Emerson Liebert DM Chilled Water Series User manual

User Manual
Liebert®DM Chilled Water Series
Precision Cooling
For Business-Critical Continuity™

LIEBERT_DM Chilled Water Series Cooling Unit
User Manual
Version: V1.0
Revision date: Nov. 03, 2012
ROM: 31012828
Emerson Network Power provides customers with technical support. Users may contact the nearest
Emerson local sales office or service center.
Copyright © 2010 by Emerson Network Power Co., Ltd.
All rights reserved. The contents in this document are subject to change without notice.
Emerson Network Power Co., Ltd.
Address: No.1 Kefa Rd., Science & Industry Park, Nanshan District 518057, Shenzhen China
Homepage: www.emersonnetworkpower.com.cn
E-mail: [e-mail]

Contents
Chapter 1 Overview ............................................................................................................................................................1
1.1 Model description.....................................................................................................................................................................1
1.2 Product introduction.................................................................................................................................................................1
1.3 Key parts ..................................................................................................................................................................................1
1.4 Options.....................................................................................................................................................................................2
1.4.1 Remote monitor............................................................................................................................................................2
1.4.2 Energy-saving card.......................................................................................................................................................2
1.5 Environmental requirement......................................................................................................................................................2
1.5.1 Operating environment.................................................................................................................................................2
1.5.2 Storage environment ....................................................................................................................................................2
Chapter 2 Mechanical Installation .......................................................................................................................................3
2.1 Unpacking inspection...............................................................................................................................................................3
2.2 Installation precaution..............................................................................................................................................................3
2.3 System installation layout.........................................................................................................................................................3
2.3.1 General layout..............................................................................................................................................................3
2.3.2 Mechanical parameters.................................................................................................................................................4
2.4 Unit installation........................................................................................................................................................................7
2.4.1 Equipment room requirement.......................................................................................................................................7
2.4.2 Installation space requirement......................................................................................................................................8
2.4.3 Installation steps...........................................................................................................................................................8
2.5 Installation of unit pipes.........................................................................................................................................................11
2.6 Items for inspection................................................................................................................................................................12
Chapter 3 Electric Installation............................................................................................................................................13
3.1 Task description .....................................................................................................................................................................13
3.2 Precautions.............................................................................................................................................................................13
3.3 Connection of unit power cable..............................................................................................................................................13
3.4 Connection of control cable....................................................................................................................................................14
3.4.1 Connection of control terminal...................................................................................................................................14
3.4.2 Connection of monitoring cable.................................................................................................................................15
3.5 Connection of energy-saving card..........................................................................................................................................16
3.6 Items for inspection................................................................................................................................................................18
Chapter 4 System Test......................................................................................................................................................19
4.1 Startup inspection...................................................................................................................................................................19
4.2 Function test...........................................................................................................................................................................19
Chapter 5 Microprocessor.................................................................................................................................................20
5.1 Features..................................................................................................................................................................................20
5.2 Appearance.............................................................................................................................................................................20
5.3 Display ...................................................................................................................................................................................21
5.4 Control key.............................................................................................................................................................................21

5.4.1 Function description...................................................................................................................................................21
5.4.2 Operation example .....................................................................................................................................................22
5.5 Control interface.....................................................................................................................................................................22
5.5.1 Shutdown interface.....................................................................................................................................................22
5.5.2 Startup interface .........................................................................................................................................................22
5.5.3 Normal interface.........................................................................................................................................................23
5.5.4 Password interface .....................................................................................................................................................23
5.6 Menu structure........................................................................................................................................................................23
5.6.1 Main menu .................................................................................................................................................................23
5.6.2 Alarm menu................................................................................................................................................................24
5.6.3 Setting point...............................................................................................................................................................27
5.6.4 System status..............................................................................................................................................................27
5.6.5 System menu..............................................................................................................................................................28
5.6.6 Help menu..................................................................................................................................................................31
Chapter 6 System Maintenance........................................................................................................................................33
6.1 Electric inspection..................................................................................................................................................................33
6.2 Unit maintenance....................................................................................................................................................................33
6.2.1 Filter...........................................................................................................................................................................33
6.2.2 Fan .............................................................................................................................................................................34
6.2.3 Drainage pipe.............................................................................................................................................................34
6.2.4 Water flow regulating valve.......................................................................................................................................34
6.3 Maintenance checklist............................................................................................................................................................36
Chapter 7 Failure Diagnosis and Troubleshooting ............................................................................................................37
Appendix 1 Menu Structure Diagram................................................................................................................................41
Appendix 2 List of Parameters..........................................................................................................................................42
Appendix 3 Introduction to SiteMonitor Software ..............................................................................................................44
Appendix 4 Symbol Table for Toxic/Hazardous Substances and Elements......................................................................46

