This manual contains important safety instructions that should be followed during the installation
and maintenance of the Liebert MC. 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 and installation, operating and safety instructions on the unit and in
this manual. Follow all operating and user instructions.
WARNING
Risk of improper handling, installation, and service. Can cause property damage, injury, or
death.
Only trained and qualified personnel should work on this unit. Read all installation,
operation and safety alerts and instructions and wear appropriate protective headgear, safety
glasses, gloves and clothing before installing, operating or servicing this unit.
WARNING
Risk of arc flash and electric shock hazard. Disconnect all local and remote electric power
supplies and wear appropriate personal protective equipment per NFPA 70E before working
within the electric control enclosure or the fan motor connection box(es). Failure to comply can
cause serious injury or death.
This unit contains lethal voltage. The line side of the unit disconnect switch remains
energized when the unit disconnect switch is in the “Off” position. Use a voltmeter to verify
that the line side input electric power to the unit disconnect switch is off before working on
any electrical components or connections.
Important Safety Guidelines
WARNING
Risk of high-speed, rotating fan blades. Can cause serious personal injury or death.
Fan blades can automatically start rotating without warning at any time during a cooling
cycle or after power is restored after a power failure. Disconnect all local and remote electric
power supplies and verify with a voltmeter that the power is off and that the fan blades have
stopped rotating before working within the cabinet or servicing fan motors.
WARNING
Risk of electric shock. Can cause injury or death.
The variable speed control may contain a stored electrical charge. Disconnect all local and
remote electrical power supplies and wait 10 minutes before working within condenser main
electrical enclosure or fan electrical enclosure.
WARNING
Risk of heavy condenser falling or tipping over. Can cause property damage, serious injury or
death.
Confirm that all components of the lifting system are rated for the weight of the condenser by
an OSHA Certified rating organization before attempting to lift and/or move the condenser.
See 2.2 - Dimensions and Weights for the condenser weights.
CAUTION
Risk of hot surfaces. Can cause injury.
Fan motors, transformers, piping and other components may become extremely hot during
normal operation. Wear thermally insulated gloves and appropriate protective clothing and
allow time for components to cool when working within the cabinet or electric control
enclosure.
®
1Liebert
MC
™
Page 8
Important Safety Guidelines
!
!
CAUTION
Risk of sharp edges, splinters and exposed fasteners. Can cause personal injury.
Only properly trained and qualified personnel wearing appropriate safety headgear, gloves,
shoes, and glasses should attempt to move, lift, remove packaging from or prepare unit for
installation.
CAUTION
Risk of explosive discharge of high-pressure gas. Can cause injury.
Relieve system pressure and verify that the indoor and outdoor units are Off before making
piping connections/disconnections.
NOTICE
Risk of overhead interference. Can cause unit and/or structure damage.
Refer to the installation plans before moving the unit to verify clearances.
NOTICE
Risk of improper storage. Can cause unit damage.
Keep unit upright and protected from contact damage.
Liebert® MC
™
2
Page 9
Liebert MC Nomenclature
LIEBERT MC NOMENCLATURE
Model Number – Part 1/2Model DetailsPart 2/2
12 345678910111213141516171819202122232425
MCM040E1AD0A0VU000000****
1-2. Unit Family; MC = Microchannel Condenser12. Panel Material
3. Platform SizeA = Bright Aluminum
S = Small13. Connection Pipe Unit of Measurement
M = Medium0 = Inches (Std. ACR Copper)
L = Large14. Legs Included
4-6. Nominal Condenser Capacity, kWV = 18" Tall Legs (Std.)
Example: 040 = 40kW @ 95°F(35°C) & 27°R (15°K) ITDX = 36" Tall Legs with Bracing
7. Control/Fan TypeY = 48" Tall Legs with Bracing
E = Premium & EC FanZ = 60" Tall Legs with Bracing
10. Packaging1 = Factory Set for Liebert Lee-Temp Kits
D = Domestic, Non-Stackable (Horizontal Airflow Orientation)18-21. Undefined - Reserved For Future Use
E = Export Crating - Non-Stackable (Horizontal Airflow Orientation) 22-25. Factory Configuration Number
11. Coil Coating
0 = None
E = E-Coat (Epoxy)
Configuration
®
3Liebert
MC
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Page 10
1.0INTRODUCTION
1.1 Product Description and Features
The Liebert MC condenser is a low-profile, direct-drive propeller fan-type air-cooled unit suitable for
mounting outdoors. It provides heat rejection for either one or two separate refrigeration circuits,
matches the heat rejection capacity corresponding with the outdoor ambient temperature, and with
each corresponding compressor heat rejection requirements. Constructed with an aluminum cabinet,
galvanized steel frame and microchannel coil, the unit is quiet and corrosion resistant. The condenser
is quickly and easily installed, because all internal wiring is completed at the factory with only
electrical connections to be made at the job site. All electrical connections and controls are enclosed in
an integral weatherproof section of the condenser.
Figure 1Two-fan Liebert MC condenser
Introduction
1.1Control/Fan Types
1.1.1Premium Efficiency Control/EC Fan
Premium Efficiency Controls and EC fans are matched to provide superior system energy efficiency.
The premium control board allows CANbus communication with the indoor unit’s Liebert iCOM
control. This communication feature provides compressor run signals, condenser operating mode
changes, condenser alarm monitoring, simplified system charging procedures and outdoor ambient
temperature monitoring. The EC fan is an integral assembly of an electronically commutated motor,
quiet fan blade assembly and finger/hail guard. The fans are controlled by the premium control board
using pressure transducer signals from the refrigerant circuit and factory programming to control the
refrigerant head pressure.
The premium control board uses inputs from the indoor unit, condenser refrigerant pressures and
temperatures and ambient temperatures to modulate the EC fan motor speed from 0 to 100% RPM,
maintaining refrigerant head pressure setpoints. The control board, EC fan(s) and transducer(s) are
factory-wired. Dual refrigeration circuit condensers adjust fans of each circuit independently to match
each circuit’s head pressure conditions. Multiple fan single refrigeration circuit condensers adjust all
fans to the same RPM to maintain head pressure. The control system provides refrigerant head
pressure control for outdoor ambient temperatures as low as -30°F (-35°C), provided that the total
design range (from minimum to maximum) is 125°F (70°C) or less. Liebert Lee-Temp
required only when the design temperature ranges exceed 125°F (70°C) for standard match ups and
115°F (65°C) for Liebert Quiet-Line
Liebert® MC
™
™
match ups.
®
™
kits are
4
Page 11
1.1.2Liebert Lee-Temp™ Refrigerant Control
The Liebert Lee-Temp head pressure control system utilizes head pressure control valve(s), extra
refrigerant and insulated refrigerant receiver(s) with heater pads to assist system starting and to
maintain proper operating head pressures in outdoor ambient temperatures below the rating point of
the Liebert MC control type. The system works by flooding the condenser coil with liquid refrigerant
to a level that balances the system condensing requirements with the condenser coil surface available
to reject the system heat. During the summer, the system requires the entire condenser coil surface
for heat rejection and most of the refrigerant is stored in the receiver. In the winter, the same amount
of heat can be rejected by only a fraction of the coil surface. As head pressure begins to fall, the control
valve restricts the flow of liquid refrigerant existing from the condenser. This extra liquid refrigerant
reduces the effective condenser surface area available for heat transfer. The head pressure control
valve also bypasses hot gas into the receiver to warm the liquid and maintain liquid pressure for
proper operation of the expansion valve. Liebert Lee-Temp kit is optional for condensers and is
field-installed. Condenser control boards are factory-configured for Liebert Lee-Temp if ordered with
Liebert Lee-Temp receivers. They can be field-configured if Liebert Lee-Temp system is added later.
1.2Sound Level
Liebert MC condensers utilize low air resistance coil(s) and slower speed fan motors to yield the
required heat rejection at significantly lower sound levels. EC fans are designed to yield the same
maximum sound levels at summer design conditions to help your facility meet noise codes with
moderate operating sound levels.
Introduction
1.2.1Liebert Quiet-Line Match Up
Special match ups of premium condensers are available for applications needing to meet even lower
governmental sound regulations. Lower sound levels are achieved by oversizing the condenser, which
will decrease the maximum airflow and sound level produced by the condenser at design outdoor air
temperatures. This feature requires special setup of the indoor unit. Liebert Lee-Temp may be
required for these applications.
1.3Surge Protection Device (Optional)
An optional surge protection device (SPD) can be field-wired to protect the condenser from surges that
threaten sensitive equipment. The condenser’s electrical panel provides a terminal block to allow the
SPD to be wired in parallel with the high-voltage power. An additional low-voltage terminal block is
provided on condensers with Premium Control Boards to allow monitoring of the SPD alarm circuit.
The Liebert PowerSure CM
protection. An illuminated green LED indicates the SPD is On and providing full protection. An
illuminated red LED indicates that the device’s protection may have been reduced and may require
replacement.
Both lights extinguished indicates there is no power to the condenser or the condenser disconnect is in
the Off position.
™
surge protection device provides 50kA per mode of surge current
®
5Liebert
MC
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Page 12
2.0SITE PREPARATION
2.1Site Considerations
• Condensers should be installed in a location offering maximum security and access for
maintenance.
• Avoid ground-level sites with public access and areas prone to heavy snow or ice accumulations.
• To ensure adequate air supply, Emerson
with clean air, away from loose dirt and foreign matter that might clog the coil. In addition,
condensers should be located no closer than 3 feet (1m) from a wall, obstruction or adjacent unit.
• For roof installation, mount the condenser on suitable curbs or other supports in accordance with
local codes.
• Condensers must not be installed in a pit.
• Condensers must be installed on a level surface to ensure proper refrigerant flow.
• Use caution when installing condensers below the indoor unit. Condensers must not be installed
more than 15ft. (4.6m) below the indoor unit. Condensers with Liebert Lee-Temp
be installed at or above the level of the indoor units to maintain proper subcooling.
• Liebert Lee-Temp receiver tanks should be mounted on the condenser legs for proper operation.
Contact Emerson Application Engineering Department for assistance with applications requiring
remote mounting of receivers.
• Condensers must be installed in vertical airflow orientation to maintain the electrical box’s
NEMA 3R rating.
Site Preparation
®
recommends that condensers be installed in an area
™
receivers must
2.2Dimensions and Weights
Table 1Condenser net weights, shipping weights, dimensions and volume, approximate
Domestic PackagingExport Packaging
Condenser
Number
Model #
MCS0281154 (70)335 (152)
MCM0401231 (105)410 (186)
MCM0802441 (200)750 (340)
MCM1203672 (305)1110 (503)
MCM1604860 (390)1425 (646)
MCL0551344 (156)525 (238)
MCL1102602 (273)910 (413)
MCL1653891 (404)1330 (603)
MCL22041186 (538)1755 (796)
Net and packaged weights will increase with factory options: legs taller than 18", coated coils and seismic options.
Field-installed receivers also add to net weights. Consult factory for additional information.
* 18" legs standard for all models. Cross-bracing required for legs longer than 18". Number varies according to model and options.
See Tables 1 and 2 for weights, including added weight for legs of various lengths. Source: DPN002172, Rev. 3; and DPN002189, Rev. 4.
No.
FansAIn. (mm)
One-Fan
Condenser
39-5/16"
(999mm)
44-3/8"
B
In. (mm)
(1127mm)
Electric Box End
C
ANCHOR PLAN
E
Provided On
Four-Fan Models
C
In. (mm)
D
In. (mm)
E
In. (mm)
46"
(1168mm)
D
Leg supplied for
each Liebert
Lee-Temp kit on
2- & 4-fan models
39-5/16"
(999mm)
(1127mm)
Electric Box End
46-5/16"
(1177mm)
Leg
Height
F * In
(mm)GH
60 (1524) 73-5/8 (1870) 81-5/8 (2073)
44-3/8"
Liebert® MC
™
8
Page 15
Figure 5Condenser planning dimensions–MCM120
A
Shown with typical 60" legs.
152-3/4"
(3880mm)
46-1/4"
1175mm
B
C
A
144-5/16"
(3666mm)
Liebert DSE receiver adds
8-1/2" (216mm) to the unit
width and may be mounted
on the right or left side.
DETAIL A
Electrical Box End
46"
(1169mm)
Fastener assembly,
fender washer and
hex nuts.
4 each required,
2 places
Spacer
2 each required,
2 places
Emerson recommends a clearance of
36" (915mm) on each end and each side
for proper operation and component access.
46-5/16" (1177mm)
39-5/16"
(999mm)
44-3/8"
(1127mm)
1-7/8"
(48mm)
94-7/16"
(2398mm)
Install two (2) each 1/8"(3.18mm)
leg spacers in each of these
locations (see note below)
NOTE:
Install (2) two condenser leg spacers, part number 304679P1, in two places where shown, between each pair of legs
that adjoin each other.
