Precision Cooling
For Business-Critical Continuity™
Liebert® DM Series Air Conditioner
Technical Manual
Liebert_DM Series Air Conditioner
Technical Manual
Version
Revision date
BOM
V1.0
Emerson Network Power provides customers with technical support. Users may contact the
nearest Emerson local sales office or service center and company headquarters.
Copyright © 2012 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
Postcode: 518057
Customer Service Hotline: 4008876510
Homepage: www.emersonnetworkpower.com.cn
E-mail: support@emersonnetwork.com.cn
Contents
Chapter 1 Preface ............................................................................................................................................................... 1
1.1 Special Requirements On The Equipment Room Environment ............................................................................ 1
1.2 Liebert_DM Series AC – Designed For Equipment Room .................................................................................... 1
Chapter 2 Overview ............................................................................................................................................................ 3
2.1 Appearance .......................................................................................................................................................... 3
2.2 Model Description ................................................................................................................................................. 3
2.3 Product Introduction .............................................................................................................................................. 3
2.4 Main Components ................................................................................................................................................. 4
2.4.1 Indoor Unit ................................................................................................................................................. 4
2.4.2 Outdoor Unit .............................................................................................................................................. 4
2.5 Options ................................................................................................................................................................. 5
2.5.1 Humidifier .................................................................................................................................................. 5
2.5.2 Heater ........................................................................................................................................................ 5
2.5.3 Remote Monitor ......................................................................................................................................... 5
2.5.4 Energy-Saving Card .................................................................................................................................. 5
2.5.5 Power SPD ................................................................................................................................................ 5
Chapter 3 Technical Parameter .......................................................................................................................................... 6
3.1 Technical Parameter Of The Indoor Unit .............................................................................................................. 6
3.2 Technical Parameter Of The Outdoor Unit............................................................................................................ 7
3.3 Mechanical Parameter .......................................................................................................................................... 7
3.3.1 Indoor Unit ................................................................................................................................................. 7
3.4 Outdoor Unit.......................................................................................................................................................... 8
3.5 Operation Environment ......................................................................................................................................... 9
Chapter 4 Application Guidline .......................................................................................................................................... 10
4.1 General Arrangement ......................................................................................................................................... 10
4.2 General Principles............................................................................................................................................... 10
4.3 Piping .................................................................................................................................................................. 11
4.4 Model Configuration ............................................................................................................................................ 12
4.5 Cooling Circulation .............................................................................................................................................. 12
Chapter 5 Micro-Processing controller .............................................................................................................................. 13
5.1 Appearance ........................................................................................................................................................ 13
5.2 LCD Screen ........................................................................................................................................................ 13
5.3 Control Buttons ................................................................................................................................................... 13
5.3.1 Function Description ................................................................................................................................ 13
5.3.2 Operation Example .................................................................................................................................. 14
5.4 Control Screen .................................................................................................................................................... 14
5.4.1 ON Screen ............................................................................................................................................... 14
5.4.2 Normal Screen......................................................................................................................................... 14
5.4.3 Password Screen .................................................................................................................................... 15
5.5 Control Logic ....................................................................................................................................................... 15
5.5.1 Cooling logic ............................................................................................................................................ 15
5.5.2 Heating Logic........................................................................................................................................... 16
5.5.3 Dehumidifying Logic ................................................................................................................................ 16
5.5.4 Humidifying Logic .................................................................................................................................... 18
5.5.5 Outdoor Fan Control ................................................................................................................................ 18
5.5.6 Economy Mode Control ........................................................................................................................... 19
5.5.7 Sleep Mode Control ................................................................................................................................. 19
5.5.8 Host/Standby Unit Control ....................................................................................................................... 19
5.6 Alarm Function .................................................................................................................................................... 20
5.6.1 Alarm Category........................................................................................................................................ 20
5.6.2 Alarm State And History .......................................................................................................................... 20
5.6.3 Alarm Prerequisites And Handling Methods ............................................................................................ 20
5.7 Other Functions .................................................................................................................................................. 23
5.7.1 Real-Time Clock ...................................................................................................................................... 23
5.7.2 Operating Record .................................................................................................................................... 23
5.7.3 Parameter Protection ............................................................................................................................... 23
5.7.4 Password Protection ................................................................................................................................ 23
5.7.5 Shutdown Mode ....................................................................................................................................... 23
5.7.6 Diagnosis Output ..................................................................................................................................... 24
5.7.7 Sensor Calibration ................................................................................................................................... 24
5.7.8 Deployment Management........................................................................................................................ 24
Appendix 1 Menu Structure ............................................................................................................................................... 25
Appendix 2 Wiring Diagram............................................................................................................................................... 26
Appendix 3 Glossary ......................................................................................................................................................... 28
Chapter 1
Preface
1
Chapter 1 Preface
This chapter mainly introduces the special requirements on the equipment room environment and the features and
advantages of Liebert_DM series air conditioners (AC for short).
1.1 Special Requirements For The Equipment Room Environment
The precise environment control is very important for the operation of the computers , therefore, the computers have
strict requirements for the equipment room environment, which cannot be achieved by the commercial air conditioners
designed for comfort. The relevant requirements mainly include the following four aspects.
Temperature control: Huge amount of sensible heat is generated when computers and exchanges are operating in
the equipment room, whose density is 6 to 10 times of that of the general offices. To ensure that the computers and the
devices exert their optimal effect, the temperature of the equipment room is best controlled within 24°C±1°C; This
requires that the AC units have sufficient cooling capacity and timely response regulatory capacity to cope with drastic
changes in temperature, which cannot be implemented by the commercial air conditioners.
Humidity control: In computer room, ultra-high or ultra-low humidity will damage the computers. The ultra-high
humidity makes the air moisture condense to form condensation water in the computers, resulting in short-circuit or
damage of the host hardware. The ultra-low humidity will make the static electricity generate in the computer room,
making the computers unable to operate or even crash. The commercial air conditioners cannot control the humidity
within the required range.
Airflow / cleanliness control: Computers and exchanges will produce huge sensible heat during the operation. To
eliminate the heat rapidly, The ACs are required to have large enough large cooling cycle airflow and long blowing
distance. Besides, because of the strict requirement of air cleanliness, the AC should provide an airflow equivalent to
the ventilating rate of 30 times per hour, so as to filter the air. The commercial ACs cannot achieve these.
All-year-round running: The commercial ACs (cooling operation) are only used in summer and they only run for 8 ~
10 hours each day. In the equipment room, however, the ACs are required to work all year round even in winter when
the temperature reached -34°C outdoors.
1.2 Liebert_DM Series AC – Designed For Equipment Room
The Liebert_DM series AC includes units with a cooling capacity of 7.5kW and 12.5kW. You can configure them freely
to meet different requirements of large-, medium-, and small-sized equipment rooms and base stations. Besides, the
AC has precise temperature/ humidity control and reliability design, fully meeting the special use environment
requirement of the equipment rooms.
Special development: As a part of the integration solution to equipment room, the Liebert_DM series ACs are
specially designed for the electrical devices and provides a proper environment for the running of the precise devices,
such as sensitive devices, industry process devices, communication devices and computers.
Considerate design: Being concerned about inter-device practical applications, the Liebert_DM series ACs are
designed to keep the overall layout between devices and ensure onsite installation and maintenance.
2
2
Saving space: The Liebert_DM series AC occupies 0.3 m and a total of 1 m area is required plus the maintenance
space.
Precise control: The precise control system of the Liebert_DM series ACs implement precision control over indoor
environment, guaranteeing the safe working and stable running of devices to a maximum degree. For the indoor unit
control panel, see Figure 1-1.
Liebert DM Series Air Conditioner Technical Manual
2
Chapter 1
Preface
J13 Board power
supply input J34 Temp/Hum detection board J23 Pressure sensor
J14 Monitoring
J12 Display board power supply
ON
J39 Display board data line
J18 SCR output
to contactor
J21 Switch input, such as high
pressure switch
J31 DI input power supply
J28 Output, such as J19 Remote switch
electric heater output
Figure 1-1
Control board of the indoor unit
Outstanding man-machine interface: The Liebert_DM series ACs provide a large Chinese/English LCD, a
user-friendly man-machine interface and an expert diagnosis system, as well as implement multi-level password
protection (avoid misoperation) and intelligent display of running states.
High reliability: Relying on the excellent quality and considerate services of Emerson, the Liebert_DM series ACs
ensure 24-hour reliable running all year round.
