Lennox VRF VEC027N432U User manual

Mini VRF
Cooling Only System
User Manual
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and keep it for further reference.
VEC027N432U
VEC034N432U
VEC042N432U
VEC048N432U
VEC055N432U
VEC060N432U

To Users
Thank you for selecting LENNOX’s product. Please read this instruction manual carefully before
installing and using the product, so as to master and correctly use the product. In order to guide you
to correctly install and use our product and achieve expected operating effect, we hereby instruct as
below:
(1) This appliance is not intended for use by persons (including children) with reduced physical,
sensory or mental capabilities, or lack of experience and knowledge, unless they have been
given supervision or instruction concerning use of the appliance by a person responsibility
for their safety. Children should be supervised to ensure that they do not play with the
appliance.
(2) In order to ensure reliability of product, the product may consume some power under
stand-by status for maintaining normal communication of system and preheating refrigerant
and lubricant. If the product is not to be used for long, cut off the power supply; please
energize and preheat the unit in advance before reusing it.
(3) Please properly select the model according to actual using environment, otherwise it may
impact the using convenience.
(4) This product has gone through strict inspection and operational test before leaving the
factory. In order to avoid damage due to improper disassembly and inspection, which may
impact the normal operation of unit, please do not disassemble the unit by yourself. You can
contact with the special maintenance center of our company if necessary.
(5) When the product is faulted and cannot be operated, please contact with our maintenance
center as soon as possible by providing the following information.
1) Contents of nameplate of product (model, cooling/heating capacity, product No.,
ex-factory date).
2) Malfunction status (specify the situations before and after the error occurs).
(6) All the illustrations and information in the instruction manual are only for reference. In order
to make the product better, we will continuously conduct improvement and innovation. We
have the right to make necessary revision to the product from time to time due to the reason
of sales or production, and reserve the right to revise the contents without further notice.
(7) The final right to interpret for this instruction manual belongs to LENNOX.

Exception Clauses
Manufacturer will bear no responsibilities when personal injury or property loss is caused by the
following reasons:
(1) Damage the product due to improper use or misuse of the product.
(2) Alter, change, maintain or use the product with other equipment without abiding by the
instruction manual of manufacturer.
(3) After verification, the defect of product is directly caused by corrosive gas.
(4) After verification, defects are due to improper operation during transportation of product.
(5) Operate, repair, maintain the unit without abiding by instruction manual or related
regulations.
(6) After verification, the problem or dispute is caused by the quality specification or
performance of parts and components that produced by other manufacturers.
(7) The damage is caused by natural calamities, bad using environment or force majeure.

Contents
1 Safety Notices (Please be sure to abide)................................................................. 1
2 Product Introduction ................................................................................................. 3
2.1 Names of Main Parts ........................................................................................................ 3
2.2 Combinations of Indoor and Outdoor Units ....................................................................... 4
2.3 Operating Range .............................................................................................................. 4
3 Preparation before Installation ................................................................................. 4
3.1 Standard Parts.................................................................................................................. 5
3.2 Installation Site ................................................................................................................. 5
3.3 Piping Work Requirements ............................................................................................... 6
4 Installation Instruction .............................................................................................. 6
4.1 Dimension of Outdoor Unit and Mounting Hole ................................................................. 7
4.2 Connection Pipe ............................................................................................................... 8
4.3 Installation of Connection Pipe.........................................................................................12
4.4 Disassembly of Compressor Feet ....................................................................................16
4.5 Vacuum Pumping, Refrigerant Adding .............................................................................16
4.6 Electric Wiring..................................................................................................................18
5 Check Items after Installation and Test Operation................................................ 21
5.1 Check Items after Installation...........................................................................................21
5.2 Test Operation and Debugging ........................................................................................21
6 Common Malfunctions and Troubleshooting........................................................ 26
7 Error Indication ........................................................................................................ 27
8 Maintenance and Care............................................................................................. 29
8.1 Outdoor Heat Exchanger .................................................................................................29
8.2 Drain Pipe........................................................................................................................30
8.3 Notice before Seasonal Use ............................................................................................30
8.4 Maintenance after Seasonal Use .....................................................................................30
8.5 Parts Replacement ..........................................................................................................30
9 After-sales Service................................................................................................... 30

