LG LA121CNM, LA121HNM Schematic
website http://www.lgservice.com
LG
Room Air Conditioner
SERVICE MANUAL
MODELS: LA121CNM LA121HNM
LG
CAUTION
• BEFORE SERVICING THE UNIT, READ THE SAFETY
PRECAUTIONS IN THIS MANUAL.
• ONLY FOR AUTHORIZED SERVICE PERSONNEL.
Air Conditioner Service Manual
TABLE OF CONTENTS
Safety Precautions..........................................................................................................................................3
Dimensions......................................................................................................................................................9
Symbols Used in this Manual.....................................................................................................................9
Indoor Unit.....................................................................................................................
Outdoor Unit....................................................................................................................
Introduction ...............................................................................................................................
Symbols Used In This Manual........................................................................................................
Features .......................................................................................................................
Installation ...............................................................................................................................
Installation Parts..............................................................................................................
Installation Tools.......................................................................................................................................12
Installation Map ........................................................................................................................................13
Confirm The Refrigerant...........................................................................................................................14
Select The Best Location ........................................................................................................................15
Piping Length and Elevation.....................................................................................................................16
How to Mount Installation Plate................................................................................................................17
Drill a Hole in the Wall..............................................................................................................................17
Flaring Work.............................................................................................................................................18
Connecting The Piping.............................................................................................................................19
Connection of The Drain Hose.................................................................................................................24
Connection of Piping -Outdoor.................................................................................................................24
Connection of The Cable..........................................................................................................................25
Checking The Drainage............................................................................................................................27
Forming The Piping..................................................................................................................................28
Air Purging ...............................................................................................................................................29
Air purging with Vacuum Pump ................................................................................................................29
Charging...................................................................................................................................................31
Test Running .................................................................................................................................................32
Operation ......................................................................................................................................................33
Function of Controls .................................................................................................................................33
Display Function ......................................................................................................................................37
Self-diagnosis Function............................................................................................................................37
Remote Control Operations......................................................................................................................38
Disassembly ..................................................................................................................................................39
Indoor Unit................................................................................................................................................39
Troubleshooting Guide ................................................................................................................................42
Refrigeration Cycle Diagram ....................................................................................................................42
2-way, 3-way Valve ..................................................................................................................................43
Cycle Parts...............................................................................................................................................49
Electronic Parts ........................................................................................................................................50
Schematic Diagram.......................................................................................................................................58
Electric Control Device.............................................................................................................................58
Wiring Diagram.........................................................................................................................................60
Components Location ..............................................................................................................................62
Product Specifications ................................................................................................................................65
Exploded View...............................................................................................................................................67
Replacement Parts List ................................................................................................................................69
.............................9
.........................10
....................11
..........11
............................11
......................12
.........................12
2 Room Air Conditioner
Safety Precautions
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.
This symbol indicates the possibility of death or serious injury.
This symbol indicates the possibility of injury or damage to properties only.
■ Meanings of symbols used in this manual are as shown below.
Be sure not to do.
Be sure to follow the instruction.
■ Installation
Do not use damaged power
cords, plugs, or a loose socket.
• There is risk of fire or electric
shock.
Install the panel and the cover of
control box securely.
• There is risk of fire or electric
shock.
For electrical work, contact the
dealer, seller, a qualified electrician, or an Authorized Service
Center.
• There is risk of fire or electric
shock.
Do not modify or extend the
power cord.
• There is risk of fire or electric
shock.
Always use the power plug and
socket with the ground terminal.
•Thereisriskofelectricshock.
Do not install, remove, or reinstall the unit by yourself (customer).
• There is risk of fire, electric
shock, explosion or injury.
Service Manual 3
Safety Precautions
8ft(2.4m)
Be cautious when unpacking
and installing the product.
• Shape edges could cause injury.
Be especially careful of the sharp
edges.
Be sure the installation area
does not deteriorate with age.
