. Pre-installation ...........................................................................................................................................................................................................13
2.1.1. Transportation & Movement............................................................................................................................................................13
2.1.2. Unpacking ........................................................................................................................................................................................................14
2.1.3. Inspection..........................................................................................................................................................................................................16
2.2. Installation Preparation (Site Preparation)...................................................................................................................................16
2.2.1. Equipment Room Requirements................................................................................................................................................16
2.2.2. Installation Space Requirements.............................................................................................................................................. 17
2.2.3. Maintenance Space Requirement ...........................................................................................................................................18
2.2.4. Installation Tools......................................................................................................................................................................................20
2.2.5. System Arrangement during Installation..........................................................................................................................21
2.2.6. System Installation Mode................................................................................................................................................................24
2.3. Mechanical Installation ....................................................................................................................................................................................27
2.3.1. Indoor Unit Size and Weight (Product Dimension)................................................................................................. 27
2.3.2. Plenum Dimensions (for Upow Unit)................................................................................................................................29
2.3.3. Dimension and Weight of Condenser..................................................................................................................................29
2.3.4. Base Plate Cut-out Position and Dimension ................................................................................................................29
2.3.5. Position and Dimension of Air Outlet on Top Cover.............................................................................................35
2.3.6. Indoor Installation ...................................................................................................................................................................................36
2.3.7. Installing Floor Stand............................................................................................................................................................................38
2.3.8. Installation of Indoor Unit................................................................................................................................................................38
2.3.9. Pipe Installation Unit (Air-cooled Units)...........................................................................................................................39
2.3.10. Infrared Humidication Inlet Pipe Connection........................................................................................................40
2.3.11. Connection of Copper Pipe (Discharge and Liquid pipe) between
Indoor and Outdoor Unit .................................................................................................................................................................41
2.3.12. Height Dierence Requirements and Equivalent Length Calculation..............................................43
2.3.13. Pipe Installation Unit (Water-cooled unit)....................................................................................................................44

Vertiv | Liebert® PEX3™ Series Precision Air Conditioner | User Manual iii
Table of Contents
2.3.14. Connection between Water inlet and Outlet Pipe of Cooling Water..................................................44
2.3.15. Lowering the Fan...................................................................................................................................................................................46
2.3.16. Removing Transportation Fixing Plate of the Compressor..........................................................................49
2.3.17. Removing of Fasteners of Infrared Humidier..........................................................................................................49
2.3.18. Removing Pipe Fasteners.............................................................................................................................................................50
2.3.19. Installation Inspection.......................................................................................................................................................................50
2.4. Electrical Installation...........................................................................................................................................................................................51
2.4.1. Installation Precautions.......................................................................................................................................................................51
2.4.2. Wiring of Indoor Unit............................................................................................................................................................................51
2.4.3. Connecting Control Cables...........................................................................................................................................................55
2.4.4. Connecting Water-Under-Floor Sensor............................................................................................................................56
2.4.5. Remote Shutdown Control Line Connection...............................................................................................................56
2.4.6. Customized Alarm Terminal.........................................................................................................................................................56
2.4.7. External General Alarm......................................................................................................................................................................56
2.4.8. Condenser Wiring................................................................................................................................................................................... 57
2.4.9. Check the Installation.........................................................................................................................................................................58
Chapter 3: Touchscreen Operation...........................................................................................................................................................59
3.1. Touchscreen Display and User Interface....................................................................................................................................... 59
3.2. Touchscreen Status Dial ................................................................................................................................................................................ 61
3.2.1. Dial Background-Color Status Indication..........................................................................................................................61
3.3. Control Header........................................................................................................................................................................................................ 63
3.3.1. Powering-On iCOM and Logging-in/ Unlocking Controls................................................................................63
3.3.2. Powering-on the Thermal Management Unit .............................................................................................................63
3.3.3. Powering-O the Thermal Management Unit.............................................................................................................65
3.3.4. Logging Out..................................................................................................................................................................................................65
3.3.5. Setting the Date and Time.............................................................................................................................................................66