Strong adaptability to power grid: The Liebert_DM series ACs allow a wide range of voltage and provide the
following distinctive functions: unique phase loss protection, phase-sequence detection and protection, automatic
high-voltage & low-voltage detection and protection, self-recovery upon power failure.
All-weather operation: According to the distinct heating load feature of equipment rooms, the Liebert_DM series ACs
implement 24-hour running all year round in temperature ranging from -15°C to +45°C. If a Lee-Temp outdoor unit is
configured, the allowed running temperature ranges from -34°C to +45°C.
Strong network management: Being configured with a standard RS485 monitor interface, the Liebert_DM series
ACs implement flexible automatic switchover between active and standby devices, work shift, remote turn-off and
turn-on, remote alarm, and fault query and troubleshooting over standard telecommunication protocols.
Easy maintenance: The Liebert_DM series ACs provide a full front maintenance structure, facilitating maintenance.
Table 1-1 describes the differences between the Liebert_DM series ACs and commercial ACs.
Table 1-1 Differences between the Liebert_DM series ACs and commercial ACs
Design focus
Precision
Temperature control
Monitoring
All-rear-round continually operating
Testing before delivery
Control design
Cleanliness
Liebert_DM series AC
±1°C; ±1%RH
Humidifying and dehumidifying control
Local and romote monitoring
All-year-around cooling
Strict requirement
Precise control
High
Commercial AC
Generally ±3°C
None in general
None
No cooling needed in winter
Simple testing
CPU
Low
Liebert DM Series Air Conditioner Technical Manual
Chapter 2
Overview
3
Chapter 2 Overview
This chapter expounds the appearance, model description, product introduction, components and variety of accessory
options.
2.1 Appearance
Taking the indoor unit of the Liebert_DM series air conditioner as an example, the appearance as shown in Figure 2-1.
Figure 2-1 Indoor unit of the air conditioner
2.2 Model Description
The model description of the air conditioner is shown in Figure 2-2.
DM E 07 M C T
1
1: Standard; 2: High efficiency
Version code
C: cooling only; O: with heater; H: with heater and humidifier
Input power supply. M: 380V-3-ph-50Hz
Cooling capacity. 07: 7.5kW ; 12: 12.5kW
E: indoor unit; C: outdoor unit; L: Lee-Temp outdoor unit
Liebert_D series air conditioner
Figure 2-2 Model description
2.3 Product Introduction
The Liebert_DM AC is a small precise environment control system, specially designed for cooling the electrical
devices. It is applicable to environment control in equipement room and computer room. Featuring high reliability, it
can maintain a favorable environment for precise devices such as sensitive devices, industry process devices,
communication devices and computers.
The cooling kit is provided as standard and it can precisely control the ambient temperature. The heater and humidifier
are provided as options and they can precisely control the ambient humidity. If the AC unit is only available for cooling,
the options are not needed.
Liebert DM Series Air Conditioner Technical Manual
4
Chapter 2
Overview
The Liebert_DM AC provides a micro-processing controller that can automatically switch over to the required function
(cooling or heating, dehumidifying or humidifying), based on the programmed setpoints and room ambient conditions.
Each Liebert_DM AC consists of an indoor unit and an outdoor unit. Both units are installed on the floor separately.
Indoor unit
The Liebert_DM AC includes units with a cooling capacity of 7.5kW and 12.5kW, which are applicable to power supply
of 380V, 3-ph. You can select them according to the actual equipment room conditions.
Outdoor unit
The outdoor unit adopts air cooled mode. It is classified into two models: standard model and Lee-Temp model. The
Lee-Temp model can be used at lower temperature (see Table 1-1) than the standard model.
2.4 Main Components
2.4.1 Indoor Unit
The indoor unit consists of evaporator, compressor, fan, micro-processing controller, thermal expansion valve, strainer,
filter, heater (optional), humidifier (optional) and surge protective devices (SPD, optional). For option introduction, refer
to 2.5 Options.
Evaporator
Adopt a fin-tube heat exchanger with high efficiency. The distributor is designed and verified according to individual
model to ensure that the refrigerant is distributed evenly in each loop, improving the efficiency of the heat exchanger to
a great extent.
Compressor
Adopt a compressor with high efficiency ratio. It features low vibration, low noise and high reliability.
Fan
Adopt a centrifugal fan with high efficiency and high reliability. It features large airflow, long blowing distance, direct
driving and easy maintenance.
Micro-processing controller
Provide a simple-operation user interface with multi-level password protection, self-recovery upon power failure,
high-voltage & low-voltage protection, phase loss protection, automatic phase-sequence switching upon anti-phase
and rotate speed control of the outdoor fan. The expert-level fault diagnose system can automatically display current
fault information to facilitate equipment maintenance by maintenance personnel.
Thermal expansion valve
Adopt a thermal expansion valve with external equalizer type. It collects temperature and pressure signals at the same
time to accurately regulate the refrigerant flow.
Strainer
Filtrate the impurities generated during long-term system operation and ensure normal system operation.
Filter
Adopt nylon filter material with big mesh for Liebert_DM AC. The filter features compact structure and easy
maintenance. It can be washed repeatedly.
2.4.2 Outdoor Unit
The outdoor unit consists of fan and condenser. Other than the above components, the Lee-Temp model also includes
a low-temperature unit.
Fan
Adopt axial flow blades with low noise. The single-phase motor with high performance is customized based on the
power grid of base stations, so it can work over a wide voltage range with high reliability.
Liebert DM Series Air Conditioner Technical Manual
Chapter 2
Overview
5
Condenser
Adopt a fin-tube heat exchanger with high heat dissipation and wavy fins. It is free of dust accumulation, and can be
easily cleaned and maintained.
Low-temperature unit
Make the AC unit operate in cooling mode normally at the lowest outdoor temperature of -34°C.
2.5 Options
2.5.1 Humidifier
The humidifier can add pure water vapor (up to 2.5kg/hour) into the room to control the indoor humidity within ranges
required by devices and computer.
The humidifier consists of a steam canister with automatic flushing control function, inlet tube, drain tube, solenoid
valve and steam distributor.

Note
1. The electrode humidifier should be installed and tested in factory.
2. The Liebert_DM AC can control the ambient humidity only after a humidifier is installed.
2.5.2 Heater
A ceramic heater with positive temperature coefficient can be selected. It is safe and reliable. When the surface
temperature is too high, it will reduce the heating power to avoid danger caused by over-temperature. A temperature
switch is provided on the surface of the heater, and it will cut off the power of the heater when the surface temperature
is too high. When the surface temperature decreases to normal, the temperature switch will restore the operation of
the heater automatically.
2.5.3 Remote Monitor
The Liebert_DM AC communicates with the host computer through a configured RS485 port and receives the control
of the host software. You can also select and configure a monitoring card to realize different monitoring functions. For
the descriptions of the host monitoring software SiteMonitor developed by Emerson, refer to
Appendix 3 SiteMonitor Software Introduction.
2.5.4 Energy-Saving Card
The Liebert_DM AC can monitor the maximum room temperature with the energy-saving card located outside the unit
cabinet. The card is placed in position with high heat load and temperature. Up to four cards can be used for an AC
unit. When the temperatures measured by all energy-saving cards are lower than the setpoint in ‘Sleep Mod’ and only
indoor fan is running, if the ‘Sleep Mod’ is set to ‘ENAB’, the AC unit will turn off the indoor fan and enter the sleep
mode for saving the energy.
2.5.5 Power SPD
The power SPD is used for second level (C level) lightning over-voltage protection of the AC power. It can be
maintained easily and provides status indicating and alarm function.

Note
The power SPD should be installed in factory.
Liebert DM Series Air Conditioner Technical Manual
6
Chapter 3
Technical Parameter
Chapter 3 Technical Parameter
This chapter expounds the technical parameter, mechanical parameter and operating environment of the
indoor/outdoor unit of the Liebert_DM series AC.
