LG A2UW18GFH0 Service Manual Download

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Please read this manual carefully before operating
your set and retain it for future reference.

General
Multi-Inverter Type

P/NO : MFL68280204

SERVICE MANUAL

AIR

CONDITIONER

Summary of Contents for A2UW18GFH0

Page 1: ...Please read this manual carefully before operating your set and retain it for future reference General Multi Inverter Type P NO MFL68280204 SERVICE MANUAL AIR CONDITIONER ...

Page 2: ...urifying 19 4 Installation Functions 20 5 Reliability 21 6 Convenience Functions Controls 22 7 Special Function KIT 29 Part 3 Basic Control 32 1 Normal operation 33 2 Compressor control 33 3 EEV Electronic Expansion Valve control 33 4 Oil return control 34 5 Defrost control 34 6 Protection control 35 Part 4 Test Run 36 1 Check before Test Run 37 2 Test Run Flow chart 38 3 Test Runing 39 Part 5 Tro...

Page 3: ...l Information 3 Copyright 2017 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only 1 Safety Precautions 4 2 Model Line Up 7 3 Nomenclature 10 Part 1 General Information ...

Page 4: ... cause death or severe injury if come in contact with it Do not touch the discharging refrigerant gas during the repair work The refrigerant gas can cause frostbite Release the refrigerant gas completely at a well ventilated place first Otherwise when the pipe is disconnected refrigerant gas or refrigerating machine oil discharges and it can cause injury When the refrigerant gas leaks during work ...

Page 5: ...uum pump or Inert nitrogen gas when doing leakage test or air purge Do not compress air or Oxygen and Do not use Flammable gases Otherwise it may cause fire or explosion There is the risk of death injury fire or explosion Do not turn on the breaker or power under condition that front panel cabinet top cover control box cover are removed or opened Otherwise it may cause fire electric shock explosio...

Page 6: ...rge section and the non charge metal section Earth position If the resistance value is low a disaster such as a leak or electric shock is caused at user s side Check the drainage of the indoor unit after the repair If drainage is faulty the water to enter the room and wet floor Check to see if the power cable plug is not dirty or loose If the plug is dust or loose it can cause an electrical shock ...

Page 7: ...NW09GB1B0 LSN090HSV4 ASNW12GB1B0 LSN120HSV4 AMNW15GDBB0 LMN158HVT SC ASNW18GC2B0 LSN180HSV4 AMNW24GDCB0 LMN248HVT ART COOL Mirror SB ASNW09GBRB0 LAN090HSV4 ASNW12GBRB0 LAN120HSV4 SC ASNW18GCRB0 LAN180HSV4 ART COOL Gallery SF AMNW09GAF11 LMAN097HVP AMNW12GAF11 LMAN127HVP Ceiling cassette 4 way TR AMNW07GTRA0 LMCN077HV AMNW09GTRA0 LMCN097HV AMNW12GTRA0 LMCN125HV TQ AMNW18GTQA0 LMCN185HV Ceiling conc...

Page 8: ...del Name A2UW18GFH0 LMU180HHV A3UW24GFH0 LMU240HHV A4UW30GFH0 LMU300HHV No of connectable indoor units Min Max 2 2 2 3 2 4 Total capacity index of connectable indoor units 24 33 40 Power supply 208 230V 1Ø 60Hz Chassis Model Name A5UW36GFH0 LMU360HHV A6UW42GFH0 LMU420HHV No of connectable indoor units Min Max 2 5 2 6 Total capacity index of connectable indoor units 48 56 Power supply 208 230V 1Ø 6...

Page 9: ...s Branch Type No of BD Units Accessory Model Name Applicable Model Specifications Gas Liquid Y Branch 2 PMBL5620 MULTIFMAX To BD unit Ø19 05 3 4 Ø19 05 3 4 To ODU Ø19 05 3 4 To BD unit Ø9 52 3 8 Ø9 52 3 8 To ODU Ø9 52 3 8 No of connectable indoor units Min Max 1 2 1 3 1 4 Model name PMBD3620 PMBD3630 PMBD3640 PMBD3641 Connectable indoor unit capacity kBtu h 9 24 9 24 9 24 9 36 BD unit ...

