LG ARNU Series User manual

System
Indoor Unit
SERVICE MANUAL R410A
MODEL : ARNU Series
URNU Series
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

- 2 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Air Conditioner Service Manual
TABLE OF CONTENTS
Part 1 General Information .......................................................................................................3
Model Names ...............................................................................................................................4
External Appearance ...................................................................................................................5
Nomenclature ...............................................................................................................................6
Part 2 Indoor Units ......................................................................................................................7
Ceiling Mounted Cassette Type (1 way) ........................................................................................8
Ceiling Mounted Cassette Type (2 way) ......................................................................................16
Ceiling Mounted Cassette Type (4 way)(1)..................................................................................21
Ceiling Mounted Cassette Type (4 way)(2)..................................................................................27
Art Cool Type(Mirror) ...................................................................................................................34
Art Cool Type(Gallery) .................................................................................................................45
Ceiling Concealed Duct Type (Low static) ...................................................................................55
Ceiling Concealed Duct Type (Built in) ........................................................................................61
Ceiling Concealed Duct Type (High static) ..................................................................................67
Wall Mounted Type ......................................................................................................................76
Ceiling & Floor Ceiling Suspended ..............................................................................................87
Floor Standing Type.....................................................................................................................94
Vertical Air Handling Unit ...........................................................................................................101
Part 3 Trouble shooting guide...............................................................................109

- 3 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Part 1
General Information
1. Model Names .............................................4
2. External Appearance .................................5
3. Nomenclature .............................................6

Model Names
- 4 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
1. Model Names
h* ART COOL- SE/S8( * R:Mirror, V:Silver, B : Blue), 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))
7.5
(2.2)
9.6
(2.8)
12.3
(3.6)
15.4
(4.5)
19.1
(5.6)
24.2
(7.1)
28.0
(8.2)
30.0
(8.8)
36.2
(10.6)
42.0
(12.3)
48.1
(14.1)
54.0
(15.8)
76.4
(22.4)
95.5
(28.0)
Wall Mounted
(General)
SE
ARNU07
3SE*2 ARNU09 3SE*2 ARNU12 3SE*2 ARNU15 3SE*2
S5
ARNU18
3S5*2 ARNU24 3S5*2
ART
COOL Mirror
SE
ARNU07
3SE*2 ARNU09 3SE*2 ARNU12 3SE*2 ARNU15 3SE*2
S8
ARNU18
3S8*2 ARNU24 3S8*2
Ceiling
Cassette
1 Way TJ
ARNU07
3TJ*2 ARNU09 3TJ*2 ARNU12 3TJ*2
2 Way TL
ARNU18
3TL*2 ARNU24 3TL*2
4 Way
TR
ARNU07
3TR*2 ARNU09 3TR*2 ARNU12 3TR*2
TQ
ARNU15
3TQ*2 ARNU18 3TQ*2
TP
ARNU24
3TP*2 ARNU28 3TP*2
TN
ARNU36
3TN*2
TM
ARNU42
3TM*2 ARNU48 3TM*2
Ceiling
Concealed
Duct
High Static
BH
ARNU07
3BHA2 ARNU09 3BHA2 ARNU12 3BHA2 ARNU15 3BHA2 ARNU18 3BHA2 ARNU24 3BHA2
BG
ARNU28
3BGA2 ARNU36 3BGA2 ARNU42 3BGA2
BR
ARNU483
BRA2
B8
URNU76
3B8A2 URNU96 3B8A2
Low Static
B1
ARNU07
3B1G2 ARNU09 3B1G2 ARNU12 3B1G2 ARNU15 3B1G2
B2
ARNU18
3B2G2 ARNU24 3B2G2
Built In
B3
ARNU07
3B3G2 ARNU09 3B3G2 ARNU12 3B3G2 ARNU15 3B3G2
B4
ARNU18
3B4G2 ARNU24 3B4G2
Ceiling & Floor VE
ARNU09
3VEA2 ARNU12 3VEA2
Ceiling Suspended VJ
ARNU18
3VJA2
Floor
Standing
With Case
CE
ARNU07
3CEA2 ARNU09 3CEA2 ARNU12 3CEA2 ARNU15 3CEA2
CF
ARNU18
3CFA2 ARNU24 3CFA2
Without
Case
CE
ARNU07
3CEU2 ARNU09 3CEU2 ARNU12 3CEU2 ARNU15 3CEU2
CF
ARNU18
3CFU2 ARNU24 3CFU2
Vertical AHU
NJ
ARNU18
3NJA2 ARNU24 3NJA2 ARNU30 3NJA2 ARNU36 3NJA2
NK
ARNU42
3NKA2 ARNU48 3NKA2 ARNU54 3NKA2