Vertiv | Liebert® PEX3™ Series Precision Air Conditioner | User Manual iv
Table of Contents
3.3.6. Searching.........................................................................................................................................................................................................66
3.3.7. Using Context-Sensitive Help .....................................................................................................................................................67
3.3.8. About iCOM Version.............................................................................................................................................................................67
3.3.9. Accessing the User and Service Functions...................................................................................................................67
3.3.10. User Menu....................................................................................................................................................................................................67
3.3.11. Service Menu..............................................................................................................................................................................................68
3.3.12. Advanced Menu......................................................................................................................................................................................69
3.4. User Operation........................................................................................................................................................................................................ 70
3.4.1. Editing Humidity Setpoints ............................................................................................................................................................70
3.4.2. Editing Temperature Setpoints.................................................................................................................................................70
3.4.3. Viewing Unit Alarms..............................................................................................................................................................................71
3.4.4. Silencing an Audible Alarm............................................................................................................................................................ 71
3.4.5. Acknowledging Alarms.......................................................................................................................................................................71
3.4.6. Viewing the Event Log....................................................................................................................................................................... 72
3.4.7. Viewing Sensor Data ............................................................................................................................................................................ 73
3.4.8. Managing Run Hours for a Component............................................................................................................................ 73
3.4.9. Setting Run Hours to Zero............................................................................................................................................................. 73
3.4.10. Viewing Teamwork, Stand-by, Cascade and Operating Status...............................................................74
Chapter 4: iCOM Controller Operation.................................................................................................................................................75
4.1. LCD Screen...................................................................................................................................................................................................................75
4.2. Button and Indicator Panel..........................................................................................................................................................................75
4.3. Structure Chart of Control Menu...........................................................................................................................................................77
4.4. Start-Up Interface.................................................................................................................................................................................................78
4.5. Main Interface...........................................................................................................................................................................................................78
4.6. User Menus.................................................................................................................................................................................................................79
4.7. Password.......................................................................................................................................................................................................................80

Vertiv | Liebert® PEX3™ Series Precision Air Conditioner | User Manual v
Table of Contents
4.8. Setpoints.......................................................................................................................................................................................................................80
4.9. Event Log...................................................................................................................................................................................................................... 81
4.10. Graphics....................................................................................................................................................................................................................... 81
4.11. Set Alarms...................................................................................................................................................................................................................82
4.12. Display Setup ......................................................................................................................................................................................................... 83
4.13. Total Run Hrs .........................................................................................................................................................................................................84
4.14. Sleep Mode .............................................................................................................................................................................................................. 86
4.15. Service Info...............................................................................................................................................................................................................86
4.16. Active Alarms......................................................................................................................................................................................................... 86
Chapter 5: Application of INTELLI SLOT ...........................................................................................................................................87
5.1. Introduction of Host Communication Card...................................................................................................................................87
5.2. Commissioning Host Communication Component............................................................................................................ 88
5.2.1. Assigning the Card’s IP Address ...............................................................................................................................................88
5.2.2. Connect an Ethernet Cable ..........................................................................................................................................................89
5.2.3. Connect a RS-485 Serial Cable................................................................................................................................................ 90
Chapter 6: System Operation and Maintenance........................................................................................................................91
6.1. Routine Maintenance Inspection Items (Monthly)................................................................................................................ 91
6.2. Routine Maintenance Inspection Items (Semi-Annual)................................................................................................. 92
6.3. Self-Diagnostic System .................................................................................................................................................................................. 93
6.4. Check the Electrical Connections and Maintenance ....................................................................................................... 93
6.5. Appearance Inspection and Maintenance of Controller Components............................................................94
6.6. Air-Cooled Condenser Maintenance Guide ............................................................................................................................... 95
6.7. Water-Cooled Condenser Maintenance Guide........................................................................................................................ 95
6.8. Filter Maintenance Guide.............................................................................................................................................................................96
6.9. Infrared Humidier Maintenance Guide..........................................................................................................................................97