Use (4) four of part number: 301375G1 (fastener assembly), 301369P1 (washer fender) and 301392P1 (nut hex),
to secure each pair of legs and spacers together.
* 18" legs standard for all models. Cross-bracing required for legs longer than 18". Number varies according to model and options.
See Tables 1 and 2 for weights, including added weight for legs of various lengths.
Source: DPN002555, Rev. 1
B
In. (mm)
In. (mm)
C
9Liebert
®
MC
™
Page 16
Figure 6Condenser planning dimensions—MCL055, MCL110, MCL165 and MCL220
Emerson recommends a clearance of
36" (915mm) on each side for proper
operation and component access.
Eyebolts for lifting condenser
provided on 3&4 fan models
55-5/8"
(1413mm)
55-1/2"
(1409mm)
53-7/8"
(1368mm)
Electric Box End
48-3/4"
(1239mm)
Height to Top
of Fan Guard
DPN002416
Rev. 2
ANCHOR PLAN
Provided on
3- & 4- Fan Models
D
E
For typical footprint
dimensions, see Figure 2
See Table 3 for
dimensions F, G and H
Site Preparation
Table 3Condenser leg height and additional weight, MCL055, MCL110, MCL165 and MCK220
# of
Model #
MCL0551
MCL1102
MCL1653
MCL2204
* 18" legs standard for all models. Cross-bracing required for legs longer than 18" (457mm). Number varies according to model and options.
See Tables 1 and 2 for weights, including added weight for legs of various lengths.
Source: DPN002416, Rev. 2
FansAin. (mm)Bin. (mm)Cin. (mm)Din. (mm)Ein. (mm)
68
(1727)
124-1/8
(3152)
180-1/4
(4578)
236-5/16
(6003)
—
—
73-7/16
(1866)
129-9/16
(3291)
56
(1423)
112-1/8
(2848)
168-1/4
(4274)
224-3/8
(5699)
54-3/8
(1381)
110-1/2
(2806)
110-1/2
(2806)
110-1/2
(2806)
—18 (457)
—36 (914)
56-1/8
(1425)
112-1/4
(2851)
Leg Height
F * In. (mm)GIn. (mm)HIn. (mm)
35-7/8
(911)
53-7/8
(1368)
48 (1219)
60 (1524)
65-7/8
(1673)
77-7/8
(1978)
43-5/8
(1108)
61-5/8
(1565)
73-5/8
(1870)
85-5/8
(2175)
Liebert® MC
™
10
Page 17
Site Preparation
Emerson recommends a clearance of
36" (915mm) on each side for proper
operation and component access.
Eyebolts for lifting condenser
provided on 3&4 fan models
55-1/2"
(1409mm)
53-7/8"
(1368mm)
55-5/8"
(1413mm)
Height
to Top
of Fan
Guard
54-3/8"
(1381mm)
Electric Box End
48-3/4"
(1239mm)
ANCHOR PLAN
(1) leg supplied for
each Liebert
Lee-Temp
kit on 2, 3, & 4
fan models
Provided on
3- & 4- Fan
Models
D
E
DPN002415
Rev. 3
For typical footprint
dimensions, see Figure 2
Figure 7Cabinet and anchor dimensions—MCL055, MCL110, MCL165 and MCL220 with Liebert
Lee-Temp
™
receiver
# of
Model #
MCL0551
MCL1102
MCL1653
FansAin. (mm)Bin. (mm)Cin. (mm)Din. (mm)Ein. (mm)
MCL2204
* 18" legs standard for all models. Cross-bracing required for legs longer than 18" (457mm). Number varies according to model and options.
See Tables 1 and 2 for weights, including added weight for legs of various lengths.
Source: DPN002415, Rev. 3
68
(1727)
124-1/8
(3152)
180-1/4
(4578)
236-5/16
(6003)
73-7/16
(1866)
129-9/16
(3291)
—
—
56
(1423)
112-1/8
(2848)
168-1/4
(4274)
224-3/8
(5699)
Leg Height
F *
In. (mm)GIn. (mm)HIn. (mm)
54-3/8
(1381)
110-1/2
(2806)
110-1/2
(2806)
110-1/2
(2806)
11Liebert® MC
—18 (457)
—36 (914)
56-1/8
(1425)
112-1/4
(2851)
48 (1219)
60 (1524)
35-7/8
(911)
53-7/8
(1368)
65-7/8
(1673)
77-7/8
(1978)
43-5/8
(1108
61-5/8
(1565)
73-5/8
(1870)
85-5/8
(2175)
™
Page 18
3.0INSPECTIONAND INSTALLATION
!
!
!
3.1Equipment Inspection
Before unpacking the condenser, verify that the labeled equipment matches the bill of lading.
Carefully inspect all items for damage, either visible or concealed. Report any damage immediately to
the carrier and your local Emerson representative. File a damage claim with the carrier and send a
copy to your local Emerson representative.
3.1.1Packing Material
All material used to package this unit is recyclable. Save it for future use or dispose of the material
appropriately.
SAFETY INFORMATION
WARNING
Risk of improper handling. Can cause equipment damage, injury or death.
Read all of the following instructions before attempting to move, lift, remove packaging from
or preparing unit for installation.
WARNING
Risk of heavy condenser falling or tipping over. Can cause property damage, serious injury or
death.
Confirm that all components of the lifting system are rated for the weight of the condenser by
an OSHA Certified rating organization before attempting to lift and/or move the condenser.
See 2.2 - Dimensions and Weights for the condenser weights.
Inspection and Installation
CAUTION
Risk of sharp edges, splinters and exposed fasteners. Can cause personal injury.
Only properly trained and qualified personnel wearing appropriate safety headgear, gloves,
shoes, and glasses should attempt to move, lift, remove packaging from or prepare unit for
installation.
NOTICE
Risk of overhead interference. Can cause unit and/or structure damage.
Refer to the installation plans before moving the unit to verify clearances.
NOTICE
Risk of improper forklift handling. Can cause unit damage.
Keep the forklift tines level and at a height that will fit under the skid.
NOTICE
Risk of improper storage. Can cause unit damage.
Keep unit upright and protected from contact damage.
Liebert® MC
™
12
Page 19
Figure 8Equipment recommended for handling a Liebert condenser
ForkliftCrane
Lift Beam, Slings
and Spreader Bars
308111
Pg. 1, Rev. 1
308111
Pg. 1, Rev. 1
3.2Handling Unit on the Skid
Transport unit using a forklift or a crane with sling and spreader bars.
• If using a fork lift, make sure the forks (if adjustable) are spread to the widest allowable distance
to still fit under the skid.
• Type of fork lift used will be dependent on the terrain the unit to be moved across during
handling.
• Minimum fork lift fork length for use on 1 and 2 fan units to be 48" (1219mm).
• When moving the packaged unit, do not lift the unit any higher than 6"(152mm) off the ground. If
circumstances require the unit to be lifted higher than 6" (152mm), great care must be exercised
and all personnel not involved in moving the unit must be at least 20' (5m) from the lift point of
the unit.
Inspection and Installation
Figure 9Forklift position with one-fan or two-fan condensers
• When using a forklift to off-load or move for installation, it is recommended to lift one narrow end
off the ground no more than 6" (152mm). Use the forklift to push or pull the unit.
• When using a crane to lift the unit from a flat bed or to move for installation, using slings rated
for the unit weight is recommended.
• Spreader bars are to be used for sling stability and to prevent unit pinching. Make sure spreader
bars are wider than the unit.
• Slings are to be placed near the ends of the unit, under the top deck boards of the skid.
3.3Unit Storage
• Store the fan in the original shipping packaging in a dry area protected from the weather, or
protect it from dirt and weather until final installation.
• Avoid temperatures below -30°F (-34°C) and above 150°F (65°C).
• Avoid storing the Liebert MC condenser for longer than one year.
13Liebert® MC
™
Page 20
3.4Unpacking the Condenser—All Unit Sizes
Step 5
Step 1-DomesticStep 1 - Export
Step 2
Detail Area
Unit Legs
(Fasteners in bag
attached to legs)
308111
Rev. 1
Steps 3 and 4
Step 6
To unpack a condenser with one to two fans:
1. Remove the fence for domestic packaging (for export packaging, remove the crate).
2. Remove corner and side foam planks from around the unit.
3. Remove the steel band holding the unit to the skid.
4. Set unit legs aside for use later.
5. Remove corrugated panels covering the Liebert MC’s coil(s).
6. Remove the bolts securing unit to the skid.
Figure 10 Removing protective material
Inspection and Installation
Liebert® MC
™
14
Page 21
Inspection and Installation
308111
Rev. 1
308111
Pg. 2, Rev. 1
Straps go against
legs on one-fan and
two-fan units
Straps or chains go against
eyebolts on three-fan and
four-fan units
3.5Preparing a Condenser for Moving and Installation—Units with One or Two Fans
The following procedure is one recommended method for removing a Liebert condenser from its
shipping skid. Other methods may be used, provided that they are safe for personnel, the condenser
and equipment.
3.5.1Attaching Legs, Removing the Skid and Attaching Slings-Units with One or Two Fans
1. Attach legs to the unit at indicated locations.
Use the fasteners provided with the legs.
Recommended tools for attachment is a 5/8" socket and ratchet.
More legs may be available for installation than shown. This will depend on the unit type and
number of fans.
Figure 11 Attaching legs to one-fan or two fan condensers
B
Detail B
2. Place slings around the unit between the unit and the top deck boards of the skid:
• One-fan and two-fan units: against the inside of the attached legs.
• Three-fan and four-fan units: against the outside of the attached eye bolts.
3. Use spreader bars, a lift beam and a crane to lift the unit off the skid.
NOTICE
Risk of improper lifting. Can cause equipment damage.
Make sure that the spreader bars wider are than the unit. If the spreader bars are too short,
the slings may crush the unit.
Figure 12 Securing slings to condensers for lifting off skid
15Liebert® MC
™
Page 22
4. Lift the unit 24" (610mm) off the top deck of the skid.
308111
Pg. 3, Rev. 1
5. Move the skid from under the unit.
6. A mechanized method is preferred, but if not available, uses a minimum of four properly protected
individuals to turn the unit upright so that the legs point down.
Unit legs must be pointing toward the ground.
Figure 13 Remove skid, set condenser on floor
Inspection and Installation
7. Set the upright unit on the ground so the legs support unit weight.
8. Remove the straps from around unit.
9. One-fan and two-fan units: Route the straps through the large holes in the side of the legs.
Spreader bars are still required.
On three-fan and four-fan units: Secure straps or chains to the eyebolts on top of the unit.
Spreader bars are still required.
NOTICE
Risk of improper lifting. Can cause equipment damage.
Make sure that the spreader bars wider are than the unit. If the spreader bars are too short,
the slings may crush the unit.
The unit is ready to be lifted and moved to its installation location.
Liebert® MC
™
16
Page 23
Figure 14 Lifting condensers with one, two, three or four fans
Spreader Bars
(must be wider
than the
Liebert MC to
prevent crushing
force)
Straps go through holes in legs
on one-fan and two-fan units
Straps or chains go through
eyebolts on three-fan and
four-fan units
308111
Pg. 3, Rev. 1
Inspection and Installation
3.6Mounting the Condenser
The condenser must be installed so that it is level within 1/2" (13mm) to ensure proper refrigerant
flow. For roof installation, mount the condenser on suitable curbs or other supports; follow all local
and national codes. Secure the legs to the mounting surface using a field-supplied 1/2" (13mm)
diameter bolt in each of the two 1/2" x 1" (12.7x25.4mm) obround holes in each leg. See Figures 3
through 7 for anchor dimensions.
17Liebert® MC
™
Page 24
4.0ELECTRICAL CONNECTIONS
!
!
Line voltage electrical service is required for all models. Refer to equipment nameplate regarding
wire size and circuit protection requirements. Electrical service must conform to national and local
electrical codes. Refer to Figure 16 for electrical service entrances into unit. Refer to electrical
schematic when making connections.
A manual electrical disconnect switch should be installed in accordance with local codes. Consult local
codes for external disconnect requirements.
All internal wiring is completed at the factory.
WARNING
Risk of electrical shock. Can cause injury or death.
The variable speed control may contain a stored electrical charge. Disconnect all local and
remote electrical power supplies and wait 10 minutes before working within the condenser’s
main electrical enclosure or fan electrical enclosure.
The Liebert MC contains lethal voltage in some circuits. The line side of the disconnect
remains energized when the condenser unit disconnect is switched to the Off position.
Use a voltmeter to verify that the line-side electrical power is Off before making any electrical
connections or performing any electrical and/or mechanical service and/or maintenance
operations.
Electrical Connections
WARNING
Risk of high-speed, rotating fan blades. Can cause serious injury or death.
Fan blades can automatically start rotating without warning at any time during a cooling
cycle or after power is restored after a power failure. Disconnect all local and remote electric
power supplies and verify with a voltmeter that the power is off and that the fan blades have
stopped rotating before working within the cabinet or servicing fan motors.
