LG AMNH076LQL0 User manual

LG
Multi Type Air Conditioner
SERVICE MANUAL
LG
CAUTION
website http://www.lgservice.com
e-mail http://lgservice.com/techsup.html
• BEFORE SERVICING THE UNIT, READ THE SAFETY
PRECAUTIONS IN THIS MANUAL.
• ONLY FOR AUTHORIZED SERVICE PERSONNEL.
MODEL
• Indoor Unit:
AMNH076LQL0
AMNH096LQL0
AMNH096LRL0
AMNH126LRL0
AMNH186LTL0
AMNH246LTL0
AMNH096AP*1
AMNH126AP*1
AMNH076DZ*0
AMNH096DU*0
AMNH126DU*0
• Outdoor Unit: A2UW146FA0
A2UW146FA1
A2UW186FA0
A3UW186FA0
A3UW246FA0
A4UW246FA0
A4UW306FA0
A6UW406FA0
Room Type
Art Cool Type
Art Cool Deluxe Type
Duct Type 1 Way CST
AMNH096BTG0
AMNH126BTG0
AMNH186BTG0
AMNH096BPA0
AMNH126BPA0
AMNH186BHA0
AMNH246BHA0
AMNH306BGA0
AMNH366BGA0
AMNH096TCC0
AMNH126TCC0
4 Way CST
AMNH126TEC0
AMNH186TEC0
AMNH246TFC0
AMNH306TFC0
AMNH366TDC0
CVT
AMNH096VEA0
AMNH126VEA0
AMNH186VBA0
AMNH246VBA0

Service Manual 159
2. A3UW246FA0, A4UW246FA0
Drier
Th1
Th2
Th3
Solenoid
Valve(1)
LEV-A
LEV-B
LEV-C
Header
Room C
LEV-D
Room D
Room A
Field Pi ing
Liquid Room B
Room C
Room D
Room A
Room B
Field Pi ing
4 room model 4 room model
Gas
Accumulator
Constant
Com ressor
Low Pressure
S/W
Inverter
Com ressor
Solenoid
Valve(2)
Heat
Exchanger
Check
Valve(2)
Check
Valve(1)
Reversing
Valve
Oil
Se erator
OUTDOOR UNIT
Refrigerant Flow
Cooling
Heating
Troubleshooting Guide

160 Multi type Air Conditioner
3. A4UW306FA0
Drier
Th1
Th2
Th3
LEV-A
LEV-B
LEV-C
LEV-D
Header
Room C
Room A
Field Pi ing
Gas Room B
Room D
Room C
Room A
Room B
Room D
Field Pi ing
Liquid
Accumulator
Low Pressure
S/W
Constant
Com ressor Inverter
Com ressor
Solenoid
Valve(1)
Solenoid
Valve(2)
Heat
Exchanger
Reversing
Valve
Check
Valve(2)
Check
Valve(1)
OUTDOOR UNIT
Oil
Se erator
Refrigerant Flow
Cooling
Heating
Troubleshooting Guide

Service Manual 161
4. A6UW406FA0
Drier
Th1Th2
Th3
L.E.V.
Check Valve(1 )
Check Valve(2 )Oil
Seperator
Low Pressure S/W
Receiver
Solenoid Valve(1)
Constant Compressor Inverter
Compressor
Accumulator
Heat Exchanger
Reversing Valve
OUTDOOR UNIT
Field Piping Gas(Ø19.05) Field Piping Liquid (Ø9.52)
Refrigerant Flow
Cooling Heating
Troubleshooting Guide

162 Multi type Air Conditioner
5. BD Unit
Main Gas Piping ( Ø15.88)
Refrigerant Flow
[Indoor Unit]
D Liquid(Ø6.35)
C Liquid(Ø6.35)
B Liquid(Ø6.35)
A Liquid(Ø6.35)
D Liquid(Ø9.52)
C Liquid(Ø9.52 or Ø12.7)
B Liquid(Ø9.52 or Ø12.7)
A Liquid(Ø9.52 or Ø12.7)
Cooling Heating
Main Liquid
Piping ( Ø9.52)
Outdoor Unit
LEV-D LEV-C LEV-B LEV-A
Troubleshooting Guide