Vertiv | Liebert® PEX3™ Series Precision Air Conditioner | User Manual vi
Table of Contents
6.10. Electric Heater Maintenance Guide .................................................................................................................................................97
Chapter 7: Diagnosis and Maintenance ...............................................................................................................................................99
7.1. Fault Diagnosis and Treatment of Fans ...........................................................................................................................................99
7.2. Fault Diagnosis and Treatment of Infrared Humidier..................................................................................................100
7.2.1. Infrared Humidier Troubleshooting ..................................................................................................................................100
7.2.2. High-Temp Switch................................................................................................................................................................................ 101
7.3. Compressor and Refrigeration System - Fault Diagnosis and Treatment...................................................101
7.4. Heating System - Fault Diagnosis and Treatment.............................................................................................................105
Appendix I: Wiring Diagram Infrared Humidier (for Air-cooled)..........................................................................106
Appendix II: Wiring Diagram Infrared Humidier (for Water-cooled) ................................................................107
Appendix III: Circuit Diagram Dual Power.........................................................................................................................................108
Appendix IV: Menu Structure of iCOM Controller (Users Menus).........................................................................109
Appendix V: Table Names and Content of Harmful
Substances in Products ........................................................................................................................................................................................110
Appendix VI: Routine Maintenance Inspection Items
(Monthly)...............................................................................................................................................................................................................................111
Appendix VII: Routine Maintenance Inspection Items
(Semi-Annual)...................................................................................................................................................................................................................112

Vertiv | Liebert® PEX3™ Series Precision Air Conditioner | User Manual 1
Product Overview
Chapter 1: Product Overview
1.1. Product Introduction
The ‘Liebert PEX3 series’ is the next generation series of air conditioners that provide precise environmental
control. The Liebert PEX3 models are the latest enterprise-grade products from the Liebert family.
Incorporating the high standards associated with the Liebert name, the PEX3 series utilizes the latest
technology, system components, and streamlined manufacturing process.
Liebert PEX3 air conditioner are specically created and designed for data centers, equipment room, computer
rooms, and similar ecosystems that require high control accuracy in terms of inside environment condition. It
caters to sensitive applications that require a suitable environment for optimal performance. Therefore, care
should be taken while testing these sensitive products or maintaining a favorable environment for mission
critical equipment, as even a slight deviation may lead to inaccurate results. Precision Air Conditioning must not
only keep room conditions within a specic range but also be able to react quickly to a drastic change in heat
load and prevent wide temperature uctuations.
The PEX3 unit comes with the features such as high reliability, high sensible heat ratio, and large airow. It is
an excellent system that adheres to the standards of Precision Air Cooling in terms of energy-eiciency, space
requirements, and reliability.
Air-cooled series
The Liebert PEX air-cooled series air conditioner comprises indoor and outdoor units with the standard
conguration of Liebert PEX condenser unit, it can reduce noise pollution to the minimum while meeting
system cooling requirements through the pressure regulating the fan speed.
Water-cooled series
The Liebert PEX water-cooled series air conditioner uses integrated structure and highly eective brazed-plate
heat exchanger (BPHE), thus it is a compact, eicient and quiet in the operating conditions (only P1030 unit).

Vertiv | Liebert® PEX3™ Series Precision Air Conditioner | User Manual 2
Product Overview
1.2. Model Description
This chapter introduces the model, appearance, components, optional conguration and refrigerant
requirements of Liebert PEX3. The ‘Liebert PEX3 Series Precision Air Conditioner’ (“PEX3” for short hereafter) is
a cooling equipment, a medium-large sized precision environment control system, adapted to the environment
control of the equipment room or computer room, featuring high reliability, high sensible heat ratio and large
airow. The appearance of Liebert PEX3 models are shown in Figure 1-1.
Upflow Model
Downflow Model
Figure 1-1 Liebert PEX3 Models