Each unit is shipped from the factory with all internal wiring completed. Refer to the
electrical schematic supplied with the condenser when making line voltage supply,
low-voltage indoor unit interlock and any low-voltage alarm connections. All wiring must be
done in accordance with all applicable local, state and national electrical codes.
NOTE
Installation and service of this equipment should be done only by properly trained and
qualified personnel who have been specially trained in the installation of air conditioning
equipment.
NOTE
Use copper wiring only. Make sure that all connections are tightened to the proper torque
mentioned on the component.
Liebert® MC
™
18
Page 25
4.1Line Voltage Wiring
!
WARNING
Risk of electrical fire and short circuit. Can cause property damage, injury or death.
Select and install the line side electrical supply wire and overcurrent protection device(s)
according to the specifications on the unit nameplate(s), per the instructions in this manual
and according to the applicable national, state, and local code requirements. Use copper
conductors only.
Make sure all electrical connections are tight. Unit-specific wiring diagrams are provided on
each unit.
NOTE
The Liebert MC Condenser is designed to operate with Wye-connected power. It will not operate
properly with Delta-connected power. Refer to 4.1.1 - Wye vs. Delta Connection Power Supply.
Condenser-rated voltage should be verified with available power supply before installation. Refer to
the unit’s electrical schematic and serial tag for specific electrical requirements.
Line voltage electrical service is required for all condensers at the location of the condenser. The
voltage supply to the condenser may not be the same voltage supply as required by the indoor unit.
Consider using UPS equipment on both data center cooling units and Liebert MC condensers to
maintain uninterrupted cooling capability. Refer to the unit’s serial tag for specific condenser
electrical requirements. A unit disconnect is standard. However, a site disconnect may be required
per local code to isolate the unit for maintenance. Route the supply power to the site disconnect switch
and then to the unit. Route the conduit to the knockout provided in the bottom right end of the
electrical control enclosure. Connect the earth ground wire lead to the marked earth ground
connection terminal provided near the factory-installed disconnect switch (see Figure 16).
Electrical Connections
NOTE
™
Liebert Lee-Temp
kits require a separate line voltage electrical supply for the heated receivers.
See Table 5 for power requirements.
Table 4Electrical data, three-phase, 60Hz condenser, Premium Version (EC control)
Power Requirements
Number
Model #
MCS02813.01.41.43.81.81.8151515
MCM04012.31.41.43.21.91.9151515
MCM08024.62.82.85.53.33.3151515
MCM12036.94.24.27.54.64.6151515
MCM16049.25.65.69.86.06.0151515
MCL05515.72.82.87.13.53.5151515
MCL110211.45.65.612.86.36.3151515
MCL165317.18.48.418.59.19.1201515
MCL220422.811.211.224.211.911.9251515
1. FLA = Full Load Amps; WSA = Wire Size Amps; OPD = Maximum Overcurrent Protection Device.
2. 208V–460V premium models must be connected to Wye 3-phase systems.
Rated Voltage - Single-Phase120 208/230
Watts/Receiver
Amps
Wire Size Amps
Maximum Overcurrent
Protection Device, Amps
The Liebert Lee-Temp receiver requires a separate power feed for heaters. The condenser
is not designed to supply power to the receiver heater pads.
™
receiver, 60Hz
150300150300
1.42.80.71.4
1.83.50.91.8
15151515
4.1.1Wye vs. Delta Connection Power Supply
Figure 15 Wye vs. Delta power supply connection diagram
NOTE
The Liebert MC Condenser is designed to operate with Wye-connected power with a solidly
grounded neutral.
The Liebert MC condenser Premium EC Fan Models will not operate properly with
Delta-connected power. A field-supplied isolation transformer or other power solutions will be
needed to for proper condenser function.
NOTE
The electronically commutated motors included in the Liebert MC are suitable for connection to
power supplies with a solidly grounded neutral.
Acceptable Power Supplies—208V to 480V Nominal Units
• 208V wye with solidly grounded neutral and 120V line-to-ground
• 380V wye with solidly grounded neutral and 220V line-to-ground
• 480V wye with solidly grounded neutral and 277V line-to-ground
Unacceptable Power Supplies—208V to 480V Nominal Units
• Wye with high-resistance (or impedance) ground
• Delta without ground or with floating ground
• Delta with corner ground
• Delta with grounded center tap
Liebert® MC
™
20
Page 27
Electrical Connections
4.2Low-Voltage Control Wiring—Premium Efficiency Control Condenser
NOTICE
Risk of control malfunction. Can cause improper unit operation.
Make sure that all low-voltage electrical wiring has been performed per the schematic
diagram provided and that all low-voltage wiring connections are tight.
Premium Efficiency Control condensers are designed to use CANbus communication between Liebert
MC and Liebert iCOM
• shielded
• 24-18AWG stranded tinned copper
• twisted pair (minimum 8 twists per foot)
• low capacitance (17pf/ft or less)
• plenum rated (NEC type CMP) if required by local codes
• UV and moisture resistant or run within conduit once in an outdoor environment, and must be
temperature and voltage rated for conditions present.
Examples: Belden part number 89207(plenum rated) or Alpha Wire part number 6454 (UV
resistant outdoor rated) category 5, 5e or higher.
Do not run the CANbus cable in the same conduit, raceway or chase used for high-voltage wiring. For
CANbus network lengths greater than 350ft (107m), contact Emerson for assistance. The CANbus
wiring is for communicating directly with future versions of the Liebert iCOM, but is not currently
active. When CANbus wiring is installed, place a jumper between Terminals 70/71/230. Contact
Liebert Precision Cooling Support for additional information relative to availability of iCOM software
versions that communicate directly to the condenser.
Premium Efficiency Control condensers are also designed to operate with Terminals 70 and 71 wired
to indoor unit compressor contactor side switch to indicate compressor on signal. For dual circuit
condensers, also use Terminal 230. These signals are required if CANbus communication with Liebert
iCOM is not used.
®
control on indoor unit. The CANbus wiring is field-supplied and must be:
21Liebert® MC
™
Page 28
4.2.1Electrical Field Connection Descriptions
Fan 2
Without Liebert
Lee-Temp
With Liebert
Lee-Temp
Fan 1
DPN002374
Pg. 1, Rev. 1
DPN002169
Pg. 1, Rev. 2
Liebert Lee-Temp
receiver tank
(1 per circuit)
Electrical connection
box with cover
Electrical service connection.
Pigtails in electric handy box
are factory-wired to Liebert Lee-Temp
heater pads for field-connection
of separate continuous electric
source; wire not by Emerson
Fan 2
Fan 1
5A
5B
7
5C
8
9
6
4
2
3
1
10
12
13
70
71
230
Figure 16 Typical connections, Premium Efficiency Control
Electrical Connections
Liebert® MC
™
22
Page 29
Electrical Connections
Key Electrical Details—Typical Connections, Premium Efficiency Control
1. Three-Phase Electrical Service—Terminals are on the top of the disconnect switch for one-fan
and two-fan units. Terminals are on the bottom of the disconnect switch for three-fan and four-fan
units. Three-phase service not by Emerson. See 4.1.1 - Wye vs. Delta Connection Power Supply.
2. Earth Ground—Field lug terminal for earth ground connection. Ground terminal strip for fan
motor ground connection.
3. Primary High-Voltage Entrance—Three 7/8" (22.2mm) diameter knockouts located at the
bottom of the enclosure.
4. SPD Field Connection Terminals—High-voltage surge protection device (SPD) terminals.
SPD is an optional device.
5. CANbus Terminal Connections—Field terminals for CANbus cable connection.
• 5A is the CANbus connectors.
• TB49-1 is the input terminal for CANbus high.
• TB49-3 is the input terminal for CANbus low.
• TB50-1 is the output terminal for CANbus high.
• TB50-3 is the output terminal for CANbus low.
• Each CANbus cable shield is connected to terminal “SH;” see 9 below.
• 5B is the “END OF LINE” jumper.
• 5C is the CANbus “DEVICE ADDRESS DIP SWITCH.” CANbus cable not by Liebert. See
requirements in 4.2 - Low-Voltage Control Wiring—Premium Efficiency Control Condenser.
6. Remote Unit Shutdown—Replace exiting jumper between Terminals TB38-1 and TB38-2 with
field-supplied normally closed switch having a minimum 75VA 24VAC rating. Use field-supplied
Class 1 wiring.
7. Alarm Terminal Connections
a. Common Alarm Relay indicates when any type of alarm occurs. TB74-1 is common, TB74-2 is
normally open, and TB74-3 is normally closed. 1 Amp 24VAC is the maximum load. Use
field-supplied Class 1 wiring.
b. Shutdown Alarm Relay indicates when condenser loses power, or when a critical alarm has
occurred that shuts down the condenser unit. TB74-4 is common; TB74-5 is normally open;,
and TB74-6 is normally closed. 1 Amp 24VAC is the maximum load. Use field-supplied
Class 1 wiring.
8. Indoor Unit Interlock and SPD Alarm Terminals
a. On any call for compressor operation, normally open contact is closed across Terminals 70 and
71 for Circuit 1, and normally open contact is closed across Terminals 70 and 230 for Circuit 2
from indoor room unit.
b. During SPD alarm, normally open contact is closed across Terminals 12 and 13. SPD is an
optional device.
9. CANbus Shield Terminal—Terminal for field shield connection of the CANbus field-supplied
cables. The shield of CANbus field-supplied cables must not be connected to ground at the
condenser.
10. Primary Low-Voltage Entrance—One 7/8” (22.2mm) diameter knockout that is free for
customer low-voltage wiring.
23Liebert® MC
™
Page 30
Figure 17 Field configurations and setting adjustments, Premium Efficiency Control
DPN002374
Pg. 2, Rev. 1
Electrical Connections
Liebert® MC
™
24
Page 31
5.0PIPING
!
!
Piping
WARNING
Risk of explosive discharge from high-pressure refrigerant. Can cause equipment damage,
injury or death.
Relieve pressure before working with or cutting into piping.
WARNING
Risk of refrigerant system rupture or explosion from overpressurization. Can cause
equipment damage, injury or death.
Local building and plumbing codes may require that a fusible plug or other type of pressure
relief device be installed in the system. Do not install a shutoff valve between the compressor
and the field-installed relief device.
Consult local building and plumbing codes for installation requirements of additional
pressure relief devices when isolation valves are installed as shown in Figure 18. Do not
isolate any refrigerant circuits from overpressurization protection.
NOTE
POE (polyol ester) oil, required with R407C/R410A and used with some R22 systems, is much
more hygroscopic than mineral oils. This means that POE oil absorbs water at a much faster
rate when exposed to air than previously used mineral oils. Because water is the enemy of a
reliable refrigeration system, extreme care must be used when opening systems during
installation or service. If water is absorbed into the POE oil, it will not be easily removed and
will not be removed through the normal evacuation process. If the oil is too wet, it may require
an oil change. POE oils also have a property that makes them act as a solvent in a refrigeration
system. Maintaining system cleanliness is extremely important because the oil will tend to
bring any foreign matter back to the compressor or plug the microchannel coil. Always use a
flow of dry nitrogen when brazing.
5.1Piping Guidelines
Indoor units and condensers both ship with holding charges of inert gas. Do not vent the condenser
until all refrigerant piping is in place, ready for connection to indoor unit and condenser.
• Use copper piping with a brazing alloy with a minimum temperature of 1350°F (732°C), such as
Sil-Fos. Avoid soft solders such as 50/50 or 95/5.
• Use a flow of dry nitrogen through the piping during brazing to prevent formation of copper oxide
scale inside the piping. When copper is heated in the presence of air, copper oxide forms. POE oil
will dissolve these oxides from inside the copper pipes and deposit them throughout the system,
clogging filter driers and affecting other system components.
• A pure dry nitrogen flow of 1-3 ft
displace the air. Control the flow using a suitable metering device.
• Ensure that the tubing surfaces to be brazed are clean and that the ends of the tubes have been
carefully reamed to remove any burrs.
• Ensure that all loose material has been cleaned from inside the tubing before brazing.
• Protect all refrigerant line components within 18" (460mm) of the brazing site by wrapping them
with wet cloth or suitable heat sink compound.
• Isolate piping from building using vibration isolating supports.
• Refer to the indoor unit’s user manual for appropriate piping sizes.
• Install traps on the hot gas (discharge) lines at the bottom of any rise over 5 feet high. If the rise
exceeds 25 feet (7.5m), then install a trap in 20 foot (6m) increments or evenly divided.
• Pitch horizontal hot gas piping down at a minimum rate of 1/2" per 10 ft. (42mm per 10m) so that
gravity will aid in moving oil in the direction of refrigerant/oil flow.
• Consult factory if Liebert Lee-Temp
equipped with Liebert Lee-Temp is more than 15 ft (4.6m) below the evaporator.