3.1 Technical Parameter Of The Indoor Unit
Table 3-1 Technical parameter of DME07 series indoor unit
Model
Type
DME07
MCT1
DME07
MOT1
DME07
MHT1
DME07
MCP1
DME07
MOP1
DME07
MHP1
7500
7500
7500
7500
7500
7500
6500
6500
6500
6500
6500
6500
1800
1
1800
1
1800
1
1800
1
1800
1
1800
1
0
0
0
0
0
0
1
0.25
2
-
1
0.25
2
3.2
1
0.25
2
3.2
1
0.25
2
-
1
0.25
2
3.2
1
0.25
2
3.2
-
-
1.5
-
-
1.5
485 × 845
×8
312 × 317
×8
3
485 × 845
×8
312 × 317
×8
3
485 × 845
×8
312 × 317
×8
3
485 × 845
×8
312 × 317
×8
3
485 × 845
×8
312 × 317
×8
3
485 × 845
×8
312 × 317
×8
3
9.52
9.52
9.52
9.52
9.52
9.52
12.7
12.7
12.7
12.7
12.7
12.7
-
-
19
-
-
19
20
20
20
20
20
20
Net weight (kg)
90
92
95
Max. current (A)
6
8
20
Electrical
parameter
Air breaker
32
32
32
Note: all the cooling capacity is nominal, ±5% error exists in the actual capacity
90
6
32
92
8
32
95
20
32
Cooling
capacity and
sensible
cooling
capacity (kW)
Fan
Compressor
Evaporator coil
Electric heater
Electrode
humidifier
Filter
Port size
Cooling
capacity
Sensible
50%RH
cooling
capacity
Standard airflow (m3/h)
Number
Static pressure outside
the fan (Pa)
Number
Front face area (m2)
Face air velocity (m/s)
Power (kW)
Humidifier water rate
(kg/h)
Front filter size (mm, 1
pcs)
Side filter size (mm, 1
pcs)
Number
Liquid return pipe ID
(mm)
Discharge pipe ID (mm)
Humidifier
Charging pipe OD (mm)
Condensed water drain
pipe OD (mm)
24°CdB
Table 3-2 Technical parameter of DME12 series indoor unit
Model
Type
Cooling
capacity and
sensible
cooling
capacity (kW)
Fan
Cooling
capacity
Sensible
50%RH
cooling
capacity
Standard airflow (m3/h)
Number
Static pressure outside
the fan (Pa)
24°CdB
DME12
MCT1
DME12
MOT1
DME12
MHT1
DME12
MCP1
DME12
MOP1
DME12
MHP1
12500
12500
12500
12500
12500
12500
10200
10200
10200
10200
10200
10200
2800
1
2800
1
2800
1
2800
1
2800
1
2800
1
0
0
0
0
0
0
Liebert DM Series Air Conditioner Technical Manual
Chapter 3
Compressor
Evaporator coil
Electric heater
Electrode
humidifier
Filter
Port size
Number
Front face area (m2)
Face air velocity (m/s)
Power (kW)
Humidifier water rate
(kg/h)
Front filter size (mm, 1
pcs)
Side filter size (mm, 1
pcs)
Number
Liquid return pipe ID
(mm)
Discharge pipe ID (mm)
Humidifier
Charging pipe OD (mm)
Condensed water drain
pipe OD (mm)
Technical Parameter
1
0.37
2.1
-
1
0.37
2.1
3.2
1
0.37
2.1
3.2
1
0.37
21
-
1
0.37
2.1
3.2
1
0.37
2.1
3.2
-
-
2.5
-
-
2.5
578 × 914
×8
376 × 427
×8
3
578 × 914
×8
376 × 427
×8
3
578 × 914
×8
376 × 427
×8
3
578 × 914
×8
376 × 427
×8
3
578 × 914
×8
376 × 427
×8
3
578 × 914
×8
376 × 427
×8
3
12.7
12.7
12.7
12.7
12.7
12.7
16
16
16
16
16
16
-
-
19
-
-
19
20
20
20
20
20
20
140
10.5
32
142
10.5
32
145
22
32
Net weight (kg)
140
142
145
Max. current (A)
10.5
10.5
22
Electrical
parameter
Air breaker
32
32
32
Note: all the cooling capacity is nominal, ±5% error exists in the actual capacity
3.2 Technical Parameter Of The Outdoor Unit
Table 3-3 Technical parameter of the standard outdoor unit
Model
Item
Airflow (CMH)
Condenser coil CSA (m2)
Number of the condenser coil row
Motor power (W)
Operating temperature range (°C)
Refrigerant charge quantity (g)
Size of the liquid pipe (mm)
Size of the discharge pipe (mm)
DMC07WT1
3800
0.73
2
170
-15°C ~ +45°C
500
9.52
12.7
DMC12WT1
7300
1.1
2
340
-15°C ~ +45°C
1000
12.7
16
Table 3-4 Technical parameter of the Lee-Temp outdoor unit
Model
Item
Airflow (CMH)
Condenser coil CSA (m2)
Number of the condenser coil row
Motor power (W)
Operating temperature range (°C)
Refrigerant charge quantity (g)
Size of the liquid pipe (mm)
Size of the discharge pipe (mm)
7
DML07W1
3800
0.49
2
150
-34°C ~ +45°C
4870
9.52
12.7
3.3 Mechanical Parameter
3.3.1 Indoor Unit
The mechanical parameters of the indoor unit are listed in Figure 3-1 and Table 3-6.
Liebert DM Series Air Conditioner Technical Manual
DML12W1
7300
0.98
2
300
-34°C ~ +45°C
7150
12.7
16
8
Chapter 3
Technical Parameter
600
510
50
0
38
5
1850
1750
600
510
510
600
DME07kW
DME12kW
Figure 3-1
Dimensions of the indoor unit (unit: mm)
The shadows in Figure 3-1 indicate a reasonable installation and service space. For 7.5kW units, 510mm must be
reserved to facilitate maintenance; For 12.5kW unit, 600mm must be reserved to facilitate maintenance.
The AC unit equipped with a heater should be kept a distance of minimum 150mm from combustible substance. When
testing the AC unit, keep the external static pressure below 150Pa lest the air volume becomes too low and the heater
becomes too hot.
3.4 Outdoor Unit
The mechanical parameters of the outdoor unit are shown in Figure 3-2, Figure 3-3 and Table 3-6.
352
787
829
1240
352
787
Figure 3-2
Dimensions of standard outdoor unit (unit: mm)
Liebert DM Series Air Conditioner Technical Manual
Chapter 3
352
352
Technical Parameter
103
7
103
Figure 3-3
575
575
829
1240
7
Dimensions of Lee-Temp outdoor unit (unit: mm)
Table 3-5 Mechanical parameters of indoor unit and outdoor unit
Model
Cooling capacity (kW)
7.5
12.5
-
DME07***
DME12***
DMC07WT1
DMC12WT1
DML07W1
DML12W1
Indoor unit
Outdoor unit
Dimensions (W × D × H, mm)
510 × 385 × 1750
600 × 500 × 1850
787 × 352 × 829
787 × 352 × 1240
1037 × 352 × 829
1037 × 352 × 1240
Net weight (kg)
90
145
40
60
53
95
3.5 Operation Environment
The operation environment requirements are listed in Table 3-7.
Table 3-6 Operation environment requirements
Item
Installation position
Installation mode
Ambient temperature
Requirements
The maximum equivalent horizontal distance between the indoor unit and outdoor unit[1]: 50m;
Vertical distance ΔH[2]: -5m ≤ ΔH ≤ 20m
Indoor unit: vertical mode; mounting base ≥ 150mm;
outdoor unit: horizontal airflow mode
Indoor: 0°C ~ 40°C
Outdoor: standard model, -15°C ~ +45°C; Lee-Temp model, -34°C ~ +45°C
30%RH ~ 80%RH
Outdoor unit: IPX4
< 1000m. Derating is required when the altitude exceeds 1000m
380V (-15% ~ +15%), settable according to different environments, the error is 3%
Ambient humidity
Protection level
Altitude
Operation voltage range
Note:
[1]: The value is positive if the outdoor unit is installed above the indoor unit; negative if the indoor unit is installed above the
outdoor unit.
[2]: ΔH = Altitude of the outdoor unit - Altitude of the indoor unit
[3]:Total transportation and storage time should not exceed six months. Otherwise, the performance needs to be re-calibrated
Liebert DM Series Air Conditioner Technical Manual
9
10
Chapter 4
Application Guidline
Chapter 4 Application Guidline
This chapter mainly introduces the general arrangement, general principle, piping, model configuration and cooling
cycle.
4.1 General Arrangement
The general system arrangement diagram is shown in Figure 4-1. The standard pipe sizes are shown in Table 4-1.
Figure 4-1

General arrangement diagram
Note
1.
: Factory piping.
2.
: Field piping (by technicians).
3. *: Check valve and traps are optional and not supplied by Emerson. But they are recommended for normal system operation
and easy maintenance. They should be installed on site by technicians.
4. +: Solenoid valve is a part of extended piping kit.
