LG LA120CP Schematic
LG
Room
Air Conditioner
SERVICE MANUAL
LG
CAUTION
website http://www.lgservice.com
• BEFORE SERVICING THE UNIT, READ THE SAFETY
PRECAUTIONS IN THIS MANUAL.
• ONLY FOR AUTHORIZED SERVICE PERSONNEL.
MODELS: LA090CP
LA120CP
2 Room Air Conditioner
Air Conditioner Service Manual
TABLE OF CONTENTS
LG Model Name...............................................................................................................................................3
Safety Precautions..........................................................................................................................................4
Dimensions .....................................................................................................................................................8
Symbols used in this Manual......................................................................................................................8
Indoor Unit..................................................................................................................................................8
Outdoor Unit...............................................................................................................................................9
Installation.....................................................................................................................................................10
Select the Best Location .........................................................................................................................10
Piping Length and Elevation.....................................................................................................................10
Preparing Work for Installation.................................................................................................................11
Fixing the Indoor Unit...............................................................................................................................12
Drill a Hole in the wall...............................................................................................................................12
Flaring Work.............................................................................................................................................13
Connecting the Pipings ............................................................................................................................14
Connecting the Cables to the Indoor Unit ................................................................................................17
Connecting the Cables to the Outdoor Unit..............................................................................................18
Checking the Drainage.............................................................................................................................19
Forming the Piping...................................................................................................................................19
Air Purging ...............................................................................................................................................20
Air Purging with Vacuum Pump................................................................................................................20
Front Panel Assembly ..............................................................................................................................22
Test Running............................................................................................................................................23
Operation ......................................................................................................................................................24
Function of Controls.................................................................................................................................24
Display Function.......................................................................................................................................25
Self-diagnosis Function............................................................................................................................25
Remote Control Operations......................................................................................................................26
Disassembly..................................................................................................................................................27
Indoor Unit................................................................................................................................................27
Troubleshooting Guide.................................................................................................................................29
Refrigeration Cycle Diagram....................................................................................................................29
2-way, 3-way Valve...................................................................................................................................30
Cycle Parts...............................................................................................................................................37
Electronic Parts........................................................................................................................................38
Schematic Diagram.......................................................................................................................................47
Electric control Device..............................................................................................................................47
Wiring Diagram.........................................................................................................................................49
Components Location ..............................................................................................................................50
Product Specifications ................................................................................................................................53
Exploded View ..............................................................................................................................................54
Indoor Unit...............................................................................................................................................54
Outdoor Unit............................................................................................................................................55
Replacement Parts List ................................................................................................................................56
Indoor......................................................................................................................................................56
Outdoor ....................................................................................................................................................57
Service Manual 3
LG Model Name
12 - 345678910
Code Type Code of Model Meaning
1 Producing Center, A~Z L: Chang-won R22 N: India
Refrigerant A: Chang-won R410A Z: Brazil
C: Chang-won R407C D: Indonesia
T: China
U: China R410A
X: Mexico
K: Turkey R22
V: Vietnam
E: Turkey R410A
S: Out Sourcing
H: Thailand
2 Product Type A~Z S: Split Type Air Conditioner
3 Cooling/Heating/Inverter A~Z C: Cooling only
H: Heat pump
X: C/O + E/Heater
Z: H/P + E/Heater
V: AC Inverter C/O
N: AC Inverter H/P
Q: DC Inverter C/O
W: DC Inverter H/P
4, 5 Capacity 0~9 Cooling/Heating Capacity
Ex. "09" → 9,000 Btu/h
6 Electric Range 1~9 1: 115V/60Hz, A: 220V, 50Hz, 3Phase
A~Z 2: 220V/60Hz B: 208~230V, 60Hz, 3Phase
3: 208-230V/60Hz C: 575V, 50Hz, 3Phase
5: 200-220V/50Hz D: 440~460, 60Hz, 3Phase
6: 220-240V/50Hz E: 265V, 60Hz
7: 110V, 50/60Hz F: 200V, 50/60Hz
8: 380-415V/50Hz
9: 380-415V/60Hz
7 Chassis A~Z Name of Chassis of Unit
Ex. LSP → SP Chassi
s
8 Look A~Z Look,
Color (Artcool Model)