Chapter 1 Overview 1
User Manual of Liebert_DM Chilled Water Series Cooling Unit
Chapter 1 Overview
This chapter mainly introduces the model description, product profile, main parts, optional parts and environment
requirement of Liebert_DM chilled water series cooling unit.
1.1 Model description
The model description of Liebert_DM chilled water series cooling unit is as shown in Fig. 1-1
Version
Power Supply. M:3-ph/380V/50Hz
Air Discharge. U:upflow; F:downflow; D:duct
Cooling Capactity. 09:8.2kW; 12:11.6kW; 17:16.3kW; 25:23.2kW
Chilled Water.
Liebert_DM
Cooling System . C:cooling onl y: O:with heater;
DM H 09 U M H 2
H: with heater and humid itier
Fig.1- 1 Model description
1.2 Product introduction
The Liebert_DM chilled water series cooling unit is a small precise environment control system. It is especially
designed for the cooling of electronic equipment and applicable to the environment control of equipment room or
computer room. It is highly reliable and able to provide a proper running environment for the precision equipment, such
as sensitive equipment, industry process equipment, communication equipment and computer.
The Liebert_DM chilled water series cooling unit is equipped with microprocessor and able to automatically switch
functions according to the setting values of the program and the indoor environment conditions.
1.3 Key parts
The unit is composed of such key parts as chilled water coil, fan, microprocessor, screen and water flow regulating
valve. For the optional parts, please refer to 1.4 Options.
Chilled water coil
Fin type heat exchanger is adopted. The chilled water coil is designed and verified for specific models to ensure the
distribution evenness of chilled water in all the loops and maximize the heat exchange efficiency.
Fan
Centrifugal fan of high efficiency and high reliability is adopted, which features large blast volume, long air supply
distance, direct drive and convenient maintenance.
Microprocessor
User interface of simple operation is provided. Multi-level password protection, auto power recovery, high/low voltage
protection and phase loss protection are provided. Expert level failure diagnosis system is configured to automatically
display the failure contents and facilitate the equipment maintenance by the service personnel.

2 Chapter 1 Overview
User Manual of Liebert_DM Chilled Water Series Cooling Unit
Water flow regulating valve
The water flow regulating valve can regulate the chilled water flow according to the cooling demand. The water flow
regulating valve adopts union swivel for the connection with the system pipes, which is convenient for the onsite
installation and maintenance.
Filter
High polymer dust absorption filtering material is adopted. It has compact structure and is easy for maintenance.
1.4 Options
1.4.1 Remote monitor
The Liebert_DM chilled water series cooling unit adopts the standard protocols of Ministry of Information Industry. For
details, please refer to Centralized Power Equipment, Air Conditioning and Environment Monitoring and Management
System for Communication Stations, Part III: Protocol for Front-end Intelligent Equipment. It realizes the
communication with the host computer through the RS485 port and is controlled by the host software. For details
about the monitoring software of Emerson, SiteMonitor, please refer to Appendix IV Introduction to SiteMonitor
Monitoring Software.
1.4.2 Energy-saving card
The Liebert_DM chilled water series cooling unit adopts external energy-saving card to monitor the maximum
temperature in the room. The energy-saving card is deployed in the place with large thermal load and high
temperature. This cooling unit can be equipped with up to 4 energy-saving cards. When the temperature values
measured by all the energy-saving cards are lower than the setting value of “sleep temperature”, and only the internal
fan needs to run, if “sleep mode” is set as “enabled”, the cooling unit will shut down the internal fan and enter the sleep
mode, so as to realize energy efficiency.
1.5 Environmental requirement
1.5.1 Operating environment
The operating environment shall meet the standards of GB4798.3-90. For details, please refer to Table 1-1.
Table 1-1 Requirement of operating environment
Item
Requirement
Installation
Vertical installation, with the installation base ≥150mm
Ambient temperature
Indoor temperature: 4ºC~40ºC
Chilled water inlet temperature: 5ºC~12ºC
altitude
<1000m, derated when it is more than 1000m
Operating voltage range
3N~380V (-15%~+20%) , 50Hz
1.5.2 Storage environment
The storage environment shall meet the standards of GB4798.3-1996. For details, please refer to Table 1-2.
Table 1-2 Requirement of storage environment
Item
Requirement
Storage environment
Indoor, clean (free of dust)
Ambient humidity
5%RH~85%RH
Ambient temperature
-20ºC~+54ºC
Storage time
No more than 6 months in total (transportation plus storage), performance needs to be reevaluated after
6 months