• If the base collapses, the air conditioner could fall with it, causing
property damage, product failure,
and personal injury.
For installation, always contact
the dealer or an Authorized
Service Center.
• There is risk of fire, electric
shock, explosion, or injury.
Install the indoor unit on the
wall where the height from the
floors more then 8ft(2.4m)
• There are sharp moving parts
that could cause personal injury.
Do not install the product on a
defective installation stand.
• It may cause injury, accident, or
damage to the product.
Do not handle the pipe by yourself(customer)
• High-Pressure refrigent may
cause personal injury.
■ Operation
Use a dedicated outlet for this
appliance.
• There is risk of fire or electric
shock.
4 Room Air Conditioner
Grasp the plug to remove the
cord from the outlet. Do not
touch it with wet hands.
• There is risk of fire or electric
shock.
Do not allow water to run into
electric part.
• There is risk of fire, failure of the
product, and/or electric shock.
Safety Precautions
Do not place a heater or other
appliances near the power
cable.
•
There is risk of fire, failure of the
product, and/or electric shock.
Do not use the product in a
tightly closed space for a long
time.
Do not let the air conditioner run
for a long time when the humidity is very high and a door or a
window is left open.
• Moisture may condense and wet
or damage furnishings.
When flammable gas leaks, turn off
the gas and open a window for ventilation before turning the product on.
Do not use the telephone or turn
switches on or off.
Do not store of use flammable
gasorcombustiblesneartheair
conditioner.
• There is risk of fire or product failure.
Thinner
Wax
Unplug the unit if strange
sounds odors or smoke comes
from it.
• Oxygen deficiency could occur.
• Some ventilation by opeing window is necessary for the fresh air.
Stop operation and close any
window in storm or hurricane.
before the hurricane arrives.
• There is risk of property damage,
failure of product, or electric
shock.
• There is risk of explosion or fire.
Do not open the inlet grill of the
product during operation. (Do
not touch the electrostatic filter,
if the unit is so equipped.)
• There is risk of physical injury,
electric shock, or product.
•
There is risk of fireproduct failure
and/or electric shock.
When the product is soaked
(flooded or submerged), contact
an Authorized Service Center.
• There is risk of electrical shock.
Service Manual 5
Safety Precautions
Ventilate the product from time
to time when operating it together with a stove, etc.
• There is risk of fire or electrical
Unplug the appliance before
performing cleaning or maintenance.
• There is risk of electric shock.
shock.
Take care to ensure that nobody could step on or
fall onto the outdoor unit.
• There could result in personal injury and product
damage.
When the product is not be used
for a long time disconnect the
power supply plug or turn off
the breaker.
• There is risk of product damage
or failure, or unintended operation.
Do not insert hands or other objects through the
air inlet or outlet while the air conditioner is
plugged in.
• There are sharp and moving parts that could cause
personal injury.
■ Installation
Always check for gas(refrigerant) leakage after installation or
repair of product.
• Low refrigerant levels may cause
product failure.
6 Room Air Conditioner
Install the drain hose to ensure
that water is drained away properly.
• A bad connection may cause
water leakage.
Keep level even when installing
the product.
• To avoid vibration or water leakage.
90˚
Safety Precautions
Do not install the product where
the noise or hot air from the outdoor unit could damage the
neighborhoods.
• It may cause a problem for your
neighbors.
■ Operation
Do not direct airflow at room
occupants.
Use two or more people to lift
and transport the air conditioner
• Avoid personal injury.
Do not use the product for special
purposes, such as preserving
foods, works of art, etc. It is a
consumer air conditioner, not a
precision refrigeration system.
Do not install the product where
it will be exposed to sea wind
(salt spray) directly.
• It may cause corrosion in the
product. Corrosion, particularly
on the condenser and evaporator
fins, could cause product malfunction or inefficient operation.
Do not block the inlet or outlet
of air flow.
• This could damage your health.
Use a soft cloth to clean.
Do not use harsh detergents,
solvents, etc.
