Vertiv Liebert CW Series User guide

Liebert®
CW™ThermalManagementSystem
Installer/UserGuide
38to 400kW(10 to 114 ton) Capacity, UpflowandDownflow, 50Hzand60Hz

Vertiv | Liebert® CW™Installer/User Guide
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Visit https://www.Vertiv.com/en-us/support/ for additional assistance.
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practices or building codes as applicable for the correct methods, tools, and
materials to be used in performing procedures not specifically described in this
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TABLE OF CONTENTS
Important Safety Instructions 5
1 Nomenclature and Components 11
1.1 Liebert CWModel-number Nomenclature 11
1.2 Component Location 13
2 Pre-installation PreparationandGuidelines 15
2.1 Planning Dimensions 16
2.2 Location Considerations 17
2.3 Air-distribution Considerations for Downflow Units 17
2.4 Air-distribution Considerations for Upflow Units 19
2.5 Connections and System Setup 20
2.6 Operating Conditions 20
2.6.1 Cooling, Dehumidificationand Humidification 21
2.6.2 Heating 21
2.7 Shipping Dimensions and Unit Weights 21
3 Equipment Inspection and Handling 23
3.1 Packaging Material 24
3.2 Handling the Unit while Packaged 24
3.3 Unpacking the Unit 25
3.3.1 Removing the Unit from the Skid with a Forklift 25
3.3.2 Removing the Unit from theSkid Using Rigging 26
3.3.3 Moving the Unit to the InstallationLocationUsing PianoJacks 28
3.4 Placing the Unit on a Floor Stand 30
4 Piping Requirements 31
4.1 Drain and Humidifier Fluid Connections 32
4.1.1 Field-installed, Gravity-fed Drain Line Requirements 33
4.1.2 Condensate-pump Drain Line Requirements 35
4.1.3 Water Supply-line Requirements for the Optional Humidifier 35
4.2 Chilled-water Loop Piping Guidelines 36
4.2.1 Leak Checking for Unit and Field-installed Piping 37
5 Electrical Connections 39
6 EC Fans and Plenums 41
6.1 Downflow Units withEC Fans 41
6.1.1 Lowering the EC Fans into the Floor Stand onDownflow Models 41
6.2 Upflow-unit Plenums with EC Fans 45
6.2.1 Assembly inspection 46
6.2.2 Assemble plenum rear and side panels 51
6.2.3 Place assembled panels and EC fans on top of unit 54
3

6.2.4 Wire the EC Fans 58
6.2.5 Install front panels on plenum 60
7 Checklist for Completed Installation 73
7.1 Moving and Placing Equipment 73
7.2 Electrical InstallationChecks 73
7.3 Piping InstallationChecks 73
7.4 Other InstallationChecks 73
8 Initial Start-up Checks andCommissioningProcedure ForWarrantyInspection 75
9 Troubleshooting 77
10 Maintenance 81
10.1 Filters 82
10.2 Blower Drive System—EC Fans 83
10.2.1 Protective Features 84
10.2.2 Fan Impellers and Bearings Maintenance 84
10.2.3 FanAssembly Troubleshooting 84
10.2.4 Removing EC Fans from Downflow Units 88
10.2.5 Removing EC Fans from Upflow Units 93
10.3 Blower Drive System—Forward-curved Blowers 96
10.3.1 Blower Motor Lubrication 97
10.3.2 Belt Inspection 97
10.3.3 Electronic Variable Speed Drive - Inverter 97
10.4 Infrared Humidifier Maintenance 98
10.4.1 Cleaning Humidifier Pan and Float Switch 98
10.4.2 Changing Humidifier Lamps 99
10.5 Condensate-drain and Condensate-pump System Maintenance 100
10.5.1 Condensate Drain 100
10.5.2 Condensate Pump 100
10.6 Facility Fluid and Piping Maintenance forWaterandGlycolSystems 101
11 Preventive Maintenance Checklist 103
Appendices 107
Appendix A: Technical Support and Contacts 107
Appendix B: Submittal Drawings 109
Vertiv | Liebert® CW™Installer/User Guide
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IMPORTANT SAFETY INSTRUCTIONS
SAVE THESE INSTRUCTIONS
This manual contains important safety instructions that should be followed during the installation and maintenance of the
Liebert®CW. Read this manual thoroughly before attempting to install or operate this unit.
Only qualified personnel should move, install or service this equipment.
Adhere to all warnings, cautions, notices and installation, operating and safety instructions onthe unit and in this manual.
Follow all installation, operationand maintenance instructions and all applicable national and local building, electrical and
plumbing codes.
WARNING! Arc flash and electric shock hazard. Open all local and remote electric power-supply
disconnect switches, verify with a voltmeter that power is Off and wear appropriate,
OSHA-approved personal protective equipment (PPE) per NFPA 70E before working within the
electric control enclosure. Failure to comply can cause serious injury or death. Customer must
provide earth ground to unit, per NEC, CEC and local codes, as applicable. 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 Liebert® controller 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 the controller. The factory-supplied
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 electric shock. Can cause equipment damage, injury or death. Open all local
and remote electric power supply disconnect switches and verify with a voltmeter that power is
off before working within any electric connection enclosures. Service and maintenance work
must be performed only by properly trained and qualified personnel and in accordance with
applicable regulations and manufacturers’ specifications. Opening or removing the covers to
any equipment may expose personnel to lethal voltages within the unit even when it is
apparently not operating and the input wiring is disconnected from the electrical source.
WARNING! Risk of electric shock. Can cause serious injury or death. The Liebert® 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 the Liebert® iCOM
control. Open all local and remote electric power disconnect switches and verify with a
voltmeter that power is Off before working on any component of the system.
Important Safety Instructions 5