Vertiv | Liebert® PEX3™ Series Precision Air Conditioner | User Manual 3
Product Overview
1.3. Model Nomenclature
The Liebert PEX3 series model is fully-dened by 25 digits, as represented in Table 1-1.
Table 1-1 Liebert PEX3 Model Nomenclature
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
P 1 0 3 0 D A 1 0 6 H 9 1 2 E 1 D L 0 0 C E 0 3 2
Digit 1,2 Product Model Digit 17 Mains Switch High Voltage Option
P PEX3 0None
1-2 Number of Modules/ Bays D Main non-Locking Disconnect
Digit 3 Net Cooling Capacity kW PDual Power Supply Parallel
0-9 Nominal Net Cooling Capacity- kW A Dual Power Supply Interlocking Contactor
Digit 4 Net Cooling Capacity kW TDual Power Supply Auto Transfer Switch
0-9 Nominal Net Cooling Capacity- kW Digit 18 Installation Option
Digit 5 Net Cooling Capacity kW 0 None, Standard Pipe, No Low Ambient Kit
0-9 Nominal Net Cooling Capacity- kW H Re-heat & Humidity Lockout
Digit 6 Air Discharge L Air-cooled, Long pipe> 30 m
U Upflow Digit 19 Monitoring
D Downflow 0 None
Digit 7 System Type 7Unity Card
A Air Cooled 8Unity Card*2
W*Water Cooled Digit 20 Sensors
Digit 8 Airow 0 None
1 EC Plug Fan A Supply Air Pressure Sensor
Digit 9 Power Supply S Smoke Sensor
0 400 V/ 3 Ph/ 50 Hz+N H High Temperature
7380 / 3 Ph/ 60 Hz+N FSmoke & High Temp
C 208 V/ 3 Ph/ 60 Hz NSupply Air Temperature Sensor
D230 V/ 3 Ph/ 60 Hz 1A+S
A 460 V/ 3 Ph/ 60 Hz 2A+H
8400 V/ 3 Ph/ 50 Hz 3A+F
Digit 10 Cooling System 4N+S
4Compliant Scroll Dual Circuit, R410A 5 H+N
6 Compliant Scroll Single Circuit, R410A 6 A+N
Digit 11 Humidication 7H+N+S
0None 8 A+N+S
H Infrared Humidifier 9A+H+N
S Electrode Humidier BA+F+N
Digit 12 Display Digit 21 Packaging
9 9-inch HMI Display PPackage- Standard Cardboard and Wooden Pallet
S Small Display
C Packaging– Wooden Crate
L Large Display

Vertiv | Liebert® PEX3™ Series Precision Air Conditioner | User Manual 4
Product Overview
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
P 1 0 3 0 D A 1 0 6 H 9 1 2 E 1 D L 0 0 C E 0 3 2
Digit 13 Re-heating Digit 22 Special Requirements
0None A SFA- None
1 Electrical Heating Std. 1 Stage PFor Export with Condensate Pump
2Electrical heating Opt. 2 Stage E For Export
Digit 14 Filtration Digit 23 Order Identier
2 G4 0 Standard ESP
3F5 150 Pa ESP
Digit 15 Coil and Valves 2100 Pa ESP
E Standard DX Air Cooled Coil, EEV 3150 Pa ESP
6Water-cooled, 2-way valve 4 200 Pa ESP
Digit 16 Enclosure Option Digit 24 Order Identier
1Standard Color Black Orange Peel Grain
Coating
3 Factory Code
Digit 25 Order Identier
2 White orange peel grain coating 2 Factory Code
6 Color charcoal grey w/ double skin
The standard components are represented in ‘Bold Italic’ font in Table 1-1.
*DX Water-cooled version is applicable for 30 kW.
1.4. Components of PEX3 Model
An overview of the main components, optional components and features of the Liebert PEX3 is mentioned in
this section. Liebert PEX3 components include indoor unit, outdoor unit, and remote monitoring software.
Figure 1-2 shows main components of PEX3 model.

