Liebert.CRV Series Air Conditioner
User Manual
Version V1.4
Revision date May 28, 2012
BOM 31011886
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: support@emersonnetwork.com.cn
Important Safety Instructions
Warning
The manual is retained for the entire service life of the machine.
The user reads the manually carefully before carrying out any operations on the machine.
The machine is a piece of professional equipment for use in industry, trades, and other professions, and it is not
intended for sale to the general public.
The machine is used exclusively for the purpose for which it is intended; incorrect use of the machine shall release the
manufacturer any liability.
This manual has been prepared to enable the end-user to carry out only the operation that can be made with the panels
closed. Any operation that require the opening of doors or equipment panels must be carried out only by qualified personnel.
Each machine is equipped with an Electric Insulation device which allows the operator to work in condition of safety. Switch
off the machine with this electric insulation device before any maintenance operation to eliminate risks remaining (electric
shocks, burns, automatic restarting, moving parts and remote control).
The panel key supplied with the unit must be kept by person responsible for maintenance.
For identification of the unit (model and serial no.) in case of the necessity for assistance or spare parts, locate the
identification label on the outside of the unit.
Potential hazards
The protective covers can be removed only after the electric power has been cut off by opening the main switch.
A warning label on the front and back panels reminds that:
The machine restarts automatically.
The main switch must be opened before opening the internal compartments for any operation.
If the doors are opened immediately after the machine has been switched off, there might be some hazard related to:
Components still at high temperature
Electrical heaters
Compressor, outlet area and outlet piping (about 100°C)
Components still at low temperature Evaporator
Rotating elements Fan impellers, they might continue to rotate for a while by inertia
These residual risks are highlighted by warning labels on the machine.
Warning -
Risk of electric shock
Risk of electric shock. Can cause injury or death.
Disconnect local and remote power supplies before working within.
Before proceeding with installation, read all instructions, verify that all the parts are included and check the nameplate to be
sure the voltage matches available utility power.
The iCOM microprocessor does not isolate power from the unit, even in the ‘unit off’ mode.
Some internal components require and receive power even during the ‘unit off’ mode of iCOM control.
The factory-supplied optional disconnect switch is inside the unit. The line side of this switch contains live high-voltage.
The only way to ensure that there is NO voltage inside the unit is to install and open a remote disconnect switch. Refer to
unit electrical schematic.
Follow all local codes.
Warning -
Risk of explosive discharge from high-pressure refrigerant
Risk of explosive discharge from high-pressure refrigerant. Can cause injury or death.
This unit contains fluids and gases under high pressure. Relieve pressure before working with piping.
Warning -
Risk of refrigerant system rupture or explosion from
overpressurization
Risk of refrigerant system rupture or explosion from overpressurization. Can cause equipment damage, injury or death.
If a pressure relief device is not provided with the condenser unit, the system installer must provide and install a discharge
pressure relief valve rated for a maximum of 609 psig (42bar) in the high side refrigerant circuit. Do not install a shutoff valve
between the compressor and the field installed relief valve.
One or more additional pressure relief valves are required downstream of any and all fieldinstalled isolation. Do not isolate
any refrigerant circuits from overpressurization protection.
For systems requiring EU CE compliance (50Hz), the pressure relief valve must be CE certified to the EU Pressure
Equipment Directive by an EU ‘Notified Body’.
Digit Nomenclature
The unit is fully defined by twenty-five digits.
1 1 12 3 4 5
6 7 8 9 10 11
.. ..
25
C R 0 2 0
Digit 1 and 2: Family
CR: Liebert.CRV
Digit 3, 4 and 5: Cooling
Capacity "kW" (approx.)
