Vertiv Liebert PEX+ Series User manual

Liebert® PEX+Chilled Water 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 specified 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 Pacific
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 specifications, installation, commissioning, and maintenance procedures with troubleshooting from the
user perspective. The figures used in this document are for reference only.
Please read this manual carefully before installing, maintaining, and troubleshooting.
Liebert PEX+ Chilled Water 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 defined 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 reliabil-
ity of the device and security. Even for practices not related to physical
injury, to avoid equipment damage, performance degradation, or inter-
ruption 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 definitions, concepts, and
terminologies used in the manual.
Version History
Version Revision Date Issue Changes
31013260 05.05.2020
---

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 qualified 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 modification 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 airflow 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 fluids and gases under high pressure. Therefore, the pressure should be relieved before
working with the piping.

Various components such as electrical heater, infrared humidifiers or electrode humidifier 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 PEX+ Chilled Water | 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 PEX+CW Model .................................................................................................................................................................4
1.4.1. Cabinet .....................................................................................................................................................................................................................5
1.4.2. EC Fans...................................................................................................................................................................................................................5
1.4.3. Infrared Humidifier.......................................................................................................................................................................................5
1.4.4. Electrical Heater............................................................................................................................................................................................6
1.4.5. Water Flow Regulating Valve.............................................................................................................................................................7
1.4.6. Safety Controlling Device......................................................................................................................................................................7
1.4.7. Cooling Coil..........................................................................................................................................................................................................7
1.4.8. Filter ...........................................................................................................................................................................................................................7
1.4.9. Water Leak Detecting System..........................................................................................................................................................8
1.4.10. iCOM Controller............................................................................................................................................................................................8
1.5. Optional Components............................................................................................................................................................................................9
1.6. Storage & Operating Environment Requirements.....................................................................................................................11
1.7. Noise Level Limits.....................................................................................................................................................................................................12
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

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Table of Contents
2.2.3. Maintenance Space Requirement ............................................................................................................................................ 18
2.2.4. Installation Tools........................................................................................................................................................................................ 19
2.2.5. System Arrangement during Installation..........................................................................................................................20
2.3. Mechanical Installation.......................................................................................................................................................................................21
2.3.1. Indoor Unit Size and Weight (Product Dimension) ....................................................................................................21
2.4. Position and Dimension of Air Outlet on Top Cover.............................................................................................................23
2.4.1. Base Pallet Cut-out Location Dimension............................................................................................................................24
2.4.2. Side Panel Knock-out Location...................................................................................................................................................25
2.4.3. Plenum Dimension (for Upflow)..................................................................................................................................................27
2.4.4. Indoor Installation.....................................................................................................................................................................................28
2.4.5. Installation of Indoor Unit...................................................................................................................................................................31
2.4.6. Pipe Installation Unit...............................................................................................................................................................................31
2.4.7. Condensed Drain Piping Connection of Indoor Unit................................................................................................31
2.4.8. Water Inlet Pipe Humidifier Connection.............................................................................................................................32
2.4.9. Chilled Water Inlet and Outlet Piping Connection ................................................................................................... 34
2.5. Lowering the Fan ....................................................................................................................................................................................................36
2.5.1. Removing Fastener and Vibration Absorber .................................................................................................................. 39
2.5.2. Removing of Fasteners of Infrared Humidifier............................................................................................................. 39
2.6. Installation Inspection....................................................................................................................................................................................... 40
Chapter 3: Electrical Installation.........................................................................................................................................................................41
3.1. Installation Notes.......................................................................................................................................................................................................41
3.2. Cabling of Indoor Unit .........................................................................................................................................................................................41
3.3. Electrical Installation Checklist .................................................................................................................................................................47
Chapter 4: iCOM Controller Operation.........................................................................................................................................................48
4.1. LCD Screen....................................................................................................................................................................................................................49
4.2. Button and Indicator Panel...........................................................................................................................................................................49
4.3. Start-Up Interface ..................................................................................................................................................................................................52