• Consult factory if piping run exceeds 150 feet (46m) equivalent length on traditional DX units.
3
/min (0.5-1.5 l/s) inside the pipe during brazing is sufficient to
™
condenser is below the evaporator or if a condenser not
25Liebert® MC
™
Page 32
Piping
• Consult factory if piping run exceeds 300 feet (91m) actual length, or 450 feet (137m) equivalent
length on units installed with Liebert EconoPhase units.
• Keep piping clean and dry, especially on units with POE oil (R407C, R410A or R22 refrigerant).
• Avoid piping runs through noise-sensitive areas.
• Do not run piping directly in front of indoor unit discharge airstream.
• Refrigerant oil – do not mix oil types or viscosities. Consult indoor unit for refrigerant type and oil
requirements.
NOTE
Failure to use compressor oils recommended by compressor manufacturer will void compressor
warranty. Consult Emerson or the compressor manufacturer for further recommendations or if
you have questions about compressor oils.
Refer to ASHRAE Refrigeration Handbook for general good practices for refrigeration piping.
The Liebert indoor cooling unit has a factory-installed high-pressure safety switch in the high
side refrigerant circuit. A pressure relief valve is provided with Liebert Lee-Temp
fusible plug is factory installed in the Liebert DSE
™
receivers. Consult local building codes to
™
receivers. A
determine if condensers without receivers will require field-provided pressure relief devices. A
fusible plug kit is available for field installation.
Liebert® MC
™
26
Page 33
Figure 18 Piping schematic
Piping
Check Valve
Relief Valve
Liebert Lee-Temp Receiver
Condenser
Coil
Liebert Lee-Temp
Service
Valve
Check
Valve
Service
Valve
Liquid Return
Head Pressure
Control Valve
Hot Gas Discharge
Compressor
Liquid
Service
Valve
Sensing
Bulb
Suction
External
Equalizer
Condenser
Coil
Evaporator
Coil
Field installed relief valve(s) required
for 50Hz EU CE units
Optional Field-Installed
Fusible Plug
For rises over 25ft. (7.6m),
trap every 20ft. (6m) or at
evenly divided distances*
*Isolation
Valve
Hot Gas Discharge
Expansion
Valve
NOTES
Single refrigeration circuit shown for clarity.
Schematic representation shown. Do not use for specific connection locations.
Solenoid
Valve
Sight
Glass
Refrigerant Piping
Field Piping
Service/Schrader (Access) Connection No Valve Core
Service/Schrader (Access) Connection With Valve Core
Filter Drier
Liquid Line
* Components are not supplied by
Liebert but are recommended for
proper circuit operation and
maintenance
*Isolation
Val ve
Trap at base of risers
over 5ft. (1.5m)*
DPN002188
Rev. 1
27Liebert® MC
™
Page 34
5.2Field Piping Guidelines
One discharge line and one liquid line must be field-installed for each circuit of the indoor unit and
the outdoor condenser(s). Dual circuit condensers are available for most dual circuit indoor unit
applications. Refer to Figures 18, through 20 for additional field-installed piping needed at the
condenser. This piping is needed for proper system performance and for installation/interconnecting
receivers and head pressure control valves for Liebert Lee-Temp
NOTE
Keep the evaporator unit and condenser closed with their factory charge of inert gas while all
field piping is installed. Keep the field piping clean and dry during installation, and do not
allow it to stand open to the atmosphere.
When all the field interconnecting piping is in place, vent the condenser’s inert gas charge and
connect to the field piping. Finally, vent the evaporator unit’s charge of inert gas and make its
piping connection last.
Follow all proper brazing practices, including a dry nitrogen purge to maintain system
cleanliness.
The condenser connection pipes must be wrapped with a wet cloth to keep the pressure and
temperature sensors cool during any brazing.
™
systems.
Piping
Liebert® MC
™
28
Page 35
Figure 19 Liebert MC Condenser piping—Single-circuit units
Note: Inverted traps in
refrigerant lines are internal
to the Liebert MC condenser
and field-installation is not
needed.
Piping
Leaving
Liquid
Line
Horizontal
Optional fusible plug service kit to be brazed into the liquid line(s)
in either the vertical or horizontal position (where required).
Vertical position is preferred; horizontal position is optional.
Table 6Liebert MC Condenser piping sizes, single-circuit units
Model No.
MCS02817/85/8
MCM04017/85/8
MCM08021-1/87/8
MCM12031-3/87/8
MCL05511-1/87/8
MCL 11021-3/81-1/8
MCL 16531-3/81-1/8
MCL 22041-5/81-3/8
Vertical
Number
of Fans
A
Entering
Hot Gas
Line
Connection Sizes, OD, in (mm)
Hot Gas LineLiquid Line
Fan 2
Fan 1
Field Piping
DPN002166
Rev. 1
29Liebert® MC
™
Page 36
Figure 20 Condenser piping for single-circuit condensers (with Liebert Lee-Temp™)
B VIEW
DPN002167
REV 2
NOTE:
1.The following materials are supplied by liebert for each circuit(shipped loose with condenser)for field
installation: insulated Libert Lee-Temp storage tank with sight glasses, head pressure control valve, check valve,
rotalock valve and pressure relief valve. All other piping to be supplied and installed by others.
2. Consult factory for proper line sizing for runs longer than 150ft.(45.7m) equivalent length.
Field Piping
Detail A-A
Isolator
Metal Clamp
Fasten hot gas line to cabinet
using flat surface clamps with
isolators (field-supplied)
See Detail A-A
R-407C 1 and 2 Fan
Piping Assembly
R-410A 1 and 2 Fan MCM
1 Fan MCL
Piping Assembly
R-407C 3 and 4 Fan
Piping Assembly
R-410A 2 and 3 Fan MCL
Piping Assembly
R-410A 4 Fan
Piping Assembly
Hot Gas Line
To Condenser
Entering Hot
Gas Line
Liquid Line
From Condenser
Leaving
Liquid Line
Position Elbow to
Direct Relief Valve
Downward
GENERAL ARRANGEMENT
B
Note: Inverted traps in
refrigerant lines are internal to
the condenser and
field-installation is not needed.
Piping
Table 7Condenser piping connection sizes—single-circuit condensers with Liebert Lee-Temp
Model #
MCS0287/85/87/85/85/8
MCM0407/85/87/85/85/8
MCM0801-1/87/81-1/87/81-1/8
MCL0551-1/87/81-1/87/87/8
MCL1101-3/81-1/81-3/81-1/81-1/8
MCL1651-3/81-1/81-3/81-1/81-1/8
MCL2201-5/81-3/81-5/81-3/81-3/8
Source: DPN002167, Rev. 2
Condenser
Connections, OD.InLiebert Lee-Temp Connections
Hot GasLiquid
Hot Gas Tee
to Lee-Temp Valve
IDS In.
Liquid Line
ODS, In.
Receiver Out
IDS In.
Liebert® MC
™
30
Page 37
Figure 21 Piping: dimensions—dual circuit two-fan and four-fan units
Optional fusible plug service kit to
be brazed into the liquid line(s) in
either the vertical or horizontal
position. (where required)
(vertical position is preferred,
horizontal position is optional.)
for two circuit systems, one
fusible plug kit will need to
be installed in each circuit.
Circuit #2
Circuit #1
Horizontal
Leaving Liquid
Line
Vertical
Field Piping
Entering Hot
Gas Line
Inverted traps in refrigerant
lines are internal to
the condenser. Do not trap
external to the unit.
DPN002425
Rev. 3
Piping
Table 8Piping: dimensions—dual-circuit, two-fan and four-fan units
Model #
MCM08027/85/8
MCL11021-1/87/8
MCM160
MCL22041-3/81-1/8
Source: DPN002425, Rev. 3
# of
Fans
4
Connection Sizes, OD, in
Hot Gas LineLiquid Line
1-1/87/8
31Liebert® MC
™
Page 38
Figure 22 Piping: dimensional data with Liebert Lee-Temp™—dual circuit condensers
Hot Gas Line
To Condenser
Entering Hot
Gas Line
Piping
Position elbow to
direct relief valve
downward
Leaving
Liquid Line
B
View
Liquid Line
From Condenser
Metal Clamp
Detail AA
Fasten hot gas line to cabinet
using flat surface clamps with
isolators (field-supplied)
See Detail A A
Hot Gas Line
To Condenser
Isolator
Inverted traps in refrigerant
lines are internal to
the condenser. Do not trap
external to the unit.
GENERAL ARRANGEMENT
R407C 2 and 4 Fan
Piping Assembly
R410A 2 Fan
Piping Assembly
Note:
1. The following materials are supplied by Emerson for each circuit (shipped loose with condenser)
for field installation: insulated Liebert Lee-Temp storage tank with sight glasses, head pressure control
valve, check valve, rotalock valve and pressure relief valve. All other piping to be supplied and installed by others.
2. Consult factory for proper line sizing for runs longer than 150ft. (45.7m) equivalent length.
R410A 4 Fan
Piping Assembly
Field Piping
Liquid Line
From Condenser
Leaving
Liquid Line
Position elbow to
direct relief valve
downward
C
DPN002426
REV. 3
View
Entering Hot
Gas Line
Table 9Piping dimensions—dual circuit condensers with Liebert Lee-Temp
Model #
MCM0807/85/87/85/85/8
MCL1101-1/87/81-1/87/87/8
MCM1601-1/87/81-1/87/81-1/8
MCL2201-3/81-1/81-3/81-1/81-1/8
Liebert® MC
Condenser Connections
ODS, in.Liebert Lee-Temp Connections
Hot GasLiquid
Source: DPN002426, Rev. 3
™
Hot Gas Tee
IDS, in.
32
Liquid Line
to Lee-Temp Valve
ODS, In.
Receiver Out
IDS, in.
Page 39
5.3Refrigerant Planning Values
Piping
Planning for the refrigerant requirements of the completed system is the total of the charges from
Indoor Unit, Condenser (including Liebert Lee-Temp
™
receiver, if used) and the interconnecting
piping. Tables 10, 11 and 12 provide the approximate charge required for the condensers and the
interconnecting piping. Consult indoor unit manuals for indoor unit charge requirements.
These values can be used for obtaining adequate refrigerant for the system, but should not be used for
final charging.
NOTE
Due to the much smaller coil volume, the performance, especially subcooling, of a Liebert MC
condenser is quite sensitive to the amount of refrigerant charge. Ensure that an accurate
amount of refrigerant charge is added.
Table 10Refrigerant required, R-407C, approximate
Single Circuit, lb/circuit (kg/circuit)Dual Circuit, lb/circuit (kg/circuit)
* Model MCM120 is available with Liebert DSE™ receiver; a Liebert Lee-Temp receiver is not available with the unit.
Source: DPN002411, Rev. 3
Condensers w/o
Liebert Lee-Temp
Condensers with
Liebert Lee-Temp
Condensers with
Liebert DSE
Condensers w/o
Liebert Lee-Temp
Condensers with
Liebert Lee-Temp
Condensers with
Liebert DSE
33Liebert® MC
™
Page 40
Table 12Interconnecting piping refrigerant charge
Line Size
O.D., in.
3/8—3.7 (1.7)——
1/2—6.9 (3.1)—5.0 (2.1)
5/82.2 (1.0)11.0 (5.0)1.1 (0.51)10.0 (4.2)
3/43.1 (1.3)15.7 (7.1)1.5 (0.67)13.0 (5.7)
7/84.5 (1.9)23.0 (10.4)2.3 (1.0)21.0 (9.5)
1-1/87.8 (3.5)39.3 (17.8)3.9 (1.8)34.9 (15.6)
1-3/811.8 (5.4)59.8 (27.1)5.5 (2.5)53.2 (23.8)
1-5/816.7 (7.6)———
Charge based on Type ACR/Type L copper pipe
Source: DPN002411, Rev. 3
R-407C, lb/100 ft. (kg/30m)R-410A, lb/100 ft. (kg/30m)
Hot Gas LineLiquid LineHot Gas LineLiquid Line
5.4Equipment Application Guidelines
Pump-down must be disabled on the indoor unit when using the Liebert MC condenser, due to the
reduced volume in the condenser coil. When applying the Liebert MC condenser to existing Liebert
indoor units, Emerson
provide suitable compressor protection. Additional liquid line Schrader ports are required at the
indoor unit to properly charge systems with Liebert MC condensers applied.
®
recommends adding a discharge line check valve and crankcase heater to
Piping
5.5Refrigerant Oil Addition Procedures
Consult the user manual for the indoor unit to determine whether additional oil is required for each
circuit. Factors such as compressor, condenser type, piping lengths, and total circuit refrigerant
charge influence this requirement.
5.6System Dehydration/Leak Test
Procedures for leak check and evacuation of the entire refrigeration system are contained in the
indoor unit’s installation manual. Use the proper manual section corresponding to the winter control
system used on the condenser (with or without Liebert Lee-Temp
™
or Liebert DSE™ receivers) and the
refrigerant to be charged into the system.
