LG MULTI V IV ARNU07GTU 2 Series User manual

Outdoor Unit
SERVICE MANUAL
CAUTION
Before Servicing the unit, read the safety precautions in General SVC manual.
Only for authorized service personnel.
Internal Use Only
http://biz.lgservice.com
R410A

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Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Air Conditioner Service Manual
TABLE OF CONTENTS
Safety Precautions .....................................................................................................3
Part 1 General Information ........................................................................................8
Model Names ...............................................................................................................................9
External Appearance..................................................................................................................11
Combination of Outdoor Units .................................................................................................13
Nomenclature .............................................................................................................................14
Part 2 Outdoor Units ................................................................................................15
Part 3 PCB Setting and Test Run ...........................................................................49
Part 4 Trouble shooting guide................................................................................ 54

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Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Safety Precautions
Safety Precautions
To prevent injury to the user or other people and property damage, the following instructions must
be followed.
nIncorrect operation due to ignoring instruction will cause harm or damage. The seriousness is
classified by the following indications.
nMeanings of symbols used in this manual are as shown below.
WARNING
CAUTION
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.
WARNING
nInstallation
Have all electric work done by a licensed
electrician according to "Electric Facility
Engineering Standard" and "Interior Wire
Regulations" and the instructions given in
this manual and always use a special circuit.
• If the power source capacity is inadequate or
electric work is performed improperly, electric
shock or fire may result.
Ask the dealer or an authorized technician to
install the air conditioner.
• Improper installation by the user may result in
water leakage, electric shock, or fire.
Always ground the product.
• There is risk of fire or electric shock.
Always intstall a dedicated circuit and breaker.
• Improper wiring or installation may cause fire or
electric shock.
For re-installation of the installed product,
always contact a dealer or an Authorized
Service Center.
• There is risk of fire, electric shock, explosion, or
injury.
Do not install, remove, or re-install the unit
by yourself (customer).
• There is risk of fire, electric shock, explosion, or
injury.

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Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Safety Precautions
Do not store or use flammable gas or
combustibles near the air conditioner.
• There is risk of fire or failure of product.
Use the correctly rated breaker or fuse.
• There is risk of fire or electric shock.
Prepare for strong wind or earthquake and
install the unit at the specified place.
• Improper installation may cause the unit to top-
ple and result in injury.
Do not install the product on a defective
installation stand.
• It may cause injury, accident, or damage to the
product.
When installing and moving the air condition-
er to another site, do not charge it with a
different refrigerant from the refrigerant
specified on the unit.
• If a different refrigerant or air is mixed with the
original refrigerant, the refrigerant cycle may
malfunction and the unit may be damaged.
Do not reconstruct to change the settings of
the protection devices.
• If the pressure switch, thermal switch, or other
protection device is shorted and operated
forcibly, or parts other than those specified by
LGE are used, fire or explosion may result.
Ventilate before operating air conditioner
when gas leaked out.
• It may cause explosion, fire, and burn.
Securely install the cover of control box and
the panel.
• If the cover and panel are not installed securely,
dust or water may enter the outdoor unit and fire
or electric shock may result.
If the air conditioner is installed in a small
room, measures must be taken to prevent the
refrigerant concentration from exceeding the
safety limit when the refrigerant leaks.
• Consult the dealer regarding the appropriate
measures to prevent the safety limit from being
exceeded. Should the refrigerant leak and cause
the safety limit to be exceeded, harzards due to
lack of oxygen in the
room could result
Use a vacuum pump or inert(nitrogen) gas when
doing leakage test or air purge. Do not compress
air or Oxygen and do not use flammable gas es.
Otherwise, it may cause fire or explosion.
• There is the risk of death, injury, fire or explo-
sion.