WARNING! Risk of electric shock. Can cause serious injury or death. Open all local and remote
electric power supply disconnect switches and verify with a voltmeter that power is off before
working within the fan-motor electric-connection enclosures. Fan-motor controls can maintain
an electric charge for 10 minutes after power is disconnected. Wait 10 minutes after power is
verified as off before working within the electric control/connection enclosures. Use only fully-
trained and qualified HVAC technicians to perform maintenance on the fans.
WARNING! Risk of improper moving. Can cause equipment damage, injury or death. Use only
lifting equipment that is rated for the unit weight by an OSHA-certified rating organization. The
center of gravity varies depending on the unit size and selected options. The slings must be
equally spaced on either side of the center of gravity indicator.
Shipping weights and unit weights are listed in the tables in Shipping Dimensions and Unit
Weights on page21. Use the center of gravity indicators on the unit to determine the position of
the slings.
WARNING! Risk of improper wiring, piping, moving, lifting and handling. Can cause equipment
damage, serious injury or death. Installation and service of this equipment should be done only
by qualified personnel who have been specially-trained in the installation of air-conditioning
equipment and who are wearing appropriate, OSHA-approved PPE.
WARNING! Risk of improper piping installation, leak checking, fluid chemistry and fluid
maintenance can cause equipment damage and personal injury. Installation and service of this
equipment should be done only by qualified personnel who have been specially-trained in the
installation of air-conditioning equipment and who are wearing appropriate, OSHA-approved
PPE.
WARNING! Risk of contact with high-speed rotating fan blades. Can cause serious injury or
death. Open all local and remote electric power-supply disconnect switches, verify with a
voltmeter that power is off, and verify that all fan blades have stopped rotating before working
in the unit cabinet or on the fan assembly. If control voltage is applied, the fan motor can restart
without warning after a power failure. Do not operate the unit with any or all cabinet panels
removed.
Do not operate upflow units without installing a plenum, duct work or guard over the blower
opening(s) on the top surface of the unit cabinet.
Ductwork must be connected to the blower(s), or a plenum must be installed on the blower
deck for protection from rotating blower wheel(s) on upflow units.
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WARNING! Risk of top-heavy unit falling over. Improper handling can cause equipment
damage, injury or death. Read all of the following instructions and verify that all lifting and
moving equipment is rated for the weight of the unit before attempting to move, lift, remove
packaging from or prepare the unit for installation.
WARNING! Risk of very heavy 125-lb (56.7-kg) fan modules dropping downward suddenly. Can
cause injury or death.
Support fan modules before removing mounting hardware. Use caution to keep body parts out
of the fan modules pathway during repositioning. Only properly trained and qualified personnel
should work on this equipment.
WARNING! Risk of improper wire sizing/rating and loose electrical connections. Can cause
overheated wire and electrical connection terminals resulting in smoke, fire, equipment and
building damage, injury or death. Use correctly sized copper wire only and verify that all
electrical connections are tight before turning power On. Check all electrical connections
periodically and tighten as necessary.
CAUTION: Risk of contact with sharp edges, splinters, and exposed fasteners. Can cause
injury. Only properly trained and qualified personnel wearing appropriate, OSHA-approved PPE
should attempt to move, lift, remove packaging from or prepare the unit for installation.
CAUTION: Risk of handling heavy and lengthy parts. Can cause personal injury and equipment
damage. Cabinet panels can exceed 5 ft. (1.5 m) in length and weigh more than 35 lb. (15.9 kg).
Follow relevant OSHA lifting recommendations and consider using a two-person lift for safe
and comfortable removal and installation of cabinet panels. Only properly trained and qualified
personnel wearing appropriate, OSHA-approved PPE should attempt to remove or install
cabinet panels.
CAUTION: Risk of exposure to harmful noise levels. Can cause hearing injury or loss.
Depending on the installation and operating conditions, a sound pressure level greater than
70dB(A) may arise. Take appropriate technical safety measures. Operating personnel must
wear appropriate, OSHA-approved PPE and observe all appropriate hearing-protection safety
requirements.
Important Safety Instructions 7