Table 4-1 Standard pipe sizes
Actual cooling capacity
7.5kW unit
12.5kW unit
Liebert_DM series
Pipe length (m)
5
5
Discharge pipe OD
1/2” (12mm)
5/8” (16mm)
Liquid pipe OD
3/8” (10mm)
1/2” (12mm)
4.2 General Principles
1. Use copper pipes with quick thread connector to connect the indoor unit and the outdoor unit. If the pipe length
exceeds the standard pipe length (see Table 4-1) and straight copper pipe is used, piping joints must be brazed.
2. Follow standard industry procedures in selection and placement of pipe, system evacuation and charging with
refrigerant (only when pipeline is too long). The standard refrigerant of the AC unit is R22.
3. Give considerations to pipeline pressure drop, oil return to the compressor, to avoid oil leakage and clogging in parts
of the system and minimize noise and vibration to the greatest extend.
4. Consult Emerson before installation on whether measures such as using extended piping kit are needed, if the
equivalent length exceeds 50m, or if the vertical distance between the indoor unit and the outdoor unit exceeds the
values in Table 4-2.
Liebert DM Series Air Conditioner Technical Manual
Chapter 4
Application Guidline
11
Table 4-2 Vertical distance between indoor unit and outdoor unit
Relative position
Outdoor unit installed higher than indoor unit
Outdoor unit installed lower than indoor unit
Value
Maximum: 20m
Maximum: 5m
5. The equivalent length of each part is given in Table 4-3. The resistance loss caused by elbows and valves has been
taken into consideration. The installer should confirm if these values are appropriate for site conditions.
Table 4-3 Equivalent length of each part
Liquid pipe OD (inch)
Equivalent length (m)
45° elbow
0.10
0.12
0.15
0.18
0.24
0.3
90° elbow
0.21
0.24
0.27
0.3
0.44
0.56
3/8
1/2
5/8
3/4
7/8
1-1/8
T-type three way
0.76
0.76
0.76
0.76
1.1
1.4
4.3 Piping
All equipment must be installed vertically. The Liebert_DM AC is available in two installation modes: outdoor unit
installed higher than indoor unit and indoor unit installed higher than outdoor unit. See Figure 4-2 and Figure 4-3 for
details.
Outdoor unit
Liquid pipe (not be exposed to sun)
Max. 20m
Indoor unit
Trap
7.5m
Protection
tube
Sealed
Figure 4-2
Humidifier canister water
supply pipe (to water tap)
Isolataion
floor
Discharge pipe (slope)
1:200
Insulation
material
Outdoor unit above indoor unit
Liebert DM Series Air Conditioner Technical Manual
Floor Condensation water
drain pipe (to outdoor)
1:200
12
Chapter 4
Application Guidline
Indoor unit
Protection tube
Discharge pipe (slope)
1:200
Sealed
Humidifier canister water
supply pipe (to water tap)
Isolation floor
Min. 5m
Liquid pipe (not be
exposed to sun)
Outdoor unit
Insulation
material
Floor Condensation water
drain pipe (to outdoor)
1:200
Figure 4-3 Indoor unit above outdoor unit
4.4 Model Configuration
Table 4-4 Configuration of the indoor unit and the outdoor unit
Main power
Cooling
capacity
Single cooling
380V/3P/50Hz
7.5kW
12.5kW
DME07MCT(P)1
DME12MCT(P)1
Indoor unit
With electric
heating
DME07MOT(P)1
DME12MOT(P)1
With humidifying
and heating
DME07MHT(P)1
DME12MHT(P)1
Outdoor unit
Standard
Lee-Temp
model
model
DMC07WT1
DML07W1
DMC12WT1
DML12W1
4.5 Cooling Circulation
As shown in Figure 4-4, the compressor (1) presses the high-temperature gaseous refrigerant into the air-cooled
condenser (2). The refrigerant is condensed as fluid in the condenser and sent to the evaporator (4) after being
throttled by the thermostatic expansion valve (3). In the evaporator (4), the refrigerant performs heat exchange with
the indoor air that is driven and circulated by the indoor fan (5) and then evaporates. The refrigerant is sent back to the
compressor (1) to start a new circulation. The system adjusts the rotation speed of the outdoor fan (6) to retain the
discharge pressure normal.
The compressor (1) is configured with a crankcase heating strip to prevent the refrigerant from flowing back from the
condenser in summer. This can protect the compressor from liquid strike during startup.
Figure 4-4 Schematic diagram of the system
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Chapter 5
Micro-Processing Controller
13
Chapter 5 Micro-Processing controller
This chapter gives a detailed description on appearance, LCD screen, control buttons, control screen, control logic,
alarm function of the micro-processing controller of the Liebert_DM AC.
5.1 Appearance
The micro-processing controller panel is shown in Figure 5-1.
Figure 5-1 Micro-processing controller panel
5.2 LCD Screen
The LCD screen displays English menus with white backlight. When the system is operating normally, it displays the
current temperature & humidity (whether to display humidity is optional. Only the unit configured with a humidifier can
display humidity), unit output status (cooling, heating, dehumidifying and humidifying), unit status (single, host,
standby), unit operation status (running, standby, locked), alarm information and current date & time, as shown in
Figure 5-2.
21°
C
Heat SIG
50%rh
Hum RUN
High Hum
1/4
2012/01/01
00:00
Figure 5-2
LCD screen
More detailed operating status of certain component and alarm information are available from the Main Menu screen.
The selected menu item will be highlighted while browsing. The digit to be changed will be highlighted while you are
changing setting.
5.3 Control Buttons
5.3.1 Function Description
The micro-processing controller provides five control buttons, as shown in Figure 5-3.
ON/OFF button
Up button
Enter button
Down button
Esc button
Figure 5-3 Control keypad
The functions of the control buttons are described in Table 5-1.
Table 5-1 Function descriptions of control buttons
Control button
Function descriptions
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Chapter 5
Micro-Processing Controller
ON/OFF button
Enter button (ENT)
Esc button (ESC)
Up button
Down button
Press this button for 3s to turn on or off the unit
Enter the selected menu screen. Validate the parameter setting value
Exit the current menu and return to the Normal screen or previous menu screen. Abort parameter change;
silence the audible alarm
Move the cursor up or increase the parameter value. For a toggle selection: scroll through the options. For a
multi-screen menu: scroll up the screen
Move the cursor down or decrease the parameter value. For a toggle selection: scroll through the options.
For a multi-screen menu: scroll down the screen
5.3.2 Operation Example
Example 1: Inputting password to enter the Main Menu
After the unit is started up, you can enter the Main Menu through conducting the following operations on the Normal
screen.
1. Press the Enter button to enter the Password screen.
2. Press the Enter button to highlight the input data field in the Password screen.
3. Press the Up or Down button to change the current password number.
4. Press the Enter button to confirm the password and enter the Main Menu screen.
Example 2: changing parameters
Taking Hi Temp in Alarm Output screen as an example, the procedures are as follows:
1. Press the Up or Down button to move the cursor on the Alarm Menu in the Main Menu screen.
2. Press the Enter button to enter the Alarm Menu.
3. Press the Up or Down button to move the cursor on Alarm Output in the Alarm Menu screen.
4. Press the Enter button to enter the Alarm Output screen.
5. Press the Up or Down button to move the cursor on Hi Temp.
6. Press the Enter button to highlight the parameter field of Hi Temp.
7. Press the Up or Down button to select the parameter option.
8. After selecting, press the Enter button to confirm. The parameter will take effect.
9. Press the Esc button to return to the previous menu screen.

Note
After changing the parameter, if you do not press the Enter button to validate the changed parameter, the change will be invalid.
5.4 Control Screen
5.4.1 ON Screen
After the AC unit is powered on, the LCD screen will display the ON screen, as shown in Figure 5-4.
Connecting
Please wait...
Figure 5-4
ON screen
5.4.2 Normal Screen
After the AC unit is powered on, the Normal screen will be displayed after 10 seconds (default) for heat startup delay or
through pressing the Enter button directly, as shown in Figure 5-5. The Normal screen displays the following
information: the current temperature and humidity, unit operation state (cooling, heating, dehumidifying, humidifying),
unit mode (single, host, standby), unit operation status (running, standby, locked, off, sleep), alarm information and
current date & time.
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Chapter 5
Micro-Processing Controller
15
21°
C
Heat SIG
50%rh
Hum RUN
No alarm
0
2012/01/01
00:00
Figure 5-5
Normal screen
5.4.3 Password Screen
Press the Enter button on the Normal screen, and the Password screen will appear, as shown in Figure 5-6.