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Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
nOperation
Safety Precautions
Do not damage or use an unspecified power cord.
• There is risk of fire, electric shock, explosion, or
injury.
Use a dedicated outlet for this appliance.
• There is risk of fire or electrical shock.
Be cautious that water could not enter the product.
• There is risk of fire, electric shock, or product
damage.
Do not touch the power switch with wet hands.
• There is risk of fire, electric shock, explosion, or
injury.
When the product is soaked (flooded or
submerged), contact an Authorized Service
Center.
• There is risk of fire or electric shock.
Be cautious not to touch the sharp edges
when installing.
• It may cause injury.
Take care to ensure that nobody could step
on or fall onto the outdoor unit.
• This could result in personal injury and product
damage.
Do not open the inlet grille of the product
during operation. (Do not touch the electro-
static filter, if the unit is so equipped.)
• There is risk of physical injury, electric shock, or
product failure.
CAUTION
nInstallation
Always check for gas (refrigerant) leakage
after installation or repair of product.
• Low refrigerant levels may cause failure of
product.
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.
Keep level even when installing the product.
• To avoid vibration or water leakage.
Do not install the unit where combustible gas
may leak.
• If the gas leaks and
accumulates around the
unit, an explosion may
result.

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Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Safety Precautions
Use power cables of sufficient current
carrying capacity and rating.
• Cables that are too small may leak, generate
heat, and cause a fire.
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.
• There is risk of damage or loss of property.
Keep the unit away from children. The heat
exchanger is very sharp.
• It can cause the injury, such as cutting the finger.
Also the damaged fin may result in degradation
of capacity.
When installting the unit in a hospital, com-
munication station, or similar place, provide
sufficient protection against noise.
•
The inverter equipment, private power generator,
high-frequency medical equipment, or radio com-
munication equipment may cause the air condition-
er to operate erroneously, or fail to operate. On the
other hand, the air conditioner may affect such
equipment by creating noise that disturbs medical
treatment or image broadcasting.
Do not install the product where it is exposed to sea wind (salt spray) directly.
• It may cause corrosion on the product. Corrosion, particularly on the condenser and evaporator fins,
could cause product malfunction or inefficient operation.
nOperation
Do not use the air conditioner in special
environments.
• Oil, steam, sulfuric smoke, etc. can significantly
reduce the performance of the air conditioner or
damage its parts.
Do not block the inlet or outlet.
• It may cause failure of appliance or accident.
Make the connections securely so that the
outside force of the cable may not be applied
to the terminals.
• Inadequate connection and fastening may gen-
erate heat and cause a fire.
Be sure the installation area does not deteri-
orate with age.
• If the base collapses, the air conditioner could
fall with it, causing property damage, product
failure, or personal injury.

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Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Safety Precautions
Install and insulate the drain hose to ensure
that water is drained away properly based on
the installation manual.
• A bad connection may cause water leakage.
Be very careful about product transportation.
• Only one person should not carry the product if it weighs
more than 20 kg.
• Some products use PP bands for packaging. Do not use any
PP bands for a means of transportation. It is dangerous.
• Do not touch the heat exchanger fins. Doing so may cut
your fingers.
• When transporting the outdoor unit, suspending it at the
specified positions on the unit base. Also support the out-
door unit at four points so that it cannot slip sideways.
Safely dispose of the packing materials.
•
Packing materials, such as nails and other metal or
wooden parts, may cause stabs or other injuries.
• Tear apart and throw away plastic packaging bags
so that children may not play with them. If children
play with a plastic bag which was not torn apart,
they face the risk of suffocation.
Turn on the power at least 6 hours before
starting operation.
• Starting operation immediately after turning on
the main power switch can result in severe
damage to internal parts. Keep the power switch
turned on during the operational season.
Do not touch any of the refrigerant piping
during and after operation.
• It can cause a burn or frostbite.
Do not operate the air conditioner with the
panels or guards removed.
• Rotating, hot, or high-voltage
parts can cause injuries.
Do not directly turn off the main power
switch after stopping operation.
• Wait at least 5 minutes before turning off the
main power switch. Otherwise it may result in
water leakage or other problems.
Auto-addressing should be done in condition of
connecting the power of all indoor and outdoour
units. Auto-addressing should also be done in
case of changing the indoor unit PCB.
Use a firm stool or ladder when cleaning or
maintaining the air conditioner.
• Be careful and avoid personal injury.
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.

