Lennox VEPS075N432K User manual

DC Inverter Multi VRF System User Manual
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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 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.
(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 ......................................................................................................1
2.1 Names of Main Parts ............................................................................................................... 4
2.2 Combinations of Indoor and Outdoor Units ............................................................................. 4
2.3 Operating Range ..................................................................................................................... 4
3 Preparation before Installation ......................................................................................5
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 Vacuum Pumping, Refrigerant Adding................................................................................... 17
4.5 Electric Wiring........................................................................................................................ 19
5 Check Items after Installation and Test Operation .....................................................22
5.1 Check Items after Installation ................................................................................................ 22
5.2 Test Operation and Debugging.............................................................................................. 23
6 Common Malfunctions and Troubleshooting.............................................................28
7 Error Indication ............................................................................................................. 29
8 Maintenance and Care..................................................................................................31
8.1 Outdoor Heat Exchanger....................................................................................................... 31
8.2 Drain Pipe.............................................................................................................................. 31
8.3 Notice before Seasonal Use.................................................................................................. 32
8.4 Maintenance after Seasonal Use .......................................................................................... 32
8.5 Parts Replacement ................................................................................................................ 32
9 After-sales Service........................................................................................................32

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.
Follow this manual to
complete the installation work.
Please read this manual
carefully before turning on or
repairing the unit.
Installation should be
performed by the distributor or
qualified technicians. Do not
install the product by yourself.
Improper installation may lead
to water leakage, electric
shock or fire hazard, etc.
Before installation, please
check whether the power
supply is complied with that
specified on the nameplate
and check the safety of the
power supply.
The air conditioner must be
grounded reliably for avoiding
electric shock. Please do not
connect the earthing wire to
gas pipe, water pipe, lightning
rod or telephone line.
Be sure to use special
accessories and parts for
installation to prevent water
leakage, electric shock and
fire hazard, etc.
If refrigerant leakage
happens, please ventilate the
room immediately.
Diameter of power cord
should be large enough. The
damaged power cord and
connection wire must be
replaced with special cables.
When the power cord is
connected, please fix the
electric box cover properly to
avoid safety accidents.

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Never fail to comply with the
nitrogen-charging welding
process. Do charge nitrogen
when welding the pipes.
Never short circuit or cancel
the pressure switch to prevent
unit damage.
As for the unit controlled by
the wired controller, connect
the wired controller well firstly
and then energize the unit;
otherwise, the unit can’t
operate normally.
When installation is finished,
please check whether the
drainage pipes, pipelines and
electric wires are connected
correctly to avoid water
leakage, refrigerant leakage,
electric shock or fire, etc.
Do not insert fingers or objects
into air outlet or air return
grille.
Open the door and window
frequently to keep good
ventilation for avoiding oxygen
deficit when gas heater or oil
heater is used in the room.
Never plug in or unplug the
power plug directly to turn on
or turn off the air conditioner.
Once the air conditioner is
turned on, it can be turned off
only after it has operated for
5min at least; otherwise, it will
affect the oil return of
compressor.
Do not allow children to
operate this air conditioner. Do not operate this air
conditioner with wet hands.
The air conditioner can be
cleaned only when it has been
turned off and the power has
been cut off; otherwise, it may
cause electric shock or injury.
Never spray or flush water
towards the air conditioner;
otherwise, malfunction or
electric shock may happen.
Do not expose the air
conditioner to the moist or
corrosive environment.
Put through the power 8 hours
in advance before operation.
Do not cut off the power when
the air conditioner stops
operation for only about one
night (protect the
compressor).

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Volatile liquid, such as diluent
or gasoline, will damage the
appearance of air conditioner.
Only soft dry cloth and wet
cloth dipped with neutral
detergent can be used to
clean the outer case of air
conditioner.
Under cooling mode, please
don't set the room
temperature too low; keep the
temperature difference
between indoor and outdoor
within 5°C (41°F).
If there are any abnormal
circumstances (such as
burning smell, etc.), please
turn off the unit and cut off the
main power supply
immediately, and then contact
LENNOX appointed service
center. If those abnormal
circumstances still exit, the
unit may be damaged and it
may lead to electric shock or
fire hazard.
Do not repair the unit by
yourself. Wrong maintenance
may cause electric shock or
fire hazard. Please contact
LENNOX appointed service
center for help.
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
LENNOX 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 22.4kW to 35kW, 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.

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2.1 Names of Main Parts
Fig.1
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
Max sets of connectable IDUs
VEPS075N432K
13
VEPS096N432K
17
VEPS120N432K
20
(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
Heating
Outdoor temperature: -20°C~27°C

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3 Preparation before Installation
NOTE: Graphics here are only for reference. Please refer to actual products. Unspecified
dimensions are all in mm.
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
3Drainage hole cap 3 ——
4Drainage joint 1 ——
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:
Unit：mm
Fig.2
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
Φ12.7(1/2) ≥0.8
Φ15.9(5/8)
≥1.0
Φ19.05(3/4)
≥1.0
Φ22.20(7/8)
≥1.2
Φ25.40(8/8)
≥1.2
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.3
Unit: mm
Model A B C D E
VEPS075N432K
940
320
1430
632
350
VEPS096N432K
940
460
1615
610
486
VEPS120N432K
940
460
1615
610
486

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4.2 Connection Pipe
4.2.1 Schematic Diagram of Piping Connection
Fig.4

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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.
Fig.5 Allowable Length and Height Difference of Connection Pipe
Piping parameters of VEPS075N432K ,VEPS096N432K ,VEPS120N432K :
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 —

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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.6
Dimension of outdoor connection pipe.
Basic module
Pipe dimension
Connection method
Gas pipe (mm)
Liquid pipe (mm)
Φ19.05
Φ9.52
Welding connection
Φ22.20
Φ9.52
Φ25.40
Φ12.70
VEPS075N432K
VEPS096N432K
VEPS120N432K

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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.7
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.8
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
22.4<C≤33.5
Φ25.40
Φ12.70

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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. 9
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.10).
(4) Check if the flared part is flaring evenly and if there is any crack.

DC Inverter Multi VRF System
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Fig. 10
4.3.3 Pipe Bending
(1) Reshape the pipe by hand. Be careful not to damage the pipe.
Fig. 11 Fig. 12
(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.12. 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.13 (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 handle of wrench and make it at right angle to the pipe. as in Fig.14).
(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.

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4.3.5 Outdoor Pipe Connection
During engineering installation, the connection pipe inside the unit must be wrapped by insulation
sleeve.
(1) Pipe connection for 9(361.: As shown in Fig.15 and Fig.16,
open the outermost soundproof cotton and place a fire barrier between compressor and straight
pipe. Use a soldering gun to unsolder straight pipe 1 and straight pipe 2. Install connection pipe
1 and connection pipe 2 to the corresponding position and then seal the apertures with welding
rod. First weld the liquid side connection pipe and then weld the gas side connection pipe.
During welding, it’s necessary to use wet gauze to wrap up the two cut-off valves. Make sure
the flame won’t burn the soundproof cotton or other components.
Fig. 15
Fig.13 Fig.14
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)