Service Manual 163
■Error Indicator
•The function is to self-diagnoisis airconditioner and express the troubles identifically if there is any trouble.
•Error mark is ON/OFF for the operation LED of evaporator body in the same manner as the following table.
•If more than two troubles occur simultaneously, primarily the highest trouble fo error code is expressed.
•After error occurrence, if error is released, error LED is also released simultaneously.
•To operate again on the occurrence of error code, be sure to turn off the power and then turn on.
•Having or not of error code is different from Model.
Troubleshooting Guide
Self-diagnosis Function
Indoor Error
Error code Description INV TPS LED 1
(Red) LED 2 (Green) Indoor Status
00 No Error ON
01 Indoor Room themistor error 1time OFF
02 Indoor in-piping sensor error 2times OFF
03 Remote controller error 3times OFF
04 Drain Pump error 4times OFF
05 Communcation error between in and out 5times OFF
06 Indoor Out-Piping sensor error 6times OFF
07 Differnt mode operation 7times OFF
Outdoor Error
Error Code Description INV TPS LED 1
(Red) LED 2 (Green) Indoor Status
21 DC Peak (IPM Fault) 2times 1time OFF
22 CT 2(Max CT) 2times 2times OFF
23 DC Link Low Volt. 2times 3times OFF
24 L_P/Heater Sink 2times 4times OFF
25 Low voltage / Over voltage 2times 5times OFF
26 DC Comp Position Error 2times 6times OFF
27 PSC Fault Error 2times 7times OFF
28 DC Link High Volt 2times 8times OFF
32 D-Pipe High (INV) 3times 2times OFF
33 D-Pipe High (Normal) 3times 3times OFF
40 CT Sensor (Open/Short) 4times OOFF
41 INV. D-PipeTh Error(Open/Short) 4times 1time OFF
44 Outdoor air Th Error(Open/Short) 4times 4times OFF
45 Cond. Pipe Th Error(Open/Short) 4times 5times OFF
46 Suction Pipe Error(Open/Short) 4times 6times OFF
47 Const D-pipe Th Error(Open/Short) 4times 7times OFF
51 Capacity over 5times 1time OFF
53 Signal error (Indoor ↔Outdoor) 5times 3times OFF
60 EEPROM Check Sum Error 6times OOFF
61 Cond. Pipe High 6times 1time OFF
62 Heatsink High 6times 2times OFF
63 Cond. Pipe Low 6times 3times OFF
65 Heatsoml Th error (Open/Short) 6times 5times OFF

164 Multi type Air Conditioner
Troubleshooting Guide
Trouble analysis
1. Check temperature difference between intake and discharge air, and operating current.
All amount of refrigerant leaked out.
Check refrigeration cycle.
Refrigerant leakage
Clog of refrigeration cycle
Defective compressor
Excessive amount of refrigerant
Normal
Notice:
Temperature difference between intake and discharge air depends on room air humidity. When the room air
humidity is relatively higher, temperature difference is smaller. When the room air humidity is relatively lower
temperature difference is larger.
2. Check temperature and pressure of refrigeration cycle.
Notice:
1. The suction pressure is usually 4.5~6.0 kg/cm2G at normal condition.
2. The temperature can be measured by attaching the thermometer to the low pressure tubing and wrap it with
putty.
Temp. difference : approx. 0°C
Current : less than 80% of
rated current
Temp. difference : approx. 8°C
Current : less than 80% of
rated current
Temp. difference : less than 8°C
Current : near the rated
current
Temp. difference : over 8°C
Temp. Difference
Operating Current
Suction pressure Temperature
(Compared with (Compared with Cause of Trouble Description
the normal value) the normal value)
High Defective compressor Current is low.
Normal Excessive amount of High pressure does not quickly
refrigerant rise at the beginning of operation.
Insufficient amount of Current is low.
Lower Higher refrigerant(Leakage)
Clogging
Higher
Cycle Troubleshooting Guide

Service Manual 165
Troubleshooting Guide
Electronic Parts Troubleshooting Guide
❇Refer to electronic contorol device drawing & schematic diagram.
1. A2UW146FA0, A2UW146FA1, A2UW186FA0, A3UW186FA0
The Product doesn’t operate at all.
Turn off the main power and wait until LED on outdoor PCB is off.
Turn on the main power again.
Does "Beeping" sound is made from the indoor unit?
• Primarily, the operating condi-
tion of Micom is O.K.
• Check CN-DISP1
Check the voltage of power(AC220V/AC240V, 50Hz).
• The voltage of main power.
• The voltage applied to the unit.
• The connecting method of Indoor/Outdoor connecting cable (each color)
• The P.W.B. Ass'y
(Fuse, Noise Filter, Power Transformer, IC01D, IC02D, etc.)
Trouble 1
NO YES
The operation check of the P.C.B. Ass'y
Procedure
1) The input voltage of power trans-
former.
2) The output voltage of power
transformer.
3) IC01D(7812)
4) IC02D(7805)
5) IC01A(KIA7036)
Specification
1) AC230V ± 30V
: Check the rated voltage
2) 14V ± 3V
3) DC12V
4) DC5V
5) The voltage of micom pin 29
: DC4.5V↑
Remedy
1) Replace
power transfomer.
2) Replace
power transfomer.
3) Replace IC01D.
4) Replace IC02D.
5) Replace IC01A.