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Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Part 1
General Information
1. Model Names ..................................................................9
1.1 Indoor Unit ...............................................................9
1.2 Outdoor Unit ............................................................9
2. External Appearance .....................................................11
2.1 Indoor Unit .............................................................11
2.2 Outdoor Unit ..........................................................12
3. Combination of Outdoor Units .....................................13
4. Nomenclature.................................................................14
4.1 Indoor Unit .............................................................14
4.2 Outdoor Unit ..........................................................14

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Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
1. Model Names
1.1 Indoor Unit
Model Names
hIn matters of combination with Outdoor unit system, refer the PDB of that outdoor units.
h*
ART COOL- SE/S8( * R:Mirror, V:Silver), SF(* E:Red, V:Silver, G:Gold , 1: Kiss (Photo changeable))
*Wall Mounted- A: Basic, L:Plasma, *Ceiling Cassette- A: Basic, C:Plasma
Category
Chassis
Name
Capacity(Btu/h(kW))
5k
(1.6)
7k
(2.2)
9k
(2.8)
12k
(3.6)
15k
(4.5)
18k
(5.6)
21k
(6.2)
24k
(7.1)
28k
(8.2)
36k
(10.6)
42k
(12.3)
48k
(14.1)
54k
(15.8)
76k
(22.4)
96k
(28.0)
Wall
Mounted
General S5 O O
Libero SB OOOO
SC O O
ART COOL Mirror SE OOOO S8 O O
Gallery SF O O O
Ceiling
Cassette
1 Way TU OOO
TT O O
2 Way TL O O
4 Way
TR OOOO
TQ O O
TP O O
TN O
TM OO
Ceiling
Concealed
Duct
High Static
BH OOOOO O
BG OOO
BR OO
B8 OO
Low Static
L1 OOO
L2 OOO
L3 O O
Built In
(Low Static)
B3 OOOO
B4 O O
Ceiling & Floor VE O O
Ceiling Suspended
VJ O O
VK O
VL O
Floor
Standing
With Case CE OOOO
CF O O
Without
Case
CE OOOO
CF O O
Console QA OOOO
Fresh Air Intake Unit BR O
B8 OO

Model Names
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Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
1.2 Outdoor Unit
Heat Pump ARUN
Power Supply 8HP 10HP 12HP 14HP 16HP 18HP 20HP 22HP
3Ø, 380 ~ 415V, 50Hz
3Ø, 380V, 60Hz
080LTE4
080LTS4
100LTE4
100LTS4
120LTE4
120LTS4
140LTE4
140LTS4
160LTE4
160LTE4
180LTE4
180LTS4
200LTE4
200LTS4
220LTE4
220LTS4
Power Supply 24HP 26HP 28HP 30HP 32HP 34HP 36HP 38HP
3Ø, 380 ~ 415V, 50Hz
3Ø, 380V, 60Hz
240LTE4
240LTS4
260LTE4
260LTS4
280LTE4
280LTS4
300LTE4
300LTE4
320LTE4
320LTS4
340LTE4
340LTE4
360LTE4
360LTS4
380LTE4
380LTS4
Power Supply 40HP 42HP 44HP 46HP 48HP 50HP 52HP 54HP
3Ø, 380 ~ 415V, 50Hz
3Ø, 380V, 60Hz
400LTE4
400LTS4
420LTE4
420LTS4
440LTE4
440LTS4
460LTE4
460LTS4
480LTE4
480LTS4
500LTE4
500LTS4
520LTE4
520LTS4
540LTE4
540LTS4
Power Supply 56HP 58HP 60HP 62HP 64HP 66HP 68HP 70HP
3Ø, 380 ~ 415V, 50Hz
3Ø, 380V, 60Hz
560LTE4
560LTS4
580LTE4
580LTS4
600LTE4
600LTS4
620LTE4
620LTS4
640LTE4
640LTS4
660LTE4
660LTS4
680LTE4
680LTS4
700LTE4
700LTS4
Power Supply 72HP 74HP 76HP 78HP 80HP
3Ø, 380 ~ 415V, 50Hz
3Ø, 380V, 60Hz
720LTE4
720LTS4
740LTE4
740LTS4
760LTE4
760LTS4
780LTE4
780LTS4
800LTE4
800LTS4