Nominal cooling capacity
Digit 6 - Air Discharge
R: Horizontal airflow
Digit 7 - System Type
A: System Type - Air cooled
W: System Type - Water cooled
C: System Type - Chilled Water
Digit 8 - Airflow
1: Airflow - EC Plug Fan
Digit 9 - Power Supply
0: Power Supply - 380V ~ 415V /3ph/50Hz+N
C: Power Supply - 208V/3ph/60Hz
A: Power Supply - 460V/3ph/60Hz
Digit 10 - Cooling System
2: Cooling System - CW with two way valve
3: Cooling System - CW with three Way
7: Cooling System - DX with digital scroll single
circuit R410A
Digit 11 - Humidification
0: Humidification - None
S: Humidification - Electrode humidifier
Digit 12 – Display
A: Display - Small Display 1 T+H Sensor
N: Display - Small Display 1 Temp Sensor Only
D: Display - Large Display 1 T+H sensor
C: Display - Large Display 1 Temp sensor Only
Digit 13 - Re-Heating
0: None
1: Electric heating 1 Level
Digit 14 - Air Filter
0: G4 (EU4)
1: F5 (EU5)
2: G4 (EU4) + Clogged Filter Alarm
3: F5 (EU5) + Clogged Filter Alarm
8: Merv 8 + Clogged Filter Alarm
9: Merv 11 + Clogged Filter Alarm
Digit 15 - Coil
1: Air cooled - water cooled two ways water valve
7: Water cooled 3 ways water valve
H: CW Standard coil
Digit 16 - Enclosure options
1: Color Standard
2: Color Special
Digit 17 - Condensate pump/crankcase heater
A: DX units - crankcase heater
E: DX units - condensate pump & crankcase heater
L: CW units - no condensate pump
5: CW units - condensate pump
Digit 18 - Option Package
0: None
L: Option Package #1 – humidifier and reheat
lockout & compressor jacket & one additional alarm
H: Option Package - Reheat & Humidifier Lockout
C: Option Package #2 - humidifier and reheat
lockout & one additional alarm
D: Option Package #3 – compressor jacket
Digit 19 - Monitoring
N: Without IS housing
0: With IS housing/no card
1: One IS web card
2: Two IS web cards
3: One IS485 card
4: Two IS485 cards
5: IS web & IS 485 cards
Digit 20 - Sensors
0: Sensors - None
H: Sensors - High Temperature - Firestat
S: Sensors - Smoke Sensor - Smokestat
F: Sensors - Smoke & High Temp - Smoke and
Firestat
Digit 21 - Packaging
P: PLP and pallet Domestic
C: PLP and wooden crate Export
S: Seaworthy
Digit 22 - Special Requirements
A: SFA - none
X: SFA included
Digit 23-25 - Order Identifier
Contents
Chapter 1 Preliminary Operations ....................................................................................................................................... 1
1.1 Inspection ............................................................................................................................................................. 1
1.2 Handling ................................................................................................................................................................ 1
1.3 Operating Limits .................................................................................................................................................... 2
1.4 Noise Level Limits ................................................................................................................................................. 4
1.5 Product Description ............................................................................................................................................... 4
Chapter 2 Unit Positioning ................................................................................................................................................... 8
Chapter 3 Unpacking And Installation ............................................................................................................................... 13
3.1 Reference Guide For Receiving, Unpacking, And Preparing For Installation ...................................................... 13
3.1.1 Equipment Inspection .............................................................................................................................. 13
3.1.2 Packing Material ...................................................................................................................................... 13
3.2 Recommended Unit Handling Equipment ........................................................................................................... 13
3.3 Handling The Unit While Packaged .................................................................................................................... 14
3.4 Unpacking The Unit ............................................................................................................................................ 14
3.5 Installation ........................................................................................................................................................... 16
Chapter 4 Refrigeration Connections ................................................................................................................................ 19
4.1 Refrigeration Pipeline Connections For Air-Cooled (A) Units .............................................................................. 19
4.1.1 General Layout ........................................................................................................................................ 19
4.1.2 Pipe Diameter And Thickness ................................................................................................................. 20
4.1.3 Installing Pipelines ................................................................................................................................... 21
4.2 Vacuum Creation And Refrigerant Charge ......................................................................................................... 22
4.2.1 R410A Precharge For Air-Cooled (A) Units ............................................................................................. 23
4.2.2 Refrigerant Charge For Air-Cooled (A) Units ........................................................................................... 24
4.3 Refrigeration Circuits .......................................................................................................................................... 24
Chapter 5 Water Connections ........................................................................................................................................... 25
5.1 General Warning ................................................................................................................................................. 25
5.2 Water Connections – Supply Humidifier And Drain Water (All Units) .................................................................. 26
5.3 Chilled Water Connections For Water/Glycol-Cooled (W) Units ......................................................................... 27
5.3.1 Notes For Open Circuit Applications ........................................................................................................ 27
5.3.2 Notes For Closed Circuit Applications ..................................................................................................... 27
5.4 Chilled Water Connections For Chilled Water (C) Units ...................................................................................... 28
Chapter 6 Electrical Connections ...................................................................................................................................... 30
6.1 Cable Entry Ports, Routing Cables And Connection Procedures ........................................................................ 30
6.2 Protective Features Of EC Fans ......................................................................................................................... 31