Vertiv | Liebert® PEX3™ Series Precision Air Conditioner | User Manual 5
Product Overview
No. Description
1Evaporator Coil
2Compressor
3 Electrical Panel
4 HMI Display
5Filter
6 Electronic Expansion Valve (EEV)
7EC Fan
Figure 1-2 Main Components of PEX3 Model
1.4.1. Indoor Unit Parts
The PEX3 Air-cooled indoor unit includes Compressor, Evaporator, Electronic Expansion Valve, Infrared
Humidier, EC Fan, Electrical Heating, Sight Glass, Filter Dryer and iCOM Controller. The description of the main
components is tabulated in the Table 1-2. In case of the water-cooled series indoor unit also includes BPHE and
MBV (2-way).

Vertiv | Liebert® PEX3™ Series Precision Air Conditioner | User Manual 6
Product Overview
Table 1-2 List of Indoor Unit Components
Component Description
Cabinet
The cabinet frame is constructed from 2.5mm, 2.0mm and 1.2mm folded galvanized steel. The
exterior panels are constructed from 1.2mm zinc coated sheet of steel and insulated with foam
insulation. The cabinet is powder coated in Charcoal Grey color and has a textured nish. The
hinged front doors can be removed, and includes captive 1/4 turn fasteners.
Compressor Equipped with compliant scroll compressor, it withstands high vibration, and features low noise and
high reliability.
Evaporator
• Uses parallel ow micro-channel evaporator with higher heat transfer eiciency. The material
used for evaporator is Aluminum.
• Detailed design and verication for internal distributor of the evaporator to ensure uniformity of
distribution of the refrigerant, the utilization of the evaporator is considerably improved.
Electronic
Expansion
Valve (EEV)
• The EEV is designed for precision modulating control of the refrigerant mass ow.
• The EEV simultaneously collects temperature and pressure signals to accurately regulate the
refrigerant ow. The EEV’s wide operating envelope also reduces the condensing pressure,
thereby resulting in signicant energy savings.
Infrared
Humidier
• Infrared humidier structure is simple, easy to disassemble, clean and maintain.
• The infrared humidier application reduces the dependence on water quality, it takes a very
short time to start up and reach the humidication requirement, it has the performances like high
humidifying capacity and high eiciency.
EC Fan
• Uses EC fans with PP plastic blade material that enable high eiciency, space-saving, low noise
characteristics.
• The structure of EC fan unit is carefully designed, downow unit adopts a “in-oor” design, this
design can lower the EC fan below the oor to supply air, to further improve the eiciency of air
supply.
Electrical
Heating
Electrical heating features faster heating rate, uniform heating, safety and reliability. The material
used for electrical heating is PTC ceramic heating element and aluminum pipe.
Sight Glass
The windows of the system loop observe the state of the refrigerant, detects the system’s moisture
content. The background color of sight glass changes once the moisture of the system exceeds
permissible limits.
Filter Dryer It can eectively remove moisture present in the system, while the system is operating for
long-term. To ensure the normal operation of the system removal of impurities is vital.
BPHE (Water
Cooled)
The brazed plate auto-cleansing BPHE is used, where plates are constructed by 316 stainless steel
and brazing material is copper. It features compact structure and high heat exchanging eiciency.
The maximum working pressure for BPHE is 46 bar. Rotalock connections are provided for water
and refrigerant sides.
MBV (Water
Cooled)
The 2-way motorized ball valve is used. The water ow in the BPHE can be regulated through the
intelligent valve position control of the control board, so as to ensure stable system operation, and
the maximum working pressure for MBV is 40 bar.