CAUTION: Risk of contact with hot surfaces. Can cause injury. The electronics housing,
humidifier components, fan motor, and some electrical components are extremely hot during
unit operation. Allow sufficient time for them to cool to a touch-safe temperature before
working within the unit cabinet. Use extreme caution and wear appropriate, OSHA-approved
PPE when working on or near hot components.
CAUTION: Risk of smoke generation. Can cause fire suppression and alarm system activation,
resulting in injury during building evacuation and mobilization of emergency fire and rescue
services. Start-up operation of optional electric reheat elements can create smoke or fumes
that can activate the facility alarm and fire suppression system. Prepare and take appropriate
steps to manage this possibility. Activating reheat during initial start-up may burn off
particulates from electric reheat elements. Before beginning initial start-up checks, make
certain that unit was installed according to the instructions in this manual. All exterior panels
must be in place.
NOTICE
Risk of improper power-supply connection. Cancause equipment damage and loss of warranty coverage.
Prior to connecting any equipment to a main or alternate power source (for example: back-up generator
systems) for start-up, commissioning, testing, or normal operation, ensure that these sources are correctly
adjusted to the nameplate voltage and frequency of all equipment to be connected. In general, power-source
voltages should be stabilized and regulated to within±10% of the load nameplate nominal voltage. Also, ensure
that no three-phase sources are single-phased at any time.
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NOTICE
Risk of piping-system corrosionand freezing fluids. Cancause leaks resulting inequipment and expensive
building damage. Cooling coils, heat exchangers and piping systems are at highrisk of freezing and premature
corrosion. Fluids in these systems must contain an inhibitor to prevent premature corrosion.
The system coolant fluid must be analyzed by a competent fluid-treatment specialist before start up to
establishthe inhibitor level and evaluated at regularly scheduled intervals throughout the life of the system to
determine the patternof inhibitor depletion. The fluid complexity and variations of required treatment
programs make it extremely important to obtain the advice of a competent and experienced fluid-treatment
specialist and follow a regularly scheduled coolant-fluid system-maintenance program.
Fluid chemistry varies greatly as do the required additives, called inhibitors, that reduce the corrosive effect of
the fluids onthe piping systems and components.
The chemistry of the coolant fluid used must be considered, because some sources may contain corrosive
elements that reduce the effectiveness of the inhibited formulation. Sediment deposits prevent the formationof
a protective oxide layer onthe inside of the coolant system components and piping. The coolant fluid must be
treated and circulating throughthe system continuously to prevent the buildup of deposits and/or growth of
bacteria. Proper inhibitor maintenance must be performed to prevent corrosion of the system.
Consult fluid manufacturer for testing and maintenance of inhibitors.
Commercial-grade coolant fluid is generally less corrosive to the common metals of construction than water
itself. It will, however, assume the corrosivity of the coolant fluid from whichit is prepared and may become
increasingly corrosive withuse if not properly inhibited.
Vertiv recommends installing a monitored fluid-detection system that is wired to activate the automatic-
closure of field-installed coolant-fluid supply and returnshut-off valves toreduce the amount of coolant-fluid
leakage and consequential equipment and building damage. The shut-off valves must be sized to close-off
against the maximum coolant-fluid system pressure in case of a catastrophic fluid leak.
NOTICE
Risk of frozen pipes and corrosion from improper coolant mixture. Can cause water leaks resulting in
equipment and building damage.
When the cooling unit or piping may be exposed to freezing temperatures, charge the system with the proper
percentage of glycol and water for the coldest designambient temperature. Automotive antifreeze is
unacceptable and must NOTbe used inany glycol fluid system. Use only HVAC glycol solution that meets the
requirements of recommended industry practices. Do not use galvanized pipe.
NOTICE
Risk of no-flow condition. Can cause equipment damage. Do not leave the water/coolant fluid-supply circuit in a
no-flow condition. Idle fluid allows the collection of sediment that prevents the formationof a protective oxide
layer onthe inside of tubes. Keep unit switched Onand water/coolant fluid-supply circuit system operating
continuously.
Important Safety Instructions 9