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Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
External Appearance
2. External Appearance
2.1 Indoor Unit
hIn matters of combination with Outdoor unit system, refer the PDB of that outdoor units.
Wall mounted (Libero)
ART COOL Mirror
Ceiling Cassette- 1Way
Ceiling Cassette- 4Way
Ceiling & Floor
Ceiling Suspended
ARNU07GTU*2
ARNU09GTU*2
ARNU12GTU*2
ARNU05GTR*2
ARNU07GTR*2
ARNU09GTR*2
ARNU12GTR*2
ARNU15GTQ*2
ARNU18GTQ*2
ARNU24GTP*2
ARNU28GTP*2
ARNU36GTN*2
ARNU42GTM*2
ARNU48GTM*2
Ceiling Concealed Duct - Low Static
ARNU05GL1G2
ARNU07GL1G2
ARNU09GL1G2
ARNU12GL2G2
ARNU15GL2G2
ARNU18GL2G2
ARNU21GL3G2
ARNU24GL3G2
ARNU07GSB*2
ARNU09GSB*2
ARNU12GSB*2
ARNU15GSB*2
ARNU18GSC*2
ARNU24GSC*2
ARNU07GSE*2
ARNU09GSE*2
ARNU12GSE*2
ARNU15GSE*2
ARNU18GS8*2
ARNU24GS8*2
ARNU09GVEA2
ARNU12GVEA2
URNU18GVJA2
URNU24GVJA2
URNU36GVKA2
URNU48GVLA2
Console
ARNU07GQAA2
ARNU09GQAA2
ARNU12GQAA2
ARNU15GQAA2
Floor Standing
With case
ARNU07GCEA2
ARNU09GCEA2
ARNU12GCEA2
ARNU15GCEA2
ARNU18GCFA2
ARNU24GCFA2
Without case
ARNU07GCEU2
ARNU09GCEU2
ARNU12GCEU2
ARNU15GCEU2
ARNU18GCFU2
ARNU24GCFU2
Ceiling Concealed Duct - High Static
ARNU07GBHA2
ARNU09GBHA2
ARNU12GBHA2
ARNU15GBHA2
ARNU18GBHA2
ARNU24GBHA2
ARNU28GBGA2
ARNU36GBGA2
ARNU42GBGA2
ARNU48GBRA2
ARNU54GBRA2
ARNU76GB8A2
ARNU96GB8A2
Ceiling Concealed Duct – Built-in (Low Static)
ARNU07GB3G2
ARNU09GB3G2
ARNU12GB3G2
ARNU15GB3G2
ARNU18GB4G2
ARNU24GB4G2
* A:Basic, L:Plasma
ART COOL Gallery
ARNU07GSF*2
ARNU09GSF*2
ARNU12GSF*2
* E:Red V:Silver
G:Gold 1: Kiss (Photo changeable)
* A:Basic, C:Plasma
* R:Mirror, V:Silver
ARNU18GTT*2
ARNU24GTT*2 * A:Basic, C:Plasma
Ceiling Cassette -2Way
ARNU18GTL*2
ARNU24GTL*2
* A:Basic, C:Plasma
Fresh Air Intake Unit
ARNU48GBRZ2
ARNU76GB8Z2
ARNU96GB8Z2