6.3 Protective Features Of Electrical Heaters ........................................................................................................... 32
6.4 Temperature Probes Placed On Racks .............................................................................................................. 32
Chapter 7 Start-Up ............................................................................................................................................................ 35
7.1 First Start-Up (Or After Long Standstill) .............................................................................................................. 35
7.2 Automatic Restart ............................................................................................................................................... 36
7.3 Checking The Refrigeration Piping Pressure Drops ............................................................................................ 36
7.4 Chilled Water Valve Of Chilled Water (C) Units .................................................................................................. 36
Chapter 8 Operation .......................................................................................................................................................... 38
Chapter 9 Calibrations & Regulation (At Start-Up) ............................................................................................................ 39
9.1 Setting Thermostatic Expansion Valve ............................................................................................................... 39
9.2 Water Leakage Sensor ....................................................................................................................................... 39
9.3 Environment Protection ....................................................................................................................................... 39
Chapter 10 Maintenance & Spare Parts ............................................................................................................................ 40
10.1 Safety Instructions ............................................................................................................................................ 40
10.2 Spare Parts ....................................................................................................................................................... 40
10.3 Maintenance Schedule ..................................................................................................................................... 40
10.4 Air Filter Check Or Substitution ......................................................................................................................... 41
10.5 Condensate Drain And Condensate Pump Systems ........................................................................................ 43
10.5.1 Condensate Drain .................................................................................................................................. 43
10.5.2 Condensate Pump ................................................................................................................................. 43
10.6 Air-Cooled Condenser And Drycoolers ............................................................................................................. 43
10.7 Electrical Heaters .............................................................................................................................................. 43
10.8 Refrigeration Circuit .......................................................................................................................................... 43
10.8.1 Refrigerant Charge Of The Water-Cooled Units .................................................................................... 44
10.8.2 Oil Charge R410A ................................................................................................................................. 44
10.8.3 Oil Topping-Up Of An Installed Circuit ................................................................................................... 44
10.9 Dismantling The Unit ......................................................................................................................................... 44
10.10 Regulation (EC) No. 842/2006 (F-Gas) ........................................................................................................... 45
10.11 Unit Diagnostic ................................................................................................................................................ 46
Appendix 1 Humidair Humidifier ........................................................................................................................................ 47
1. Preface ................................................................................................................................................................. 47
2. Installation ............................................................................................................................................................. 47
3. Humidifier Components ........................................................................................................................................ 49
4. Start-Up And Operation ........................................................................................................................................ 49
4.1 Start-Up ...................................................................................................................................................... 49
4.2 Operation .................................................................................................................................................... 49
5. Maintenance ......................................................................................................................................................... 50
5.1 Removing The Steam Cylinder ................................................................................................................... 50
5.2 Replacing The Steam Cylinder ................................................................................................................... 50
5.3 Annual Maintenance ................................................................................................................................... 50
6. Replacing Humidifier Spare Parts ......................................................................................................................... 51
Appendix 2 Technical Data Tables .................................................................................................................................... 52
Appendix 3 Installation Drawing ........................................................................................................................................ 55
Appendix 4 Refrigerant, Hydraulic And Electrical Connections ......................................................................................... 59
Appendix 5 Refrigeration & Hydraulic Circuits ................................................................................................................... 64
Appendix 6 Wiring Diagram ............................................................................................................................................... 67
Chapter 1 Preliminary Operations 1
Liebert.CRV Series Air Conditioner User Manual
Chapter 1 Preliminary Operations
This chapter introduces the preliminary operations of the Liebert.CRV series air conditioner (Liebert.CRV for short),
including inspection, handling, operating limits, noise level limits and product description.