5.7Liebert MC Condenser Charging, Units with Liebert Lee-Temp™ Systems
Consult the indoor unit’s manual for charging systems with Liebert Lee-Temp receivers. These
procedures will be identical to systems with fin/tube condenser coils, but the refrigerant volumes will
be much lower. Consult Tables 10 and 11 for condenser with Liebert Lee-Temp refrigerant required.
5.8Liebert MC Condenser Charging with Liebert DSE™ Units
Consult the Liebert DSE’s manual (SL-18925) for charging Liebert DSE systems. All Liebert DSE
units require installation of a Liebert DSE receiver on each condenser circuit, with or without a
Liebert EconoPhase pump module installed. Consult Table 11 for condenser and receiver refrigerant
requirements.
Liebert® MC
™
34
Page 41
5.9Liebert MC Condenser Charging, Units without Liebert Lee-Temp™ Systems
Liebert MC condensers are charge-sensitive and require accurate calculation of the system charge to
avoid overcharging. To avoid overcharge, additional guidelines are recommended to ensure trouble
free operation.
• When charging system in an outdoor ambient below 50°F (10°C), recheck the subcooling against
Table 13 when the ambient is above 60°F (15.6°C)
• The indoor space should be maintained at 70 to 80°F (21 to 26.7°C) return air before final charge
adjustments are made.
• Charging unit at greater than 80°F (26.7°C) return air may result in the unit being overcharged.
• Charge by subcooling measurement at the indoor unit. See Table 13 for target subcooling
temperatures.
• Pressure and temperature measuring instruments should be capable of measuring to ±10 psig
(103.4kPa) and ± 2°F (1.1°C) for best subcooling measurement.
1. Check indoor nameplate for refrigerant type to be used. Unit control configurations differ
depending on refrigerant type.
2. Refrigerant charging requires unit operation. Refer to the indoor unit’s user manual for details
regarding indoor unit operation and 6.0 - Checklist for Completed Installation for the Liebert
MC condenser operation.
3. Calculate the amount of charge for the system. Refer to the indoor unit user manual, and
condenser and refrigerant line charge data in Tables 10 and 12.
4. Accurately weigh in as much of the system charge as possible before starting the unit. Do not
exceed the calculated charge by more than 0.5 lb (.37kg).
Piping
NOTICE
Risk of improper refrigerant charging. Can cause equipment damage.
Refrigerant R-407C and R-410A are blended refrigerants and must be introduced and charged
from the cylinder only as a liquid.
When adding liquid refrigerant to an operating system, it may be necessary to add the
refrigerant through the compressor suction service valve. Care must be exercised to avoid
damage to the compressor. Emerson recommends connecting a sight glass between the
charging hose and the compressor suction service valve. This will permit adjustment of the
cylinder hand valve so that liquid can leave the cylinder while allowing vapor to enter the
compressor.
NOTICE
Risk of refrigerant overcharge. Can cause equipment damage.
Do not use the sight glass as an indicator when charging Liebert MC condenser systems.
5. Turn On the Liebert MC disconnect switch.
6. Turn on the indoor unit disconnect switch. Operate the unit for 30 minutes using the charging
function of the indoor unit control for each circuit of the system. The charging function is in the
diagnostic section of the Liebert iCOM
charging function operates the compressor(s) at full capacity and energizes the liquid line
solenoid valve(s). The reheat and humidifier are disabled. Manual operation of the indoor fans
from the diagnostic menu of the Liebert iCOM is required. A minimum 20psig (138kPa) must be
established and maintained for the compressor to operate. The charging function can be reset as
many times as required to complete unit charging.
7. Attach pressure and temperature instruments to the liquid line of the indoor unit. Measure the
initial subcooling and continue to add charge until recommended subcooling for the current
outdoor ambient temperature is reached. See Table 13. The outdoor ambient can be read from
the Liebert MC condenser control menu ID F02.
®
control (see Liebert iCOM user manual, SL-18835). The
35Liebert® MC
™
Page 42
NOTE
To determine subcooling measurement, a liquid line pressure reading (at the factory-installed
Schrader tap) needs to be measured along with obtaining a temperature reading on the liquid
line. Convert the liquid line pressure reading into a temperature by utilizing a PressureTemperature Guide or Table 15. The difference between this converted temperature and the
actual temperature will determine the system’s subcooling. For R-407C make sure to use the
saturated liquid temperature to calculate subcooling.
Table 13Target subcooling for ambient outdoor temperature
Ambient Temp
°F (C°)
0 (-17.8)22 (12.0)
10 (-12.2)22 (12.0)
20 (-6.7)22 (12.0)
30 (-1.1)22 (12.0)
40 (4.4)22 (12.0)
50 (10.0)21 (11.7)
60 (15.6)19 (10.8)
70 (21.1)17 (9.3)
80 (26.7)13 (7.2)
90 (32.2)9 (5.0)
95 (35.0)7 (3.9)
100 (37.8)5 (2.9)
105 (40.6)3 (1.8)
110 (43.3)1 (0.7)
125 (51.7)0
DPN002411, Rev. 3
Subcooling
°F (C°)
Piping
8. Verify the subcooling calculated from measured values at the evaporator against the subcooling
reading of the Liebert MC control [menu ID F50 & F51]. If the subcooling calculated with gauges
differs from the Liebert MC subcooling by more than 3°F (1.7°C), then adjust the charge amount
to achieve the target subcooling per Table 13 based the Liebert MC control subcooling. Failure to
check measured subcooling with refrigerant gauges vs. Liebert MC subcooling may result in an
overcharged system. See Note below and Table 14 for corrections to Liebert MC subcooling that
may be required based on condenser elevation above the indoor evaporator.
NOTE
The evaporator subcooling will be greater than the condenser subcooling when the Liebert MC
is mounted higher than the indoor evaporator. Subcooling adjustment is needed when the
Liebert MC is more than 40 ft. (12m) above evaporator.
NOTE
Subcooling should be viewed at the Liebert MC condenser for a minimum of 1 minute and the
subcooling should be approximately ±2°F before recording subcooling to be compared against
subcooling from the field refrigerant gauges and thermometers.
Liebert® MC
™
36
Page 43
Sample Calculations
The Liebert MC is 40 ft (12.2m) above the evaporator of an R-407C system. The outdoor ambient
from the Liebert MC condenser control menu ID F02, is 94.8°F (34.9°C). The liquid pressure is
300psig (2068kPa) and 113°F (45°C). The subcooling from the Liebert MC control is 5°F (2.8°C).
Determine the subcooling and verify the calculated subcooling against the reading of the Liebert
MC control [menu ID F50 & F51].
Evaporator Subcooling Calculation
Refrigerant TypeR-407C
1.Ambient Temperature94.8°F (34.9°C)
2.Condenser Elevation40 ft (12.2m)
3.Condenser Elevation Temperature Correction4°F (2.2°C)
4.Liquid Line Pressure300psig (2068kPa)
5.Liquid Pressure Converted to Temperature120.3°F (49.0°C)
6.Measured Liquid Line Temperature113.2°F (45.1°C)
7.MC Condenser Subcooling Reading
(Menu ID F50 for Circuit #1 or
Menu ID F51 for Circuit #2)
Subtract Line 6 (Measured Line Temperature) from Line 5 (Liquid Pressure converted to
Temperature) to obtain Calculated Subcooling.
5°F (2.8°C)
Piping
Line 5 120.3°F(49.0°C)
Line 6-113.2°F(45.1°C)
8.Calculated Subcooling
7.1°F or 7°F(3.9°C or (4°C)
Elevation Correction
Subtract Line 3 (Correction for Condenser Elevation above Evaporator) from Line 8 (Calculated
Subcooling) to obtain Corrected Subcooling.
Line 8 7°F(3.9°C)
Line 3 -4°F- (2.2°C)
9.Corrected Subcooling
3°F(1.7°C)
Verification Against MC Condenser
Subtract Line 7 (MC Condenser Subcooling Reading) from Line 9 (Corrected Subcooling) to obtain
Difference.
Line 9 3°F(1.7°C)
Line 7 -5°F-(2.8°C)
10. Difference
-2°F(-1.1°C)
• If Line 10 (Difference value) is less than ± 3°F (±1.7°C), NO charge adjustment is needed.
• If Line 10 (Difference value) is less than -3°F (-1.7°C), add additional charge.
If Line 10 (Difference value) is greater than +3°F (+1.7°C), the system is overcharged and
some of the charge must be removed.
Table 14Difference in subcooling measurements—Indoor minus outdoor
Liebert MC Elevation Above
Evaporator, ft (m)
Refrigerant
* Assumes liquid line is sized for no more than 2°F (1.1°C)pressure drop.
DPN002411, Rev. 3
R-407C10 (5.5)7 (3.8)4 (2.2)1 (0.6)
R-410A6 (3.3)4 (2.2)2 (1.1)0 (0.0)
Subcooling Elevation Correction - °F (°C)
80 (24)60 (18)40 (12)20 (6)
37Liebert® MC
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Page 44
Piping
9. As head pressure builds, the variable fan speed controlled condenser fan begins rotating. The fan
will run at full speed when sufficient head pressure is developed.
Table 15Liquid pressure and temperature chart
PressureR-407C *R-410A *R-22 *
PSIGBar°F°C°F°C°F°C
17011.781.527.559.815.490.632.6
18012.485.129.563.117.394.334.6
19013.188.631.566.319.197.936.6
20013.892.033.369.520.8101.438.6
21014.595.235.172.522.5104.740.4
22015.298.336.875.424.1108.042.2
23015.9101.438.578.225.7111.144.0
24016.6104.340.280.927.2114.245.7
25017.2107.241.883.628.7117.147.3
26017.9109.943.386.230.1120.048.9
27018.6112.644.888.731.5122.850.4
28019.3115.346.391.132.8125.552.0
29020.0117.847.793.534.2128.253.4
30020.7120.349.195.835.5130.854.9
31021.4122.850.498.136.7133.356.3
32022.1125.251.8100.338.0135.857.7
33022.8127.553.1102.539.2138.259.0
34023.4129.854.3104.640.3140.660.3
35024.1132.155.6106.741.5142.961.6
36024.8134.356.8108.742.6145.262.9
37025.5136.458.0110.743.7147.464.1
38026.2138.659.2112.744.8149.665.4
39026.9140.660.3114.545.9151.866.5
40027.6142.761.5116.446.9153.967.7
50034.5161.371.8133.556.4173.178.4
60041.4177.480.8148.164.5189.587.5
* Values are for saturated liquid
DPN002411, Rev. 3
Liebert® MC
™
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Evaporator Subcooling Calculation Worksheet
Circuit 1Circuit 2
Refrigerant Type
1.Ambient Temperature
2.Condenser Elevation
3.Condenser Elevation Temperature Correction
4.Liquid Line Pressure
5.Liquid Pressure converted to Temperature
6.Measured Liquid Line Temperature
7.MC Condenser Subcooling Reading
(Menu ID F50 for Circuit #1 or
Menu ID F51 for Circuit #2)
Subtract Line 6 (Measured Line Temperature) from Line 5 (Liquid Pressure converted to
Temperature) to obtain Calculated Subcooling.
Circuit 1Circuit 2
Line 5
Line 6
8.Calculated Subcooling
Piping
Elevation Correction
Subtract Line 3 (Correction for Condenser Elevation above Evaporator) from Line 8 (Calculated
Subcooling) to obtain Corrected Subcooling.
Circuit 1Circuit 2
Line 8
Line 3
9.Corrected Subcooling
Verification Against MC Condenser
Subtract Line 7 (MC Condenser Subcooling Reading) from Line 9 (Corrected Subcooling) to obtain
Difference.
Circuit 1Circuit 2
Line 9
Line 7
10. Difference
• If Line 10 (Difference value) is less than ± 3°F, NO charge adjustment is needed.
• If Line 10 (Difference value) is greater than -3°F, add additional charge.
• If Line 10 (Difference value) is greater than +3°F, remove charge.
39Liebert® MC
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Page 46
6.0CHECKLISTFOR COMPLETED INSTALLATION
6.1Moving and Placing Equipment
___ 1. Unpack and check received material.
___ 2. Proper clearance for service access has been maintained around the equipment.
___ 3. Equipment is level and mounting fasteners are tight.
6.2 Electrical
___ 1. Line voltage connected and matches equipment nameplate.
___ 2. Power line circuit breakers or fuses have proper ratings for equipment installed.
___ 3. Control wiring connections completed between indoor cooling unit and condenser.
___ 4. All internal and external high-voltage and low-voltage wiring connections are tight to the
proper torque ratings shown on the components.
___ 5. Confirm that unit is properly grounded to an earth ground.
___ 6. Electrical service conforms to national and local codes.
___ 7. Monitoring wiring connections completed, when equipped, to indoor cooling unit or external
monitoring panel.