9 Function A~Z
10 Serial No. 1~9 LG Model Development Serial No.
* ARTCOOL COLOR
Basic A
Basic+4Way B
Plasma Filter C
Plasma Filter+4 Way D
Tele+LCD E
Tele+LCD+Nano plasma+4Way F
Nano Plasma F+(A/changeove)+A/clean+Low A G
Nano Plasma F+(A/changeove)+A/clean+4way+Low A H
Tele+LED+4way I
Internet J
Plasma F+4Way+Oxy generator K
Nano Plasma F+(A/changeove)+A/clean L
Nano Plasma F+(A/changeove)+A/clean+4way M
Nano Plasma F+(A/changeove)+A/clean+PTC N
Nano Plasma F+(A/changeove)+Autoclean+4way+PTC P
Nano Plasma F+(A/changeove)+A/clean+4way+Low A+PTC Q
Negative ION+A/Clean R
(Nano)Plasma+Negative ION+A/Clean S
4way+(Nano)Plasma F+Negative ION+Healthy dehumidification+A/Clean
T
Nano Plasma F+4Way+(A/changeove)+A/clean+Oxy generator U
4way+(Nano)Plasma F+Negative ION+Healthy dehumidification+A/Clean+Oxy generator
V
Dry Contact W
Wired Remocon 8
R Mirror
W White
B Blue
D Wood
M Metal
C Cherry
N Walnut
A Gogh
S Sisley
Q Quran
K Mecca
CHASSIS Look
D
K
L
G
M
N
D
P
Division
Panel Type(Deluxe)
Fighting 'Look'
(LG1)
(LG2)-SEMI PANEL
OEM1
OEM2
Panel Type(Deluxe)
LG3
S4/S5
S6
SQ
SR
ST
2003~
4 Room Air Conditioner
Safety Precautions
To prevent injury to the user or other people and property damage, the following instructions must
be followed.
■ Incorrect operation due to ignoring instruction will cause harm or damage. The seriousness is
classified by the following indications.
■ Meanings of symbols used in this manual are as shown below.
This symbol indicates the possibility of death or serious injury.
This symbol indicates the possibility of injury or damage to properties only.
Be sure not to do.
Be sure to follow the instruction.
Always perform grounding. Don’t use a power cord, a plug
or a loose socket which is
damaged.
For installation of the product,
always contact the service center or
a professional installation agency.
• Otherwise, it may cause electrical
shock.
• Otherwise, it may cause a fire or
electrical shock.
• Otherwise, it may cause a fire, electrical shock, explosion or injury.
Securely attach the electrical
part cover to the indoor unit
and the service panel to the
outdoor unit.
Always install an air leakage
breaker and a dedicated
switching board.
Do not keep or use flammable
gases or combustibles near
the air conditioner.
• If the electrical part cover of the
indoor unit and the service panel of
the outdoor unit are not attached
securely, it could result in a fire or
electric shock due to dust, water, etc.
• No installation may cause a fire and
electrical shock.
• Otherwise, it may cause a fire or the
failure of product.
■ Installation
Wax
Thinner
Service Manual 5
Safety Precautions
■ Operation
Do not modify or extend the
power cord randomly.
Take care so that the power
cord may not be pulled during
operation.
Unplug the unit if strange
sounds, smell, or smoke
comes from it.
• Otherwise, it may cause a fire or
electrical shock.
• Otherwise, it may cause a fire or
electrical shock.
• Otherwise, it may cause electrical
shock or a fire.
• Sharp edges may cause injury. • It will cause an electric shock or a
fire due to heat generation.
• Otherwise, it may cause a fire or
electrical shock.
Use caution when unpacking
and installing.
Do not share the outlet with
other appliances.
Do not use the damaged
power cord.
Ensure that an installation
frame of the outdoor unit is
not damaged due to use for a
long time.
Do not disassemble or repair
the product randomly.
Do not install the product at a
place that ther is concern of
falling down.
• It may cause injury or an accident. • It will cause a fire or electrical shock. • Otherwise, it may result in personal
injury.