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Table of Contents
4.4. Main Interface............................................................................................................................................................................................................52
4.5. User Menus ..................................................................................................................................................................................................................53
4.5.1. Password............................................................................................................................................................................................................ 54
4.5.2. Setpoints .......................................................................................................................................................................................................... 54
4.5.3. Event Log..........................................................................................................................................................................................................55
4.5.4. Graphics.............................................................................................................................................................................................................55
4.5.5. Set Alarms....................................................................................................................................................................................................... 56
4.5.6. Sensor Data ................................................................................................................................................................................................... 58
4.5.7. Display Setup................................................................................................................................................................................................ 58
4.5.8. Total Run Hrs ...............................................................................................................................................................................................60
4.5.9. Sleep Mode...................................................................................................................................................................................................... 61
4.6. Service Info....................................................................................................................................................................................................................61
4.7. Active Alarms..............................................................................................................................................................................................................62
4.8. Event Name and Definition...........................................................................................................................................................................62
4.9. Multi-units and Teamwork Modes ........................................................................................................................................................65
4.10. Teamwork Modes.................................................................................................................................................................................................66
4.10.1. Application of Teamwork Modes.............................................................................................................................................66
4.10.2. Standby – Rotation ..............................................................................................................................................................................69
4.10.3. Standby and Cascade........................................................................................................................................................................ 70
Chapter 5: Application of INTELLI SLOT...................................................................................................................................................71
5.1. Introduction of Host Communication Card..................................................................................................................................... 71
5.2. Installing Host Communication Card...................................................................................................................................................72
5.2.1. Installing communication card......................................................................................................................................................72
5.2.2. Connection......................................................................................................................................................................................................72
5.2.3. Assigning the Card’s IP Address.................................................................................................................................................73
5.2.4. Connect an Ethernet Cable.............................................................................................................................................................75
5.2.5. Connect a RS-485 Serial Cable ...................................................................................................................................................75
5.3. Configure the Card................................................................................................................................................................................................76

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Table of Contents
5.3.1. Enable Protocols..........................................................................................................................................................................................78
5.3.2. Enable Modbus Protocol....................................................................................................................................................................79
5.3.3. Configure Modbus TCP.......................................................................................................................................................................79
5.3.4. Configure Modbus RTU ......................................................................................................................................................................79
5.3.5. Enable BACnet Protocol ....................................................................................................................................................................80
5.3.6. Configure BACnet IP Protocol........................................................................................................................................................81
5.3.7. Configure BACnet MSTP Setting...............................................................................................................................................83
5.3.8. Enable SNMP................................................................................................................................................................................................84
Chapter 6: System Start-up Commissioning..........................................................................................................................................85
6.1. Start-up Commissioning...................................................................................................................................................................................85
6.1.1. Preparation Before Commissioning.......................................................................................................................................... 85
6.2. Commissioning Procedures.........................................................................................................................................................................85
6.3. Inspection after Commissioning..............................................................................................................................................................86
Chapter 7: System Operation and Maintenance.................................................................................................................................87
7.1. Routine Maintenance Inspection Items (Monthly).................................................................................................................. 87
7.2. Routine Maintenance Inspection Items (Semi-Annual)....................................................................................................88
7.3. Self-Diagnostic System.....................................................................................................................................................................................88
7.4. Check the Electrical Connections and Maintenance...........................................................................................................88
7.5. Appearance Inspection and Maintenance of Controller Components ...............................................................89
7.6. Filter Maintenance Guide............................................................................................................................................................................... 90
7.7. Fan..........................................................................................................................................................................................................................................92
7.8. Infrared Humidifier Maintenance Guide............................................................................................................................................92
7.9. Electric Heater Maintenance Guide......................................................................................................................................................93
7.10. Water Flow Control Valve..............................................................................................................................................................................94
Chapter 8: Diagnosis and Troubleshooting.............................................................................................................................................95
8.1. Fault Diagnosis and Treatment of Fans..............................................................................................................................................95
8.2. Fault Diagnosis and Treatment of Infrared Humidifier.......................................................................................................96

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Table of Contents
8.2.1. Infrared Humidifier Troubleshooting......................................................................................................................................96
8.3. Refrigeration System - Fault Diagnosis and Treatment....................................................................................................96
8.4. Heating System - Fault Diagnosis and Treatment................................................................................................................. 97
Appendix I: Content of Harmful Substances in Products..........................................................................................................98