___ 8. Check to confirm Premium EC Fan Condenser is not connected to Delta Power Supply.
___ 9. Check that the CANbus wiring, CANbus “END of Line” jumper position, and the CANbus
“Device Address DIP Switch” setting is correct according to the application at the job site.
___ 10. If Terminals 70, 71 and 230 are used, verify they are properly wired with special attention
paid to systems that use two condensers for one indoor unit.
Checklist for Completed Installation
6.3Piping
___ 1. Piping is completed to corresponding indoor cooling unit refrigeration circuit.
___ 2. Piping is leak-checked, evacuated, and charged with specified refrigerant.
___ 3. Additional refrigerant oil added, if required, per circuit.
___ 4. Piping is properly sized, sloped, and trapped for proper oil return.
___ 5. Piping is routed to reduce potential of rub-through or chaffing.
___ 6. Hot gas line on Liebert Lee-Temp
6.4Other
___ 1. Fans rotate freely and in proper direction. EC fans rotate counterclockwise in operation as
___ 2. Foreign material removed from in and around all equipment installed (construction
___ 3. Installation materials and tools have been removed from in and around all equipment
___ 4. Blank startup sheet located, ready for completion by installer or start-up technician.
™
is fastened to the side of the cabinet and isolated for
vibration reduction.
viewed from the fan guard side.
materials, construction debris, etc.).
(literature, shipping materials, tools, etc.).
Liebert® MC
™
40
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7.0INITIAL STARTUP CHECKSAND COMMISSIONING
!
!
WARNING
Risk of electric shock. Can cause injury or death.
Disconnect all local and remote electric power supplies and wait 10 minutes before working
within condenser main electrical enclosure or fan electrical enclosure. Unit contains
potentially lethal electrical voltage. Line side of factory disconnect remains energized when
disconnect is Off. Use a voltmeter to make sure power is turned Off before checking any
electrical connections or functions.
Only properly trained and qualified personnel may perform repair, maintenance, and
cleaning operation.
WARNING
Risk of high-speed, rotating fan blades. Can cause injury or death.
Fan blades can start rotating without warning at any time during a cooling cycle or after
power is restored after a power failure. Disconnect all electrical power supplies to the unit,
verify with a voltmeter that the power is Off and verify that all fan blades have stopped
rotating before working on or near the fans.
7.1Startup Checklist
Refer to 6.0 - Checklist for Completed Installation and verify that all installation items have
been completed before beginning to start the condenser.
This document must be completed and forwarded to your local Emerson sales office to validate
warranty.
• Contact your local Emerson sales representative or Emerson Network Power
support about any questions or problems during unit startup and commissioning.
Local Emerson sales offices and Liebert Precision Cooling support contacts can be found at
www.liebert.com
or by calling 1-800-LIEBERT.
®
Liebert Services
41Liebert® MC
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8.0CONTROL OPERATION
301471
Pg. 2, Rev. 3
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Spare Digital
Outputs (Not
Used)
Call for
Cooling
Remote
Shutdown
Fan
Contactor
Output
Mother
Board
24VAC
Earth
Ground
Fan 4
Fan 3
Fan 2
Fan 1
CPU
Board
RS485
Communication
to Fans
Spare Analog
Outputs (Not Used)
Communication
from
indoor unit
Communication
from
indoor unit
CANbus
Service
Pressure
Inputs
Circuit 1
Circuit 2
Circuit 1
Circuit 2
Ambient
Temperature
Inputs
Alarm & Shutdown
Circuits
Ethernet and CANbus addressing
and signal indication
Indicator Lights: ON - Signal Present
Indicator Lights:
ON - Signal
Present
Control Fuses
RS485 Service
Terminal
BAR CODE
24VAC
CAUTION
For Continued Protection Against Risk of Fire,
Replace Only With Same Type and Rating of Fuse
ACM01M1
VER:A02
2010.08.10
BAR CODE
Human
Machine
Interface
(HMI)
Circuit 1
Circuit 2
F3 T3.15A, 250VAC
F2 T3.15A, 250VAC
ACM01U1 VER:A03 2010.08.10
1
1
Fuses are rated to 3A/250V
#1
#3
#2
J5
The Liebert MC Premium Efficiency Control takes approximately 30 seconds to boot up once power is
applied to the condenser. The LED on the Premium Efficiency Control Board reads “888” while the
board is booting up. Once the control has booted up, the display shows “F00” and then the value for
F00. With the control operational, the condenser fan(s) turn in less than 5 seconds after receiving a
signal from the indoor unit that the compressor(s) are On. Consider using UPS equipment on both
data center cooling units and Liebert MC condensers to maintain uninterrupted cooling capability.
For the first 60 seconds of operation after the compressor turns on, the condenser fan(s) will run at a
fixed speed, set at the factory, based on ambient temperature: faster at higher temperatures, slower
at lower temperatures. After 60 seconds, the control adjusts the fan speed based on the liquid
pressure transducer. If the liquid pressure transducer fails, the condenser uses temperature sensors
to control the fan speed based on the liquid line temperature. The condenser fans continue to operate
for approximately 30 seconds after compressors turn Off.
The Liebert MC fans have various alarm conditions, such as loss of voltage and loss of control signal,
that will stop the condenser fans. Once the alarm condition is no longer present the Liebert MC fans
will turn on automatically if compressors are On.
8.1Premium Efficiency Control Board and Interface
The Liebert MC Premium Efficiency Control board has a stacked board arrangement. There are three
seven-segment LED’s and four keys as human machine interface (see Figure 24).
Control Operation
NOTE
Indicator lights should be on, to indicate signal is present. See Figure 23, #1, 2 and 3.
Figure 23 Premium efficiency fan control board
Liebert® MC
™
42
Page 49
Figure 24 Premium Efficiency Control Interface - Human Machine Interface (HMI)
F0016.1F0016.1
F--------A--------H--------0C--------
Analog Signals
Menu
Active Alarms
Menu
History Alarms
Menu
Configuration
Menu
Down
Up
Control Operation
The Premium Efficiency Controls are factory-configured for refrigerant type and whether the
condenser was sold with a Liebert Lee-Temp
and efficient condenser operation.
8.1.1Initial Screen Upon Power-On
The controller displays the initial screen after it is powered On. The initial screen shows the first item
of analog signals menu. The F00 and value of condenser pressure 1 are displayed alternatively and
F00 means the item ID of condenser pressure 1. The display sequence is shown Figure 25. In the
figure, 16.1 is an example and the value is dependent on the sampling result).
Figure 25 Initial controller display
8.1.2Main Menu Description
In initial screen, presses ESC key, the LED enters the first menu of the main menu. The main menu
includes four menus:
• Analog Signals Menu
• Active Alarms Menu
• History Alarms Menu
• Configuration Menu
In the Main Menu, press Up and Down keys to switch to different menus, and press the ENT key to
enter the submenus of the current menu. The operation and structure of main menu are shown in the
following figure.
Figure 26 Main Menu operation and structure
™
system. No field-configuration is necessary for proper
NOTICE
Risk of improperly altered configuration menu settings. Can compromise equipment
operation.
Changing the configuration menu settings can cause unanticipated results. These settings
should be changed only by properly trained and qualified personnel or as directed by the
factory.
43Liebert® MC
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Page 50
8.1.3Analog Signals Menu Description
F-------
F00
F01
F02
F03
F04
F10
F92
...
16.1
15
0
-15
20
200
000
...
Initial Screen
Up
ESC
Down
ENT
In analog signals menu F-----------, press the ENT key to enter its items. The information of analog
signal items includes condenser pressure, temperature and EC Fan actual speed. The display mode is
that the item ID and signal value are displayed alternatively. The operation and item structure of
analog signals menu are shown in the following figure.
Figure 27 Analog Signals Menu
Control Operation
Table 16Analog signal definitions
Item IDMeaning
F00Condenser pressure 1psibar
F01Condenser pressure 2psibar
F02Ambient temperature°F°C
F03Refrigerant temperature 1°F°C
F04Refrigerant temperature 2°F°C
F10EC Fan 1 actual speedRPMRPM
F11EC Fan 1 requested speed%%
F20EC Fan 2 actual speedRPMRPM
F21EC Fan 2 requested speed%%
F30EC Fan 3 actual speedRPMRPM
F31EC Fan 3 requested speed%%
F40EC Fan 4 actual speedRPMRPM
F41EC Fan 4 requested speed%%
F50Subcooling 1°F°C
F51Subcooling 2°F°C
F90Firmware Version Major
F92Firmware Version Build—
Units (C90)
ImperialMetric
1.02.004F91Firmware Version Minor—
Liebert® MC
™
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8.2Premium Efficiency Condenser Alarm Codes
A-------
---001
105
304
210
033
Down
Up
ESC
ENT
or
No Alarm
The following procedure and chart details the alarm codes that may be displayed from the Active and
History Alarm registers.
8.2.1Active Alarms Menu Description
In active alarms menu “A——,” press the ENT key to enter its items. The active alarm item displays
all the active alarms of condenser. When there is an active alarm, the alarm information ID will be
directly displayed. When there is no alarm, “---” is displayed. When there are multiple alarms, the
alarm information ID’s will be displayed according to the time sequence (the most-recent alarm will
be displayed first). The operation and items structure of active alarms menu are shown in the
following figure. The meanings of alarm information ID are found in Tables 17 and 18.
Figure 28 Active alarms menu
Control Operation
45Liebert® MC
™
Page 52
8.2.2History Alarms Menu Description
H-------
H01001
105
304
---
--
Down
Up
ESC
ENT
or
---
H02
H03
H04
H00
---
In history alarms menu “H——?”, press ENT key to enter its items. The history alarm items display
100 history alarm records of the condenser. The item ID is for the sequence number of the history
alarms. The display mode is that the item ID and alarm information ID are displayed alternatively.
When there is no alarm, “---” is displayed. Alarm history can be cleared using the C98 configuration
menu item. The operation and items structure of history alarms menu are shown in the following
figure. The meanings of alarm information ID are given in Tables 17 and 18.
Figure 29 History alarms menu
Control Operation
Liebert® MC
™
46
Page 53
Control Operation
Table 17System alarm information
Alarm ID
000CAN communication failure
001Ethernet communication failure
002USB communication failureUSB device or file is damaged.Replace USB device or file.
003Data corruptionMemory chip is damagedReplace PCB board
004System errorInternal error
005Remote shutdown
006Shutdown due to EC Fan alarmAll fans have failedConsult factory
007SPD alarmSPD damagedReplace SPD
008Condenser pressure Sensor 2 failure
009Condenser pressure Sensor 2 failure
010Condenser pressure 1 high alarm
011Condenser pressure 2 high alarm
012Condenser pressure 1 low alarm
013Condenser pressure 2 low alarm
014
015
016Ambient temperature sensor failure
017Ambient temperature high alarmAmbient temperature highNo action is needed.
018Ambient temperature low alarmAmbient temperature lowNo action is needed.
019
020
021Condenser temperature 1 high alarm
022Condenser temperature 2 high alarm
023Condenser temperature 1 low alarm
024Condenser temperature 2 low alarm
025
026
MeaningPossible CauseHandling Method
Communication circuit missing or
damaged
Ethernet hardware or connection
failure
Check communication circuit.
Ignore alarm on condensers
without CAN connections
Ignore alarm, Ethernet connection
is not present
Reboot. If reboot fails, consult
factory.
1. Remote shutdown signal is
available
2. TB38 is not connected
Condenser pressure Sensor 1
damaged
Condenser pressure Sensor 2
damaged
High pressure: Fan failure,
clogged coils.
Low pressure: Loss of charge
For Cause 1, check the remote
shutdown signal.
For Cause 2, connect TB38.
Replace condenser pressure
Sensor 1
Replace condenser pressure
Sensor 2
High-pressure alarms: Fix fan and
clean coil.
Low-pressure alarms: Check for
refrigerant leak.
EC Fan speed mode maximum must
be overridden due to condenser
Condenser pressure 1 highNo action is needed.
pressure 1 high
EC Fan speed mode maximum must
be overridden due to condenser
Condenser pressure 2 highNo action is needed.
pressure 2 high
Condenser temperature Sensor 2
failure
Condenser temperature Sensor 2
failure
Ambient temperature sensor
damaged
Condenser temperature Sensor 2
damaged
Condenser temperature Sensor 2
damaged
High temperature: Fan failure,
clogged coils.
Low temperature: Consult factory
Replace ambient temperature
sensor
Replace condenser temperature
Sensor 1
Replace condenser temperature
Sensor 2
High-temperature alarms: Fix fan
and clean coils.
Low-temperature alarms: consult
factory.