• There is risk of fire, electric shock
or damage to the plastic parts of
the product.
• There is risk of damage or loss of
property.
Do not touch the metal parts of
the product when removing the
air filter. They are very sharp!
• There is risk of personal injury.
• It may cause product failure.
Do not step on or put anything
on the product. (outdoor unit)
• There is risk of personal injury
and failure of product.
Service Manual 7
Dimensions
Always insert the filter securely. Clean the filter
every two weeks or more often if necessary.
• A dirty filter reduces the efficiency of the air conditioner and
Use a firm stool or ladder when cleaning or maintaining the air conditioner.
• Be careful and avoid personal injury.
Do not drink the water drained from the unit.
• It is not sanitary and could cause serious health
issues.
Replace all the batteries in the remote.
• There is risk of fire or explosion.
■ Disuse
Do not recharge or disassemble the batteries. Do
not dispose of batteries in a fire.
• They may burn or explode.
8 Room Air Conditioner
If the liquid from the batteries gets onto your skin
or clothes, wash it well with clean water. Do not
use the remote if the batteries have leaked.
• The chemicals in batteries could cause burns or
other health hazards.
Dimensions
Installation plate
D
H
W
Symbols Used in this Manual
This symbol alerts you to the risk of electric shock.
This symbol alerts you to hazards that could cause harm to the
air conditioner.
Dimensions
NOTICE
Indoor Unit
This symbol indicates special notes.
Model
12k Btu Series
Dimension
W mm 915(36.0)
H mm 282(11.1)
D mm 165(6.5)
Service Manual 9
Outdoor Unit
W
L2
L3
L1
D
H
L4
L5
Gas side
(3-way valve)
Liquid side
(2-way valve)
1. 12k
Dimensions
MODEL
DIM unit
W mm(inch) 770(30.3)
H mm(inch) 540(21.3)
D mm(inch) 245(9.6)
L1 mm(inch) 287(11.3)
L2 mm(inch) 64(2.5)
L3 mm(inch) 518(20.4)
L4 mm(inch) 10(0.4)
L5 mm(inch) 100(3.9)
10 Room Air Conditioner
12k
Introduction
Air Intake Vents
Air Outlet Vents
Connecting
Wires
Piping
Drain Hose
Base Plate
Air Outlet
Vents
Air Intake
Vents
Piping
Connecting
Wires
Drain Hose
Base Plate
Air Filter
Air Inlet
Front Panel
Signal Receptor
Symbols Used In This Manual
This symbol alerts you to the risk of electric shock.
This symbol alerts you to hazards that may cause harm to the air conditioner.
Introduction
NOTICE
Features
This symbol indicates special notes.
Service Manual 11
Installation
Figure FigureName
Screw driver
Electric Drill
Measuring Tape, Knife
Hole Core Drill
Spanner
Torque wrench
Ohmmeter
Hexagonal wrench
Ammeter
Gas Leak Detector
Thermometer,
Level
Flaring Tool Set
Name
Type "A" screw and plastic anchor
Type "B" screw
Remote Control Holder
Installation plate
Installation
Read carefully, and then follow step by step.
Installation Parts
Installation Tools
12 Room Air Conditioner
Installation Map
Installation parts you should purchase.
Vinyl tape (Wide)
• Apply after carrying out a
drainage test.
• To carry out the drainage
test, remove the air filters
and pour water into the heat
exchanger.
Saddle
Forced Operation Button
Gas side piping (Optional Parts)
Liquid side piping (Optional Parts)
Additional drain pipe
Vinyl tape (Narrow)
Drain Hose
Base Plate
Air Outlet Vents
Air Inlet Vents
Connecting cable
(Optional Parts)
Installation plate
Sleeve
Bushing-Sleeve
Putty(Gum Type Sealer)
Bend the pipe as closely
on the wall as possible,
but be careful that it
doesn't break.