6 Room Air Conditioner
Safety Precautions
Keep the flames away.
Take the power plug out if necessary, holding the head of the plug
and do not touch it with wet hands.
Do not use the power cord
near the heating tools.
• Otherwise, it may cause a fire. • Otherwise, it may cause a fire or
electrical shock.
• Otherwise, it may cause a fire and
electrical shock.
Do not open the suction inlet
of the indoor/outdoor unit during operation.
Do not allow water to run into
electrical parts.
Never touch the metal parts of
the unit when removing the filter.
• Otherwise, it may electrical shock
and failure.
• Otherwise, it may cause the failure of
machine or electrical shock.
• They are sharp and may cause
injury.
Do not step on the indoor/outdoor unit and do
not put anything on it.
Do not place a heavy object on the power cord.
• It may cause an injury through dropping of the unit or
falling down.
• Otherwise, it may cause a fire or electrical shock.
When the product is submerged into water,
always contact the service center.
Take care so that children may not step on the
outdoor unit.
• Otherwise, it may cause a fire or electrical shock. • Otherwise, children may be seriously injured due to
falling down.
Service Manual 7
Safety Precautions
■ Installation
Install the drain hose to
ensure that drain can be
securely done.
Install the product so that the
noise or hot wind from the
outdoor unit may not cause
any damage to the neighbors.
Always inspect gas leakage
after the installation and repair
of product.
• Otherwise, it may cause water leakage.
• Otherwise, it may cause dispute with
the neighbors.
• Otherwise, it may cause the failure of
product.
Wax
Thinner
Keep level parallel in installing the product. Avoid excessive cooling and perform ventila-
tion sometimes.
• Otherwise, it may cause vibration or water leakage. • Otherwise, it may do harm to your health.
Use a soft cloth to clean. Do not use wax, thinner, or a strong detergent.
When gas leaks, open the window for ventilation before operating the unit.
• The appearance of the air conditioner may deteriorate,
change color, or develop surface flaws.
• Otherwise, it may cause explosion, and a fire.
■ Operation
8 Room Air Conditioner
Dimensions
Dimensions
Pipe Hole
Fix Hole
Hanger Hole
H
W
D
W mm 570
H mm 568
D mm 137
Model
Dimension
INDOOR UNIT
Indoor Unit
This symbol alerts you to the risk of electric shock.
This symbol alerts you to hazards that may cause harm to the
air conditioner.
This symbol indicates special notes.
NOTICE
Symbols used in this Manual
Service Manual 9
W
L2
L3
L1
D
H
L4
L5
Gas side
(3-way valve)
Liquid side
(2-way valve)
MODEL
9K, 12K Models
DIM unit
W mm 770
H mm 540
D mm 245
L1 mm 285
L2 mm 64
L3 mm 518
L4 mm 10
L5 mm 100
Dimensions
10 Room Air Conditioner
Installation
Installation
Indoor unit
• Do not have any heat or steam near the unit.
• Select a place where there are no obstacles in
front of the unit.
• Make sure that condensation drainage can be conveniently routed away.
Do not install near a doorway.
• Ensure that the space around the left and right of
the unit is more than 50cm. The unit should be
installed as high on the wall as possible, allowing a
minimum of 10cm from ceiling.
• Use a stud finder to locate studs to prevent unnecessary damage to the wall.
Outdoor unit
• If an awning is built over the unit to prevent direct
sunlight or rain exposure, make sure that heat
radiation from the condenser is not restricted.
• Ensure that the space around the back and sides
is more than 10cm. The front of the unit should
have more than 70cm of space.
• Do not place animals and plants in the path of the
warm air.
• Take the air conditioner weight into account and
select a place where noise and vibration are minimum.
• Select a place so that the warm air and noise from
the air conditioner do not disturb neighbors.
More than 10cm
More
than 50cm
More than 2m
More
than 50cm
More than 10cm More than 10cm
More
than 60cm
More than 60cm
More than 70cm
CAUTION:
Install the indoor unit on the wall
where the height from the floor is more than 2
meter.
CAUTION:
• Capacity is based on standard length and maximum
allowance length is on the basis of reliability.