166 Multi type Air Conditioner
Troubleshooting Guide
Turn on main power.
While the compressor has been stopped, the compressor does not operate
owing to the delaying function for 3 minutes after stopped.
When the compressor stopped Indoor Fan is driven by a low speed.
At this point the wind speed is not controlled by the remote controller.
(When operated in the Sleeping Mode, the wind speed is set to the low speed as force.)
Caused by the remote controller. Caused by other parts except
the remote controller
When the mark ( ) is displayed in LCD
screen, replace battery. Check the contact of CN-DISP 1 connector
When the detect switch (double key) inside the
remote controller door is fault, it is impossible to
operate temperature regulating(▲/▼) and wind
speed selecting.
Check DISP PWB Ass'y
-Voltage between CN1 ➀-➆:DC+5V
Check the Display PWB Ass'y •Check receiver ass'y
Product doesn't operate with the remote controller.
Trouble 2

Service Manual 167
Troubleshooting Guide
Turn on the main power.
When in air circulation mode, compressor/outdoor fan is stopped.
Turn off main power.
Check the electrical wiring diagram of Outdoor side.
Check the open or short of connecting wires between Indoor and Outdoor.
Check the sensor for Indoor temperature is attatched as close as to be effected by the
themperature of Heat Exchange (EVA.)
When the sensor circuit for Indoor temperature and connector are in bad connection or are
not engaged, Compressor/Outdoor fan is stopped.
•Check the related circuit of R02H(12.1K), R01H(1K), R04H(6.2K), R03H(1K), C01H(102),
C02H(102), Micom(pin No. , ).
•Check the Indoor temperature sensor is disconnected or not (about 10K at 25°C).
Check the Relay(RY-PWR, RY-START) for driving Compressor.
•Check the voltage between brown and blue cable of terminal to connect the Outdoor
(About AC220V / 240V).
•Check the related circuit of relay in Outdoor PCB Ass'y.
Operate Cooling Mode by setting the disired temperature of the remote controller is less
than one of the Indoor temperature by 1°C at least.
The Compressor/Outdoor Fan are don't operate
Trouble 3
Check Point
Between Micom(No. 19) and
GND DC 5V DC 0V
DC 12VDC 1V↓
Between IC01M(No. 10) and
GND
Comp. ON Comp. OFF

168 Multi type Air Conditioner
Troubleshooting Guide
When indoor Fan does not operate.
Trouble 4
Check the SSR high speed operation by remote control.
(the Indoor Fan Motor is connected)
Turn off main power.
Check the connection of CN-FAN.
Check the Fan Motor.
Check the Fuse(AC250V, T2A).
Turn on the main power
Check the related circuit of indoor Fan Motor.
•The pin No.
38 of micom and the part for driving SSR.(Q01M)
•Check the related pattern.
•Check the SSR.
- SSR Open: Indoor Fan Motor never operate.
- SSR short: Indoor Fan Motor always operates in case of ON or OFF.
The voltage of Pin No 1(orange) and 3(black) of CN-FAN.
About AC 160V over About AC 50V over
SSR is not damaged Check SSR

Service Manual 169
Troubleshooting Guide
•Confirm that the vertical louver is normally geared with the shaft of Stepping Motor.
•If the regular torque is detected when rotating the vertical louver with hands ⇒Normal
•Check the connecting condition of CN-U/D or CN0L/R Connector
•Check the soldering condition(on PCB) of CN-U/D or CN0L/R Connector
Check the operating circuit of the vertical louver
•Confirm that there is DC +12V between pin ➀of CN-U/D, CN0L/R and GND.
•Confirm that there is a soldering short at following terminals.
- Between 1,2,3and 4of MICOM - Between 17 , 18 , 19 and 20 of MICOM
- Between 4,5,6and 7of IC01M - Between 5,6,7and 8of IC01M
When the louver does not operate.
Trouble 5
If there are no problems after above checks.
•Confirm the assembly condition that are catching and interfering parts in the link of the
vertical louver