DC Inverter Multi VRF System
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1 Safety Notices (Please be sure to abide)
WARNING: If not abide strictly, it may cause severe damage to the unit or the people.
NOTE! If not abide strictly, it may cause slight or medium damage to the unit or the people.
This sign indicates that the operation must be prohibited. Improper operation may cause
severe damage or death to people.
This sign indicates that the items must be observed. Improper operation may cause damage
to people or property.
WARNING!
This product can’
t be installed at corrosive, inflammable or explosive environment or the
place with special requirements, such as kitchen. Otherwise, it will affect the normal operation
or shorten the service life of the unit, or even cause fire hazard or serious injury. As for above
special places, please adopt special air conditioner with anti-corrosive or anti-explosion
function.
Please install the unit
according to instructions in this
manual. Read this manual
carefully before starting up or
checking the machine.
Installation should be
performed by distributor or
qualified technicians. Do not
install the product by yourself.
Improper installation may
result in water leakage, electric
shock or fire hazard.
Before installation, please
check the power cord if it
complies with the power
supply requirement on the
nameplate. Make sure the
power supply is safe.
This air conditioner must be
properly grounded through the
receptacle to avoid electric
shock. The ground wire
shouldn’t be connected with
gas pipe, water pipe, lightning
arrester or telephone line.
When installing, specialized
parts and accessories must be
used. Otherwise, it may result
in water leakage, electric
shock or fire hazard.
R410A refrigerant can produce
poisonous gas once it meets
fire, so please ventilate the
room immediately if refrigerant
leaks out during installation.
Diameter of power cord must
be large enough. Damaged
power cord or connecting wire
must be replaced by
specialized electric cable.
After the power cord is
connected, please install the
cover of electric box to avoid
danger.
Nitrogen must be charged
according to technical
requirements.
Short circuit is forbidden. Do
not cancel the pressure switch,
otherwise unit may be
damaged.

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For units with wired
controllers, do not connect
power supply until the wired
controller is well installed.
Otherwise, the wired controller
cannot be used.
When installation is finished,
please check and make sure
the drain pipe, pipeline and
electric wire are all well
connected so as to avoid
water leakage, refrigerant
leakage, electric shock and fire
hazard.
Do not extend fingers or
objects into air outlet or return
air grille.
If you use gas heater or
petroleum heater in the same
room, please open the door or
window to maintain good air
circulation, otherwise the room
may be lack of oxygen.
Never start or stop the air
conditioner by inserting or
removing the power cord.
Do not turn off the air
conditioner until it runs for at
least 5 minutes. Otherwise, oil
return of the compressor will
be affected.
Children are not allowed to
operate the air conditioner.
Do not operate the air
conditioner with wet hands.
Please turn off and unplug
your air conditioner before
cleaning. Otherwise, it may
cause electric shock or
personal injury.
Do not spray water on the air
conditioner or it will cause
malfunction or electric shock.
Do not expose the air
conditioner directly under
damp or corrosive
surroundings.
Connect power 8 hours before
operation. Do not disconnect
power when you want to stop
the unit in a short period of
time, e.g. in one night (This is
for protecting the compressor).
Volatile liquid like thinner or
gasoline will damage the
appearance of air conditioner
(Please use soft dry cloth and
wet cloth with mild detergent to
clean unit’s outer case).
Under cool mode, do not set
the indoor temperature too
low. Keep the difference
between indoor temp and
outdoor temp within 5°C.