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Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
External Appearance
2.2 Outdoor Unit
2.2.1 Heat Pump
CHASSIS Model Name Model
UX2
ARUN080LTE4/LTS4
ARUN100LTE4/LTS4
ARUN120LTE4/LTS4
UX3
ARUN140LTE4/LTS4
ARUN160LTE4/LTS4
ARUN180LTE4/LTS4
ARUN200LTE4/LTS4
UX2
UX2
ARUN220LTE4/LTS4
ARUN240LTE4/LTS4
UX3
UX2
ARUN260LTE4/LTS4
ARUN280LTE4/LTS4
ARUN300LTE4/LTS4
ARUN320LTE4/LTS4
UX3
UX3
ARUN360LTE4/LTS4
ARUN380LTE4/LTS4
ARUN340LTE4/LTS4
ARUN400LTE4/LTS4
UX3
UX3
UX2
ARUN420LTE4/LTS4
ARUN440LTE4/LTS4
ARUN460LTE4/LTS4
ARUN480LTE4/LTS4
ARUN500LTE4/LTS4
ARUN520LTE4/LTS4
UX3
UX3
UX3
ARUN540LTE4/LTS4
ARUN560LTE4/LTS4
ARUN580LTE4/LTS4
ARUN600LTE4/LTS4
UX3
UX3
UX3
UX3
ARUN620LTE4/LTS4 ARUN720LTE4/LTS4
ARUN640LTE4/LTS4 ARUN740LTE4/LTS4
ARUN660LTE4/LTS4 ARUN760LTE4/LTS4
ARUN680LTE4/LTS4 ARUN780LTE4/LTS4
ARUN700LTE4/LTS4 ARUN800LTE4/LTS4

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Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Combination of Outdoor Units
3. Combination of Outdoor Units
3.1 Heat Pump
Model Name
Number
of Units
Module(HP)
8 101214161820
ARUN080LTE4/LTS4 1 1
ARUN100LTE4/LTS4 1 1
ARUN120LTE4/LTS4 1 1
ARUN140LTE4/LTS4 1 1
ARUN160LTE4/LTS4 1 1
ARUN180LTE4/LTS4 1 1
ARUN200LTE4/LTS4 1 1
ARUN220LTE4/LTS4 2 1 1
ARUN240LTE4/LTS4 2 2
ARUN260LTE4/LTS4 2 1 1
ARUN280LTE4/LTS4 2 1 1
ARUN300LTE4/LTS4 2 1 1
ARUN320LTE4/LTS4 2 1 1
ARUN340LTE4/LTS4 2 11
ARUN360LTE4/LTS4 2 11
ARUN380LTE4/LTS4 2 11
ARUN400LTE4/LTS4 2 2
ARUN420LTE4/LTS4 3 1 1 1
ARUN440LTE4/LTS4 3 1 1 1
ARUN460LTE4/LTS4 3 1 1 1
ARUN480LTE4/LTS4 3 1 11
ARUN500LTE4/LTS4 3 1 2
ARUN520LTE4/LTS4 3 1 2
ARUN540LTE4/LTS4 3 12
ARUN560LTE4/LTS4 3 12
ARUN580LTE4/LTS4 3 12
ARUN600LTE4/LTS4 3 3
ARUN620LTE4/LTS4 4 211
ARUN640LTE4/LTS4 4 22
ARUN660LTE4/LTS4 4 112
ARUN680LTE4/LTS4 4 22
ARUN700LTE4/LTS4 4 11 2
ARUN720LTE4/LTS4 4 112
ARUN740LTE4/LTS4 4 112
ARUN760LTE4/LTS4 4 22
ARUN780LTE4/LTS4 4 13
ARUN800LTE4/LTS4 4 4