170 Multi type Air Conditioner
Troubleshooting Guide
General Information
■Error Indicator (Indoor)
•The function is to self-diagnosis air conditioner and express the troubles if there is any trouble.
•Error mark is displayed on display window of indoor units and wired-remote controller, and LED of outdoor unit
control board.
•If more than two troubles occur simultaneously, lower number of error code is first displayed.
•After error occurs, if error is released, error LED is also released simultaneously.
■Indoor Error
1 digit 10 digit
Case of errorContents
Error
code
Open / ShortOutlet pipe sensor06 Different operation modeDifferent operation mode07
Communication Poorly
Float switch Open
Communication Poorly
Open / Short
Open / ShortAir sensor (open/short)01 Inlet pipe sensor02 Communication(Indoor ↔ Wired R/Control)03 Drain pump/ Float switch04 Communication(Indoor ↔ Outdoor)05 Off
Off
Off
Off
Off
Off
Off
Indoor
Status

Service Manual 171
Troubleshooting Guide
■Error Indicator (Outdoor)
Outdoor Error
Ex) Error 21 (DC Peack)
1 Time 1 Time 1 Time
2 Times2 Times2 Times
1 Sec.
2 Sec. 2 Sec.
1 Sec. 1 Sec.
LED01G
(RED)
LED02G
(GREEN)
Case of error
LED02G
(Green)
LED01G
(Red)
Contents
Error
code
Compressor malfunction,IPM Fault
Current is 14A
DC Link volt. Is 140V
Low / High press switch OPEN
Abnormal AC volt. Input.
Off
Off
Off
IPM Fault (Compressor Over current)
CT 2(Max. Current)
DC Link Low Volt.
Low / High press
AC Low / AC High Volt.
DC Compressor Position
PSC Fault
DC Link High Volt
Discharge Pipe Temp. High (INV)
Discharge Pipe Temp. High (Cons.)
21
22
23
24
25
26
27
28
32
33
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Outdoor
Status
2 times
2 times
2 times
2 times
2 times
2 times
2 times
2 times
3 times
3 times
1 time
2 times
3 times
4 times
5 times
6 times
7 times
8 times
2 times
3 times

172 Multi type Air Conditioner
Troubleshooting Guide
■Error Indicator (Outdoor)
Outdoor Error
Case of error
LED02G
(Green)
LED01G
(Red)
Contents
Error
code
CT Circuit malfunction
Open / Short
Open / Short
Open / Short
Open / Short
Open / Short
Over load combination
Communication Poorly
Check sum mismatching
Cond. Temp. high
Heat sink temp. high
Open / Short
CT Circuit
D-pipe sensor INV. (open/ short)
Air sensor (open/ short)
Cond. Pipe sensor (open/ short)
Suction pipe sensor (open/ short)
D-pipe sensor Cons. (open/ short)
Over capacity
Communication (Indoor Outdoor)
EEPROM check sum
Cond. Pipe sensor temp. high
Heat sink sensor temp. high
Heat sink sensor (open/ short)
40
41
44
45
46
47
51
53
60
61
62
65
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Off
Outdoor
Status
4 times
4 times
4 times
4 times
4 times
4 times
5 times
5 times
6 times
6 times
6 times
6 times
1 time
4 times
5 times
6 times
7 times
1 time
3 times
1 time
2 times
5 times

Service Manual 173
Troubleshooting Guide
1) Troubleshooting CH01, CH02, CH06
Ω
10kΩ
Check the resistance Check the voltage
V
2.5Vdc
01
02
06
Indoor air sensor
Indoor inlet pipe sensor
Indoor outlet pipe sensor
•Open / Short
•Soldered poorly
•Internal circuit error
•Open / Short
•Soldered poorly
•Internal circuit error
•Open / Short
•Soldered poorly
•Internal circuit error
Normal resistor : 10KΩ/at25°C (Unplugged)
Normal voltage : 2.5Vdc / at 25°C (plugged)
Normal resistor : 5KΩ/at25°C (Unplugged)
Normal voltage : 2.5Vdc / at 25°C (plugged)
Normal resistor : 5KΩ/at25°C (Unplugged)
Normal voltage : 2.5Vdc / at 25°C (plugged)
Display
code Title Cause of error Check point & Normal condition
Check Point
1. Unplug the sensor on Indoor unit PCB.
2. Estimate the resistance of each sensor.
3. If the resistance of the sensor is 10KΩ/5KΩat 25°C, then sensor is normal.
4. If the resistance of the sensor is 0 KΩor ∞, then sensor is abnormal. →Change the sensor.
5. Plug the sensor on Indoor unit PCB and Power ON.
6. Estimate the voltage of each sensor.
7. If the voltage of the sensor is 2.5Vdc at 25°C, then sensor is normal.
8. If the resistance of the sensor is 0 or 5Vdc, then sensor is abnormal. →Repair or Change the PCB.