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If abnormal condition occurs
(e.g. unpleasant smell), please
turn off the unit at once and
disconnect power supply.
Then contact LENNOX authorized
service center. If the air
conditioner continues to
operate despite of abnormal
condition, it may be damaged
and cause electric shock or
fire hazard.
Do not repair the air
conditioner by yourself.
Improper repair will cause
electric shock or fire hazard.
Please contact LENNOX
authorized service center and
ask professional technicians to
repair it.
This appliance can be used by children aged from 8 years and above and persons with reduced physical, sensory or
mental capabilities or lack of experience and knowledge if they have been given supervision or instruction concerning
use of the appliance in a safe way and understand the hazards involved. Children shall not play with the appliance.
Cleaning and user maintenance shall not be made by children without supervision.
Install units according to national wiring codes.
If the supply cord is damaged, it must be replaced by the manufacturer or its service agent or a similarly qualified
person in order to avoid a hazard.
An all-pole disconnection device which has at least 3mm clearances in all poles, and disconnection must be
incorporated in the fixed wiring in accordance with the wiring rules.
LENNOX will not assume responsibility for any personal injury or property loss caused
by improper installation, improper debugging, unnecessary repair or not following the instructions of this manual.
2 Product Introduction
LENNO Multi VRF System adopts inverter compressor technology. By changing the displacement
of compressor, stepless capacity regulation within range of 10%~100% can be realized. Various
product lineups are provided with capacity range from 8kW to 18kW, which can be widely used in
residential, commercial and working area and especially applicable to places with big load change.
LENNOX residential air conditioner is absolutely your best choice.
2.1 Names of Main Parts
Fig 2.1.1
VEC048N432U
VEC055N432U
VEC060N432U

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No.
①②③④⑤
Name Motor Fan blade Electric box
assembly
Gas pipe valve Liquid pipe valve
Fig 2.1.2
No.
①②③④⑤
Name Motor Fan blade Electric box
assembly
Gas pipe valve Liquid pipe valve
2.2 Combinations of Indoor and Outdoor Units
(1) See below the number of indoor units that can be connected to the outdoor unit.
(2) The total capacity of indoor units should be within 50%~135% of that of the outdoor unit.
Model
Min sets of connectable IDUs
Max sets of connectable IDUs
VEC027N432U
2
4
VEC034N432U
2
5
VEC042N432U
2
6
VEC048N432U
2
8
VEC055N432U
2
9
VEC060N432U
2
10
(3) Can be connected to various indoor units. When any one of the indoor units receives
operating command, outdoor unit will start operation as per required capacity. When all
indoor units stop, outdoor unit will be shut off.
2.3 Operating Range
Cooling
Outdoor temperature: -5°C~48°C
3 Preparation before Installation
NOTE! Graphics here are only for reference. Please refer to actual products. Unspecified
dimensions are all in mm.
VEC027N432U
VEC034N432U
VEC042N432U

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3.1 Standard Parts
Please use the supplied standard parts as required.
Parts for Outdoor Unit
No.
Name
Appearance
Qty
Remark
1 User Manual 1
2 Wiring (match with
resistance) 1
Must be connected to the
last IDU of communication
connection
3 Corrugated pipe 1
4 Chassis gluey plug 3
5 Drainage joint 1
6 Tube Connector
Sub-assy 1
VEC027N432U
VEC034N432U
VEC042N432U
3.2 Installation Site
Forbidden item! Improper operation might lead to personal injury or even death.
Item needs to be followed. Improper operation might lead to personal injury or property damage.
Select a location which is strong
enough to hold unit’s weight so
that unit can stand still and
erect.
The installation position should
withstand strong wind, typhoon
and earthquake. The unit must be
installed stably.
Please keep the unit away from
inflammable, explosive and
corrosive gas or waste gas.
Make sure the location has space
for heat exchange and
maintenance so that unit can
operate reliably with good
ventilation.
ODU and IDU should stay as
close as possible to shorten the
length of refrigerant pipe and
reduce bend angles.
Select a location which is out of
children’s reach. Keep the unit
away from children.