Page 10: ...indoor unit using R410A Model type W DC Inverter heat pump Ex 7 000 Btu h Class 07 18 000 Btu h Class 18 Cooling heating capacity Electrical rating G 1Φ 208 230V 60Hz Chassis naem Only Multi Indoor unit type Only Multi A ART COOL Gallery D Wall Mounted ART COOL Mirror T Ceiling cassette B Ceiling concealed duct N Vertical AHU Function A Basic L Plasma Wall mounted C Plasma ceiling cassette Front p...

Page 11: ...0 220V 50Hz 6 220 240V 50Hz 7 110V 50 60Hz 7 Chassis A Z Name of Chassis 8 Look A Z Look Color Artcool Model 9 Function A Z 10 Serial No 1 9 LG Model Development Serial No 1 2 3 4 5 6 7 8 9 10 Basic A Basic 4Way B Basic Deodorizing Filter Carbon filter C Plasma A changeove A clean 2Way Ion E Plasma A changeove A clean 4way Ion Lamp F Plasma A changeove A clean Low A G Plasma A changeove A clean 4w...

Page 12: ...al rating Indicates that this is multi system outdoor unit using R410A Ex A4U Connectable max 4 indoor units A6U Connectable max 6 indoor units Model type W DC inverter heat pump Ex 24 000 Btu h Class 24 42 000 Btu h Class 42 Cooling heating capacity G 1Φ 208 230V 60Hz Multi type Function A Basic H High Heat F Free joint multi type Serial number 3 2 Outdoor Unit Global ...

Page 13: ...raining and service purposes LGE Internal Use Only P M BD 36 2 0 Serial number Number of connectable indoor units Max capacity of connectable indoor units 36 mean that 7 36kBtu h Class Indoor unit connected to BD unit BD Branch distributor M Multi system outdoor unit P Parts 3 3 BD units Global ...

Page 14: ... 19 4 Installation Functions 20 4 1 E S P External Static Pressure Setting 20 5 Reliability 21 5 1 Hot start 21 5 2 Self diagnosis Function 21 5 3 Soft dry operation 21 6 Convenience Functions Controls 22 6 1 Cooling heating Operations 22 6 2 Auto cleaning operation 23 6 3 Auto Operation Artificial Intelligence 23 6 4 Auto restart Opeartion 24 6 5 Child Lock Function 25 6 6 Forced operation 25 6 7...

Page 15: ...tion Drain pump X X X O O O X E S P control X X X X O O O Electric heater X X X X X X ANEH053B1 5kW ANEH103B2 10kW High ceiling operation X X X O X X X Auto Elevation Grille X X X X X X X Reliability Hot start O O O O O O O Self diagnosis O O O O O O O Soft dry operation O O O O O O O Conven ience Auto changeover X X X X X X X Auto cleaning O O O X X X X Auto operation artificial intelligence O O ...

Page 16: ...tart O Test function X Convenience Night Silent Operation O Wiring Error Check O Peak Control O Mode Lock O Forced Cooling Operation Outdoor Unit O Network function Network soluation LGAP O Device A2UW18GFH0 LMU180HHV A3UW24GFH0 LMU240HHV A4UW30GFH0 LMU300HHV A5UW36GFH0 LMU360HHV A6UW42GFH0 LMU420HHV Central Controller AC Ez Simple Controller PQCSZ250S0 PQCSZ250S0 AC Ez Touch PACEZA000 PACEZA000 A...

Page 17: ...low direction control key input the left right louver automatically operates with the auto swing or it is fixed to the desired direction 2 2 Auto swing up down By the auto swing key input the upper lower vane automatically operates with the auto swing or it is fixed to the de sired direction 2 3 Chaos swing up down By the Chaos swing key input the upper lower vane automatically operates with the c...

Page 18: ...the Jet Cool mode is oper ated In the Jet Cool mode the indoor fan is operated at super high speed for 30 min at cooling mode operation In the Jet Cool mode operation the room temperature is controlled to the setting temperature 18 C When the sleep timer mode is input while in the Jet Cool mode operation the Jet Cool mode has the priority When the Jet Cool key is input the upper lower vanes are re...

Page 19: ...tem not only removes microscopic contaminants and dust but also removes house mites pollen and pet fur to help prevent allergic diseases like asthma This filter that can be used over and over again by sim ply washing with water 3 Air purifying Ionizer Photo Catalyst Coated Mesh Dust particles Odour Dust electrode discharge Odour molecule Generating plasma Polluted Air Purified fresh Air 4 8KV disc...