• Oil trap should be installed every 5~7 meters.
If the piping length is more than 5m
Outdoor unit
Indoor unit
A
B
Outdoor unit
Indoor unit
A
B
A
Oil trap
Outdoor unit
Indoor unit
B
I
Selection of the Best Location
Piping Length and Elevation
5k~14k
3/8"(Ø9.52) 1/4"(Ø6.35) 4 or 7.5 7 15 20
1/2"(Ø12.7) 1/4"(Ø6.35) 4 or 7.5 7 15 20
1/2"(Ø12.7) 1/4"(Ø6.35) 4 or 7.5 15 30 20
18k~28k 5/8"(Ø15.88) 1/4"(Ø6.35) 4 or 7.5 15 30 20
5/8"(Ø15.88) 3/8"(Ø9.52) 4 or 7.5 15 30 30
30k~38k
5/8"(Ø15.88) 3/8"(Ø9.52) 7.5 15 30 30
3/4"(Ø19.05) 3/8"(Ø9.52) 7.5 15 30 50
Pipe Size
Capacity
(Btu/h)
GAS LIQUID
Max.
Length
A (m)
Additional
Refrigerant
(g/m)
Max.
Elevation
B (m)
Standard
Length
(m)
Service Manual 11
Remove pipe cover and side cover
1. Remove two screws(for fixing pipe cover)
2. Pull up the side cover of desired connecting direction,
and then side cover is separated.
3. Pick the pipe hole of the side cover.
CAUTION: After removing the pipe
hole, cut the burr for safety.
When making pipe path through rear
wall, you don’t need to pick the pipe hole.
Drain hose junction
1. Remove the rubber stopple in the desired drain direction.
2. Insert drain hose into the handle of drain pan, and
join drain hose and connecting hose according to the
figure by.
NOTICE
Open front panel
1. Push the front panel backward and lift it up to remove the two screws.
2. As soon as you lift the both lower parts of panel front, you can hear the sound from panel front. At this moment
panel front is separated
3. After pulling down this panel a bit, separate connecting wire from the product.
Installation
Panel Front
Connector
Pipe hole
Side cover
rubber cap
Only the
desired direction
Connecting
part
Adhesive
Drain
hose
Preparing Work for Installation
12 Room Air Conditioner
Installation
Fixing the Indoor Unit
• Drill the piping hole with a ø50mm hole core drill.
Drill the piping hole at either the right or the left with
the hole slightly slanted to the outdoor side.
Drill a Hole in the Wall
5-7mm
(0.2~0.3")
Indoor
WALL
Outdoor
I
1. Attach an Installation guide map on the
desired surface.
INSTALLA TION GUIDE MAP
2. Make a hole with a diameter of 6mm and
depth of 30-35mm by piercing a screw
point.
INSTAIIATION GUIDE MAP
3. Drive the fore plastic anchors into drilled
points.
Plastic anchors
IN
STA
LLAT
IO
N
G
UID
E M
A
P
4. Hang the hole of product at the upper
screws, and remove the map. (Falling
IN
attention)
Hanger hole
(Rear side of
the product)
S
T
A
L
L
A
T
IO
N
G
U
ID
E
M
A
P
6. Look at suited horizon by horizontal
meter on the horizontal setting line, and
fix lightly the map by adhesive tape.
N
S
T
A
L
L
A
Horizontality
Drill the pierted part as a diameter of 50mm
7.
T
IO
N
G
U
ID
E
M
A
P
for connecting piping. (In case of piercing
rear surface)
8.
First, Drive the two points of the upper
parts by screws. (Leave 10mm for hanging
the product)
INSTALLA TION GU
m
10m
9. Drive the lower parts after facing the hole
of product with plastic anchors, and fix
completely the upper screws.
Plastic anchors
5. Check the fixed product with light power.
10.
In case of nothing wrong, connect the
pipe and the wire. (Refer to installation
manual)
Service Manual 13
Installation
Flaring Work
Cutting the pipes and the cable.
1. Use the piping kit accessory or the pipes purchased
locally.