174 Multi type Air Conditioner
Troubleshooting Guide
2) Troubleshooting CH03
Check the Volt.
Indoor Unit
V
12Vdc
12V S GND
Check the Volt.
Wired R/C
V
12Vdc
12V S GND CN-REMO
03 Communication
Wired R/C •Open / Short
•Wrong connection
•Connection of wire
•Main PCB Volt. DC12V
•Noise interference
Display
code Title Cause of error Check point & Normal condition
Check Point
1. Check the wire connection. (Open / Short) →Repair the connection
2. Check the soldering state of connector. (Soldered poorly) →Repair or Change the PCB.
3. Check the volt. Of main PCB power source. (DC 12V, DC 5V) →Repair or Change the main PCB.
4. Check the installation of wired remote controller. (Noise interference) →Adjust the state of installation

Service Manual 175
Troubleshooting Guide
3) Troubleshooting CH04
Check the resistance
Ω
0Ω
CN Float
CN-Float
CN-D/PUMP
04 Drain pump
/ Float switch •Float switch Open.
(Normal : short)
•The connection of wire(Drain pump/ Float switch)
•Drain pump power input. (220V)
•Drain tube installation.
•Indoor unit installation. (Inclination)
Display
code Title Cause of error Check point & Normal condition
Check Point
1. Check the wire connection. (Open, Soldered poorly) →Repair the connection or change the PCB.
2. Check the resistance of float switch (Abnormal : Open, Normal : short) →Check the float switch.
3. Check the level of water
4. Check the volt. Of Drain pump power supply. (AC 230V) →Repair or Change the main PCB.

176 Multi type Air Conditioner
4) Troubleshooting CH05, CH53
04
/
53
Communication
(Indoor →Outdoor) •Communication poorly
•Power input AC 220V. (Outdoor, Indoor)
•The connector for transmission is disconnected.
•The connecting wires are misconnected.
•The GND1,2 is not connected at main GND.
•The communication line is shorted at GND.
•Transmission circuit of outdoor PCB is abnormal.
•Transmission circuit of indoor PCB is abnormal.
Display
code Title Cause of error Check point & Normal condition
Check Point
1. Check the input power AC230V. (Outdoor, Indoor unit)
2. Check the communication wires are correctly connected.
→Adjust the connection of wire
→Confirm the wire of “Live”,“Neutral”
3. Check the resistance between communication line and
GND. (Normal : Over 2MΩ)
4. Check the connector for communication is correctly
connected.
5. Check the connection of GND1, GND2, and main GND.
6. If one indoor unit is operated normally, outdoor PCB is no
problem.
→Check the another indoor unit.
* CH05 is displayed at indoor unit, CH53 is displayed at out-
door unit.
Troubleshooting Guide

Service Manual 177
5) Troubleshooting CH21
Ω
Comp Copper
pipe
Resistance(Ω) at 20°C
Resistance(Ω) at 20°C
0.64
0.64
0.64
Inverter
comp.
V-W
W-U
U-V
Terminal
0.8
0.8
0.8
Constant
comp.
2MΩ
2MΩ
2MΩ
Inverter
comp.
V-GND
W-GND
U-GND
Terminal
2MΩ
2MΩ
2MΩ
Constant
comp.
V
U
W
Ω
Comp
21 DC Peak •Instant over current
•Over Rated current
•Poor insulation of IPM
•An instant over current in the U,V,W phase
- Comp lock
- The abnormal connection of U,V,W
•Over load condition
- Overcharging of refrigerant
- Pipe length.
•Poor insulation of compressor
Display
code Title Cause of error Check point & Normal condition
Check Point
1. Check the wire connection. (U,V,W)
2. Check the load condition. (Refrigerant, Pipe length, …)→Adjust the load condition
3. Check the electricity leakage of the compressor. →Normal : Over 2MΩ.
4. Check the resistance of compressor. →Normal : 0.65Ω(INV), 0.8Ω(Cons.) →No difference at each terminal.
5. Check the insulation from water at IPM part. →Check the trace of water.
6. Check the IPM circuit.
Troubleshooting Guide