NOTICE
Risk of clogged or leaking drain lines and leaking water-supply lines. Cancause equipment and building
damage.
This unit requires a water drain connection. Drainlines must be inspected at start-up and periodically, and
maintenance must be performed to ensure that drainwater runs freely throughthe drainsystem and that lines
are clear and free of obstructions and ingood conditionwithnovisible sign of damage or leaks. Thisunit may
also require an external water supply to operate.
Improper installation, application and service practices can result in water leakage from the unit. Water
leakage canresult incatastrophic and expensive building and equipment damage and loss of critical data
center equipment.
Do not locate unit directly above any equipment that could sustain water damage.
We recommend installing a monitored fluid-detection system to immediately discover and report coolant-fluid
system and condensate drain-line leaks.
NOTICE
Risk of doorway/hallway interference. Cancause unit and/or structure damage. The unit may be toolarge to fit
througha doorway or hallway while onthe skid. Measure the unit and passageway dimensions, and refer to the
installation plans prior to moving the unit to verify clearances.
NOTICE
Risk of damage from forklift. Cancause unit damage. Keep tines of the forklift level and at a height suitable to
fit below the skid and/or unit to prevent exterior and/or underside damage.
NOTICE
Risk of improper storage. Cancause unit damage.
Keep the unit upright, indoors and protected from dampness, freezing temperatures and contact damage.
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1 NOMENCLATURE AND COMPONENTS
This section describes the model number for Liebert® CWunits and components.
1.1 Liebert CW Model-number Nomenclature
Table 2.2 below describes each digit of the model number.
Model-number digits 1 to 10 Factory-configuration Number Configuration Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
C W 0 3 8 D C 1 A 1 1 2 3 4 A
Table 2.1 CW Model Number Example
Digit Description
Digits 1 and 2 = Unit Family
CW= Liebert®CWfloor-mounted, chilled-water unit
Digit3, 4, 5=Nominal CoolingCapacity, kW
038 = 38kW
041 = 41kW
051 = 51kW
060 = 60kW
076= 76kW
084= 84kW
106= 106kW
114= 114kW
146= 146kW
181 = 181kW
300 = 300kW
400 = 400kW
Digit6= AirDistribution
D= Downflow
U= Upflow
Digit7 = CoolingType
C= Chilledwater
Table 2.2 CW Model-number Digit Definitions
1 Nomenclatureand Components 11

Digit Description
Digit8 = FanType
S= Forward-curvedblower withstandardmotor
V= Forward-curvedblower withvariable-speeddrive
1 = ECfan
H= ECfanwith THD
Digit9= Voltage
A= 460V- 3ph- 60Hz
B = 575V- 3ph- 60Hz
C= 208V-3ph -60Hz
D= 230V-3ph -60Hz
2 = 380V-3ph -60Hz
F= 380V- 3ph -50Hz
G= 415V- 3ph- 50Hz
M= 380-415V- 3ph- 50Hz
Digit 10 = Valve Type
1 = 2-way valve, highpressure
T= 3-way valve, highpressure
Digit11-14= Factory ConfigurationNumber
Digit15 = Configuration Code
A-Z = Standardconfiguration
S= SFA
Table 2.2 CW Model-number Digit Definitions (continued)
Not all combinations of options are available on all units:
•Models CW146, CW181, CW300, and CW400 only available in downflow configuration.
•Disconnect switch, Locking
•Not available on 208-V units with20-hp motor
•Flow switchthat activates the warning system
•Ships loose
•Humidification and Reheat
•Not available on CW300 and CW400
•Steam/Hot-water reheat package
•Not available on units with EC fans
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1.2 Component Location
The unit component locations are described inthe submittal documents included inthe Submittal Drawings on page109.
The following table lists the relevant documents by number and title.
Document Number Title
DPN002869 Component Location, DownflowModels
DPN002868 Component Location, UpflowModels
Table 2.3 Component-location Drawings
1 Nomenclatureand Components 13