NOTICE
Air Discarge
Vertical Air deflector
Operation Indication Lamps/
Signal Receptor
Installation
Service Manual 13
Confirm The Refrigerant
1. Check the quality label on the indoor and outdoor unit.
2. Make certain that the refrigerant is R-410A.
NOTICE
THIS PRODUCT CONTAINS R-410A REFRIGERANT
1) Different compressor oil
- R-410A(Polyol ester) / R-22(Mineral).
- Do not mix the existing mineral oil.
- Do not apply used pipe, tools and gauges covered with the existing mineral oil.
2) Absorption of moisture
-Compressor’s oil has the high absorption rate of moisture.
3) Composition
- R-410A(R32:R125=50:50wt%).
NOTE: Never mix with other refrigerants
Example : Split type 12,000 Btu/h
120
100
100
80
93
89
84
76
60
40
20
0
R-410A
R-22
100%
70% 50% 30%
0%
100%70%50%30%0%
4) High pressure.
- 1.6 times higher than R-22.
- High Pressure refrigerant may cause personal injury.
Boiling Pt.(
°C) Vapor pressure(25°C)(kg f/cnf) Vapor density(25°C)(kg/m2)
R-410A -51.4 15.9 64
R-22 -40.8 9.6 44.4
Do not handle the pipe by yourself (customer) High-pressure refrigerant may cause personal injury.
- manifold gauge ,charging and any piping tools must be dedicated to R-410A systems.
14 Room Air Conditioner
Select the Best Location
More than
12cm(4.7in)
More than
30cm(11.8in)
More than
30cm(11.8in)
More than 8ft(2.4m)
More than
10cm(3.9in)
More than
10cm(3.9in)
More than
60cm(23.6in)
More than
60cm(23.6in)
More than
70cm(27.6in)
Indoor unit
1. Do not have any heat or steam near the unit.
6. Use a stud finder to locate studs to prevent
unnecessary damage to the wall.
2.Selectaplacewheretherearenoobstaclesin
frontoftheunit.
3. Make sure that condensation drainage can be
conveniently routed away.
4. Do not install near a doorway.
5. Ensure that the space around the left and right
of the unit is more than 30cm(11.8in). The unit
should be installed as high on the wall as possible, allowing a minimum of 12cm(4.7in) from
ceiling.
Install the indoor unit on the wall where the height from the floors more than 2.3meters(7.6ft).
A minimum pipe run of 7.5meters(24.6ft) is required to minimize vibration and excessive noise.
Outdoor unit
1. 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.
5. Select a place so that the warm air and noise
from the air conditioner do not disturb neighbors.
2. Ensure that the space around the back and
sides is more than 10cm(3.9in). The front of the
unit should have more than 70cm(27.6in) of
space.
3. Do not place animals and plants in the path of
the warm air.
4. Take the air conditioner weight into account and
select a place where noise and vibration are
minimum.
Rooftop Installations
Iftheoutdoorunitisinstalledonaroofstructure,besuretoleveltheunit.Ensuretheroofstructureand
anchoring method are adequate for the unit location. Consult local codes regarding rooftop mounting.
If the outdoor unit is installed on roof structures or walls, this may result in excessive noise and vibration, and may be also classed as non serviceable installation.
Service Manual 15
Piping Length and Elevation
Outdoor unit
Indoor unit
A
B
Outdoor unit
Indoor unit
A
B
A
Oil trap
Outdoor unit
Indoor unit
B
Capacity
(Btu/h)
9k
Pipe Size
Suction Evap
Standard
Length
m(ft)
3/8" 1/4" 7.5(25) 7.5(25) 15(49) 20(0.22)
Max.