Warning
- Risk of top-heavy unit falling over
Risk of top-heavy unit falling over. Can cause death, injury and equipment damage. Read all of the following instructions before
attempting to move, lift or remove packaging from the unit.
Caution
- Risk of sharp edges, splinters and exposed fasteners
Risk of sharp edges, splinters and exposed fasteners. Can cause personal injury. Only trained personnel wearing appropriate
safety headgear, gloves, shoes and glasses should attempt to move, lift or remove packaging from the unit or prepare the unit for
installation.
Caution
- Risk of overhead interference
Risk of overhead interference. Can damage the unit and structure. The unit may be too tall to fit through a doorway while on the
skid. Measure the unit and doorway heights and refer to the installation plans to verify clearances before moving the unit.
Caution
- Risk of frozen fluids
Risk of frozen fluids. Can cause equipment damage. Keep the unit upright, indoors and protected from dampness, freezing
temperatures and contact damage.
1.1 Inspection
Upon arrival of the unit, and before unpacking it, verify that the delivered equipment matches the bill of lading.
Examine the packaging for any signs of mishandling or damage. Inspect all items for damage, visible or concealed.
Report any damage immediately to the carrier and file a damage claim. Send a copy to Emerson Corporation or to
your sales representative.
1.2 Handling
Always keep the unit vertically upright and do not leave it out in the open.
If possible, transport the Liebert.CRV using a forklift or pallet jack. Otherwise use a crane with belts or cables
and spreader bars to protect the unit’s sides from damage.
If using a forklift or pallet jack, make sure the forks (if adjustable) are spread to the widest distance that fit under
the skid. Also, ensure the fork length is suitable for the unit length.
When moving the packaged unit, do not lift it any higher than 152 mm off the ground. Exercise great care if the
unit must be lifted higher than 152 mm; any personnel not directly involved in lifting the unit must be at least 5m
from the unit.
Take care of the Center of Gravity indicated on the package.
2 Chapter 1 Preliminary Operations
Liebert.CRV Series Air Conditioner User Manual
Table 1-1 Center of gravity
Model
Distance from corner (unit: m)
x
y
z
X (±0.05m) Y (±0.05m) Z (±0.05m)
CR020 0.52 0.30 0.71
CR035 0.50 0.30 0.80
CR040 0.54 0.30 0.80
Note: The center of gravity on the Liebert.CRV varies with the options and the model’s size
Moving by a forklift and unit weight
The schematic diagram of moving the unit by a forklift is shown in Figure 1-1. The unit weight is given in Table 1-2.
Figure 1-1 Moving the unit by a forklift
Table 1-2 Unit weight (unit: kg)
Model Power supply
Weight (±5%)
Air-cooled Water/Glycol-cooled
Chilled water
CR020 380V ~ 415V/3-phase/50Hz 335 350 CR035 380V ~ 415V /3-phase/50Hz 365 385 CR040 380V ~ 415V /3-phase/50Hz - - 330
Note: Weights of full version units without packaging
1.3 Operating Limits
The units are designed to operate within working ranges (see Table 1-3 ~ Table 1-7). These limits are referred to new
machines or to those that have been correctly installed and serviced.
The warranty clauses are no longer valid for any possible damage or malfunction that may occur during or due to
operation outside the application values.
For all units
Table 1-3 Operating limits for all units
Item From To
Room air
conditions
Temperature 18°C 40°C
Humidity ratio 5.5g/kg 11g/kg
Relative humidity 20% 60%
Storage
conditions
Temperature -20°C 50°C
Power supply
tolerances
Voltage ±10%
Frequency ±2Hz
Chapter 1 Preliminary Operations 3
Liebert.CRV Series Air Conditioner User Manual
For air-cooled (A) units
Table 1-4 Operating limits for air-cooled (A) units
Item Description
Outdoor
temperature: lower
limit (-20°C)
To install an air conditioner in places in which external temperature reaches very low values sometime in
the year requires some means of control to maintain adequate condensing pressures to ensure proper
liquid system operation.