External Appearance
- 5 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
2. External Appearance
Wall Mounted
ART COOL Mirror
Ceiling Cassette- 1Way
Ceiling Cassette- 4Way
Ceiling & Floor
Ceiling Suspended
ARNU073TJ*2
ARNU093TJ*2
ARNU123TJ*2
Ceiling Cassette -2Way
ARNU183TL*2
ARNU243TL*2
ARNU073TR*2
ARNU093TR*2
ARNU123TR*2
ARNU153TQ*2
ARNU183TQ*2
ARNU243TP*2
ARNU283TP*2
ARNU363TN*2
ARNU423TM*2
ARNU483TM*2
Ceiling Concealed Duct - Low Static
ARNU073B1G2
ARNU093B1G2
ARNU123B1G2
ARNU153B1G2
ARNU183B2G2
ARNU243B2G2
ARNU073SE*2
ARNU093SE*2
ARNU123SE*2
ARNU153SE*2
ARNU183S5*2
ARNU243S5*2
ARNU073SE*2
ARNU093SE*2
ARNU123SE*2
ARNU153SE*2
ARNU183S8*2
ARNU243S8*2
ARNU093VEA2
ARNU123VEA2
ARNU183VJA2
ARNU243VJA2
Floor Standing
With case
ARNU073CEA2
ARNU093CEA2
ARNU123CEA2
ARNU153CEA2
ARNU183CFA2
ARNU243CFA2
Without case
ARNU073CEU2
ARNU093CEU2
ARNU123CEU2
ARNU153CEU2
ARNU183CFU2
ARNU243CFU2
Vertical AHU
ARNU183NJA2
ARNU243NJA2
ARNU303NJA2
ARNU363NJA2
ARNU423NKA2
ARNU483NKA2
ARNU543NKA2
Ceiling Concealed Duct - High Static
ARNU073BHA2
ARNU093BHA2
ARNU123BHA2
ARNU153BHA2
ARNU183BHA2
ARNU243BHA2
ARNU283BGA2
ARNU363BGA2
ARNU423BGA2
ARNU483BRA2
URNU763B8A2
URNU963B8A2
Ceiling Concealed Duct – Built-in
ARNU073B3G2
ARNU093B3G2
ARNU123B3G2
ARNU153B3G2
ARNU183B4G2
ARNU243B4G2
* A:Basic, L:Plasma
* A:Basic, C:Plasma
* A:Basic, C:Plasma
* A:Basic, C:Plasma
* R:Mirror
V:Silver
B : Blue

Nomenclature
- 6 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
3. Nomenclature
ARN U 307 ATJ 2
Generation
Chassis Name
Electrical Ratings
1:1Ø, 115V, 60Hz 2: 1Ø, 220V, 60Hz
6:1Ø, 220 - 240V, 50Hz 7: 1Ø, 100V, 50/60Hz
3:1Ø, 208/230V, 60Hz
Total Cooling Capacity in Btu/h Class
EX) 18,000 Btu/h Class → '18'
Combination of Inverter Type and
Cooling Only or Heat Pump
N: AC Inverter and H/P V: AC Inverter and C/O
U: DC Inverter and H/P and C/O
System with
Indoor Unit using R410A
❈LGETA:U Ex) URN
Combinations of functions
A: Basic function
L: Neo Plasma(Wall Mounted)
C:Plasma(Ceiling Cassette)
G: Low Static
U: Floor Standing without Case
ART COOL Type Panel Color
B:Blue R:Mirror V: Silver

- 7 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Part 2
Indoor Units
Ceiling Cassette
1 Way.................................................................................8
2 Way...............................................................................13
4 Way(1)...........................................................................20
4 Way(2)...........................................................................23
Art Cool Series
ART COOL Miror..............................................................34
ART COOL Gallery ..........................................................45
Ceiling Concealed Duct
Low Static ........................................................................55
Built In ..............................................................................62
High Static........................................................................67
Wall Mounted(General)
Wall Mounted ...................................................................76
Ceiling & Floor
Ceiling & Floor
Ceiling Suspended...........................................................87
Floor Standing
Floor Standing..................................................................94
Vertical Air Handling Unit................................................117