Password: 1***
Figure 5-6 Password screen
Three levels of passwords are provided for accessing the menus. The detailed descriptions are listed in Table 5-2.
Table 5-2 Password level
Password level
User
Initial password
Level 1
General operator
0001
Level 2
Level 3
Maintenance personnel
Factory technician
-
Remark
Browse all menu information. Only set temperature and
humidity setpoints (see Figure 5-12) and cannot change any
values and settings
Set all parameters
-
For detailed operation on entering the password, refer to 5.3.2 Operation Example. If entering a wrong password, you
can only view the menu, but cannot change the settings. In this case, you can press the Esc button to return to the
Normal screen, and then press the Enter button to enter the Password screen again.

Note
If pressing the Enter button in the Password screen instead of inputting any password, you can only view the menu settings but
cannot change any parameters.
5.5 Control Logic
5.5.1 Cooling logic
When the actual temperature = set temperature + temperature precision value, the cooling requirement reaches
100%.
When the actual temperature = set temperature, the cooling requirement is 0%.
When the actual temperature rises to the degree corresponding to the 100% cooling requirement, cooling starts; when
the actual temperature drops to the degree corresponding to the 0% cooling requirement, cooling stops (the
compressor is turned off).
Figure 5-7 shows the cooling logic diagram.
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Chapter 5
Micro-Processing Controller
The compressor is
turned off
Indoor temperature
0%
Set point
Figure 5-7
The compressor
is turned on
+100%
Cooling logic
5.5.2 Heating Logic
When the actual temperature = set temperature - temperature precision value, the heating requirement reaches 100%.
When the actual temperature = set temperature, the heating requirement is 0%.
When the actual temperature drops to the degree corresponding to the 100% heating requirement, heating starts;
when the actual temperature rises to the degree corresponding to the 0% heating requirement, heating stops (the
electronic heater is turned off).
Figure 5-8 shows the heating logic diagram.
Electric heater
is turned on
Electric heater
is turned off
-100%
Indoor temperature
0%
Set point
Figure 5-8
Heating logic
5.5.3 Dehumidifying Logic
1. Relative humidity control logic
Dehumidifying is activated when the cooling requirement is smaller than 125% and the dehumidifying requirement is
larger than 100%.
Dehumidifying is deactivated when the dehumidification requirement is no larger than 50%.
Figure 5-9 shows the dehumidifying activation and deactivation requirements.
Exit
dehumidifying mode
Enter dehumidifying
mode
Indoor humidity
Set point
Figure 5-9
+50%
+100%
Dehumidifying activation and deactivation requirements
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Micro-Processing Controller
17
In the dehumidifying mode, the fan switches to high gear immediately when the cooling requirement is larger than
125%. The fan switches back to low gear when the temperature drops normal.
Figure 5-10 shows the high/low gear switch diagram of the fan in the dehumidifying mode.
Switch to
high gear
Switch to low gear
+125%
Set point
Figure 5-10
Indoor
temperature
High/low gear switch diagram of the fan in the dehumidifying mode
In the temperature compensation mode, the compressor is turned on when the cooling requirement is larger than 0%
and it is turned off when the cooling requirement is smaller than -100%; the electronic heater is turned on when the
cooling requirement is smaller than 0% and it is turned off when the cooling requirement is larger than 25%.
Figure 5-11 shows the control logic of the compressor in a) and the control logic of the electronic heater in b).
The
compressor
is turned off
-100%
Indoor
temperature
Set point
Set point
a) Control logic of the compressor
Figure 5-11
The electric heater
is turned off
The electric heater
is turned on
The compressor
is turned on
+25%
Indoor
temperature
b) Control logic of the electronic heater
Dehumidification logic in the temperature compensation mode
In the non-temperature compensation mode, the compressor is turned on and the electronic heater is turned off when
the cooling requirement is no smaller than 0%; the compressor is turned off and the electronic heater is turned on
when the cooling requirement is smaller than -100%.
Figure 5-12 shows the control logic of the compressor in a) and the control logic of the electronic heater in b).
The
compressor
is turned off
-100%
Set point
a) Control logic of the compressor
Figure 5-12
The electric
heater is
turned off
The electric
heater is
turned on
The
compressor
is turned on
Indoor
temperature
-100%
Set point
Indoor
temperature
b) Control logic of the electronic heater
Dehumidifying logic in the non-temperature compensation mode
2. Absolute Humidity Control Logic
If absolute humidity control logic is used, users should calculate the absolute humidity based on the actual
temperature and humidity and perform humidity control by referring to 1. Relative humidity control logic in this section.
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Chapter 5
Micro-Processing Controller
5.5.4 Humidifying Logic
1. Relative humidity control logic
When the actual humidity = set humidity - humidity precision value, the humidification requirement reaches 100%.
When the actual humidity = set humidity, the humidification requirement is 00%.
When the actual humidity drops to the value corresponding to the 100% humidification requirement, humidification
starts; when the actual humidity rises to the value corresponding to the 0% humidification requirement, humidification
stops.
Figure 5-13 shows the humidification logic diagram.
The
humidifier is
turned off
The
humidifier is
turned on
0%
Set point
-100%
Figure 5-13
Indoor
temperature
Humidification logic
2. Absolute humidity control logic
If absolute humidity control logic is used, users should calculate the absolute humidity based on the actual
temperature and humidity and perform humidity control by referring to 1. Relative humidity control logic in this section.
5.5.5 Outdoor Fan Control
1. If the pressure sensor is faulty, the fan operates at full speed.
2. If frequency deviation happens, the fan stops operating.
3. If the compressor is supplied with power and the pressure in the condenser meets requirements for starting the fan,
the fan starts.
4. If the compressor is supplied with power and the pressure in the condenser meets requirements for stopping the fan,
the fan stops. Alternatively, if the compressor is stopped for more than one minute, the fan stops.
5. Figure 5-14 shows the voltage control curve during fan operating, which is on the basis of FSC1P control curve.
V
100%
Vin
F
E
L2
B
MaxV
C
D
A
Vx
L1
H
MinV
100% output
Condensation pressure point
G
Pband
Pv100 = (Pset + Pband + 5)
I
Poff
Pset
Px
Pmaxv Pv100
P
Figure 5-14 FSC1P control curve
During fan startup, the voltage is obtained based on the pressure-voltage curve if the pressure is kept within the set
range and the voltage is the value of MaxV if the pressure exceeds the set range. During fan operating, the power
system stops supplying power to the fan if the condensation pressure is smaller than (Pset - 1), namely Poff. The
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Micro-Processing Controller
19
control process is A -> B -> C -> D -> E -> F -> C -> B -> A -> G -> H -> I (point A corresponds to the pressure ranging
from B to G). In the case of 100% voltage output, the voltage restores to MaxV after the pressure drops by 2 bars to
the point of Pmaxv. Table 5-3 lists the voltage and pressure parameters.
Table 5-3 Voltage and pressure setting table
Parameter
Min. power supply voltage (%)
Max. power supply voltage (%)
Start pressure (Bar)
Pressure bandwidth (Bar)
Lower limit
30
60
11
4
Upper limit
50
100
15
6
Default
30
100
13
5
5.5.6 Economy Mode Control
1. The AC units enter the Economy mode after this mode is enabled.
2. When the system starts to operate in this mode, the temperature control precision is added with the precision
amplification value. When the system exits this mode, the normal precision value recovers.
Table 5-4 lists the parameter setting in the Economy mode.
Table 5-4 Parameter setting in the Economy mode
Parameter
Economy mode
Start At
Start At
Zoom (°C)
Default value
OFF (0)
22: 00
7: 00
2
Lower limit
OFF (0)
18: 00
5: 00
2
Upper limit
ON (1)
3: 00
10: 00
10
5.5.7 Sleep Mode Control
1. The AC units enter the Sleep mode when there is one energy-saving card or more.
2. In this mode, the fan stops operating when the following conditions are met:
1) All the other moving parts do not need to operate except for the indoor fan.
2) The temperature of all energy-saving cards (four at most) is lower than the sleep temperature.
3) The energy-saving cards are kept in the temperature for 600 seconds.
3. The AC units exit the Sleep mode when either of the following conditions is met:
1) The temperature of an energy-saving card exceeds the value of sleep temperature plus 2 and the energy-saving
card is kept in the temperature for 30 seconds.
2) No energy-saving card is available.