Chapter 2 Mechanical Installation 3
User Manual of Liebert_DM Chilled Water Series Cooling Unit
Chapter 2 Mechanical Installation
This chapter will describe the mechanical installation of the Liebert_DM chilled water series cooling unit in detail,
including unpacking inspection, unit installation and pipe installation.
2.1 Unpacking inspection
Move the equipment to the place closest to the final installation site before unpacking.
In case any loss or damage of any parts is discovered during inspection, the same shall be reported to the carrier
immediately. Concealed damages noted shall also be reported to the carrier and the local office of the goods supplier.
Please do not accept the damaged equipment.
2.2 Installation precaution
1. The Liebert_DM chilled water series cooling unit adopts standalone installation mode. The unit must be installed on
the ground of the equipment room or computer room.
2. Before installing the equipment, check if the installation environment meets the relevant requirements as specified in
1.5 Environmental Requirement. And check if the building needs to be reformed for the pipe laying, wiring and
ventilation pipe mounting.
3. Install the equipment strictly according to the design drawing, and reserve corresponding installation/maintenance
space. Please refer to the engineering dimensions provided by the manufacturer.
2.3 System installation layout
2.3.1 General layout
The general layout of the system is as shown in Fig.2-1.
冷冻水进口
冷冻水出口
平衡阀或隔离阀*
水过滤器*
排水阀*
隔离阀*冷冻水进出
口螺纹连接
放气阀
软接口*
换热器盘管
水流量调节阀
Air discharge valve
Heat exchanger coil
Water flow regulating valve
Chilled water
inlet/outlet
threaded joint
Soft joint *
Water discharge valve *
Isolating
valve *
Water filter *
Holding valve or isolating valve *
Chilled water inlet
Chilled water outlet
冷冻水进口
冷冻水出口
平衡阀或隔离阀*
水过滤器*
排水阀*
隔离阀*冷冻水进出
口螺纹连接
放气阀
软接口*
换热器盘管
水流量调节阀
Air discharge valve
Heat exchanger coil
Water flow regulating valve
Chilled water
inlet/outlet
threaded joint
Soft joint *
Water discharge valve *
Isolating
valve *
Water filter *
Holding valve or isolating valve *
Chilled water inlet
Chilled water outlet
Fig.2-1 General layout diagram
Note
1. : Pipeline provided by the manufacturer.
2. : Pipeline laid onsite (by the technical staff)
3.*: These components are not provided by Emerson Network Power Co., Ltd, but they are recommended to be used
for the normal operation of the system and maintenance.
4. After finishing the installation, air discharge must be carried out before pouring water so as to ensure the heat
transfer effect of the heat exchanger.
5. In winter in the northern region, the air conditioning unit must be emptied of water to prevent frosting the heat
exchanger if it will be idle for a long time.

4 Chapter 2 Mechanical Installation
User Manual of Liebert_DM Chilled Water Series Cooling Unit
2.3.2 Mechanical parameters
Dimensions (mm)
For the mechanical parameters of the unit, please refer to Fig.2-2 and Table 2-1.
510
1740
386
608
1900
575
DMH09 unit DMH12 unit
1102
386
1740
1900
1202
575
DMH17 unit DMH25 unit
Fig.2-2 Outline dimensions of the units (unit: mm)