With low temperatures the refrigerant condensates in pipeline and the liquid tends to fulfill the
condenser.
It's mandatory to install the following components:
1. Non return valve (liquid line)
Install a non-return valve in the liquid line directly out of the condenser. It doesn’t allow the liquid to come
back to the condenser (that means efficiency loss and dangerous stress for the compressor).
2. Variex fan speed control (the CRV standard outdoor unit has been configured with the function)
Use Variex fan speed control to regulate the condensing pressure and have a continuous and better
subcooling control.
It’s suggested to have:
3. Horizontal condenser position
The condenser horizontal disposition (vertical flow) is necessary to reduce subcooling variations due to
direct wind exposure. (very important to have a good subcooling control).
For all exceptions contact the Emerson sales representative
Outdoor
temperature: higher
limit
This limit is determined by coupled condenser model. Exceeding of this limit (or a lack of maintenance),
will caused a compressor stop by HP safety thermostat. Reset to normal operation can only be carried
out manually.
Once the condensing pressure rises at or above the 34bar / 493psi value, the capacity of the
compressor is reduced by 20% compared to the requested capacity. This because iCOM control tries to
maintain the unit's operability reducing the cooling power of digital scroll
Table 1-5 Relative position of room unit and 50Hz remote condenser
Item Description
From unit to condenser max distance equivalent length1 50m
From unit to condenser max geodetic height2 -8m ~ 30m
Requirements
Pipe diameter
See Table 4-2
Oil traps on vertical line of gas refrigerant
Install one every 6m
Extra oil charge
See Table 5 and Table 6 in the appendix
Note:
1: If the equivalent length from the indoor unit to the condenser exceeds 50m, please consult with Emerson sales representative;
2: Positive difference in height: condenser above conditioner; Negative difference in height: condenser below conditioner
For water/glycol-cooled (W) units
Table 1-6 Operating limits for water/glycol-cooled (W) units
Item Description
Water or mixture temperature to condenser Min. 5°C
Other information See Chapter 5 Water Conections
For chilled water (C) and water/glycol-cooled (W) units
Table 1-7 Operating limits for chilled water (C) and water/glycol-cooled (W) units
Item
Description
CR020RW CR035RW CR040RC
Max. water pressure (bar) 16 16 16
Max. differential pressure through the
closed valve: Dpcv (kPa)
300 300 175
Max. differential pressure across the
valve for modulating service: Dpms (kPa)
300 300 175
4 Chapter 1 Preliminary Operations
Liebert.CRV Series Air Conditioner User Manual
1.4 Noise Level Limits
The sound pressure level in free field at 1.5m height and 2m in front of the air conditioner, with compressor and fan in
operations, is less than 70dBA for all models (excluding the chilled water unit).
1.5 Product Description
Appearance
The appearance of the air conditioner is shown in Figure 1-2.
Figure 1-2 Appearance of the air conditioner
Example of installation
The Liebert.CRV is a range of full-featured compressorized (air, water, glycol cooled) and chilled water cooling units
to be installed within a row of high density computing racks in a ‘hot-aisle-cold-aisle’ configuration.
The example of high density installation with cold aisle and hot aisle alternation is shown in Figure 1-3.
CR
CR
CR
CR
CR
CR
CR
CR
Hot aisle
Cold aisle
Hot aisle
Hot aisle
Cold aisle
Hot aisle
Cold aisle
Hot aisle
Cold aisle
Hot aisle
Figure 1-3 Example of high density installation with cold aisle and hot aisle alternation
Chapter 1 Preliminary Operations 5
Liebert.CRV Series Air Conditioner User Manual
Thermal performance
The thermal performance (at 1.1m from floor) of a system with 2 CRV and 20 racks is shown in Figure 1-4.
Figure 1-4 Schematic diagram of thermal performance
Inlet air enters this unit from the hot aisle, is filtered, cooled and conditioned, and is returned to the cold aisle. It
provides all the necessary functions of a standard precision air conditioner, including cooling, heating, humidification,
dehumidification, air filtration, condensate management, temperature control, alarm functions and data
communications. The Liebert.CRV is optimized for maximum cooling capacity in minimal footprint.
iCOM display panel
The iCOM display panel is shown in Figure 1-5.