Table 5-5 lists the parameter setting in the Sleep mode.
Table 5-5 Parameter setting in the Sleep mode
Parameter
EngySave Cd Num
Sleep At
Default value
0
27°C
Lower limit
0
15
Upper limit
4
40
5.5.8 Host/Standby Unit Control
1. The host unit automatically switches as a standby unit after a rotate cycle ends.
2. The host unit switches as a standby unit and the standby unit switches as an host unit after a fault occurs in the host
unit or standby unit, such as high pressure locking, low pressure locking, or discharge locking.
3. The standby unit works as a host unit after a high temperature alarm is generated by the host unit.
Table 5-6 lists the parameter setting for host/standby unit control.
Table 5-6 Parameter setting for host/standby unit control
Parameter
Unit Status
Switch Mod
Rt Time
Lower limit
0
0
Upper limit
2
1
By day (1, 2, 3, 4, 5, 6, and 7)
Default
0
0
1
Remark
0: SIG; 1: HST; 2: Standby
0: Standby; 1: Rotate
The number indicates the interval days
between two polling cycles.
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Chapter 5
Micro-Processing Controller
Rt At
0: 00
23: 00
12: 00
-
5.6 Alarm Function
5.6.1 Alarm Category
Alarms fall into the following categories: high pressure alarm, low pressure alarm, discharge temperature alarm, high
temperature alarm, low temperature alarm, high humidity alarm, low humidity alarm, humidifier fault, fault of return air
temperature sensor, high pressure locking, low pressure locking, discharge temperature locking, floor wetting, power
loss, over-voltage alarm, under-voltage alarm, frequency deviation, loss phase alarm, negative phase alarm, custom
alarm 1 (lightning protection), energy-saving card fault, air flow loss, pressure sensor fault, humidity sensor fault, air
flow sensor fault, and custom alarm 2.
5.6.2 Alarm State And History
1. Alarm state recording
1) Alarms are recorded based on alarm occurrence time.
2) Both the alarm category and alarm time are recorded.
3) Alarm states are cleared upon power failure.
2. Alarm history recording
1) Historical alarms are recorded based on alarm occurrence time.
2) A maximum of 200 historical alarms are recorded.
3) A historical alarm includes the alarm SN., alarm category, alarm time, and alarm clearance time.
4) Historical alarms are saved upon power failure.
5) Historical alarms can be manually cleared.
6) Two-level password protection is enabled for historical alarms.
5.6.3 Alarm Prerequisites And Handling Methods
Table 5-7 Alarm prerequisites and handling methods
No.
Alarm
Alarm Prerequisite
Alarm Mode
Clearance Method
Alarm
reporting
delay (unit:
second)
Alarm Output
High
pressure
alarm
The high pressure switch is
kept open-circuited for a
duration of alarm reporting
delay
The alarm is
triggered and
the
compressor is
forcibly closed
Keep the high
pressure switch turned
off for a duration of
alarm reporting delay
3
Enabled/
disabled
2
Low
pressure
alarm
The low pressure switch is
kept open-circuited for a
duration of alarm reporting
delay in the case of
compressor operating. The
state of the low pressure
switch is ignored for 180
seconds. The duration is
configurable, ranging from
30 seconds to 600 seconds
The alarm is
triggered and
the
compressor is
forcibly closed
Keep the low pressure
switch turned off for a
duration of alarm
reporting delay
30
Enabled/
disabled
3
Discharge
temperature
alarm
The discharge temperature
switch is kept turned off for a
duration of alarm reporting
delay in the case of
compressor operating
The alarm is
triggered and
the
compressor is
forcibly closed
Keep the discharge
temperature switch
turned off for a
duration of alarm
reporting delay
3
Enabled/
disabled
4
High
temperature
alarm
The fan is enabled for 10
minutes and the return air
temperature is kept higher
The alarm is
triggered and
the electronic
Keep the return air
temperature lower
than the value (current
30
Enabled/
disabled/
closed
1
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No.
Alarm
Alarm Prerequisite
than the high temperature
threshold for a duration of
alarm reporting delay while
the return air temperature
sensor operates normally
Alarm Mode
heater is
closed
Micro-Processing Controller
Clearance Method
Alarm
reporting
delay (unit:
second)
Alarm Output
high temperature
threshold - 2°C) for a
duration of alarm
reporting delay
Low
temperature
alarm
The fan is enabled for 10
minutes and the return air
temperature is kept lower
than the low temperature
threshold for a duration of
alarm reporting delay while
the return air temperature
sensor operates normally
The alarm is
triggered and
the cooling
system is
closed
Keep the return air
temperature higher
than the value (current
low temperature
threshold + 2°C) for a
duration of alarm
reporting delay
30
Enabled/d
isabled/
closed
High
humidity
alarm
The fan is enabled for 10
minutes and the return air
humidity is kept higher than
the high humidity threshold
for a duration of alarm
reporting delay while the
return air humidity sensor
operates normally
The alarm is
triggered and
humidification
stops
Keep the return air
humidity lower than
the value (current high
humidity threshold 2%) for a duration of
alarm reporting delay
30
Enabled/
disabled/
closed
7
Low
humidity
alarm
The fan is enabled for 10
minutes and the return air
humidity is kept lower than
the low humidity threshold
for a duration of alarm
reporting delay while the
return air humidity sensor
operates normally
The alarm is
triggered and
dehumidificati
on stops
Keep the return air
humidity higher than
the value (current low
humidity threshold +
2%) for a duration of
alarm reporting delay
30
Enabled/
disabled/
closed
8
Humidifier
fault
The humidifier switch is kept
turned off for a duration of
alarm reporting delay
The alarm is
triggered
Keep the humidifier
switch turned off for a
duration of alarm
reporting delay
10
Enabled/
disabled/
closed
9
Fault of the
return air
temperature
sensor
The return air temperature is
kept out of the allowed range
for a duration of alarm
reporting delay
The alarm is
triggered and
the cooling
system is
forcibly started
Keep the return air
temperature within the
allowed range for a
duration of alarm
reporting delay
10
Enabled/
disabled/
closed
10
High
pressure
locking
The high pressure alarm is
reported for three times
within an hour or the alarm is
kept uncleared within 10
minutes
The alarm is
triggered and
the
compressor is
locked
Manually clear the
alarm
/
Enabled/
disabled
11
Low
pressure
locking
The low pressure alarm is
reported for three times
within an hour or the alarm is
kept uncleared within 10
minutes
The alarm is
triggered and
the
compressor is
locked
Manually clear the
alarm
/
Enabled/
disabled
12
Discharge
temperature
locking
The discharge temperature
alarm is reported for three
times within an hour or the
alarm is kept uncleared for
20 minutes
The alarm is
triggered and
the
compressor is
locked
Manually clear the
alarm
/
Enabled/
disabled
13
Floor
wetting
alarm
The floor wetting switch is
kept turned off for a duration
of alarm reporting delay
The alarm is
triggered and
humidification
stops
Keep the floor wetting
switch turned off for a
duration of alarm
reporting delay
10
Enabled/
disabled/
closed
5
6
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Chapter 5
No.
Micro-Processing Controller
Alarm
Alarm Prerequisite
Alarm Mode
Clearance Method
Alarm
reporting
delay (unit:
second)
Alarm Output
14
Power loss
Power loss occurs when the
AC units are in operation
The alarm is
triggered
The alarm is
automatically cleared
one second later
/
Enabled/
disabled/
closed
15
Over-voltag
e alarm
The input voltage increases
by 15%
The alarm is
triggered and
the system is
locked
Restore the input
voltage
3
Enabled/
disabled/
closed
16
Under-volta
ge alarm
The input voltage decreases
by 15%
The alarm is
triggered and
the system is
locked
Restore the input
voltage
3
Enabled/
disabled/
closed
17
Frequency
deviation
The input frequency is
deviated by 5Hz
The alarm is
triggered and
the system is
locked
Restore the frequency
3
Enabled/
disabled/
closed
18
Open phase
alarm
Open phase occurs
The alarm is
triggered and
the system is
locked
Manual restoration
3
Enabled/
disabled/
closed
19
Negative
phase alarm
Negative phase occurs
The alarm is
triggered and
the system is
locked
Manual restoration
/
Enabled/
disabled/
closed
20
Custom
alarm 1
(lightning
protection)
The set polarities are kept
inconsistent with those input
for a duration of alarm
reporting delay
The alarm is
triggered
Keep the set polarities
consistent with those
input for a duration of
alarm reporting delay
30
Enabled/
disabled/
closed
Energy
saving card
fault
The number of normally
online energy-saving cards
is less than the set number
or more than one
energy-saving card exceed
the allowed temperature
range
The alarm is
triggered and
the dormancy
mode cannot
be activated if
all
energy-saving
cards are
faulty
Keep the number of
the cards consistent
with the set number
and keep the cards in
normal temperature
30
Enabled/
disabled/
closed
22
Air flow loss
The value (temperature
measured by using the
sensor NTC0 - return air
temperature) is kept larger
than the set temperature for
a duration of alarm reporting
delay when the fan is in
normal operation. The air
flow detection thermal
resistor output is closed
when the fan is shut down.