Elevation
B m(ft)
Max.
length
A
m(ft)
Additional
Refrigerant
g/m(oz/ft)
1/2" 1/4" 7.5(25) 7.5(25) 15(49) 20(0.22)
12k 1/2" 1/4" 7.5(25) 7.5(25) 15(49) 20(0.22)
18k
1/2" 1/4" 7.5(25) 15(49) 30(98) 20(0.22)
5/8" 1/4" 7.5(25) 7.5(25) 15(49) 20(0.22)
24k 5/8" 1/4" 7.5(25) 7.5(25) 15(49) 20(0.22)
In case more than 5m(16.4ft)
• Capacity is based on standard length and maximum allowance length is on the basis of reliability.
• Oil trap should be installed every 5~7meters (16.4~23.0ft).
16 Room Air Conditioner
How to Mount Installation Plate
Chassis
Hook
Installation Plate
Type “A”
5-7mm
(0.2~0.3")
Indoor
WALL
Outdoor
Installation plate
Left rear piping Right rear piping
Ø70mm
Ø70mm
D
B
A
C
The wall you select should be strong and solid enough
to prevent vibration
1. Mount the installation plate on the wall with
type "A" screws. If mounting the unit on a concrete
wall, use anchor bolts.
• Mount the installation plate horizontally by aligning the
centerline using a level.
2. Measure the wall and mark the centerline. It is also important to use caution concerning the location of the installation plate-routing of the wiring to power outlets is through the walls typically. Drilling the hole through the wall
for piping connections must be done safely.
CHASSIS
(Grade)
S4 50 105 59 105
SE 65 110 85 110
S5 95 122 235 122
ABCD
Distance (mm)
Drill a Hole In The Wall
• Drill the piping hole with a ø70mm(2.76in) hole
core drill. Drill the piping hole at either the right
or the left with the hole slightly slanted to the outdoor side.
Service Manual 17
Flaring Work
Bar
Copper pipe
Clamp handle
Red arrow mark
Cone
Yoke
Handle
Bar
"A"
Pipe
Reamer
Point down
Copper
pipe
90°
Slanted Uneven Rough
Flare nut
Copper tube
Main cause for gas leakage is due to defect in flaring work. Carry out correct flaring work in the following procedure.
Cut 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(59.1in) longer than the pipe length.
Burrs removal
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
• Carry out flaring work using flaring tool as shown below.
Outside diameter A
mm inch mm inch
Ø6.35 1/4 0~0.5 0~0.020
Ø9.52 3/8 0~0.5 0~0.020
Ø12.7 1/2 0~0.5 0~0.020
Ø15.88 5/8 0~1.0 0~0.039
Firmly hold copper pipe in a die in the dimensionshowninthetableabove.
18 Room Air Conditioner
Connecting The Piping
Indoor
1. Prepare the indoor unit's piping and drain hose for installation through the wall.
2. Remove the plastic tubing retainer(see the illustration by) and pull the tubing and drain hose
away from chassis.
3. Replace only the plastic tubing holder 1, not the
holder 2 in the original position.
For left rear piping
Route the indoor tubing and the drain
hose in the direction of rear left.
Insert the connecting cable into the indoor unit
from the outdoor unit through the piping hole.
• Do not connect the cable to the indoor unit.
• Make a small loop with the cable for easy con-
nection later.
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.
NOTICE
If the drain hose is routed inside the room, insulatethehosewithaninsulationmaterial*sothat
dripping from "sweating"(condensation) will not
damage furniture or floors.
*Foamed polyethylene or equivalent is recom-
mended.
1 2
Connecting
cable
Drain pipe
Indoor unit installation
• Hook the indoor unit onto the upper portion of
the installation plate.(Engage the three hooks of
the rear top and rear lower of the indoor unit with
the upper edge and lower edge of the installation
plate.) Ensure that the hooks are properly seated
on the installation plate by moving it left and
right.