Figure 1-5 iCOM display panel
The iCOM display panel shows: air inlet temperature and humidity, air outlet temperature, fans status, cooling power
status, next service time.
Component locations
The component locations of Liebert.CRV air-cooled (A), water/glycol-cooled (W) and chilled water (C) units are
shown in Figure 1-6.
6 Chapter 1 Preliminary Operations
Liebert.CRV Series Air Conditioner User Manual
1
2
3
4
8
6
5
9
7
1. iCOM control display 2. Electric Box 3. Evaporator / CW Coil 4. Condensate pump 5. Electric heaters
6. Humidifier distributor 7. Top water connections 8. Drain tray 9. EC fans
Figure 1-6 Component locations
The component locations of Liebert CR020 ~ CR035 air-cooled (A) units are shown in Figure 1-7.
8
1
10
3
4
7
9
2
5
6
1. Termostatic expansion valve 2. Solenoid valve 3. Sight glass 4. Filter dryer
5. Liquid receiver 6. Safety valve 7. Humidity/Temp. sensor 8. Humidifier
9. Top refrigerant connections 10. Bottom refrig. connections
Figure 1-7 Component locations of Liebert CR020 ~ CR035 air-cooled (A) units
Chapter 1 Preliminary Operations 7
Liebert.CRV Series Air Conditioner User Manual
The component locations of Liebert CR020 ~ CR035 water/glycol-cooled (W) units are shown in Figure 1-8.
2
3
1
4
5
1. Top Water connections 2. Compressor 3. Water condenser
4. Bottom water connections 5. Three-way water valve
Figure 1-8 Component locations of Liebert CR020 ~ CR035 water/glycol-cooled (W) units
The component locations of Liebert CR040 chilled water unit are shown in Figure 1-9.
2
3
1
5
4
1. Top CW connections 2. Filters 3. Three-way CW valve 4. Bottom CW connections 5. Humidifier
Figure 1-9 Component locations of Liebert CR040 chilled water unit
8 Chapter 2 Unit Positioning
Liebert.CRV Series Air Conditioner User Manual
Chapter 2 Unit Positioning
This chapter provides some ideas of typical installation of the Liebert.CRV unit(s), shows several examples of the
server room layouts and applications using Liebert.CRV units.
For best performances of Liebert.CRV is important to:
Reduce at minimum recirculation from hot aisle around the ends and/or over the top of the racks, prevent gaps
between the racks.
Reduce at minimum recirculation from hot aisle through server racks by using blanking panels.
Ensure cold air is being distributed across the front of all neighboring equipment racks by properly placed
Liebert.CRV unit(s).
Distribute load within the rack – it is generally advised to distribute the load as much possible uniformly across
the rack height, except for the rack closest to the Liebert.CRV unit, where it is suggested to have the higher
density load in the bottom and central part of the rack.
For more details refer to following details or contact Emerson Sales Representative.
1. Placement in the row of racks
For single row application with one Liebert.CRV unit it is not preferred to put the unit in the middle of the row because
of possible hot spots at top part of racks, unless in combination with CoolFlex or in application with more Liebert.CRV
units. The best approach is to place the Liebert.CRV at the end of the row, resulting into much better air distribution.
Please refer to the sample case study comparing the same server room with different Liebert.CRV position. The CFD
(Computational fluid dynamics) analysis results are shown in Figure 2-1 (height 1.8m off the floor for all following
cases).
Good approach:
Not advised approach:
End of row is preferred.
CRV
CRV
Figure 2-1 CFD analysis results of comparing the same server room with different Liebert.CRV position
2. Number of racks / length of the row
Standard application with one Liebert.CRV unit is with 2 ~ 6 racks. The exact number of racks depends on size of
Liebert.CRV unit used and heat load per rack. Whenever applying more than 6 racks for one CRV or heat load more
than 10kW per rack contact Emerson sales representative.