- 8 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
1. Functions ......................................................................................9
2. Operation Details........................................................................10
3. Dimensions .................................................................................12
Ceiling Mounted Cassette Type (1Way)

- 9 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Functions
1. Functions
Indoor Unit
Operation ON/OFF by Remote controller
Sensing the Room Temperature
Room temperature control
Starting Current Control
Indoor Fan Speed Control
Soft Dry Operation Mode
Airflow Direction Control
Deice (defrost) control (Heating)
Auto Restart
Hot-start Control (Heating) • The indoor fan does not rotate until the evaporator pip-
ing temperature will be reached at 25°C(76°F).
Compact and light design • To install a unit is very convenient because of smaller
size than textile.
Low noise • The most advanced low-noise design.
• The adoption of turbo fan and round type heat exchang-
er give the quietest operation.
Long life filter • Long life wrinkle(type) and washable and anti-bacteria
filter is adopted.
High head Drain pump • Built-in drain pump automatically drains water.
• A standard drain-head height of up to 700mm(27-9/16inch) is
possible.
High-Ceiling corresponding Function • According to the height of ceiling, the RPM of indoor fan
motor is selected to increase air reaching distance.
Central Control(Optional) •
It is operating individually or totally by central control function.
• Room temperature sensor. (Thermistor)
•
Maintains the room temperature in accordance with the Setting Temperature.
• Indoor fan is delayed for 5 seconds at the starting.
• Jet, High, Med, Low, Lolow
• Intermittent operation of fan at low speed.
• The louver can be set at swing up and down automatically.
• Although the air-conditioner is turned off by a power failure, it is restarted auto-
matically previous operation mode after power supply.
• Both the indoor and outdoor fan stops during defrosting.
• Hot start after defrost ends.

- 10 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
2. Operation Detail
nAuto Swing Control
• This function is to swing the louver up and down automatically.
nSoft-Dry Operation
• The indoor fan speed is automatically set to the low, so the shift of the indoor fan speed is impossible because of
already being set to the best speed for Dry Operation by microcontroller control.
nCooling Mode Operation
• When selecting the Cooling( ) Mode Operation, the unit will operate according to the setting by the remote con-
troller and the operation diagram is as following
(1) The function of main control
Operation Detail
Thermal ON Thermal OFF
Indoor Unit mode ST+0.5 ST-0.5
2TH (Remo.+Indoor) To be selected higher temperature To be selected higher temperature
contrast Indoor Unit and Remo. contrast Indoor Unit and Remo.
Remo. Mode ST+0.5 ST-0.5
Intake Air Temperature
Thermo. ON
(SET TEMPERATURE
+0.5°C(33°F))
Thermo. OFF
(SET TEMPERATURE
More than More than
-0.5°C(33°F))
3 minutes 3 minutes
Selected Selected Selected
Speed Speed Speed
INDOOR FAN Low Low

- 11 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
nHeating Mode Operation
The unit will operate according to the setting by the remote controller and the operation diagram is shown as following.
nHot-start Control
•The indoor fan does no rotate until the evaporator piping temperature will be reached to 25°C(76°F).
• The operation diagram is as following.
35°C(94°F)
30°C(86°F)
27°C(80°F)
25°C(76°F)
22°C(72°F)
Pipe
temperature
OFF
Indoor fan
speed
LO
LOW
LOW SELECTED
FAN LOW LOLOW
COMP ON
Operation Detail
Thermal OFF
ON
OFF ON
ON
ON
Outdoor fan
Indoor fan
4 Way ON
Room
Temperature
Thermal Off
Thermal On
Indoor pipe
Temperature
33°C(92°F)
25°C(76°F)
20°C(68°F)
36°C(96°F)
Minimum
3min
Setting
fan
speed
Setting
fan
speed
Setting
fan
speed
Stop Low Stop StopLow LowLow Low
Thermal ON Thermal OFF
Indoor Unit mode ST+2 ST+4
2TH To be selected lower temperature To be selected lower temperature
(Remo.+Indoor) contrast Indoor Unit and Remo. contrast Indoor Unit and Remo.
Remo. mode ST+0 ST+2