Vertiv | Liebert® PEX3™ Series Precision Air Conditioner | User Manual 7
Product Overview
Component Description
Long Pipe Kit
The long pipe kit can prevent the refrigerant from returning and concentrating after the compressor
is turned o, ensuring normal start of the compressor and making the system safer. The solenoid
valve is installed internally, and the check valve is supplied loose for installation on site.
iCOM
Controller and
HMI Display
• The standard features available in PEX3 unlike legacy PEX series are the highest capability for
unit control, communication, and monitoring of CRAC units.
• Oers the highest capability for unit control, communication, monitoring of CRAC units.
• Speeds setup and installation and simplies control of CRAC units, putting cooling-system
monitoring and management at customers ngertips.
• Uses a rm touch, or consider a stylus when interacting with the touchscreen.
• User and service menus are password-protected to prevent unauthorized changes to cooling
unit operation.
• The touchscreen is back-lit and auto-dims after a period of non-use, the turns o and touch the
screen to re-illuminate the main screen.
• iCOM ships with default settings for eicient and eective operation of most cooling-units and is
easily congured to meet any requirements.
• iCOM menus and displays are based on the options installed on the cooling units that it monitors
and manages.
• LCD screens with dark-gray backlight and 800x480 pixels.
• Display the real-time values of the CRAC’s status, active and history alarms.
• Self-recovery after power failure.
• It can store up to 400 history event records.
1.4.2. 9-Inch Color Display
PEX3 unit is available with 9-inch touch screen as a standard display, using multi-color 800×480 dot-matrix
liquid crystal touch screen with white backlight as shown in Figure 1-3. The operation of the unit becomes
simpler and more convenient, and the status view of the unit is more visualized.
Figure 1-3 iCOM Controller Display

Vertiv | Liebert® PEX3™ Series Precision Air Conditioner | User Manual 8
Product Overview
1.4.3. Condenser
Two types of condensers are available, for details, refer to “Liebert PEX Condenser User Manual” and “LVC
Series Condenser User Manual”.
1.4.4. Remote Monitoring Software
Liebert PEX3 units interface with the BMS system through Modbus/ SNMP/ BACnet communication protocol
by unity card, which enables Liebert PEX3 to communicate with the host computer and receive the control
instructions from the host software. By default one unity card is congured in the unit, but on the request two
unity cards can be congured.
1.5. Optional Components
1.5.1. Electrode Humidier
The electrode humidier uses the electrodes to boil the water in humidier bottle to produce steam for
humidication purpose. It has a specic (soft water) requirements in terms of water quality and sizes of inlet/
outlet pipes as compared to the standard infrared humidier.
1.5.2. 2-stage Electrical Heating
The 2-stage electrical heating can be selected based on the heating requirement. The electrical heating can
be divided into two stages by conguring the controller. The heater starts step-wise according to the heating
requirement. It not only maintains the room temperature but also reduces the energy consumption.
1.5.3. Dual Power Supply- ATS
The dual power ATS can automatically detect both the power sources (source 1 & source 2). In case of
break-down of the preferred power source, ATS is equipped to automatically switch to the source 2. It can also
provide an output signal associated with power alarm.
1.5.4. Dual Power Supply- Parallel
In dual power supply parallel, there are two sources of power- one is connected through UPS to the fan and
the control board. While, the components such as electrical heating and humidier are connected to other
power source which is directly coupled with the main supply. Hence, the fan and the control board can still be
operated when the main connection fails without aecting the room ventilation.

Vertiv | Liebert® PEX3™ Series Precision Air Conditioner | User Manual 9
Product Overview
1.5.5. Plenum Conguration
All plenums have grills at the outlet to streamline the air-ow movement across the room. The plenum grills
can be manually regulated by changing the direction of air-ow as per the site requirement. In the case of
customized design requirement of the Plenum, contact Vertiv local representative.
1.5.6. Dual Power (Interlocked Contactors)
It consists of dual power supply (interlocking contractor 3P). It uses an automatic power switching circuit
between the common power supply and backup power supply that is activated if an emergency power supply is
required.
1.5.7. Large & Small Display
According to the requirement, Large & Small display are optional, using 480x480 pixel for large display and
128x64 pixels for small display. Both displays have 9 buttons on front board and use the multi-level password
to prevent unauthorized operation. Congure the setpoints of CRAC unit, displays the real-time values of the
CRAC’s status, active and history alarms.
Large Display Small Display
Figure 1-4 Large & Small Display
1.5.8. IS-UNITY-DP Card Assembly
By default, each card supports the Vertiv Protocol, Remote Service Delivery Protocol and HTTP Web. Control
and conguration capabilities are protected by an administrator’s user-name and password combination.
Optionally, status information can be password-protected. The default user-name for the administrator is
‘Liebert’ and the default password is also ‘Liebert’.