Chapter 2 Mechanical Installation 5
User Manual of Liebert_DM Chilled Water Series Cooling Unit
Table 2-1 Outline dimensions and weights of the units
Product model
Size (W×D×H) (mm)
Net Weight (kg)
DMH09
510×386×1740
≤90
DMH12
608×575×1900
≤127
DMH17
1102×386×1740
≤169
DMH25
1202×575×1900
≤210
Base cutting position and dimensions
The base cutting position and dimensions are as shown in Fig.2-3.
Back of the unit
Left side of the unit Right side of the unit
Chilled w ater outlet
Chilled w ater inlet
Condensed w ater
drainage hole
Cablet inlet
4 ground retaining holes
Front of the unit
Back of the unit
Left side of the unit Right side of the unit
Chilled w ater outlet
Chilled w ater inlet
Condensed w ater
Cablet inlet
4 ground retaining holes
Front of the unit
Base cutting position of DMH09 unit
Backof theunit
Left sideof theunit Right side of the unit
Chilledwater outlet
Chilledwater inlet
Condensedwater
drainage hole
Cablet inlet
4groundretaining holes
Front of the unit
Backof theunit
Left sideof theunit
Chilledwater outlet
Chilledwater inlet
Condensedwater
Cablet inlet
4groundretaining holes
Front of the unit
Right side of the unit
Base cutting position of DMH12 unit

6 Chapter 2 Mechanical Installation
User Manual of Liebert_DM Chilled Water Series Cooling Unit
Back of the unit
Left side of
the unit Right side
of the unit
Chilled w ater outlet
Condensed w ater drainage hole
Cablet inlet
4 ground retaining holes
Front of the unit
Back of the unit
Left side of
the unit Right side
of the unit
Chilled w ater outlet
Condensed w ater drainage hole
Cablet inlet
Front of the unit
Chilled w ater inlet
Base cutting position of DMH17 unit
Back of the unit
Left side
of the unit Right side of the unit
Chilled w ater outlet
Chilled w ater inlet
Condensed w ater drainage hole
Cablet inlet
4 ground retaining holes
Front of the unit
Back of the unit
Left side
of the unit Right side of the unit
Chilled w ater outlet
Chilled w ater inlet
Condensed w ater drainage hole
Cablet inlet
4 ground retaining holes
Front of the unit
Base cutting position of DMH25 unit
Fig.2-3 Base cutting position and dimensions (unit: mm)
Side plate cutting position dimensions
If it is unable to lay pipes and cables from the base, side connection may be adopted. The position and size of the
knock-out holes are as shown in Fig.2-4. The inlet and outlet can be selected according to the actual situation, but any
two of the pipes, power cables and signal cables shall not enter/exit the unit through the same hole.

Chapter 2 Mechanical Installation 7
User Manual of Liebert_DM Chilled Water Series Cooling Unit
F ront of the unit Bac k of the unit
C hilled water outlet
C hilled water inlet
F ront of the unit Bac k of the unit
C hilled water outlet
C hilled water inlet
DMH09/DMH17 side
plate
Front of the unit Back of the unit
Chilled water outlet
Chilled water inlet
Front of the unit Back of the unit
Chilled water outlet
Chilled water inlet
DMH09/DMH25 side plate
Fig.2-4 Side plate knock-out hole (unit: mm)
2.4 Unit installation
2.4.1 Equipment room requirement
The detailed requirements on equipment room are as follows:
1. The equipment room shall have good thermal insulation and air-tight damp course.
Note
To ensure the normal operation of the environment control system in the air conditioning room, damp proof and
thermal insulation are the most important factors.
2. The outdoor air shall be prevented from entering the equipment room. The entry of the outdoor air will increase the
cooling and dehumidification load of the system. It is suggested to maintain the absorption amount of the outdoor air
below 5% of the air circulating in the equipment room.