2. Measure the distance between the indoor and the outdoor unit.
3. Cut the pipes a little longer than measured distance.
4. Cut the cable 1.5m longer than the pipe length.
Removing burrs
1. Completely remove all burrs from the cut cross section of
pipe/tube.
2. Put the end of the copper tube/pipe in a downward direction as you remove burrs in order to avoid dropping burrs
into the tubing.
Putting nut on
• Remove flare nuts attached to indoor and outdoor unit,
then put them on pipe/tube having completed burr
removal.
(not possible to put them on after flaring work)
Flaring work
1. Firmly hold copper pipe in a die in the dimension shown
in the table below.
2. Carry out flaring work with the flaring tool.
Copper
pipe
90°
Slanted Uneven Rough
mm inch mm
Ø6.35 1/4 0~0.5
Ø9.52 3/8 0~0.5
Ø12.7 1/2 0~0.5
Ø15.88 5/8 0~1.0
Ø19.05 3/4 1.0~1.3
Outside diameter A
Bar
Copper pipe
Clamp handle
Red arrow mark
Cone
Yoke
Handle
Bar
"A"
Main cause for gas leakage is due to defect in flaring work. Carry out correct flaring work in the following procedure.
Pipe
Reamer
Point down
Flare nut
Copper tube
14 Room Air Conditioner
Installation
Check
1. Compare the flared work with the figure by.
2. If a flared section is defective, cut it off and do flaring
work again.
Indoor
Preparing the indoor unit's piping and drain hose for installation through the wall.
If the drain hose is routed inside the room, insulate the hose with an insulation
material* so that dripping from "sweating"(condensation) will not damage furniture
or floors.
*Foamed polyethylene or equivalent is recommended.
NOTICE
Route the indoor tubing and the drain hose in the
direction of rear left or right
Tape the tubing, drain hose and the connecting
cable. Be sure that the drain hose is located at the
lowest side of the bundle. Locating at the upper
side can cause drain pan to overflow inside the unit.
Inclined
Inside is shiny without scratches
Smooth all round
Even length
all round
Surface
damaged
Cracked Uneven
thickness
= Improper flaring =
Connecting the Pipings
Drain hose
Connecting
cable
Drain hose
Loop
Gas side piping
Liquid side piping
Service Manual 15
Connecting the pipings with the indoor unit
and drain hose with drain pipe
1. Align the center of the pipings and sufficiently tighten
the flare nut by hand.
2. Tighten the flare nut with a wrench.
3. When extending the drain hose at the indoor unit,
install the drain pipe.
Wrap the insulation material around the
connecting portion.
1. Overlap the connection pipe insulation material and
the indoor unit pipe insulation material. Bind them
together with vinyl tape so that there may be no gap.
2. Wrap the area which accommodates the rear piping
housing section with vinyl tape.
3. Bundle the piping and drain hose together by wrapping them with vinyl tape over the range within which
they fit into the rear piping housing section.
Installation
Wrap with vinyl tape
Drain hose
Pipe
Vinyl tape(wide)
mm inch kg.m
Ø6.35 1/4 1.8
Ø9.52 3/8 4.2
Ø12.7 1/2 5.5
Ø15.88 5/8 6.6
Ø19.05 3/4 6.6
Outside diameter Torque
Vinyl tape
Adhesive
Drain hose
Indoor unit drain hose
(narrow)
Indoor unit tubing Flare nut Pipes
Wrench
Indoor unit tubing
Open-end wrench (fixed)
Flare nut
Connection pipe
Connection
pipe
Vinyl tape
(wide)
Plastic bands
Connecting cable
Vinyl tape(narrow)
Insulation material
Wrap with vinyl tape
Indoor
unit pipe
Pipe
16 Room Air Conditioner
Installation
Outdoor
Align the center of the pipings and sufficiently tighten
the flare nut by hand.
Finally, tighten the flare nut with torque wrench until the
wrench clicks.