EC Fan speed mode maximum must
be overridden due to refrigerant
Refrigerant temperature 1 highNo action is needed.
temperature 1 high
EC Fan speed mode maximum must
be overridden due to refrigerant
Refrigerant temperature 2 highNo action is needed.
temperature 2 high
47Liebert® MC
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Page 54
Control Operation
Table 18EC Fan alarm information
Alarm ID
(1-4) 00EC Fan high link current
(1-4) 01EC Fan drive errorEC Fan is damaged.Replace EC Fan
(1-4) 02EC Fan earth to ground faultEC Fan is damaged.Replace EC Fan
(1-4) 03
(1-4) 04EC Fan Hall failureEC Fan is damaged.Replace EC Fan
(1-4) 05EC Fan IGBT failureEC Fan is damaged.Replace EC Fan
(1-4) 06EC Fan line faultPower supply abnormalCheck power supply
(1-4) 07EC Fan motor lockedMotor is lockedCheck if EC Fan is locked.
(1-4) 08EC Fan motor thermal overload
(1-4) 09EC Fan phase failure alarmPhase failureCheck power supply
(1-4) 10
(1-4) 11
(1-4) 12
(1-4) 13EC Fan high link voltage
(1-4) 14EC Fan low link voltage
(1-4) 15EC Fan 485 communication failure
MeaningPossible CauseHandling Method
For cause 1, check if EC Fan is
locked.
For cause 2, replace EC Fan
For cause 1, check if EC Fan is
locked.
For cause 2, replace EC Fan
For cause 3, check ambient
temperature.
For cause 1, check if EC Fan is
locked.
For cause 2, replace EC Fan
For cause 3, check ambient
temperature.
Re-boot condenser if fans not
running. If alarm persists and fans
not running, replace fan.
For cause 1, check if EC Fan is
locked.
For cause 2, replace EC Fan
For cause 3, check ambient
temperature.
For cause 1, measure power
supply voltage and check if the
voltage is normal
For cause 2, replace EC Fan
For cause 1, check EC Fan
communication circuit
For cause 2, replace EC Fan
For cause 3, replace PCB board
For cause 4, check fan model is
not set for “0”, check that the
contactor for the particular fan is
energized, and check fan fuses.
EC Fan electronics heat sink thermal
overload
EC Fan-specific uncategorized alarm
detected
EC Fan-specific uncategorized
warning detected
EC Fan electronics high-temperature
condition.
1. EC Fan is locked.
2. EC Fan is damaged.
1. EC Fan is locked.
2. EC Fan is damaged.
3. Ambient temperature is too
high
1. EC Fan is locked.
2. EC Fan is damaged.
3. Ambient temperature is too
high
Internal EC Fan issue
1. EC Fan is locked.
2. EC Fan is damaged.
3. Ambient temperature is too
high
1. EC Fan input power supply
high voltage
2. EC Fan is damaged.
1. EC Fan input power supply low
voltage
2. EC Fan detection error
1. Communication between EC
Fan and PCB board failure
2. EC Fan 485 communication
failure
3. Board has problems
4. EC fan not receiving power
Liebert® MC
NOTE
(1-4) means the EC Fan addresses. For example, (1-4) 00 means 100 for EC Fan1, and means
200 for EC Fan2, and means 300 for EC Fan3, and means 400 for EC Fan4.
™
48
Page 55
9.0SYSTEM MAINTENANCE
!
!
WARNING
Risk of electrical shock. Can cause injury or death.
Unit contains potentially lethal voltage in some circuits.
Disconnect all local and remote electric power supplies and wait 10 minutes before working in
the unit. The line side of the unit disconnect switch remains energized when the switch is in
the Off position. Use a voltmeter to make sure power is turned Off before making any
electrical connections.
Only properly trained and qualified personnel may perform repair, maintenance, and
cleaning operations.
WARNING
Risk of high-speed, rotating fan blades. Can cause injury or death.
The fan blades can start rotating without warning any time during a cooling cycle or after
power is restored after a power failure. Disconnect all local and remote electrical power
supplies to the unit, wait 10 minutes and verify with a voltmeter that the power is Off and
that all fan blades have stopped rotating before working on or near the fans.
9.1General Procedures
System Maintenance
NOTE
When ordering replacement parts for equipment, it is necessary to specify unit model number,
serial number and voltage. Please record those numbers in the spaces below.
• Model Number ________________
• Serial Number ________________
• Voltage / Phase / Frequency ________________
Periodic attention is necessary for continued satisfactory operation of your unit. Restricted air flow
through the condenser coil, reduced airflow from non-functioning fans and low refrigerant system
charge levels will reduce the operating efficiency of the unit and can result in high condensing
temperatures and loss of cooling. In winter, do not permit snow to accumulate around the sides or
underneath the condenser coil.
Monthly and semi-annual inspections and maintenance are recommended for proper system
operation. Use copies of 9.4.3 - Maintenance Inspection Checklist for each of these inspections.
If performance or operation problem are detected at anytime, refer to 8.2 - Premium Efficiency Condenser Alarm Codes for required action.
9.2Condenser Cleaning
Keeping the outdoor condenser coils clean is an important factor in maintaining peak efficiency,
reliability and long life of the equipment. The unit will operate more efficiently with frequent
cleanings. Delaying cleaning until heavy buildup occurs may create head pressure problems with the
evaporator units.
9.2.1When to Clean the Condenser Coil
Normal conditions typically dictate cleaning twice a year, spring and fall. On-site or area conditions
such as cottonwood trees, construction, etc., can increase cleaning frequency. On your standard
monthly preventive maintenance schedule, Emerson recommends a visual inspection of the coil to
monitor conditions.
49Liebert® MC
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9.2.2What to Use to Clean the Condenser Coil
The best overall condenser coil cleaner to use is plain water. If the coil has been maintained and
cleaned at regular intervals, water is sufficient to remove dirt and debris from the fins. Heavy build
up on the exterior of the fins can be removed with a brush. Water pressure from a garden hose and
sprayer usually works well. If a pressure washer is used, make sure the equipment is set to a lower
pressure setting and that the nozzle is set to the fan spray, not stream. Otherwise, damage to the fins
could result. If a cleaner is required, Emerson recommends using a neutral cleaner, neither acidic nor
base. Acid-type cleaners can damage the coil fins and surrounding areas. Many sites do not allow the
use of acidic cleaners for environmental reasons.
9.2.3How to Clean the Condenser Coil
The Liebert MC coil is accessible for cleaning through the innovative cleaning window design,
allowing you to clean the coil without removing the fans from the unit. First, this requires
disconnecting the power supply before working on the unit and then opening the cleaning window(s)
on the side of the unit by loosing the mounting screws. Then insert a spray nozzle on the end of a
suitable extension and apply the water/cleaning solution, working back and forth across the coil face.
The solution will push the dirt and debris out the bottom of the coil. If you are using a cleaner along
with the spraying process, follow recommended manufacturer instructions and be sure to rinse the
coil thoroughly. Any residue left on the coil can act as a magnet to dirt. Reinstall the cleaning
window(s) and reconnect the power supply to the condenser.
Spraying the coil from the outside repeatedly can push a majority of the dirt to the inner section of the
fins and continue to restrict air flow. Keep in mind you may not have the luxury of shutting the
unit(s) down for an extended time. A scheduled shutdown with the operator may be in order.
System Maintenance
NOTICE
Risk of using damaging cleaning agents, including non-base paint solvents. Can cause
equipment damage and damage to property and loss of refrigerant charge.
Using acid-based or sodium hydroxide-based cleaners can damage the Liebert MC condenser
coil and cause a loss of charge. This could cause equipment damage as well as damage to the
surrounding structure.
NOTE
Clean the EC fan with water only when temperatures are greater than 50°F (10°C)
• Make sure that no water gets into the inside of the motor.
• Do not hold the jet spray directly on the motor openings and seals.
• During cleaning work using a jet spray, no guarantee is assumed regarding corrosion
formation/paint adhesion for unpainted/painted fans.
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9.3Fan Replacement
!
!
!
!
WARNING
Risk of electric shock. Can cause injury or death.
Disconnect all local and remote electric power supplies and wait 10 minutes before working
within condenser main electrical enclosure or fan electrical enclosure. Unit contains
potentially lethal electrical voltage. Line side of factory disconnect remains energized when
disconnect is Off. Use a voltmeter to make sure power is turned Off before checking any
electrical connections or functions.
Only properly trained and qualified personnel may perform repair, maintenance, and
cleaning operation.
WARNING
Risk of high-speed, rotating fan blades. Can cause injury or death.
Fan blades can start rotating without warning at any time during a cooling cycle or after
power is restored after a power failure. Disconnect all electrical power supplies to the unit,
verify with a voltmeter that the power is Off and verify that all fan blades have stopped
rotating before working on or near the fans.
CAUTION
Risk of contact with hot surface. Can cause injury.
Use proper skin protection when touching the electronics housing or allow time for the
housing to cool before replacing parts. The electronics housing can get hot and can cause
severe burns.
System Maintenance
CAUTION
Risk of improper moving, lifting and handling. Can cause equipment damage or injury.
Only properly trained and qualified personnel should work on this equipment. Fan modules
for MCL models weigh in excess of 92lb. (40.8kg) each and fan modules for MCS and MCM
models weigh in excess of 40lb. (18.1kg.) each. Use OSHA-approved lifting techniques, proper
body mechanics and extreme caution to avoid injury and dropping of fans during removal and
installation.
NOTE
If at any time a parameter is entered and the display does not show 888 or it displays Err, try
to re-enter the parameter. If the display still shows Err after ENT is pressed, power cycle the
control board by unplugging P24, waiting 15 seconds and plugging P24 back in. Contact the
factory if the parameter still displays Err after ENT is pressed.
NOTE
If replacing a Ziehl-Abegg fan with an EBM fan, the existing ferrule must be removed from the
end of the wires on the communication cable for all fans except the last fan. Twist wires
together before inserting into the terminal block.
Example:
Twist RSA labeled conductor of the input cable to RSA labeled conductor of the output cable.
Insert the wires into the properly marked terminal on the fan, two wires per RSA, RSB, and
GND terminal as shown in detail “A” on EBM MCS/MCM series drawing.
1. Turn off power to the unit using the disconnect. With a voltmeter verify that voltage is no longer
present at the unit. Wait a minimum of 10 minutes to allow the EC Fan capacitors to discharge
before proceeding.
2. Remove fan cover, disconnect electrical connections internal to EC fan and remove cable glands
from EC fan (see Figures 31, 32 and 33).
3. Remove hardware that mounts EC fan to condenser body.
4. Reinstall electronic cover. Maximum torque for the fan cover screws is 2.3Nm (20 in-lb).
51Liebert® MC
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System Maintenance
5. Install a spreader bar over the EC fan
NOTICE
Risk of improper fan rigging. Can cause equipment damage.
MCL model EC fans weigh over 90lb. (40.8kg) each and MCS and MCM EC fans weigh over
40lb. (18.1kg) each. Make sure that the wire harness is secured out of the way before lifting
the fan.
6. Verify that lifting cable/chains are not coming into contact with fan blades before lifting.
7. Install new fan in unit and connect mounting hardware; connect electrical cable glands. Torque
for cable glands is 2.5Nm (22 in-lb). Make sure fan blades rotate freely when installed in unit.
Reconnect wiring to proper terminals and verify that run jumper is in place. Refer to
Figures 30, 31 and 32 for wiring details. Torque for electrical terminals are 1.3Nm (11.5 in-lb).
8. Turn power On.
9. The control board will flash F00 on the display when it has completed its boot cycle. Refer to Figures 23 and 24.
10. Press the ESC button.
11. Use the Up or Down arrow until C-- is on the display.
12. Press ENT button.
13. Use the Up or Down arrow until C03 is on the display.
14. Press ENT button.
15. Use the Up or Down arrow to select one of three options.
Configuration
CodeFan #Value
C03Fan 1
C04Fan 2
C05Fan 3
C06Fan 4
0 = No Fan
1 = EBM Papst
2 = Ziehl-Abegg
16. Press the ENT button.
17. If the new value was entered into the control board, the display will flash 888.
18. Press the ESC button for C03 to show on the display.
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System Maintenance
18. Repeat Steps 11 thru 18 for the remaining fans’ configuration codes, C04, C05 and C06.
19. Unplug all the contactor output plugs except for the fan to be addressed. Plugs listed below.
•P23 = Fan 1
•P27 = Fan 2
•P28 = Fan 3
•P29 = Fan 4
20. Wait 30 seconds.
21. Use the Up or Down arrow to select one of the following parameters.
The correct parameter depends on the supplier of the fan that will be addressed.
• C00—EBM Papst fan
• C01—Ziehl Abegg fan
22. Press the ENT button.
23. Use the Up or Down arrow to the correct fan address number. Fan 1 should be 1 (fan closest to
electric panel end). Fan 2 should be 2, etc.