The CFD analysis result of one Liebert.CRV unit with 2 ~ 6 racks is shown in Figure 2-2.
Chapter 2 Unit Positioning 9
Liebert.CRV Series Air Conditioner User Manual
2 ~ 6 racks (0.6m ~ 5m)
CRV
Figure 2-2 CFD analysis result of one Liebert.CRV unit with 2 ~ 6 racks
3. Placement in the room
1) Width of hot aisle/cold aisle
For good air distribution it is recommended to keep width of the cold aisle as small as possible for single row server
room. Otherwise the cold air discharged by Liebert.CRV unit is being led far from server suction and hot air may
by-passed from hot aisle.
Exceptions where wider cold aisle may be used are: applications with CoolFlex (Cold Aisle Containment) or with two
rows facing each other.
The width of hot aisle/cold aisle is shown in Figure 2-3.
Min. 0.65m
CRV
0.6m ~ 1.2m
Figure 2-3 Width of hot aisle/cold aisle
The CFD analysis result of cold aisle with different width is shown in Figure 2-4.
Not advised approach:
Good approach:
CRV
CRV
< 1.2m
> 1.2m
Note: Please refer to the service area dimensions in Appendix 3.
Figure 2-4 CFD analysis result of cold aisle with different width
10 Chapter 2 Unit Positioning
Liebert.CRV Series Air Conditioner User Manual
2) Distance between the ends of rows and walls
For single row application with one Liebert.CRV unit it is not preferred to put the unit at wall because of not proper air
paths and possible hot spots at furthest racks, unless in combination with CoolFlex (cold aisle containment) or in
application with more Liebert.CRV units. The best approach is to keep a gap between at least 0.65m or to use more
Liebert.CRV units. Good approach is also having wall at the furthest rack.
Please refer to the following sample case study comparing various Liebert.CRV positions. The CFD analysis result is
shown in Figure 2-5.
CRV
CRV
Min. 0.65m Variable
CRV
Example of an application with gaps on both sides
Not advised approach:
Good approach:
Figure 2-5 CFD analysis result of Liebert.CRV unit in different positions
Chapter 2 Unit Positioning 11
Liebert.CRV Series Air Conditioner User Manual
As you can see on CFD result above, it is not advised to place Liebert.CRV at the wall in single row layout. On the
contrary, it is not an issue in application with two rows and two or more Liebert.CRV units, as shown in Figure 2-6.
CRV
CRV
0.6m ~ 1.8m
Min. 0.1m
Good approach:
Note: Please refer to the service area dimensions in Appendix 3.
Figure 2-6 CFD analysis result of two rows and two or more Liebert.CRV units
4. Solutions with redundancy
Following an example of more complex applications where N+1 redundancy provided.
Please note the number and size of Liebert.CRV units have to be designed in order to achieve required cooling
capacity if any of the units fails. The other option to easily achieve redundancy is CoolFlex (Cold aisle containment),
see point 5 below.
The CFD analysis result of solutions with redundancy is shown in Figure 2-7.
CRV
CRV
CRV
Off
Example of an application with one row and N+1 redundancy
(right side unit failed).
Example of an application with two rows and N+1 redundancy
(unit placed right down failed).
CRV
CRV
Figure 2-7 CFD analysis result of solutions with redundancy
5. Example of applications with CoolFlex
When high density IT equipment is used (typically over 10kW per rack) or load distribution in the row(s) of racks is not
constant and high energy efficiency is required it is strongly recommended to apply CoolFlex (cold aisle containment)
together with Liebert.CRV.
12 Chapter 2 Unit Positioning
Liebert.CRV Series Air Conditioner User Manual
Other advantage of the CoolFlex application is less limitations, see above points.
The CFD analysis result of applications with CoolFlex is shown in Figure 2-8.
CRVCRV
CRV
CoolFlex
CoolFlex
Figure 2-8 CFD analysis result of applications with CoolFlex
6. Example of applications with Liebert XD
When high density IT equipment is used (typically over 10kW per rack) with less floor space available especially
when scalable solution is required (starting from less heat load and ready for future grown), the best answer is Liebert
CRV together with Liebert XD system.