8 Chapter 2 Mechanical Installation
User Manual of Liebert_DM Chilled Water Series Cooling Unit
3. All the doors and windows shall be air-tight, and the gaps shall be as small as possible.
2.4.2 Installation space requirement
Note
The DMH chilled water series cooling unit will produce condensed water. If there exists any water leakage, the
adjacent precision equipment may be damaged. Therefore, the cooling unit shall not be installed near the precision
equipment, and drainage pipe shall be provided at the installation site.
The detailed requirements on installation site are as follows
1. To ensure the normal operation of the unit, spacious and open place shall be selected as the installation site.
2. The unit shall not be installed in the narrow space. Otherwise, the air flow will be blocked, and the cooling cycle will
be shortened, causing return airflow short circuit and air noise.
3. The unit shall not be installed in cavity or at the end of the slender room.
4. To avoid crossover of airflow, unbalanced load and competitive operation, do not install several units side by side.
5. To facilitate the routine maintenance, do not install any equipment (e.g., smoke detector) above the cabinet.
6. A maintenance clearance of at least 600mm shall be reserved in front of the cooling unit.
The unit installation position diagram is as shown in Fig.2-5.
合理位置
空调机组
注：
表示安装时需预留的维修空间
600
不合理位置
空调机组
Proper position
Cooling unit
Improper position
Cooling unit
Note:
Indicates the maintenance clearance reserved for installation
合理位置
空调机组
注：
表示安装时需预留的维修空间
600
不合理位置
空调机组
Proper position
Cooling unit
Improper position
Cooling unit
Note:
Indicates the maintenance clearance reserved for installation
Fig.2-5 Unit installation position diagram Installation steps
1. Use the M10X20 expansion bolts to fix the self-made installation base to the selected unit installation position. The
installation base and size are as shown in Fig.2-6.

Chapter 2 Mechanical Installation 9
User Manual of Liebert_DM Chilled Water Series Cooling Unit
橡
胶
垫
（
8
m
m
～
1
0
m
m
厚
）
脚
掌
钢
板
（
1
0
0
×
1
0
0
×
4
）
H
>
1
5
0
角
钢
（
4
0
×
4
0
×
3
）
橡
胶
垫
（
8
m
m
厚
）
D
M
E
1
2
机
组
安
装
底
座
俯
视
图
4
个
膨
胀
螺
栓
安
装
孔
4
个
机
组
安
装
孔
D
M
E
9
机
组
安
装
底
座
俯
视
图
D
M
E
9
/
D
M
E
1
2
机
组
安
装
底
座
示
意
图
后
面
前
面
前
面
后
面
4 unit mounting holes
Rubber gasket (8mm~10mm) thick
Steel angle (40
×
40
×
3)
4 expansion bolt mounting holes
Rubber gasket 8mm thick
Footer steel plate (100
×
100
×
4)
Schematic diagram for DME9/DME12 unit installation base
Back
Back
Front
Front
Top view of DME9 unit installation bas
Top view of DME12 unit installation base
橡
胶
垫
（
8
m
m
～
1
0
m
m
厚
）
脚
掌
钢
板
（
1
0
0
×
1
0
0
×
4
）
H
>
1
5
0
角
钢
（
4
0
×
4
0
×
3
）
橡
胶
垫
（
8
m
m
厚
）
D
M
E
1
2
机
组
安
装
底
座
俯
视
图
4
个
膨
胀
螺
栓
安
装
孔
4
个
机
组
安
装
孔
D
M
E
9
机
组
安
装
底
座
俯
视
图
D
M
E
9
/
D
M
E
1
2
机
组
安
装
底
座
示
意
图
后
面
前
面
前
面
后
面
4 unit mounting holes
Rubber gasket (8mm~10mm) thick
Steel angle (40
×
40
×
3)
4 expansion bolt mounting holes
Rubber gasket 8mm thick
Footer steel plate (100
×
100
×
4)
Schematic diagram for DMH9/DMH12 unit installation base
Back
Back
Front
Front
Top view of DMH9 unit installation bas
Top view of DMH12 unit installation base