24. Press ENT button. The display will flash 888 when the command is accepted.
25. Press the ESC button for the parameter to be shown on the display.
26. Repeat Steps 19 through 25 for the rest of the fans that need to be addressed.
27. After the last fan is addressed, unplug the power plug, P24, from the control board.
28. Wait 30 seconds.
29. Plug all the contactor output plugs back into the board in their correct positions.
30. Plug P24 back into the control board.
31. Once the control board has completed its boot cycle and all the contactors are energized, wait
5 seconds.
32. Press the ESC button.
33. Use the Up or Down arrow until A-- is on the display.
34. Press ENT button.
35. Use the Up or Down arrow to see if any of the following errors are shown.
• 115: Unable to communicate with Fan 1.
• 215: Unable to communicate with Fan 2.
• 315: Unable to communicate with Fan 3.
• 415: Unable to communicate with Fan 4.
36. If any of these errors appear, check the communication wiring at the problem fan and the fan
before it.
37. If the wiring is correct and properly wired to the terminal, and none of the errors mentioned in
Step 35 are displayed, press the ESC button.
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System Maintenance
Verify the Fan Address
Verify that each fan has a unique address by:
1. Use the Up or Down arrow until C-- is on the display.
2. Press the ENT button.
3. In the Manual/System Control Selection parameter use the Up or Down arrow until C24 is on the
display.
4. In the Manual Control configuration parameter press ENT button.
5. Use the Up or Down arrow to select 0.
6. Press the ENT button. The display will read 888 if the command was accepted.
7. Press the ESC button for C24 to show on the display.
8. Use the Up or Down arrow until C34 is on the display.
9. Press ENT button.
10. If Fan 1 is currently running, the fans speed should be displayed in terms of percentage of full
speed. If Fan 1 is not running, 0.00 should be displayed.
11. Use the Up or Down arrow to enter 100% speed.
12. Press the ENT button. The display will read 888 if the command was accepted.
13. Fan 1 should speed up to 100% and all the other fans should stay the same.
14. If Fan 1 is not running or any of the other fans also speed up to 100%, the fan-addressing
procedure (Steps 19 through 25) must be repeated.
15. Press the ESC button for the parameter to be shown on the display.
16. Repeat Steps 4 through 9 for the rest of the fans, if present.
•C35: for Fan 2.
• C36:. for Fan 3.
•C37: for Fan 4.
17. All fans should be at 100% speed.
18. 5Use the Up or Down arrow until C24 is on the display.
19. Press the ENT button.
20. In the System Control configuration parameter, use the Up or Down arrow to select 1.
21. Press the ENT button. The display will flash 888 if the command was accepted.
22. Press the ESC button for C24 to be shown on the display.
23. All fans should return to a normal speed based on the pressure input and the state of indoor unit’s
compressor.
PCB Notes
• J4 and J6 are the CANbus termination jumpers. If the condenser is the last device in the CANbus
• A jumper must be present at J2. If no jumper is present, the control board will not boot properly
Liebert® MC
communication line, the jumper must be placed between pins 1 and 2 of J6, and between pins 2
and 3 on J4. If the condenser is not the last device in the CANbus communication line, then both
jumpers on J4 and J6 must be placed on Pins 2 and 3. If the jumpers are not in the correct
positions, CANbus communication errors may occur.
during power startup
™
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Figure 30 EBM small and medium fan, Liebert MC series MCS/MCM
Connect uninsulated drain wires from
communication cables to ground
connection (GND) as shown below.
The drain wires must be tied together
with cable ties and routed away from
the high-voltage terminals.
NOTE
If replacing a Ziehl-Abegg fan with an
EBM fan, the existing ferrule must be
removed from the end of the wires on
the communication cable for all fans
except the last fan. Twist wires
together before inserting into the
terminal block.
Example:
Twist RSA-labeled conductor of the
input cable to RSA-labeled conductor
of the output cable.
Insert the wires into the properly
marked terminal on the fan, two
wires per RSA, RSB and GND
terminal as shown in Detail A.
Connect uninsulated drain wires from
communication cables to ground
connection (GND) as shown below.
The drain wires must be tied together
with cable ties and routed away from
the high-voltage terminals.
NOTE
If replacing a Ziehl-Abegg fan with
an EBM fan, the existing ferrule
must be removed from the end of
the wires on the communication
cable for all fans except the last
fan. Twist wires together before
inserting into the terminal block.
Example:
Twist RSA-labeled conductor of
the input cable to RSA-labeled
conductor of the output cable.
Insert the wires into the properly
marked terminal on the fan, two
wires per RSA, RSB and GND
terminal as shown in Detail B.
System Maintenance
Figure 31 EBM large fan—Liebert MC series MCL
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System Maintenance
Figure 32 Ziehl-Abegg small, medium and large fan, Liebert MC series MCS, MCM and MCL
9.4Premium Efficiency Control Board Replacement
9.4.1Replacement Preparation
1. Verify that the following jumpers are installed on the new board (see Figure 33):
• Jumper at J4 and J6 on Pins 2 and 3.
•Jumper on J2.
• Jumper on J5 on Pins 1 and 2.
2. Locate the latest revision of the HMI parameters label, 303847P1, included with new control
board.
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Figure 33 Jumper locations on Control Board
301471
Pg. 2, Rev. 3
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Spare Digital
Outputs (Not
Used)
Call for
Cooling
Remote
Shutdown
Fan
Contactor
Output
Mother
Board
24VAC
Earth
Ground
Fan 4
Fan 3
Fan 2
Fan 1
CPU
Board
RS485
Communication
to Fans
Spare Analog
Outputs (Not Used)
Communication
from
indoor unit
Communication
from
indoor unit
CANbus
Service
Pressure
Inputs
Circuit 1
Circuit 2
Circuit 1
Circuit 2
Ambient
Temperature
Inputs
Alarm & Shutdown
Circuits
Ethernet and CANbus addressing
and signal indication
Indicator Lights: ON - Signal Present
Indicator Lights:
ON - Signal
Present
Control Fuses
RS485 Service
Terminal
BAR CODE
24VAC
CAUTION
For Continued Protection Against Risk of Fire,
Replace Only With Same Type and Rating of Fuse
ACM01M1
VER:A02
2010.08.10
BAR CODE
Human
Machine
Interface
(HMI)
Circuit 1
Circuit 2
F3 T3.15A, 250VAC
F2 T3.15A, 250VAC
ACM01U1 VER:A03 2010.08.10
1
1
Fuses are rated to 3A/250V
#1
#3
#2
J5
J2
J5J6J4
System Maintenance
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9.4.2Installation
!
WARNING
Risk of arc flash and electric shock hazard. Disconnect all local and remote electric power
supplies and wear appropriate personal protective equipment per NFPA 70E before working
within the electric control enclosure or the fan motor connection box(es). Failure to comply can
cause serious injury or death.
This unit contains lethal voltage. The line side of the unit disconnect switch remains
energized when the unit disconnect switch is in the “Off” position. Use a voltmeter to verify
that the line side input electric power to the unit disconnect switch is off before working on
any electrical components or connections.
1. Turn Off the disconnect switch on the enclosure cover.
2. Open the control enclosure cover.
3. Manually turn On the disconnect switch. Power is On and a shock hazard exists with exposure to
hazardous voltage components.
4. If the board can still be powered up and has a display, record the parameter settings. To obtain
parameters go to the C-- menu and press the Up or Down button to read and record the values for
C03-09, and C27.
5. Record all of the DIP switch positions for the CANbus dip switch package. Retain these for setting
up the new board.
6. Record positions of the jumpers for J2, J4, J5, and J6 on control board in unit. Retain these for
set-up of new board.
7. Disconnect power from the Liebert MC Condenser unit by turning Off the main disconnect switch.
8. Use a voltmeter to check the unit and ensure that voltage is no longer present in the unit.
9. Remove the plugs and field-installed wires from the old board. Note the polarity for the CANbus
wiring going to P49 and P50, if present.
10. Mark wires P49-1, P49-3, etc, if they are not already marked as such.
11. Remove the mechanical fasteners holding the control board in place and remove the old control
board.
12. Install the new control board using the fasteners removed in Step 11.
13. Reattach the plugs. Reference the hot-stamps on the wire harnesses that correspond to the correct
plug on the board. Verify that the plugs are installed properly.
14. Change the CANbus DIP switch positions so they match the old control board that is being
removed. If the Liebert MC condenser is the second condenser on the CANbus communication
line, set Position 1 of the CANbus DIP switch from On to Off.
15. Change the jumper positions for J2, J4, J5, and J6 to match the old control board. If the Liebert
MC condenser is the last device on the CANbus communication line, move the jumper at J6 from
Pins 2 and 3 to Pins 1 and 2 (see Figure 33).
16. Power up the unit.
17. Change the parameters to match the parameters from the old control board if they can be
obtained from the old board. See Step 18 if parameters were unavailable.
18. If the old board parameters were unavailable, use the new HMI label included in kit to obtain the
proper settings. Parameters C03, C04, C05 and C06 must be programmed with the proper EC fan
supplier used on the unit, then address the fans (refer to 9.3 - Fan Replacement).
19. Compare the HMI label that is on the unit with the latest revision.
If there are differences, clean and dry the surface of the old HMI label; stick the new label on top
of the old label. Completely cover the old label with the new.
20. Verify that the control board is reading pressure and temperature.
21. Verify that there are no communication alarms with the fans or the with the cooling unit the
Liebert MC is serving.
22. Verify proper fan operation by adjusting the cooling unit that this condenser serves so that it calls
for cooling.
System Maintenance
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9.4.3Maintenance Inspection Checklist
Date: Prepared By:
Model #: Serial Number:
NOTE
Regular inspections are necessary to ensure that the cooling fins are clean. Should inspection
reveal dirt or corrosion, appropriate cleaning should be performed.
MonthlySemiannually
System Maintenance
Condenser
___ 1. Coil surfaces free of debris.
___ 2. Fans free of debris.
___ 3. Fans securely mounted.
___ 4. Motor bearings in good condition.
___ 5. Check all refrigerant lines and capillaries
for vibration isolation. Support as
necessary.
___ 6. No refrigerant leaks.
Surge Protection Device (If Installed)
___ 1. Check SPD protection status indicator
lights.
Notes
Condenser
___ 1. Complete all monthly items.
___ 2. Piping in good condition.
___ 3. Inspect refrigerant lines for signs of oil
leaks. Repair leaks as found.
___ 4. Check refrigerant charge level in each
receiver tank (if required), based on
procedures in the indoor unit’s manual.
Continuous system operation required.
___ 5. Wash coil as needed.
___ 6. Repair bent or damaged fins.
Condenser Electrical Panel
___ 1. Check all electrical connections.
___ 2. Check contactors for pitting.
___ 3. Operational sequence/set points.
Fan Motors
___ 1. Motor # 1 amp draw amps
___ 2. Motor # 2 amp draw
___ 3. Motor # 3 amp draw
___ 4. Motor # 4 amp draw
amps
amps
amps
Signature
Make photocopies of this form for your records.
59Liebert® MC
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10.0 TROUBLESHOOTING
Table 19Troubleshooting
SymptomPossible CauseCheck or Remedy
No power to condenser.Check voltage at input terminal block.
Condenser will not start
Low discharge pressure
High discharge pressure
SPD green and red LEDs
are extinguished
SPD red LED is
illuminated
Control Board LEDs do
not light.
Fan will not run
Circuit breaker or fuse for low-voltage
transformer in condenser is tripped.
No low-voltage signal to/from indoor
unit.
Faulty head pressure control valve or
condenser control board (PEC/BEC).
Dirty condenser fins.Clean coil.
Condenser fans not operating.
High refrigerant chargeCheck refrigerant charge.
No voltage or improper phasing exists
at condenser.
Electrical connections to SPD are faulty.Locate connection problem and repair.
Condenser disconnect is turned Off.
A surge exceeding the rating of the SPD
has occurred.
Connection to P24 is loose or
disconnected.
Fuse located next to P24 has blown.
24V transformer has failed.
Control Board (PEC/BEC) has failed.
Jumper not installed between 24V and
DIN1 (for Ziehl-Abegg fan motor).
Locate problem in condenser electrical panel and
repair.
Locate open circuit and repair.
Replace if defective.
Check for low-voltage signal from indoor unit.
Check fan motors and fuses.
Check voltage at input terminal block.
Recheck lights with disconnect switch in the On
position.
Replace SPD and inspect other components for
damage and replace them if necessary.
Check the connection to P24 to verify that is
connected securely.
Check the connector from the transformer for loose
terminals.
Verify that the fuses next to P24 have not blown.
Replace as needed.
With a voltmeter verify that the output from the
transformer is 24Vac ±10%. If the value exceeds
±10%, verify that the correct primary leads are
being used.
If there is no output voltage, verify that the primary
connections are secure and receiving the correct
voltage. If they are, replace the transformer.
Install jumper between 24V and DIN1 (for Ziehl
Abegg fan motor).
Troubleshooting
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