Vertiv | Liebert PEX+ Chilled Water | User Manual 1
Product Overview
Chapter 1: Product Overview
1.1. Product Introduction
The Liebert®PEX+Chilled Water units (hereafter Liebert PEX+CW ) are the next generation series of Precision
Air Conditioners (PAC) that provide precise environmental control. The Liebert PEX+ chilled water models
consist of wide range of cooling capacity from 30 kW to 200 kW for large, medium and small data centers.
Incorporating the high standards associated with the Liebert name, the PEX+CW series utilizes the latest
technology, system components, and streamlined manufacturing process.
Liebert PEX+CW air conditioners are products that are specifically designed for the special requirements of data
centers, computer rooms, and similar ecosystems wherein optimum cooling is required along with a high degree
of reliability and variability. It addresses the needs and challenges associated with such critical applications and
setups. It caters to sensitive applications which need 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 specific range but also be able to react quickly to a drastic change in heat
load and prevent wide temperature fluctuations.
The PEX+CW PAC unit comes with the features such as high reliability, high sensible heat ratio, and large airflow.
It is an excellent system that adheres to the standards of Precision Air Cooling in terms of energy-eiciency,
space requirements, and reliability.

Vertiv | Liebert PEX+ Chilled Water | User Manual 2
Product Overview
1.2. Model Description
This chapter introduces the model, appearance, components, optional configuration and refrigerant
requirements of Liebert®PEX+. The appearance of ‘Liebert PEX+ Chilled Water Series Precision Air Conditioner’
(“PEX+ CW” for short hereafter) is shown in Figure 1-1.
Figure 1-1 Liebert PEX+ Series Model

Vertiv | Liebert PEX+ Chilled Water | User Manual 3
Product Overview
1.3. Model Nomenclature
The Liebert®PEX+CW series model is fully-defined by 25 digits, as represented in Table 1-1.
Table 1-1 Liebert PEX+CW 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 2 0 9 0 D C 1 N 2 H S 1 2 L 1 D 0 0 0 C E 0 0 0
Digit 1 Product Model Digit 16 Enclosure Option
P PEX+ 1 Standard Color Black, Orange Peel Grain Coating (ZP7021)
Digit 2 Product Modulus 2 White Orange Peel Grain Coating (G101)
1-3 Number of Modules/ Bays 6 Color Charcoal Grey w/ Double Skin (ZP0420)
Digit 3 Net Cooling Capacity kW Digit 17 Mains Switch High Voltage Option
0-9 Nominal Net Cooling Capacity- kW D Main non-Locking Disconnect
Digit 4 Net Cooling Capacity kW P Dual Power Supply Parallel
0-9 Nominal Net Cooling Capacity- kW A Dual Power Supply Interlocking Contactor
Digit 5 Net Cooling Capacity kW T Dual Power Supply Auto Transfer Switch
0-9 Nominal Net Cooling Capacity- kW Digit 18 Installation Option
Digit 6 Air Discharge 0 None, Standard Pipe, No Low Ambient Kit
U Upflow H Re-heat & Humidity Lockout
D Downflow Digit 19 Monitoring
Digit 7 System Type 0 None
C Chilled Water 7 Unity Card
Digit 8 Airflow 8 Unity Card*2
1 EC Plug Fan Digit 20 Sensors
Digit 9 Power Supply 0 None
C 208 V/ 3 Ph/ 60 Hz A Supply Air Pressure Sensor
D 230 V/ 3 Ph/ 60 Hz S Smoke Sensor
A 460 V/ 3 Ph/ 60 Hz H High Temperature
M 380-415 V / 3 Ph/ 50 Hz F Smoke & High Temp
N 380-415 V / 3 Ph/ 50/ 60 Hz+N N Supply Air Temperature Sensor
Digit 10 Cooling System R Remote Sensor
2 CW Two way Valves W Water Temperature Sensor IN/OUT
3 CW Three way Valves L Water Flow Sensor
Digit 11 Humidification X Other Sensor
0 None Digit 21 Packaging
H Infrared Humidifier P Package- Standard Cardboard and Wooden Pallet
S Electrode Humidifier C Packaging– Wooden Crate
Digit 12 Display Digit 22 Special Requirements
9 9-inch HMI Display E For Export
S Small Display Digit 23 Order Identifier
L Large Display 0 Standard Static
Digit 13 Re-heating 1 High ESP 100 Pa
0 None 2 High ESP 200 Pa
1 Electrical Heating Std. 1 Stage 3 Other High ESP
2 Electrical heating Opt. 2 Stage X SFA Included