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Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Nomenclature
4. Nomenclature
4.1 Indoor Unit
4.2 Outdoor Unit
ARN U G07 ATR 2
Serial Number
Chassis Name
Electrical Ratings
1:1Ø, 115V, 60Hz 2: 1Ø, 220V, 60Hz
6:1Ø, 220 ~ 240V, 50Hz 7: 1Ø, 100V, 50/60Hz
G:1Ø, 220 ~ 240V, 50Hz / 220V 60Hz
Total Cooling Capacity in Btu/h
EX) 5,000 Btu/h →'05' 18,000 Btu/h → '18'
Combination of Inverter Type and
Cooling Only or Heat Pump
U: DC Inverter and H/P and C/O
System with
Indoor Unit using R410A
Combinations of functions
A:Basic function
L:Neo Plasma(Wall Mounted)
C:Plasma(Ceiling Cassette)
G: Low Static
ART COOL Type Panel Color
R:Mirror V:Silver B:Blue
V: Silver E:Red G:Gold 1:Kiss X: DX-Coil
ARU N L E200 T4
Serial Number
Primary. Main Fuction
S : Standard
E : High Efficiency
Secondary. Usage Embient
H : High Ambient
C : Cold Area
R : Anti-Corosion
Electrical Ratings
Air Discharge Type
S: Side Discharge
T: Top Discharge
N: Top Discharge Standard H/P(380V)
8: 3Ø, 380 ~ 415V, 50Hz 9: 3Ø, 380V, 60Hz
A: 3Ø, 220V, 50Hz B: 3Ø, 220V, 60Hz
L: 3Ø, 380 ~ 415V, 50Hz / 3Ø, 380V, 60Hz
Total Cooling Capacity in Horse Power(HP) unit
EX) 10HP → '100'
Combination of Inverter Type and
Cooling Only or Heat Pump
N: Inverter and H/P V: Inverter and C/O
System with
Outdoor Unit using R410A
※ Heat recovery ventilator refer to the DX-Coil manual

- 15 -
Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Part 2
Outdoor Units

- 16 -
Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
• Function ........................................................................................17
ARUN Series

- 17 -
Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Function
1. Basic control ...................................................................................................................18
1.1 Normal operation .......................................................................................................18
1.2 Compressor control....................................................................................................18
1.3 Master and slave unit's EEV control ..........................................................................19
2. Special control ................................................................................................................20
2.1 Oil return control ........................................................................................................20
2.2 Defrost control............................................................................................................22
2.3 Partial Defrost ............................................................................................................23
2.4 Stop operation............................................................................................................24
2.5 Oil equalizing control..................................................................................................24
3. Protection control ...........................................................................................................25
3.1 Pressure protection control ........................................................................................25
3.2 Discharge temperature control...................................................................................26
3.3 Inverter protection control ..........................................................................................26
3.4 Phase detection .........................................................................................................27
3.5 Pressure switch..........................................................................................................27
4. Other control ...................................................................................................................28
4.1 Initial setup.................................................................................................................28
4.2 Emergency operation.................................................................................................30
4.3 Refrigerant Auto Charging ........................................................................................32
4.4 Pump Out...................................................................................................................33
4.5 Refrigerant amount automatic judgment....................................................................34
4.6 ITR(Cooling)...............................................................................................................35
4.7 ITR(Heating) ..............................................................................................................36
4.8 FDD Code ..................................................................................................................38
4.9 Multi V ITR result report .............................................................................................39
4.10 Pump Down .............................................................................................................40
4.11 Pump Out .................................................................................................................42
4.12 Auto Back Up Function_Inverter compressor ..........................................................44
4.13 Night Low Noise Function ........................................................................................45
4.14 Vacuum Mode ..........................................................................................................46
4.15 Static pressure compensation mode........................................................................46
4.16 Cool & Heat selector ................................................................................................47
Function