Indoor unit
Spacer
Installation plate
8cm
Service Manual 19
Plastic bands
Insulation material
Connection pipe
Flare nut
Indoor unit tubing
Torque wrench
Spanner (fixed)
Vinyl tape(narrow)
Adhesive
Drain pipe
Indoor unit drain hose
Connecting the pipings to the indoor unit
Indoor unit tubing Flare nut Pipings
Drain hose
Vinyl tape(narrow)
Connection
pipe
Connecting cable
Vinyl tape
(wide)
Wrap with vinyl tape
Indoor
unit pipe
Pipe
Wrap with vinyl tape
Drain hose
Pipe
Vinyl tape(wide)
and drain hose to drain pipe.
Wrap the insulation material around the
connecting portion.
• Put a couple drops of refrigerant oil on the face
of the flare before assembling taking care not to
add any contaminants.
• Align the center of the pipings and sufficiently
tighten the flare nut by hand.
• Tightentheflarenutwithawrench.
Outside diameter
mm inch
Ø6.35 1/4 1.8
Ø9.52 3/8 4.2
Ø12.7 1/2 5.5
Ø15.88 5/8 6.6
Torque
• Mount the clamp on the boss with a type "B"
screw.(SE-H/P: 9k, 12k C/O: 12k)
• Overlap the connection pipe insulation material
and the indoor unit pipe insulation material. Bind
them together with vinyl tape so that there is no
gap.
• Wrap the area which accommodates the rear piping
housing section with vinyl tape.
• 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.
Type "B" screw
• When extending the drain hose at the indoor
unit, install the drain pipe.
20 Room Air Conditioner
Clamp
Boss
Drain hose
For right rear piping
Route the indoor tubing and the drain
hose to the required piping hole position.
Insert the connecting cable into the indoor
Indoor unit tubing Flare nut Pipings
Torque wrench
Indoor unit tubing
Spanner (fixed)
Connection pipe
Flare nut
Vinyl tape
Adhesive
Drain hose
Indoor unit drain hose
(narrow)
Connecting
pipe
Connecting cable
Tape
Drain hose
Drain hose
Connecting
cable
Plastic bands
Insulation material
unit.
• Don't connect the cable to the indoor unit.
• Make a small loop with the cable for easy con-
nection later.
Tape the drain hose and the connecting cable.
• Connecting cable
Indoor unit installation
• Hook the indoor unit onto the upper portion of
the installation plate.(Engage the three hooks of
the rear top and rear lower of the indoor unit with
the upper edge and lower edge of the installation
plate.) Ensure that the hooks are properly seated
on the installation plate by moving it left and
right.
Outside diameter Torque
Ø6.35 1/4 1.8
Ø9.52 3/8 4.2
Ø12.7 1/2 5.5
Ø15.88 5/8 6.6
• Mount the clamp on the boss with a type "B"
screw.(SE-H/P: 9k, 12k C/O: 12k)
Type "B" screw
Clamp
Boss
Drain hose
• When extending the drain hose at the indoor
unit, install the drain pipe.
Connecting the pipings to the indoor unit
and the drain hose to drain pipe.
• Put a couple drops of refrigerant oil on the face
of the flare before assembling taking care not to
add any contaminants
• Align the center of the pipings and sufficiently
tighten the flare nut by hand.
• Tighten the flare nut with a wrench.
Wrap the insulation material around the
connecting portion.
• Overlap the connection pipe heat insulation and
the indoor unit pipe heat insulation material.
Bind them together with vinyl tape so that there
is no gap.
Service Manual 21
Drain hose
Vinyl tape(narrow)
Pipe
Wrap with
vinyl tape(wide)
Piping for
passage through
piping hole
Drain hose
Connecting
cable
• Wrap the area which accommodates the rear
Vinyl tape(narrow)
Connection
pipe
Connecting cable
Indoor
unit piping
Pipe
Vinyl tape
(wide)
Wrap with vinyl tape
piping housing section with vinyl tape.
• Bundle the piping and drain hose together by
wrapping them with cloth tape over the range
within which they fit into the rear piping housing
section.
Reroute the pipings and the drain hose
across the back of the chassis.
Reroute the pipings and the drain hose
across the back of the chassis.
22 Room Air Conditioner
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