- 12 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
3. Dimensions
Dimensions
76, Seongsan-dong, Changwon City, Gyeongnam,
641-713, Korea CHASSIS CODE: TU
Ceiling Cassette 1-way
ARNU07GTU*2 ARNU09GTU*2 ARNU12GTU*2
Name
1 Liquid pipe connection
Unit size(7k, 9k, 12k):ø6.35
2 Gas pipe connection
Unit size(7k, 9k, 12k):ø12.7
3 Air suction grill 4 Air discharge grill
Number Descripition
Note
1. Unit should be installed in compliance with the installation manual in the product box. 2. Unit shall be grounded in accordance with the local regulations or applicable national codes.
(unit : mm)
1,100
50034
881(Air outlet Hole)
168.3
106.8
206.6
275.8
96.5
57.4
453
27
320.5
1012
88
861
(Panel Name: PT-UUC)

Dimensions
- 13 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
76, Seongsan-dong, Changwon City, Gyeongnam,
641-713, Korea CHASSIS CODE: TU
Ceiling Cassette 1-way
ARNU07GTU*2 ARNU09GTU*2 ARNU12GTU*2
Name
1 Liquid pipe connection
Unit size(7k, 9k, 12k):ø6.35
2 Gas pipe connection
Unit size(7k, 9k, 12k):ø12.7
3 Air suction grill 4 Air discharge grill
Number Descripition
Note
1. Unit should be installed in compliance with the installation manual in the product box. 2. Unit shall be grounded in accordance with the local regulations or applicable national codes.
(unit : mm)
(Panel Name: PT-UUD)
453
46.5
57.4
34
117
96.5
168.3
106.8
206.3
275.8
109.5
861
1012
88
1100
109.5
453
320.5 27
500
354.3

- 14 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
Dimensions
76, Seongsan-dong, Changwon City, Gyeongnam,
641-713, Korea CHASSIS CODE: TT
Ceiling Cassette 1-way
ARNU18GTT*2 ARNU24GTT*2
Name
1 Liquid pipe connection
Unit size(18k):ø6.35, (24k):ø9.52
2 Gas pipe connection
Unit size(18k):ø12.7, (24k):ø15.88
3 Air suction grill 4 Air discharge grill
Number Descripition
Note
1. Unit should be installed in compliance with the installation manual in the product box. 2. Unit shall be grounded in accordance with the local regulations or applicable national codes.
(unit : mm)
20.6 65.3
180.6
247.5
453.8
57.4
91
96.1
173.8
31.7
453.8
1,420
500
34
1,201(Air Outlet Hole)
65.1
1332
1176.4
(Panel Name: PT-UTC)

Dimensions
- 15 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
76, Seongsan-dong, Changwon City, Gyeongnam,
641-713, Korea CHASSIS CODE: TT
Ceiling Cassette 1-way
ARNU18GTT*2 ARNU24GTT*2
Name
1 Liquid pipe connection
Unit size(18k):ø6.35, (24k):ø9.52
2 Gas pipe connection
Unit size(18k):ø12.7, (24k):ø15.88
3 Air suction grill 4 Air discharge grill
Number Descripition
Note
1. Unit should be installed in compliance with the installation manual in the product box. 2. Unit shall be grounded in accordance with the local regulations or applicable national codes.
(unit : mm)
(Panel Name: PT-UTD)
109.5
44
132
15.2
Ø14
57
34
500
46.5 20.6
65.3 180.6
247.5
453.8
31.7
57.4
173.8
97.1
91
109.5
1420
453.8
335 96.5
22.3
65.11176.4
1332

- 16 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
1. Functions ....................................................................................17
2. Operation Details........................................................................18
3. Dimensions .................................................................................20
Ceiling Mounted Cassette Type (2Way)

- 17 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
1. Functions
Indoor Unit
Operation ON/OFF by Remote controller
Sensing the Room Temperature
Room temperature control
Starting Current Control
Indoor Fan Speed Control
Soft Dry Operation Mode
Airflow Direction Control
Deice (defrost) control (Heating)
Auto Restart
Hot-start Control (Heating) • The indoor fan does not rotate until the evaporator pip-
ing temperature will be reached at 25°C(76°F).
Compact and light design • To install a unit is very convenient because of smaller
size than textile.
Low noise • The most advanced low-noise design.
• The adoption of turbo fan and round type heat exchang-
er give the quietest operation.
Long life filter • Long life wrinkle(type) and washable and anti-bacteria
filter is adopted.
High head Drain pump • Built-in drain pump automatically drains water.
• A standard drain-head height of up to 700mm
(27-9/16inch) is possible.
High-Ceiling corresponding Function • According to the height of ceiling, the RPM of indoor fan
motor is selected to increase air reaching distance.
Central Control(Optional) •
It is operating individually or totally by central control function.
• Room temperature sensor. (Thermistor)
•
Maintains the room temperature in accordance with the Setting Temperature.
• Indoor fan is delayed for 5 seconds at the starting.
• Jet, High, Med, Low, Lolow
• Intermittent operation of fan at low speed.
• The louver can be set at swing up and down automatically.
• Although the air-conditioner is turned off by a power failure, it is restarted auto-
matically previous operation mode after power supply.
• Both the indoor and outdoor fan stops during defrosting.
• Hot start after defrost ends.
Functions