Page 20: ... Whenever pressing the button SLo Lo Med Hi Po will be indicated 2 Select the desired air flow rate value with the temperature up down button E S P value range 0 255 E S P value will be indicated at the upper right section of the display window 3 When pressing the button currently established E S P value will be set up 4 When pressing the button and button simultaneously for more than 3 seconds af...

Page 21: ...oting guide 5 3 Soft dry operation When the dehumidification operation input by the remote control is received the intake air temperature is detected and the setting temp is automatically set according to the intake air temperature While compressor off the indoor fan repeats low airflow speed and stop While the intake air temp is between compressor on temp and compressor off temp 10 min dehumidifi...

Page 22: ...or depend on the load condition The difference between the room temp and set temp frequency restrictions If compressor operates at some frequency the operating frequency of compressor cannot be changed within 30 sec onds Condition of compressor turned off When intake air temperature reaches 4 C above the setting temperature Condition of compressor turned on When intake air temperature reaches 2 C ...

Page 23: ...temp the compressor is turned off When 0 5 C or more above the setting temp the compressor is turned on Compressor ON Temp Setting Temp 0 5 C Compressor OFF Temp Setting Temp 0 5 C At the beginning of Fuzzy mode operation the setting temperature is automatically selected according to the intake air temp at that time 26 C Intake Air Temp 25 C 24 C Intake Air Temp 26 C Intake Air Temp 1 C 22 C Intak...

Page 24: ...3 3 Fuzzy Operation for Heating According to the setting temperature selected by Fuzzy rule when the intake air temp is 3 C or more above the setting temp the compressor is turned off When below the setting temp the compressor is turned on Compressor ON Temp Setting Temp Compressor OFF Temp Setting Temp 3 C At the beginning of Fuzzy mode operation the setting temperature is automatically selected ...

Page 25: ... C 24 C Setting speed of indoor fan High speed Operating Mode Cooling Healthy Dehumidification Heating It is the function to use preventing children or others from careless using FAN SPEED FAN SPEED FAN SPEED During the operation when pressing the button and button for approx 3 seconds the Child Lock Function can be used At the time of initial setting of the Child Lock the CL Will be indicated app...

Page 26: ...cation function with one remote controller you must change the master slave setting from the indoor unit Indoor units the master slave configuration of the product after completion of indoor unit power OFF and then ON the power after 1 minutes elapsed sign up For ceiling type cassette and duct product group change the switch setting of the indoor PCB For wall mount type and stand type product chan...

Page 27: ... remote control the appliance starts to operate The timer LED is on when the on timer is input It is off when the time set by the timer is reached If the appliance is operating at the time set by the timer the operation continues While in Fuzzy operation the airflow speed of the indoor fan is automatically selected according to the temperature 6 9 2 Off Timer Operation When the set time is reached...

Page 28: ...has been completed the setting mode will be released If there isn t any button input for more than 25 seconds the installer setting mode will also be released 4 OPER MODE OPER MODE Code value Setting value 01 Remote controller 02 Indoor unit 03 2TH OPER MODE Value TEMP FAN SPEED OPER MODE h The function of 2TH has different operation characteristics according to the product Thermistor Table This i...

Page 29: ...led easily regarding any space environment 7 3 Auto Elevation Grille Auto Elevation Grille is automatically down to height of max 3 1 m So it enables to install the Indoor unit at high ceiling space And Auto Elevation Grille makes you cleaning the filter easily 7 1 Low Ambient control This Function is for cooling operating in outdoor low temperature If outdoor temperature drops below certain tempe...

Page 30: ...ont panel directly under front panel Do not drop it down or into water Or else there is worry about trou ble failure Do not press hard the Remote Controller button with nail ballpoint pen or other sharp substance Or else there is worry about trouble failure In case when obstacle such as curtain hides the signal reception part of receiver in between the space interval Remote Controller operation is...

Page 31: ...tic Stop Distance of Grill Ceiling height Low Medium High Height 3 4 m Automatic stop distance 1 5 0 5m 2 5 0 5m 3 5 0 5m Depress the down button Then suction grill descends and stops automatically at a certain distance You may stop it at wanted distance point by depressing the stop but ton when descending Depress the up button Then suction grill goes up and enters into the front panel 1 Stop the ...