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If the ODU is totally surrounded by walls, please refer to the following figures for space
dimension:
Fig 3.2.1
3.3 Piping Work Requirements
Refer to the table below for piping work requirements:
R410A Refrigerant System
Outer diameter (mm/inch) Wall thickness (mm)
Φ6.35(1/4)
≥0.8
Φ9.52(3/8)
≥0.8
Φ12.70(1/2)
≥0.8
Φ15.9(5/8)
≥1.0
Φ19.05(3/4)
≥1.0
4 Installation Instruction
NOTE! Graphics here are only for reference. Please refer to actual products. Unspecified
dimensions are all in mm.

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4.1 Dimension of Outdoor Unit and Mounting Hole
Unit Outline and Installation Dimension(mm).
Fig 4.1.1
Unit:mm
Model
A
B
C
D
E
VEC048N432U
VEC055N432U
VEC060N432U
900 340 1345 572 378
Fig 4.1.2

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Unit:mm
Model A B C D E
VEC027N432U
VEC034N432U
VEC042N432U
980 360 790 650 395
4.2 Connection Pipe
4.2.1 Schematic Diagram of Piping Connection
Fig.4.2.1.1
4.2.2 Allowable Length and Height Difference of Connection Pipe
Y type branch joint is adopted to connect indoor and outdoor units. Connecting method is shown
in the figure below:
NOTE! Equivalent length of one Y-type branch is 0.5m.
Piping parameters of VEC027N432U, VEC034N432U, VEC042N432U.
Allowable
value
Fitting pipe
Total length (actual length) of fitting pipe
250m
L1+L2+L3+a+b+c+d
Length of farthest fitting pipe (m)
Actual length
100m
L1+L2+L3+d
Equivalent length
120m
From the 1
st
branch to the farthest indoor pipe
40m
L2+L3+d

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Allowable
value
Fitting pipe
Height difference between ODU and
IDU
ODU at upper side
30m
——
ODU at lower side
30m
——
Height difference between IDUs
10m
——
Piping parameters of VEC048N432U, VEC055N432U, VEC060N432U.
Allowable
value
Fitting pipe
Total length (actual length) of fitting pipe
300m
L1+L2+L3+a+b+c+d
Length of farthest fitting pipe (m)
Actual length
120m
L1+L2+L3+d
Equivalent length
150m
From the 1
st
branch to the farthest indoor pipe
40m
L2+L3+d
Height difference between ODU and
IDU
ODU at upper side
50m
——
ODU at lower side
40m
——
Height difference between IDUs
15m
——
Fig 4.2.2.1 Allowable Length and Height Difference of Connection Pipe

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4.2.3 Dimension of Pipe (Main Pipe) from ODU to the 1st Indoor Branch
Dimension of pipe from ODU to the 1st indoor branch will be determined by the dimension of
outdoor connection pipe.
Fig 4.2.3.1
Dimension of outdoor connection pipe.
Basic module
Pipe dimension
Gas pipe (mm)
Liquid pipe (mm)
VEC027N432U
Φ15.9
Φ9.52
VEC034N432U
Φ15.9
Φ9.52
VEC042N432U
Φ15.9
Φ9.52
VEC048N432U
Φ15.9
Φ9.52
VEC055N432U
Φ19.05
Φ9.52
VEC060N432U
Φ19.05
Φ9.52
4.2.4 Selection of Indoor Branches
Select indoor branches according to the total capacity of downstream indoor units. If the capacity
exceeds that of the outdoor unit, capacity of outdoor unit prevails.
Fig 4.2.4.1