This alarm is not reported if
the fan is closed and the
temperature sensor is faulty
The alarm is
triggered and
shut down all
the devices
except for the
fan
Keep the value
(temperature
measured by using the
sensor NTC0 - return
air temperature)
smaller than the value
(set temperature - 2°C)
10
Enabled/
disabled
23
Fault of
pressure
sensor 1
The condensing pressure is
kept out of the allowed range
for a duration of alarm
reporting delay
The alarm is
triggered
Keep the condensing
pressure within the
allowed range for a
duration of alarm
reporting delay
3
Enabled/
disabled
The return air humidity is
The alarm is
Keep the return air
10
Enabled/
21
（lightning
protection）
24
Humidity
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25
Alarm
Alarm Prerequisite
sensor fault
kept out of the allowed range
for a duration of alarm
reporting delay
Air flow
sensor fault
The temperature measured
by using the air flow loss
sensor (NTC0) is kept out of
the allowed range for a
duration of alarm reporting
delay
Alarm Mode
triggered
The alarm is
triggered
Micro-Processing Controller
Clearance Method
Alarm
reporting
delay (unit:
second)
humidity within the
allowed range for a
duration of alarm
reporting delay
Keep the temperature
measured by using the
air flow loss sensor
(NTC0) within the
allowed range for a
duration of alarm
reporting delay
23
Alarm Output
disabled/
closed
10
Enabled/
disabled/
closed
Note:
1. Alarm reporting delay is a fixed configuration.
2. In the case of system locking, the compressor, heater, humidifier, and outdoor fan are locked.
5.7 Other Functions
5.7.1 Real-Time Clock
1. Set and display the system date and time.
2. This function provides the accurate time of data recording.
5.7.2 Operating Record
1. Device startup and stop record
A maximum of 50 records about device startup and stop are recorded, including the fan, compressor, electronic heater,
and humidifier.
2. Operating time record
The operating time of the fan, compressor, electronic heater, and humidifier is recorded by hour.
5.7.3 Parameter Protection
1. All parameters that need to be protected are saved in the internal EEPROM.
2. Default parameter settings can be restored.
3. Two-level password protection is enabled.
5.7.4 Password Protection
1. A password consists of four digits, ranging from 0000 to 9999. Password protection is classified into three levels.
2. Level 1 password is available for ordinary users. They can modify password protection parameters and level 1
password.
3. Level 2 password is available for operators. They can modify password protection parameters and level 1 and level
2 password.
4. Level 3 password is available for maintenance personnel. Except for level 3 password, they can modify password
parameters and level 1 and level 2 password.
5.7.5 Shutdown Mode
1. Shutdown modes fall into local shutdown, monitor shutdown, and remote shutdown.
2. Local shutdown is implemented by pressing the on/off button on the display panel.
3. Monitor shutdown is implemented through the background monitor RS485-1.
4. Remote shutdown has the highest priority and is in serial relationship with the other shutdown modes.
Liebert DM Series Air Conditioner Technical Manual
24
Chapter 5
Micro-Processing Controller
5.7.6 Diagnosis Output
1. In the diagnosis mode, devices such as the primary fan, compressor, electronic heater, and humidifier can be
tested.
2. A tested device can be automatically or manually shut down when it diagnoses another load.
3. If a device is not manually shut down within an hour, the device automatically exits the manual shutdown mode.
4. The fan must be always in operation. If the fan stops operating, the other devices are forcibly shut down. The
system must be protected in the case of major alarms, such as air flow loss, high pressure alarm, low pressure alarm,
discharge alarm and locking, and power fault.
5.7.7 Sensor Calibration
1. The temperature calibration range is ±5°C.
2. The humidity calibration range is ±10%.
5.7.8 Deployment Management
Deployment management is required during initial system operating.
Liebert DM Series Air Conditioner Technical Manual
Appendix 1
Menu Structure
Appendix 1 Menu Structure
Main Menu
Alarm Menu
Set Points
System Status
Temp Calib
Help Menu
System Menu
Temp Stpt
Analog
Hum Calib
Mntr Prtcl
Temp Sens
Time/Date
NTC0 Calib
Mntr Addr
Hum Stpt
Language
Run Time
Comp SS Record
Heat SS Record
Under Press
Pwr Freq Devia
Hi Temp
Hum SS Record
Alarm
Setpoint
Lo Temp
Out Fan SS
Record
Lo Hum
Enab Open
SS Record
Hum Sens
Air Loss
Contrast
In Fan SS Record
Alarm
Status
Alarm
History
Hi Hum
Version Info
In/Out Status
Setup
System
Baut Rate
Over Press
Min. Volt
Max. Volt
Outdoor
Unit
Out Volt
Start Press
Press BdWdth
Heat Num
Hum Num
Select
Options
CostSave Mod
EngySave Cd Num
Unit Mode
Switch Mod
Change Password
Factory Reset
Figure 1 Menu structure
Liebert DM Series Air Conditioner Technical Manual
LCD Setting
25
Appendix 2 Wiring Diagram
Appendix 2 Wiring Diagram
Black
Yellow Fuse
Yellow
Red
Transformer T2
Indoor connection
terminal TB1
Black
TB1-N
TB2-21
TB2-22
J2-2
J2-1
Black
Black
A2
J1-N
J1-L
Filter
board
KM2
J18
KM2-A1
J28-4
Black
Black
J01-7
1 2 3 4 5 6 7 8
1 2
J01
J02
Black
Black
J02
2
1
J14 2
Power
board
1
GND
J12 2 12V
Yellow-green
J03
2
1
J39 2
1
J29
J3-4
White
Black
J30
Grounding point
of the electrical
control box
SPD-NC
SPD-COM
Remote turn on/off
Grounding point
Standby unit request
of the electrical Start capacitor
control box
J19-1
J19-2
J19-5
J19-6
J19-7
J19-8
1
2
3
4
5
6
7
8
GND
4
12V
3
A
2
B
Gray
A
B
J4
1
Gray
J34
Control board
Indoor
fan
Brown
Yellow-green
KM1-A2 N1 L1
Monitoring
card
DB9
Display
board
1 2 3 4 5 6 7 8
5 4 3 2 1
Brown
Brown
J14-2
J14-1
1
J03
1 2 3 4 5 6 7 8
Electric
heater
1 2
J13 J31
J3
2 4 6 14
Brown
Electric heater belt
of the compressor
J01-5
1
2
3
4
5
J28-3
Compressor
Blue
Blue
Gray
KM1-22
KM1-6
Brown
T3
KM1-4
Black
T1
T2
J3-4
KM1-2
2
1
J18-1
J18-2
J18-3
J01-3
Black
Black
Black
J3-2
J3-1
TB2-21
KM2-1
A1 1 3 5 13
Grounding point of the
electrical control box
J1
J2
KM2-3
Black
Black
Black
KM1-21
KM1-5
2 1
A1 1 3 5 21
Black
Standby unit is available
Public alarm
KM1-A1
A2 2 4 6 22
Black
TB1-15
SPD/D
KM1
23 24 Indoor connection
2122 terminals TB2
TB1-13
L1 L2 L3
J18-3
KM1-1
380V/50Hz 3N~
Yellow
Transformer T1
TB1-N
TB1-N
TB1-11
Power SPD
J19-2
J19-1
To outdoor
unit
Yellow Fuse
Black
J01-1
Black
Black
SPD-3
Black
Black
SPD-N
N
ALARM
COM NC
Black
Power
MCB
SPD-2
Black
5
6
SPD-1
Black
QF-5
3
4
PE Yellow-green
Black
QF-3
1
2
PE N
J28-7
J28-8
J28-9
J28-10
KM1-3
PE1L1N1
QF-1
Black
Black
Yellow-green
PE
N
Black
J3-1
J3-2
Grounding point of the
electrical control box
NN
NN
NN
TB1-N
NN
TB1-1
1 11
TB1-2
2 12
TB1-3
3 13
TB1-4
4 14
TB1-5
5 15
6 16
TB1-7
7 17
TB1-8
8 18
TB1-9
9 19
TB1-10
1020
J28
J19
J21
J23
GND
VIN
+5V
3 2 1
J36
1
2
3
4
5
6
7
8
91
0
1
2
3
4
5
6
7
8
J28-3
J28-4
Black
Black
J28-7
J28-8
J28-9
J28-10
Black
Black
Black
Black
J21-5
J21-6
Black
Black
Blue
Blue
Black
Brown
Temp/Hum
detection board
KM2-A2
TB2-22
TB1-7
TB1-8
TB1-9
TB1-10
High pressure switch
Low pressure switch
Air discharging switch
Floor overflow
Black
Green
Red
Connection cables between indoor
Cable description:
and outdoor connection terminal
Factory supplied line
EnergyField supplied line
L1
L
Indoor
saving card
N1
connection
N
Parts supplied line
Pressure sensor
terminal
PE1
Inserted terminals
Outdoor
connection
Connection description:
terminal
1. This diagram is only for 7.5kW model.
2. There is no electric heater contactor KM2, electric heater and the corresponding cables in the single cooling unit.
3. There are transformer T2 and connection terminal TB2 Only when the heating function is select; The single cooling model is not equipped with transformer T2 and
connection terminal TB2.
4. The energy-saving card and the monitoring card are options; If you need them, field connection is essential.
5. The power SPD is equipped with T version unit; P version unit does not have power SPD and corresponding cables, J19-1 and J19-2 of the control board is shorted using cable.
+12V
GND
CANH
CANL
Figure 2 DME07 model
Liebert DM Series Air Conditioner Technical Manual
26
Appendix 2 Wiring Diagram
Yellow Fuse
Black
Red
Yellow
Transformer T2
Black
TB2-28
TB2-28
TB2-21
TB2-22
TB2-23
TB2-24
TB2-25
TB2-26
TB2-31
J2-2
J2-1
Black
KM3-A2
TB2-25
TLR
TLR
G
G0
AL
AL
+VR
SET
GND
AB
AB
ON
GND
DR
EV2
G
EV1
J02-2 2
1
J03 2
1
White
Brown
Drain manually
Humidify normally
J14-1
J12 2
GND
12V
J39 2
A
B
1
1
J29
J30
Grounding point
of the electrical
control box
SPD-NC
SPD-COM
AL
AL
Remote turn on/off
Standby unit request
J19-1
J19-2
J19-3
J19-4
J19-5
J19-6
J19-7
J19-8
Outlet solenoid
valve
1
2
3
4 J19
5
6
7
8
G0
J28-6
J28-4
TLR
DB9
Monitoring card
GND
12V
Gray
A
B
4
3
J4
2
1
Display
board
1 2 3 4 5 6 7 8
J3-1
J3-2
J3-4
J28-5
Blue
Black
0
J14-2
Control
board
J23
3 2 1
J36
J28-1
1
J28-2
2
J28-3
3
J28-4
4
J28-5
J28 5 J28-6
6
J28-7
7
8 J28-8
J28-9
9
J28-10
10
1
2
3
4
J21 5
6
7
8
+12V
GND
CANH
CANL
Pressure
sensor
Temp/Hum
detection board
Gray
J34
TB2-23
TB2-26
1
1
J3
KM1-A2 N1 L1
Start capacitance
G
Black
KA1-3
KM2-A1
KM3-A1
Black
J01-7
Power
board
J03
Yellow-green
1 2
J14 2
J01
J02
1
1 2
J13 J31
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
Brown
Yellow-green
Black
J18
4
5
5 4 3 2 1
Indoor
fan
Grounding point
of the electrical
control box
Electric heater
Humidifying
control board
J28-1
J28-2
KM3-6
TLR
KM3-3
Humidify
-ing tub
TAM
J19-3
J19-4
KA1
1 5 2
J18-1
1
J18-2
2
J18-3
3
J18-4
Black
2 J1-N
J1-L Black
Filter
board
3 6 4
HUM-N
HUM-L
Black
Black
Grounding point Electric heater belt of
of the electrical
the compressor
control box
J2
KM3
J28-3
Compressor
J1
2 1
KA1-4
KM3-3
5 13
A2 2 4 6 14
Brown
Brown
T3
Blue
KM1-6
Black
T2
Blue
KM1-4
Black
T1
A1 1 3
KM2
KM1-22
J3-4
KM1-2
Black
TB2-22
Black
KM3-1
Black
KM2-3
TB2-21
Black
KM2-1
Black
Black
KM1-5
KM1-3
KM1-21 Black
A1 1 3 5 13
A2 2 4 6 14
J01-5
Black
Black
Black
Black
KM1-A1
J01-1
Public alarm
SPD/D
KM1
Black
Standby unit is available
J01-3
TB1-15
Power SPD
A2 2 4 6 22
Indoor connection
terminal TB2
272829303132
21 2223242526
TB1-13
L1 L2 L3
A1 1 3 5 21
Yellow
Transformer T1
TB1-N
TB1-N
TB1-11
Black GND
Green VIN
Red +5V
Black
Black
SPD-3
Black
ALARM
COM NC
J28-7
J28-8
J28-9
J28-10
J18-3
KM1-1 Black
380V/50Hz 3N～
Black
6
N
SPD-2
4
SPD-1
2
PE N
Power
MCB
SPD-N
5
PE Yellow-green
QF-5 Black
3
J19-2
J19-1
QF-3 Black
Blue
QF-1 Black
J3-1
J3-2
Black
To outdoor unit
PE Yellow-green
N
Black
PE1 L1N1
1
N N
N N
N N
N N
1 11
2 12
3 13
4 14
5 15
6 16
7 17
8 18
9 19
10 20
TB1-N
TB1-N
TB1-N
TB1-1
TB1-2
TB1-3
TB1-4
TB1-5
TB1-6
TB1-7
TB1-8
TB1-9
TB1-10
Grounding point of the
electrical control box
Yellow Fuse
Black
Indoor connection
terminal TB1
Black
Brown
Black
Black
Black
Black
Black
Black
Black
Black
Black
Black
Blue
Blue
Black
Brown
+VR
SET
KM2-A2
TB2-24
KA1-1
TB2-31
TB1-7
TB1-8
TB1-9
TB1-10
High pressure switch
Low pressure switch
Air discharging switch
Floor overflow
Energy-saving
card
Inlet solenoid
valve
LS
LS
Water level
probe
Cable description:
Conductivity
CS
CS
probe
Connection cable between the
Factory supplied line
indoor and outdoor terminal
Field supplied line
L1
L
Indoor
N1
N
terminal
Parts supplied line
block
PE1
Inserted terminal
Outdoor
connection
Connection description:
terminal
1. This diagram is only for 12.5kW model.
2. There is no electric heater contactor KM2, electric heater, humidifying contactor KM3, inner fan relay KA1, humidifying control board and the corresponding cables in the single cooling unit.
3. There is no humidifying contactor KM2, inner fan relay KA1, humidifying control board and the corresponding cables in the heating model.
4. Both single cooling model and heating model are not equipped with inner fan relay KA1. The black plug of the inner fan connects J18-4 terminal directly;
after crimped by the closed end connectors, the blue plug connects to the electric control box.
5. There are transformer T2 and connection terminal TB2 Only when the heating and humidifying function are select; The single cooling model is not equipped with transformer T2 and
connection terminal TB2.
6. The energy-saving card and the monitoring card are options; If you need them, field connection is essential.
7. The power SPD is equipped with T version unit; P version unit does not have power SPD and corresponding cables, J19-1 and J19-2 of the control board is shorted using cable.
Figure 3 DME12 model
Liebert DM Series Air Conditioner Technical Manual
27
Appendix 3
Appendix 3 Glossary
AC
Air conditioner
ID
Inside diameter
LCD
Liquid crystal display
Lee-Temp
Low temperature
OD
Outside diameter
SPD
Surge protective device
SCR
Silicon controlled rectifier
Liebert DM Series Air Conditioner Technical Manual
Glossary
28
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Network Power assumes no responsibility and
disclaims all liability for damages resulting from use of
this information or for any errors or omissions.
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Network Power are trademarks of Emerson Electric Co.
or one of its affiliated companies.
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All rights reserved throughout the world. Specifications
subject to change without notice.
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