- 18 -
Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Note : Heating operation is not functional at an outdoor air temperature of 27°C or more.
Cooling operation is not functional at an outdoor air temperature of 2°C or less with indoor unit combina-
tion of 10% or less
*: The main EEV of ARUN***LTS4 is controlled in the same way with Low EEV. (ARUN***LTS4 have only 1
Main EEV.)
1.2 Compressor control
Fuzzy control : Maintain evaporating temperature(Te) to be constant on cooling mode and condensing
temperature(Tc) on heating mode by Fuzzy control to ensure the stable system performance.
(Tc:47 ~51°C, Te:2 ~ 5°C)
(1) Cooling mode
Te can be set various step at installation mode.
(2) Heating mode
Tc can be set various step at installation mode.
Note: By setting dip switch, Te and Tc are decided simultaneously.
1.1 Normal operation
1. Basic control
Compressor
Fan
Main EEV
Subcooling
Indoor Unit
EEV
EEV
Fuzzy control
Fuzzy control
Upper : Min. pulse
*Low : Full open
Fuzzy control
Superheat fuzzy
control
• Normal : Vapor injection
• Avoiding control of high
discharge temperature
Subcooling fuzzy control
Fuzzy control
Fuzzy control
Fuzzy control
Cooling operation Heating operationActuator
stop
stop
Stop state
Min. pulse
Min. pulse
Min. pulse
Fuzzy Control
Stop(0Hz)
Min. frequency
Fuzzy control start
Target
Inverter linear control as cooling and heating load increasing
System Capacity
Cooling and heating load
(Linear Control)
(Linear Control)
(Linear Control)
Inverter
Comp 2
Inverter
Comp 1
Inverter
Comp 2
Inverter
Comp 3
Inverter
Comp 1
Inverter
Comp 2
Inverter
Comp 3
Inverter
Comp 4
Inverter
Comp 1
Function

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Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
1.3 Master and slave Unit's EEV control
(1) Main EEV control
Main EEV operates with fuzzy control rules to keep the degree of super Heat(Superheat) (about 3°C)at
the evaporator outlet stable during heating mode
The degree of Superheat = Tsuction - Tevaporation
Tsuction : temperature at suction pipe sensor(°C)
Tevaporation : evaporation temperature equivalent to low pressure(°C)
(2) Subcooling EEV control(about 15°C)
Subcooling EEV works with fuzzy rules to keep the degree of Subcool at the outlet of subcooler during
cooling mode
The degree of Subcool = Tcondensation - Tliquid
Tliquid : temperature at outlet of subcooler(°C)
Tcondensation : condensation temperature equivalent to high pressure(°C)
(3) Avoiding excessive high discharge temperature : when main EEV opens some given opening (R410A :
800 pls) and discharge temperature is above 85°C in heating operation, subcooling EEV may control
the "subcooling out temperature-evaporating temperature" to be some given difference.
(4) Vapor injection flow-rate control at heating mode
The degree of Superheat (VI_SH) = Subcooler out(℃) – Subcooler in(℃)
- Td ≤ 80℃ : VI_SH = 3℃
- 80℃<Td ≤ 90℃ : VI_SH = -2*Td/10 + 19
- 90℃<Td : VI_SH = 1℃
Function

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Copyright ©2013 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
2.1 Oil return control
2.1.1 Oil return control on cooling mode
Oil return operation recovers Oil level in compressor by collecting oil accumulated in pipe.
Each cycle component operates as shown on the below table during oil return operation.
nOil return operation time : 3 min for running step
nStarting condition : When low oil level which is measured by oil level sensor is kept continuously then oil
return operation will be start.
nOil return process ends if compressor protection control starts
OFF
80 pulse
Normal control
30Hz
Ending
OFF
20 pulse
Normal control
Setting Value
Running
OFF
Min. pulse
Upper : Min. pulse
Low : Max. pulse
Upper : Min. pulse
Low : Max. pulse
Upper : Normal control
Low : Normal control
Normal control
30Hz
Starting
4way valve
Subcooling EEV
Main EEV
FAN
Inv Compressor
Component
OFF
40 pulse
Normal control
Normal control
Ending
ON
400 pulse
Normal control
OFF
Running
OFF
40 pulse
Normal control
Normal control
Starting
Oil return signal
Thermo off unit EEV
Thermo on unit EEV
Fan
Component
Outdoor Unit
Indoor Unit
2. Special control
Function