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R410A Refrigerant system
Total capacity of downstream indoor units X (kW)
Model
Y type branch
X<20
VEBC01A
20≤X≤30
VEBC01B
30<X≤70
VEBC02A
70<X≤135
VEBC03A
135<X
VEBC04A
4.2.5 Dimension of Pipe between Indoor Branches
Select pipe between indoor branches according to the capacity of downstream indoor units; if the
capacity exceeds that of the outdoor unit, capacity of outdoor unit prevails.
Fig 4.2.5.1
Total capacity of downstream indoor units C (kW)
Gas pipe (mm)
Liquid pipe (mm)
C ≤5.6 Φ12.7 Φ6.35
5.6<C≤14.2
Φ15.9
Φ9.52
14.2<C≤22.4
Φ19.05
Φ9.52
4.2.6 Dimension of Pipe between Indoor Branch and IDU
Dimension of pipe between indoor branch and IDU should be consistent with the dimension of
indoor pipe.
Fig 4.2.6.1

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Rated capacity of IDU C(kW)
Gas pipe (mm)
Liquid pipe (mm)
C≤2.8
Φ9.52
Φ6.35
2.8<C≤5.0
Φ12.7
Φ6.35
5.0<C≤14.0
Φ15.9
Φ9.52
14.0<C≤16.0
Φ19.05
Φ9.52
16.0<C≤28.0
Φ22.2
Φ9.52
NOTE! If the distance between IDU and its nearest branch is over 10m, then the liquid pipe of
IDU (rated capacity ≤5.0kW) shall be enlarged.
4.3 Installation of Connection Pipe
4.3.1 Precautions for the Installation of Connection Pipe
(1) Conform to the following principles during pipe connection: Connection pipe should be as
short as possible, so is the height difference between indoor and outdoor units. Keep the
number of bends as little as possible. Radius of curvature should be as large as possible.
(2) Weld the connection pipe between indoor and outdoor units. Please strictly follow the
requirements for welding process. Rosin joint or pin hole is not allowed.
(3) Radius of bending parts should be over 200mm. Note that pipes cannot be repeatedly bent
or stretched; otherwise the material will get harder. Do not bend or stretch the pipe for more
than 3 times at the same position.
4.3.2 Flaring Process
(1) Use pipe cutter to cut the connection pipe in case it is unshaped.
(2) Keep the pipe downward in case cutting scraps get into the pipe. Clear away the burrs after
cutting.
(3) Remove the flared nut connecting indoor connection pipe and outdoor unit. Then use flaring
tool to fix the flared nut into the pipe (as shown in Fig.4.3.2.1).
(4) Check if the flared part is flaring evenly and if there is any crack.
Fig 4.3.2.1
4.3.3 Pipe Bending
(1) Reshape the pipe by hand. Be careful not to damage the pipe.
Fig 4.3.3.1 Fig 4.3.3.2

DC Inverter Multi VRF System
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(2) Do not bend the pipe over 90°.
(3) If pipe is repeatedly bent or stretched, it will get hard and difficult to bend and stretch again.
Therefore, do not bend or stretch the bend for over 3 times.
(4) In case that direct bending will open cracks to the pipe, first use sharp cutter to cut the
insulating layer, as shown in Fig.4.3.3.2. Do not bend the pipe until it is exposed. When
bending is done, wrap the pipe with insulating layer and then secure it with adhesive tape.
4.3.4 Indoor Pipe Connection
(1) Remove pipe cover and pipe plug.
(2) Direct the flared part of copper pipe to the center of screwed joint. Twist on the flared nut
tightly by hand, as in Fig 4.3.4.1 (Make sure indoor pipe is correctly connected. Improper
location of the center will prevent flared nut from being securely twisted. Thread of nut will
get damaged if the flared nut is twisted forcibly).
(3) Use torque wrench to twist on the flared nut tightly until the wrench gives out a click sound
(Hold the wrench and make it at right angle to the pipe as in Fig 4.3.4.2).
(4) Use sponge to wrap the un-insulated connection pipe and joint. Then tie the sponge tightly
with plastic tape.
(5) Connection pipe should be supported by a bearer rather than the unit.
(6) The bending angle of piping should not be too small; otherwise the piping might have cracks.
Please use a pipe bender to bend the pipe.
(7) When connecting IDU with connection pipe, do not pull the big and small joints of IDU with
force in case the capillary tube or other tubes have cracks and cause leakage.
Pipe diameter Tightening torque
Φ6.35mm
15~30(N·m)
Φ9.52mm 35~40(N·m)
Φ12.7mm
45~50(N·m)
Φ15.9mm 60~65(N·m)
Fig 4.3.4.1 Fig 4.3.4.2
4.3.5 Outdoor Pipe Connection
Twist the flared nut on the connection pipe of outdoor valves. Twisting method is the same as for
indoor pipe connection.
During engineering installation, the connection pipe inside the unit must be wrapped by insulation
sleeve.