10 Chapter 2 Mechanical Installation
User Manual of Liebert_DM Chilled Water Series Cooling Unit
Fig.2-6 Installation base (unit: mm)2. Apply a layer of 8mm~10mm thick rubber gasket to the base, as shown in Fig.
2-6.
3. Place the unit on the installation base and fix it with M8X70 bolts.
6
个
膨
胀
螺
栓
安
装
孔
橡
胶
垫
（
8
m
m
厚
）
橡
胶
垫
（
8
m
m
～
1
0
m
m
厚
）
4
个
机
组
安
装
孔
脚
掌
钢
板
（
1
0
0
×
1
0
0
×
4
）
角
钢
（
4
0
×
4
0
×
3
）
H
>
1
5
0
D
M
E
1
7
/
D
M
E
2
5
机
组
安
装
底
座
示
意
图
D
M
E
1
7
机
组
安
装
底
座
俯
视
图
D
M
E
2
5
机
组
安
装
底
座
俯
视
图
前
面
后
面
后
面
前
面
4 unit mounting
holes
Rubber gasket
(8mm~10mm) thick
Steel angle (40
×
40
×
3)
Footer steel plate (100
×
100
×
4)
Rubber gasket 8mm thick
6 expansion bolt
mounting holes
Schematic diagram for DME17/DME25 unit installation base
Back
Back
Front
Front
Top view of DME17 unit installation base
Top view of DME25 unit installation base
6
个
膨
胀
螺
栓
安
装
孔
橡
胶
垫
（
8
m
m
厚
）
橡
胶
垫
（
8
m
m
～
1
0
m
m
厚
）
4
个
机
组
安
装
孔
脚
掌
钢
板
（
1
0
0
×
1
0
0
×
4
）
角
钢
（
4
0
×
4
0
×
3
）
H
>
1
5
0
D
M
E
1
7
/
D
M
E
2
5
机
组
安
装
底
座
示
意
图
D
M
E
1
7
机
组
安
装
底
座
俯
视
图
D
M
E
2
5
机
组
安
装
底
座
俯
视
图
前
面
后
面
后
面
前
面
4 unit mounting
holes
Rubber gasket
(8mm~10mm) thick
Steel angle (40
×
40
×
3)
Footer steel plate (100
×
100
×
4)
Rubber gasket 8mm thick
6 expansion bolt
mounting holes
Schematic diagram for DME17/DME25 unit installation base
Back
Back
Front
Front
Top view of DME17 unit installation base
Top view of DME25 unit installation base
4 unit mounting
holes
Rubber gasket
(8mm~10mm) thick
Steel angle (40
×
40
×
3)
Footer steel plate (100
×
100
×
4)
Rubber gasket 8mm thick
6 expansion bolt
mounting holes
Schematic diagram for DMH17/DMH25 unit installation base
Back
Back
Front
Front
Top view of DMH17 unit installation base
Top view of DMH25 unit installation base

Chapter 2 Mechanical Installation 11
User Manual of Liebert_DM Chilled Water Series Cooling Unit
2.5 Installation of unit pipes
The pipes to be connected include:
1. Drainage pipe of the unit:
2. Inlet and outlet pipes of chilled water.
Connection of the drainage pipe
The external diameter of the condensed water drainage pipe of the unit heat exchanger is 19mm. The condensed
water drainage pipe is fixed to the right side of the unit base. It shall be connected to a water pipe with the inner
diameter of 19 mm and fixed with pipe hoop.
Note
1. A Φ19 pipe hoop is delivered as an option for connecting the drainage pipe.
Connection of chilled water inlet and outlet pipes
The chilled water inlet and outlet pipes are connected to the chilled water unit through threaded joint, as shown in Fig.
2-7.The inlet and outlet pipes should be connected according to labels on the unit. Please do not reverse the
connection. The chilled water inlet and outlet pipes can be connected through the bottom plate or the side plate. For
the pipe inlet and outlet position, please refer to Fig. 2-3 and Fig. 2-4. The chilled water inlet and outlet pipes should
have soft connector at the unit connections. The chilled water inlet pipes should be equipped with the water filter with
over 60 meshes to facilitate the clearance of impurities in the pipes. The chilled water inlet and outlet pipes need to be
equipped with several isolating valves, which can cut off water sources during the period of maintenance. One of the
isolating valves can be balance valve. Chilled water system with a balance valve would be more efficient and more
accurate in controlling water distribution. For detailed distribution, please refer to Fig. 2-2.Water pressure should be
able to overcome the water pressure drop caused by all the components of water system. Considering the possibility
that water pressure drop would increase due to incrustant and impurities resulted from long-time running of the system.
Therefore, when choosing the head components (e.g. pump), we should consider making 20% ~ 25% redundancy.
The weight of water pipes connected with the unit should not be assumed by the unit. The chilled water inlet and outlet
pipes must be kept warm. Table 2-2 shows the connecting dimensions of chilled water inlet and outlet pipes of various
units.
Note
Be careful when connecting the chilled water inlet and outlet pipes. Before the operation, please read carefully the
following precautions:
1. Remove the dust shield.
2. Wipe the connecting base and threaded surface carefully with clean cloth.
3. Wind hemp thread or Teflon tape evenly on the threaded surface.
4. Tighten the threaded joint, ensuring accurate alignment of the threads.
5. Draw a vertical line from the male connector to the female connector with a marker.
6. Verify the sealing status by filling it with nitrogen or water. If any leakage is found, tighten it immediately or reconnect
the joint.