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2 PRE-INSTALLATION PREPARATIONANDGUIDELINES
NOTE: Before installing unit, determine whether any building alterations are required to run piping,
wiring and duct work. Follow all unit dimensional drawings and refer to the submittal engineering
dimensional drawings of individual units for proper clearances.
Refer to Table 2.2 onpage11, and submittal drawings to determine the type of system being installed and anticipate
building alterations, piping and duct work needed.
The unit dimensions, pipe-connectionlocations, and piping schematics are described in the submittal documents included
inthe Submittal Drawings onpage109.
•Verify that the floor is level, solid and sufficient to support the unit. See Table 3.3 onpage21,for unit weights.
•Confirm that the room is properly insulated and has a sealed vapor barrier.
•For proper humidity control, keep outside or fresh air to an absolute minimum (less than 5%of total air
circulated in the room).
•Do not install a Liebert® CWin analcove or at the end of a long, narrowroom.
•Install the units as close as possible to the largest heat load.
•Allow at least the minimum recommended clearances for maintenance and service. See the appropriate
submittal drawings for dimensions.
•We recommend installing anunder-floor water detectionsystem. Contact your Vertiv representative for
information.
2Pre-installation PreparationandGuidelines 15

2.1 Planning Dimensions
The unit, floor stand, and plenum dimensions are described in the submittal documents included in the Submittal Drawings
onpage109.
The following table lists the relevant documents by number and title.
Document Number Title
DownflowUnitswithECFans
DPN003192 Cabinet Dimensional Data, CW038to CW084
DPN003222 Cabinet Dimensional Data, Front Discharge, CW038andCW041
DPN003223 Cabinet Dimensional Data, Front Discharge, CW051, CW060, CW076, andCW084
DPN003193 Cabinet Dimensional Data, CW106, andCW114
DPN003224 Cabinet Dimensional Data, Front Discharge, CW106andCW114
DPN003208 Cabinet Dimensional Data, CW146andCW181
DPN003225 Cabinet Dimensional Data, Front Discharge, CW146andCW181
DPN003218 Cabinet Dimensional Data, CW300 andCW400 withFilter Plenums
UpflowUnitswithECFans
DPN003215 Cabinet Dimensional Data, CW038toCW084
DPN003216 Cabinet Dimensional Data, CW106andCW114
UpflowUnitswithForward-curvedBlowers
DPN003194 Cabinet Dimensional Data, CW038to CW084
DPN003195 Cabinet Dimensional Data, CW106andCW114
Floor Standsfor UnitswithECFans
DPN003212 FloorstandDimensional Data, DownflowModels, CW038 toCW041
DPN003211 FloorstandDimensional Data, DownflowModels, CW051 andCW060
DPN003210 FloorstandDimensional Data, DownflowModels, CW076andCW084
DPN003191 FloorstandDimensional Data, DownflowModels, CW106andCW114
DPN003207 FloorstandDimensional Data, DownflowModels, CW146andCW181
DPN002433 FloorstandDimensional Data, DownflowModels, CW300 andCW400
Floor Standsfor UnitswithForward-curvedBlowers
DPN001676 FloorstandDimensional Data, CW038toCW084
DPN001677 FloorstandDimensional Data, CW106andCW114
Table 3.1 Dimension Planning Drawings
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Document Number Title
Plenumsfor UnitswithECFans
DPN004604 Plenum Dimensional Data, DownflowModels, CW038to CW084
DPN004605 Plenum Dimensional Data, DownflowModels, CW106andCW114
DPN003214 Plenum Dimensional Data, UpflowModels, CW038toCW084
DPN003213 PlenumDimensional Data, UpflowModels, CW106andCW114
Plenumsfor UnitswithForward-curvedBlowers
DPN003204 PlenumDimensional Data, UpflowModels, CW038toCW084
DPN003205 Plenum Dimensional Data, UpflowModels, CW106andCW114
Table 3.1 Dimension Planning Drawings (continued)
2.2 Location Considerations
For a downflow unit, the unit can sit on an accessible, elevated flooring system. It may be necessary to furnish additional
pedestal support belowthe unit to ensure maximum structural support. A separate floor stand for the unit may be used as
support, independent of the elevated floor and installed prior to the flooring system.
For downflow and upflowunits, provide approximately 34in. (864mm) service clearance onthe left, right and in front of the
unit whenever possible. The minimum space required for service is 18in.(457mm) on the left end, 18in.(457mm) onthe
right end and 24in.(610mm) infront of the unit. This space is necessary to permit routine maintenance, suchas replacing
filters and adjusting the fanspeed. Ondownflow and upflowCW106 and CW114 models, left- and right-end minimum
clearances are 0in.(0mm) except for rear return.
Avoid installing units inanalcove or at the extreme end of a room that has a high aspect ratio (long narrow room). Also
avoid installing units too close together. This tends to reduce the effectiveness of the air distribution as compared to units
located 30to40ft(9to12mm) apart.
2.3 Air-distribution Considerations for Downflow Units
•Verify that the raised floor has beenproperly sized for the unit’s airflow and the room is free of airflow
restrictions.
•Perforated floor tiles in the raised floor should ensure minimal pressure loss.
•The raised floor must provide 7-1/2in. (191mm) of clearance.
•Ensure that there is adequate clearance above the unit for service, such as replacing filters.
•Optional plenums are available for downflow unit ducting.
•If installing units withelectrically-commutated fans (EC fans), there must be 24in. minimum clearance below
the unit to lower the fans. Fans may also remainthe in unit if desired.
•A filter plenum is required for the following units: CW146, CW181, CW300, CW400.
NOTE: The floor stand used with EC units is not symmetrical and its orientation to the Liebert® CW is
critical to lowering the EC fans. Unless the floor stand is installed in the correct position, the blowers
will not lower into the floor stand.
2Pre-installation PreparationandGuidelines 17