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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 2 0 9 0 D C 1 N 2 H S 1 2 L 1 D 0 0 0 C E 0 0 0
Digit 14 Filtration Digit 24 Order Identifier
2 G4 0 None
3 F5 1 SFA Included
Digit 15 Coil and Valves Digit 25 Order Identifier
LCW Coil, Standard Pressure MBV (� 1.6
Mpa)
0 None
1 SFA Included
H CW Coil, High Pressure MBV
The standard components are represented in ‘Bold Italic’ font in Table 1-1.
1.4. Components of PEX+CW Model
An overview of the main components, optional components and features of the Liebert®PEX+CW is mentioned
in this section. Liebert PEX+CW components include indoor unit, outdoor unit, and remote monitoring software.
Figure 1-2 shows main components of PEX+ model.
No. Description No. Description
1 Filter 4 Fan
2 Cooling Coil 5 Control Board
3 Heater 6 Infrared Humidifier
Figure 1-2 Main Components of PEX+CW Model

Vertiv | Liebert PEX+ Chilled Water | User Manual 5
Product Overview
The indoor unit includes Compressor, Evaporator, Electronic Expansion Valve (EEV), Infrared Humidifier, EC Fan,
Electrical Heating, Sight Glass, Filter Dryer, and iCOM Controller.
1.4.1. Cabinet
The cabinet frame is constructed from 2.5 mm, 2.0 mm and 1.2 mm 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 finish. The hinged front doors can be removed, and includes
captive 1/4 turn fasteners.
1.4.2. EC Fans
The EC Fans used in the Liebert®PEX+CW models are energy-eicient and innovative with integrated
electronics and a maintenance-free design.
• Ability to regulate the airflow and reduce the fan input power leading to high energy-eiciency.
• Easy-to-connect facility with minimum wiring leading to a high performance with a great variety of possible
airflow rates.
Figure 1-3 EC Fan
1.4.3. Infrared Humidifier
The infrared humidifier consists of infrared humidifier lamp, water injection valve, humidifier water dish,
temperature alarm protection devices and water level alarm device.
The infrared humidifier in the Liebert PEX+CW series provides quicker and more responsive operation which is
quite important for mission-critical applications. The humidifiers reduce the dependency of water quality and
simultaneously achieve full capacity in quick time using almost any water quality.

Vertiv | Liebert PEX+ Chilled Water | User Manual 6
Product Overview
Figure 1-4 Infrared Humidifier
1.4.4. Electrical Heater
Liebert®PEX+ CW models equipped with PTC electrical heater, which features faster heating rate, uniform
heating, safety and reliability. The material used in PTC electrical heating for heating purpose are ceramic
element and aluminum pipe.
These electrical heaters features lower running temperatures, less susceptible to overheating and long lasting
due to less wear thereby ensuring operational safety and lower maintenance and smooth operation
Figure 1-5 Electrical Heater

Vertiv | Liebert PEX+ Chilled Water | User Manual 7
Product Overview
1.4.5. Water Flow Regulating Valve
The water flow regulating valve (as shown in Figure 1-6) can regulate the chilled water flow according to the
cooling requirement of the unit by controlling the water flow passing through the cooling coil thus enables the
unit to operate stably within the temperature and humidity setpoint range. User can select two-way or three-way
water flow regulating valve according to dierent applications.
Figure 1-6 Water Flow Regulating Valve
1.4.6. Safety Controlling Device
The electrical reheat is equipped with automatic and manual reset temperature controller which can promptly
disconnect and protect the electrical heater when the temperature of the heater is too high.
The infrared humidifier is equipped with manual reset dry burning prevention temperature controller, manual
reset safe switch and high water level alarm switch. When there is dry burning and the temperature is too high,
the power of the humidifier can be automatically disconnected to protect the humidifier from the damage.
1.4.7. Cooling Coil
Liebert PEX+ CW series is equipped with a fin-tube copper cooling coil which provides high eiciency, high
Sensible Heat Ratio (SHR), and low air-side pressure drop. The coil is a construction of enhanced surface
aluminum fins mechanically bonded to the surface of copper tubes; the coil frame is fabricated from hot dipped
galvanized sheet metal. The water circuits are specifically designed for even water distribution to improve heat
transfer rate whilst maintaining pressure drop. The coil fins have a hydrophilic coating as standard and the
condensate pan is made from stainless steel.
1.4.8. Filter
The unit uses a standard filter that complies with US ASHRAE52-76 and Eurovent 4/5 standards, and the dust
resistance value is 90% (EU4 standard). It is easy to replace. To ensure eicient operation, the dust filter must be
checked once a month, and be replaced as required.