• When tightening the flare nut with torque wrench,
ensure the direction for tightening follows the arrow on
the wrench.
mm inch kg.m
Ø6.35 1/4 1.8
Ø9.52 3/8 4.2
Ø12.7 1/2 5.5
Ø15.88 5/8 6.6
Ø19.05 3/4 6.6
Outside diameter Torque
Outdoor unit
Gas side piping
(Bigger diameter)
Liquid side
piping
(Smaller
diameter)
Torque wrench
Service Manual 17
Installation
• Connect the cables to the indoor unit by connecting the wires to the terminals on the control board
dividually according to the outdoor unit connection. (Ensure that the color of the wires of the outdoor unit and the
terminal No. are the same as those of the indoor unit.)
• Before connecting the cables to the terminal block, remove the cables in the holder of the control cover and
do it.
Connecting the Cables to the Indoor Unit.
CAUTION:
• The above circuit diagram is subject to change without notice.
• The earth wire should be longer than the common wires.
• When installing, refer to the circuit diagram behind the panel front of the indoor unit.
• Connect the wires firmly so that they may not be pulled out easily.
• Connect the wires according to color codes, referring to the wiring diagram.
CAUTION: If a power plug is not
used, provide a circuit breaker
between power source and the unit
as shown by.
CAUTION:
The power cord connected to the "A" unit should be selected according to
the following specifications(Type "B" approved by HAR or SAA).
The power connecting cable connecting the indoor and outdoor unit should be selected
according to the following specifications (Type "B" approved by HAR or SAA).
Air
Conditioner
Main power source
Circuit Breaker
Use a circuit breake
or time delay fuse.
5k~9k 12k 14k~18k 24k~28k 30k, 32k 36k, 38k
0.75 1.0 1.5 2.5 2.5 5.5
Unit(A) Indoor Indoor Indoor Indoor Outdoor Outdoor
Cable Type(B) H05VV-F H05VV-F H05VV-F H05VV-F H05RN-F H05RN-F
NORMAL CROSS
-SECTIONAL AREA
Grade
(mm2)
5k~12K 14k~18k 24k~28k
1.0 1.5 2.5
Cable Type(B) H07RN-F H07RN-F H07RN-F
NORMAL
CROSS
-SECTIONAL
AREA
Grade
(mm2)
NORMAL
CROSS-SECTIONAL
AREA 0.75mm2
30k, 32k 36k, 38k
0.75 0.75
Cable Type(B) H07RN-F H07RN-F
NORMAL CROSS
-SECTIONAL AREA
Grade
(mm2)
18 Room Air Conditioner
Installation
1. Remove the control cover from the unit by loosening the screw.
Connect the wires to the terminals on the control
board individually.
2. Secure the cable onto the control board with the
cord clamp.
3. Refix the control cover to the original position
with the screw.
4. Use a recognized circuit breaker "A"
between the power source and the unit.
A disconnecting device to adequately disconnect
all supply lines must be fitted.
Terminal block
Over 5mm
Cover control
Connecting cable
Connecting cable
CAUTION: After the confirmation of the above conditions, prepare the wiring as
follows:
1) Never fail to have an individual power circuit specifically for the air conditioner. As for the method of wiring,
be guided by the circuit diagram posted on the inside of control cover.
2) The screw which fasten the wiring in the casing of electrical fittings are liable to come loose from vibrations
to which the unit is subjected during the course of transportation. Check them and make sure that they are
all tightly fastened. (If they are loose, it could cause burn-out of the wires.)
3) Specification of power source.
4) Confirm that electrical capacity is sufficient.
5) See to that the starting voltage is maintained at more than 90 percent of the rated voltage marked on the
name plate.
6) Confirm that the cable thickness is as specified in the power source specification.
(Particularly note the relation between cable length and thickness. (Refer to page 17)
7) Always install an earth leakage circuit breaker in a wet or moist area.
8) The following would be caused by voltage drop.
• Vibration of a magnetic switch, which will damage the contact point, fuse breaking, disturbance of the normal func-
tion of the overload.
9) The means for disconnection from a power supply shall be incorporated in the fixed wiring and have an air
gap contact separation of at least 3mm in each active(phase) conductors.
Outdoor Unit
5K~14K 18K 24k~28K 30k,32K 36k,38k
15 20 30 30 40
Circuit
Breaker
(A)
Grade
Connecting the Cables to the Outdoor Unit
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