Please find following an example layout of typical installation with two rows of racks with Liebert.XDV modules. Two
Liebert.CRV units are used to support the Liebert XD system and to ensure N+1 redundancy on humidity control. See
also CFD result showing site view of the room, as shown in Figure 2-9.
CRV
CRV
XDV
XDV
XDV
XDV
XDV
XDV
XDV
XDV
XDV
XDV
XDV
XDV
Figure 2-9 CFD analysis result of applications with Liebert XD
Chapter 3 Unpacking And Installation 13
Liebert.CRV Series Air Conditioner User Manual
Chapter 3 Unpacking And Installation
This chapter introduces unpacking and installation of the Liebert.CRV air conditioner, including reference guide for
receiving, unpacking, and preparing for installation, recommended unit handling equipment, handling the unit while
packaged, unpacking the unit and installation.
3.1 Reference Guide For Receiving, Unpacking, And Preparing For Installation
Warning
- Risk of top-heavy unit falling over
Risk of top-heavy unit falling over. Improper handling can cause equipment damage, injury or death. Read all of the following
instructions before attempting to move, lift, remove packaging from the unit or prepare unit for installation.
Caution
- Risk of sharp edges, splinters and exposed fasteners
Risk of sharp edges, splinters and exposed fasteners. Can cause personal injury. Only trained personnel wearing appropriate
safety headgear, gloves, shoes and glasses should attempt to move, lift or remove packaging from the unit or prepare the unit for
installation.
Notice
- Risk of overhead interference
Risk of overhead interference. Can cause unit and/or structure damage. The unit may be too tall to fit through a doorway while on
the pallet. Measure the unit and doorway heights and refer to the installation plans prior to moving the unit to verify clearances.
Notice
- Risk of unit damage if improperly stored
Risk of unit damage if improperly stored. Keep the unit vertically upright, indoors and protected from dampness, freezing
temperatures and contact damage.
3.1.1 Equipment Inspection
Upon arrival of the unit, and before unpacking, verify that the labeled equipment matches the Bill of Lading. Carefully
inspect all items for either visible or concealed damage. Damage should be immediately reported to the carrier and a
damage claim filed with a copy sent to Emerson Corporation or to your sales representative.
3.1.2 Packing Material
All material used to package this unit is recyclable. Please save the material for future use, or dispose it appropriately.
3.2 Recommended Unit Handling Equipment
The recommended unit handling equipment is shown in Figure 3-1.
Figure 3-1 Recommended unit handling equipment
14 Chapter 3 Unpacking And Installation
Liebert.CRV Series Air Conditioner User Manual
3.3 Handling The Unit While Packaged
If possible, transport the packaged unit using a fork lift or a pallet jack; otherwise use a crane with slings and
spreader bars.
If using a fork lift or pallet jack, make sure the forks (if adjustable) are spread to the widest allowable distance to
still fit under the pallet. Also, make sure the fork length is suitable for the unit length.
When moving the packaged unit with a fork lift or pallet jack, lift the unit from either end of the pallet.
When handling the packaged unit with a fork lift or pallet jack, the unit shall not be lifted any higher than 51mm ~
102mm) off the ground. All by-standing personnel shall be no closer than 3.7m to the handled packaged unit.
If circumstances require the unit to be lifted higher than 102mm great care shall be exercised and all by-standing
personnel are to be no closer than 5m to the lift point of the unit.
3.4 Unpacking The Unit
Move the product to the place closest to the final installation site before unpacking the unit.
Follow the procedures below to unpack the unit:
1. Removing the side boards and top cover.
1) CRV series air conditioner uses the international packaging. You can use a hammer or straight screwdriver to
straighten the connection hook between the side boards and top cover, as shown in Figure 3-2.
Figure 3-2 Straighten the hook
2) As shown in Figure 3-3, at first, straighten all the hooks that fix the side boards, and remove the four side boards.
At last remove the top cover.
Side panel
Top cover
Figure 3-3 Remove the side boards and top cover
2. Remove the cushion (see Figure 3-4) from the unit, exposing the bag over the unit. The bag may remain in place
for dust and panel protection, or removed for immediate unit installation.
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