Vertiv | Liebert PEX+ Chilled Water | User Manual 8
Product Overview
Figure 1-7 Filter
1.4.9. Water Leak Detecting System
The advanced water leak detecting system can signal the alarm information to the controller of PAC unit or a
stand-alone monitoring system. The number of the sensors in parallel connection is not limited, but each unit has
only one water leakage alarm.
1.4.10. iCOM Controller
The iCOM controller is designed for the special requirements of the data center, equipment or computer room. It
features good stability, high controlling precision and intelligence.
The front door of the chilled water PAC unit is facilitated with a display and operating panel. This interface
enables the operators to easily monitor, observe and deal with issues triggered during operation in time. The
iCOM controlling system also supports the multi-units and teamwork mode. There are two types of display
options: Large display with 480x480 pixels and standard Small display with 128x64 pixels, as shown in Figure 1-8.
Figure 1-8 iCOM Controller
Liebert PEX+CW PAC adopts Small display with 128 × 64 dot matrix, blue backlight LCD screen as a standard
to display the present temperature, humidity, temperature, and humidity setting values, unit output percentage
graph (fan, valve, heating, dehumidification, and humidification) and alarm information.

Vertiv | Liebert PEX+ Chilled Water | User Manual 9
Product Overview
1.5. Optional Components
• Two-stage Electric Heater
The two-stage electrical heater can be selected based on the heating requirement. The electrical heater can
be divided into two stages by configuring 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.
• Up Flow Plenum
All plenums have grills at the outlet to streamline the airflow movement across the room. The plenum grills can
be manually regulated by changing the direction of airflow as per the site requirement. In the case of customized
design requirement of the Plenum, contact Vertiv local representative.
• Belt Leak Detector
Belt leak detector can provide a signal to the controller to trigger an alarm of air conditioner unit. The controller
performs several dierent conditions according to the setpoints:
1. Water Alarm Shuts Unit Down
2. Water Alarm Shuts Hum Down
• Smoke Detectors
Smoke detection system facilitates the data center to detect smoke in the unique air-flow environment. The
equipment room is outfitted with hot and cold aisles, underfloor and overhead spaces, each separated to contain
airflow within the space. The active smoke detection technique triggers an alarm with the first sign of smoke.
• Fire Detectors
The fire detector can check the field return air temperature. It triggers fire alarm when the smoke level continues
to rise along with elevated room temperature, or the temperature is too high and reaches the fire alarm threshold.
The primary purpose of the sensor is to examine the air temperature and to initialize the anti-fire measures
installed in the facility.
• Supply Air Temperature Sensor
Supply Air Temperature Sensor is used to modulate the heating and cooling eect of the unit by controlling the
supply air temperature through plenum. Temperature limits are field adjustable via display interface. The heating
or cooling warning activates when the temperature exceeds the thresholds.

Vertiv | Liebert PEX+ Chilled Water | User Manual 10
Product Overview
• Water Temperature Sensor IN/OUT
The 2t temperature sensor can be used to measure the CW temperature status combined with the water flow
data which further used to calculate the cooling capacity of the Liebert®PEX+CW unit.
• High Eiciency Filter
The unit is also available with the option of high eiciency filter for the environment requiring higher air
cleanliness.
• Electrode Humidifier
The electrode humidifier uses the electrodes to boil the water in humidifier bottle to produce steam for
humidification purpose. It has a specific (soft water) requirements in terms of water quality and sizes of inlet/
outlet pipes as compared to the standard infrared humidifier.
• Three-way Motorized Ball Valve (MBV)
Three-way MBV can better regulate water flow in the system and also adapts as per more environmental
requirements.
• Supply Air Pressure Sensor
Supply Air Pressure Sensor is only used for downflow units. It detects the static pressure under the floor of
equipment room. The controller can read the values of static pressure.
• Dual Power Supply Parallel
In dual power supply parallel, there are two power sources (main and backup) that can be manually switched to
backup source in case of power supply failure of main power source to operation of the unit continually.
• Dual Power Supply Auto Alternate (Interlocking contactor/Automatic Transfer Switch)
It consists of dual power supply (interlocking contractor 4P). 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.
• IS - Unity Card
IS-UNITY Card can provide two kinds communication protocol: SNMP, Modbus and BACnet that supports
standards and norms of the industrial communication protocol.