- 18 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
2. Operation Detail
nAuto Swing Control
• This function is to swing the louver up and down automatically.
nSoft-Dry Operation
• The indoor fan speed is automatically set to the low, so the shift of the indoor fan speed is impossible because of
already being set to the best speed for Dry Operation by microcontroller control.
nCooling Mode Operation
• When selecting the Cooling( ) Mode Operation, the unit will operate according to the setting by the remote con-
troller and the operation diagram is as following
(1) The function of main control
Operation Detail
Thermal ON Thermal OFF
Indoor Unit mode ST+0.5 ST-0.5
2TH (Remo.+Indoor) To be selected higher temperature To be selected higher temperature
contrast Indoor Unit and Remo. contrast Indoor Unit and Remo.
Remo. Mode ST+0.5 ST-0.5
Intake Air Temperature
Thermo. ON
(SET TEMPERATURE
+0.5°C(33°F))
Thermo. OFF
(SET TEMPERATURE
More than More than
-0.5°C(33°F))
3 minutes 3 minutes
Selected Selected Selected
Speed Speed Speed
INDOOR FAN Low Low

- 19 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
nHeating Mode Operation
The unit will operate according to the setting by the remote controller and the operation diagram is shown as following.
nHot-start Control
•The indoor fan does no rotate until the evaporator piping temperature will be reached to 25°C(76°F).
• The operation diagram is as following.
35°C(94°F)
30°C(86°F)
27°C(80°F)
25°C(76°F)
22°C(72°F)
Pipe
temperature
OFF
Indoor fan
speed
LO
LOW
LOW SELECTED
FAN LOW LOLOW
COMP ON
Operation Detail
Thermal OFF
ON
OFF ON
ON
ON
Outdoor fan
Indoor fan
4 Way ON
Room
Temperature
Thermal Off
Thermal On
Indoor pipe
Temperature
33°C(92°F)
25°C(76°F)
20°C(68°F)
36°C(96°F)
Minimum
3min
Setting
fan
speed
Setting
fan
speed
Setting
fan
speed
Stop Low
Stop StopLow LowLow Low
Thermal ON Thermal OFF
Indoor Unit mode ST+2 ST+4
2TH To be selected lower temperature To be selected lower temperature
(Remo.+Indoor) contrast Indoor Unit and Remo. contrast Indoor Unit and Remo.
Remo. mode ST+0 ST+2

- 20 -
Copyright ©2010 LG Electronics. Inc. All right reserved.
Only for training and service purposes LGE Internal Use Only
3. Dimensions
Dimensions
830(32-11/16)
A
B
47.9(1-7/8)
275(10-13/16)
550(21-11/16)
69.5(2-3/4)
889.2(35)
1050(41-5/16)
640(25-3/16)
28.5(1-1/8)
4
2
1
3
TL
A
B
225(8-7/8)
126.5(5)
76, Seongsan-dong, Changwon City, Gyeongnam,
641-713, Korea www.lgeaircon.com
CHASSIS CODE: TL
Ceiling Cassette 2-way
ARNU183TL*2 ARNU243TL*2
Name
1
Liquid pipe connection
(18k) ø6.35(1/4), (24k)ø9.52(3/8)
2
Gas pipe connection
(18k) ø12.7(1/2), (24k)ø15.88(5/8)
3
Air suction grill
4
Air discharge grill
Number Descripition
Note
1. Unit should be installed in compliance with the installation manual in the product box. 2. Unit shall be grounded in accordance with the local regulations or applicable national codes.
[Unit : mm(inch)]
LG Electronics USA, HVAC Division 1000 Sylvan Avenue, Englewood Cliffs, NJ 07632 www.lgusa.com / www.lghvac.com