12 Chapter 2 Mechanical Installation
User Manual of Liebert_DM Chilled Water Series Cooling Unit
冷冻水进水管
冷冻水出水管
Chilled water inlet pipe
Chilled water outlet pipe
冷冻水进水管
冷冻水出水管
Chilled water inlet pipe
Chilled water outlet pipe
Fig.2-7 Schematic diagram for connection of chilled water pipeTable2-2 External diameter and specifications for chilled water
inlet and outlet pipes
Product model
External diameter for chilled water inlet
and outlet pipes (mm)
Specifications for threaded joint of chilled water
inlet and outlet pipes
DMH09
25
G 1″
DMH12
25
G 1″
DMH17
32
G 1-1/4″
DMH25
32
G 1-1/4″
2.6 Items for inspection
After the mechanical installation, check and verify that:
1. Certain clearance has been reserved around the unit for maintenance;
2. The equipment is vertically erected, and the fastening pieces have been locked;
3. The pipes connecting the unit have been connected;
4. The chilled water pump has been installed (if necessary);
5. The drainage pipe has been connected;
6. The joints for chilled water inlet and outlet pipes have been tightened and there is no leakage;
7. The equipment installation has been completed, and the foreign materials inside and around the equipment (e.g.,
transportation materials, structural materials, tools, etc.) have been cleared.
8. Rotate the fan blade to check if the fan rotates smoothly without any noise.
After all the above items have been inspected and confirmed, carry out the electric installation.

Chapter 3 Electric Installation 13
User Manual of Liebert_DM Chilled Water Series Cooling Unit
Chapter 3 Electric Installation
This chapter introduces the electric installation of the Liebert_DM chilled water series cooling unit, including the task
description, precautions, unit wiring and items for inspection.
3.1 Task description
The wires to be connected onsite include:
1. The unit power cable: 3×L+N+PE.
2. The unit monitor control cable (if remote monitoring is configured).
3. The energy-saving card connecting wire (if energy-saving card is configured).
3.2 Precautions
1. The connection of all the power cables, control cables and grounding cables shall comply with the national and local
electrician regulations.
2. For the full load current, please refer to the equipment nameplate. The cable size shall comply with the local wiring
rules.
3. Main power requirement: 380Vac, 50Hz, 3×L+N+PE.
4. The electric installation must be carried out by the trained and qualified personnel.
5. Before connecting the circuit, measure the input power voltage with the voltage meter to ensure that the power
supply has been disconnected.
3.3 Connection of unit power cable
Open the unit front door, and then you can see the electric control box of the unit. Insert the unit power cable through
the through-hole, and connect one end to the unit power input terminals L1, L2, L3, N and PE (fix the cable with cable
tie), and the other end to the external AC power, as shown in Fig.3-1 and Fig.3-2. When selecting the cables, please
refer to the maximum running current value on the unit nameplate.
电控盒
过线孔
电缆固定夹
Electric control box
Through hole
Cable tie
电控盒
过线孔
电缆固定夹
Electric control box
Through hole
Cable tie
地线端子
N线端子
L1
线
端
子
L2
线
端
子
L3
线
端
子
Grounding wire terminal
N line terminal
L1 line terminal L2 line terminal
L3 line terminal
地线端子
N线端子
L1
线
端
子
L2
线
端
子
L3
线
端
子
Grounding wire terminal
N line terminal
L1 line terminal L2 line terminal
L3 line terminal
Fig.3-1 Connecting position of unit power cable
Fig.3-2 Amplified view of power connecting
terminal