DC Inverter Multi VRF System
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Below is the piping diagram of VEC027N432U, VEC034N432U, VEC042N432U,
VEC048N432U, VEC055N432U, VEC060N432U.
According to customer requirement or space limit, outlet pipe can be installed from the front, right or
rear side.
Fig 4.3.5.1
Fig 4.3.5.2
4.3.6 Installation of Y-type Branch
(1) Y-type Branch.
Fig 4.3.6.1
(2) Y-type branch has several pipe sections with different dimension, which facilitates to match
with various copper pipes. Use pipe cutter to cut in the middle of the pipe section that is of
proper dimension and remove burrs as well. See Fig. 4.3.6.2.
(3) Y-type branch must be installed vertically or horizontally.

DC Inverter Multi VRF System
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Fig 4.3.6.2
(4) Branch shall be isolated by insulating material that can bear 120°C or even higher
temperature. The attached foam of branch cannot be taken as insulating material.
4.3.7 Thermal Insulation for Pipeline
(1) For multi VRF system, every copper pipe should be labeled so as to avoid misconnection.
(2) At the branch inlet, leave at least 500mm straight pipe section.
(3) Thermal insulation for pipeline.
1) To avoid condensate or water leakage on the connection pipe, the gas pipe and liquid
pipe must be wrapped with thermal insulating material and adhesive tape for insulation
from the air.
2) Thermal insulating material shall be able bear the pipe temperature. For heat pump unit,
liquid pipe should bear 70°C or above and gas pipe should bear 120°C or above. For
cooling only unit, both liquid pipe and gas pipe should bear 70°C or above.
3) Example: Polyethylene foam (bear 120°C or above); foaming polyethylene (bear 100°C
or above).
4) Joints of indoor and outdoor unit should be wrapped with insulating material and leave
no gap between pipe and wall. See Fig.4.3.7.1.
Fig 4.3.7.1
5) Thermal insulating material of branches should be the same as that of the pipeline. The
attached foam of branches cannot be taken as insulating material.
6) When wrapping the tape, the later circle should cover half of the former one. Don’t wrap
the rape too tight, otherwise the insulation effect will be weakened.
7) After wrapping the pipe, apply sealing material to completely seal the hole on the wall.

DC Inverter Multi VRF System
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4.3.8 Support and Protection of Pipeline
(1) Support should be made for hanging connection pipe. Distance between each support
cannot be over 1m.
(2) Protection against accidental damage should be made for outdoor pipeline. When pipeline
exceeds 1m, a pinch board should be added for protection.
4.4 Disassembly of Compressor Feet
In order to prevent unit from damage during transportation, 2 metal pieces are fitted to outdoor
unit’s compressor feet before unit leaves factory. See Fig.4.4.1.
Fig 4.4.1
When installing the unit, metal pieces for transportation must be removed. Then fasten the
binding nuts again and wrap back soundproofing cotton.
NOTE! If unit runs with metal pieces fitting on, compressor will shake abnormally and unit’s
operating life will be shortened.
4.5 Vacuum Pumping, Refrigerant Adding
4.5.1 Vacuum Pumping
(1) Outdoor unit has been charged with refrigerant before delivery. Field-installed connection
pipe needs to be charged with additional refrigerant.
(2) Confirm whether outdoor liquid and gas valves are closed.