Figure 3.1 Downflow unit ducting and plenum ducting
Item description
1 Field-fabricatedduct work
2
Fieldservice access for filter replacement
Minimum height = 12 in. (305 mm)
Minimum distance from unit = 2 in. (51 mm)
3 Service-accessdoor for filter replacement providedinplenum.
4 Direct-to-unitducting
5 Plenum ducting
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2.4 Air-distribution Considerations for Upflow Units
Various configurations are available:
•Front return
•Rear return
•Bottom return (not available on CW106 and CW114 models)
For in-room applications withsupply and return grilles, several feet of clearance must be maintained at the intake and
discharge of the unit.
Upflow rear-return configurations use a filter box attached to the back of the unit. Allow25in. (635mm) on one side of the
unit for access tothe rear-return filter box. Refer to the rear-returninstallationsheet, inside the rear-return filter box
package.
For ducted applications, duct flanges are supplied on the blower outlets. Follow the SMACNA-Duct Construction Standard
for single-, dual-, or triple-blower systems. Do not runduct work off the perimeter flange onthe top of the unit. This flange is
for positioning and attaching the optional air discharge plenum with grille. Attaching a duct to this flange may reduce
airflow to inadequate levels.
Figure 3.2 Upflow ducting configurations (forward-curved blowers)
Item Description
1 Typical ducting
2 Straight sections must be 1.5 to 2.5 timesthe longest blower dimension.
3 Front of unit
NOTE: Drain traps are qualified to a return duct static of negative 1.5 i.w.g. (-1.5i.w.g).
2Pre-installation PreparationandGuidelines 19

Figure 3.3 Upflow ducting configurations for EC fans
Item Description
1 Typical ducting. May runtoeither side.
2 Straight section must be 2.5 times the depth of blower.
3 Ductingonly attachedtoflangesonprovidedplenum.
NOTE: Follow standard practices in all duct work.
2.5 Connections and System Setup
•The unit requires a drain, which must comply with all applicable codes. See Field-installed, Gravity-fed Drain
Line Requirements onpage33, for details.
•Planthe routing of wiring, piping and duct work to the unit. Refer to the appropriate piping connectionlocation
drawings, piping schematics, and electrical-connection drawings for your system in Submittal Drawings on
page109.
•If seismic requirements apply, consult your Vertiv representative for information about a seismic-rated floor
stand.
NOTE: Seal openings around piping and electrical connection to prevent air leakage. Failure to do so
could reduce the unit’s cooling performance.
2.6 Operating Conditions
The Liebert® CWmust be operated in a conditioned space withinthe operating envelope that ASHRAE recommends for
data centers. The ASHRAE recommended maximum dew point is 59°F (15°C). Operating the CW outside of this envelope
candecrease equipment reliability. Refer to ASHRAE’s publication, “Thermal Guidelines for Data Processing Environments.”
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