14 Chapter 3 Electric Installation
User Manual of Liebert_DM Chilled Water Series Cooling Unit
Note
1. Only the copper wire can be used, all the wires shall be firmly connected.
2. Ensure that the power supply voltage is equal to the rated voltage on the equipment nameplate.
3. Install a disconnecting switch before the unit power input, so that the power supply can be easily disconnected for
equipment maintenance. Connect the power cable to the disconnecting switch first, and then to the equipment.
4. The equipment has high voltage. Power supply shall be cut off before performing any maintenance inside the
equipment.
3.4 Connection of control cable
3.4.1 Connection of control terminal
The control terminals are on the PCB of the electric control box, as shown in Fig.3-3.
控制端子所在印制板
The PCB where the control
terminals are located
控制端子所在印制板
The PCB where the control
terminals are located
Fig.3-3 Position of the control terminals The arrangement of the control terminals is as shown in Fig.3-4.
Note
Before connecting the control cables, the operator shall prepare corresponding antistatic measures.
自定义1
J67
自定义2主备请求
烟感 火感 远程关机 主备切换 公共报警
J68 J18
J14 J22 J8 J9 J10
Custom 1 Custom 2 Master/slave request
Smoke
detector Fire detector Remote shutdown Master/slave
switching Common
alarm
自定义1
J67
自定义2主备请求
烟感 火感 远程关机 主备切换 公共报警
J68 J18
J14 J22 J8 J9 J10
Custom 1 Custom 2 Master/slave request
Smoke
detector Fire detector Remote shutdown Master/slave
switching Common
alarm
Fig.3-4 Arrangement diagram of control terminals

Chapter 3 Electric Installation 15
User Manual of Liebert_DM Chilled Water Series Cooling Unit
Remote shutdown, smoke detector and fire detector terminals
Remote shutdown terminal J8, smoke detector terminal J14 and fire detector terminal J22 can be used to control the
remote startup/shutdown of the unit and the connection of the external smoke detector and fire detector, so that the
cooling unit can stop operation at special times. If the inputs of the three terminals are shorted, and the power input
switch of the cooling unit is closed, the cooling unit has normal output. If any of the three terminals is disconnected, the
cooling unit will stop output. The three terminals are shorted before delivery. If the control cables for smoke detector,
fire detector or remote startup/shutdown need to be connected onsite, remove the short circuited wire and connect the
external controller, smoke detector and fire detector respectively to J8, J14 and J22.
Custom 1 and custom 2 terminals
Custom 1 terminal J67 and custom 2 terminal J68 can be connected to the alarm signals beyond the cooling system.
Any external alarm can be connected to the custom terminal if it has normally open dry contact. After connecting
external alarm signals to the custom terminals, you should set the corresponding customized alarm trigger conditions
through the microprocessor. For details, please refer to the customized alarm in 5.6.2 alarm menu. When there is no
external alarm, the input status of the custom terminal is consistent with the setting. When the external alarm occurs,
the input status of the custom terminal is inconsistent with the setting, the cooling unit will generate audible alarm, and
the microprocessor LCD will display the corresponding alarm contents. If computer with Emerson monitoring software
is connected, the alarm will also be displayed on the computer.
If power supply surge protector is configured, custom 1 terminal J67 will be connected to the surge protector alarm
signal upon delivery. The alarm is set as NC.
Common alarm terminals.
The common alarm relay connected to the common alarm terminal J10 has a group of normally open dry contacts.
When there exists critical alarm, the contacts are closed. It can be used to trigger remote alarms, send signals to the
building management system or dial the paging system automatically.
Master/slave switching and Master/slave request terminals
The Master/slave switching terminal J9 and Master/slave request terminal J18 are used to connect the two cooling
units working in master/slave mode. The connecting method is as shown in Fig.3-5.
主备切换J9
主备切换J9
主备请求J18
主备请求J18
主机 从机
Master/slave request J18
Master Slave
Master/slave switching J9
Master/slave switching J9
Master/slave request J18
主备切换J9
主备切换J9
主备请求J18
主备请求J18
主机 从机
Master/slave request J18
Master Slave
Master/slave switching J9
Master/slave switching J9
Master/slave request J18
Fig.3-5 Schematic diagram for the connection of Master/slave operating modeConnection of monitoring cable
The RS485 port of the Liebert_DM chilled water series cooling unit is located at the back of the unit front door and
connected to the upstream unit with the twisted communication cable. The position of the RS485 port is as shown in
Fig.3-6.