Page 32: ...se Only Part 3 Basic Control 1 Normal operation 33 2 Compressor control 33 3 EEV Electronic Expansion Valve control 33 4 Oil return control 34 5 Defrost control 34 6 Protection control 35 6 1 High pressure protection control 35 6 2 Low pressure protection control 35 6 3 Discharge temperature control 35 6 4 Input Current control 35 ...

Page 33: ...e and constant condensing temper ature Tc on heating mode by fuzzy control to ensure the stable system performance 2 Compressor control Cooling and heating load System capacity Linear control Inverter linear control as cooling and heating load increasing Actuator Cooling operation Heating operation Stop state Compressor Fuzzy control Fuzzy control Stop Fan Fuzzy control Fuzzy control Stop EEV Supe...

Page 34: ...trol Component Starting Running Ending Compressor Normal control Setting value Normal control Fan Normal control Off Normal control EEV Thermo on Normal control Setting value Normal control EEV Thermo off Min Pulse Setting value Min Pulse 4 way valve On Off On Component Starting Running Ending Fan Normal control Off Normal control Defrost signal Off On Off Outdoor unit Component Starting Running E...

Page 35: ...709 kPa Pd 3840 kPa Frequency holding 3611 kPa Pd 3709 kPa 3 Hz up Pd 3611 kPa Normal control Pressure range Compressor Pe 310 kPa Normal control 278 kPa Pe 310 kPa 3Hz down 245 kPa Pe 278 kPa 3Hz down 212 kPa Pe 245 kPa 3Hz down Pe 212 kPa Off Pressure range Compressor Pe 294 kPa Normal control 255 kPa Pe 294 kPa 3Hz down 229 kPa Pe 255 kPa 3Hz down 203 kPa Pe 229 kPa 3Hz down Pe 203 kPa Off 6 3 ...

Page 36: ...est Run 36 Copyright 2017 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only Part 4 Test Run 1 Check before Test Run 37 2 Test Run Flow chart 38 3 Test Running 39 ...

Page 37: ...ore between power supply terminal block and ground Do not operate in the case of 2 0 MΩ or less NOTE Never carry out mega ohm check over terminal control board Otherwise the control board may break Immediately after mounting the unit or after leaving it turned off for an extended length of time the resistance of the insulation between the power supply terminal board and the ground maydecrease to a...

Page 38: ... the unit in cooling mode Does Test operation start Refer to Part 5 Trouble Shooting 4 Gas Charging 6 Electric Parts Yes No Yes Refer to Part 5 Trouble Shooting 4 Gas Charging 5 Cycle Parts No Is hot air discharged After Hot Start Yes No Is there any temperature difference between intake and discharged air Yes No Is the operating current normal Yes Normal Refer to Part 5 Troulbe Shooting No Check ...

Page 39: ...n more than 5 minutes without fail Test run will be cancelled 18 minutes later auto matically n The forced operation is started by pressing button for 2 seconds The test run is started by pressing button for 3 6 sec onds n To cancel the test run press any button 3 1 3 Settlement of outdoor unit n Anchor the outdoor unit with a bolt and nut ø10mm tightly and horizontally on a concrete or rigid moun...

Page 40: ... down timer button for 3 seconds at the same time To cancel the test run press any button 3 2 2 CHECK THE FOLLOWING ITEMS WHEN INSTALLATION IS COMPLETE After completing work be sure to measure and record trial run properties and store measured data etc Measuring data are room temperature outside temperature suction temperature blow out temperature air velocity air volume voltage current presence o...

Page 41: ...1 2 Error Indicator Outdoor 43 2 Pump Down 44 3 Evacuation 45 4 Gas Charging 46 5 Cycle Part 47 6 Electronic Parts 48 6 1 The Product doesn t operate at all 48 6 2 The Product doesn t operate with the remote controller 49 6 3 The Compressor Outdoor Fan are don t operate 49 6 4 When indoor Fan does not operate 51 6 5 When the louver does not operate 52 6 6 Troubleshooting Indoor Error 53 6 7 Troubl...

Page 42: ...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 Indoor Error 00 No Error ON 01 Indoor Room themistor error OFF 02 Indoor in piping sensor error OFF 03 Remote controller error OFF 04 Drain Pump error OFF 05 Communcation e...

Page 43: ...D Pipe Temp High Off 35 Low Pressure Error 3times 5times Excessive decrease of Low Pressure Off 39 Communication Error 3times 9times Communication Error Between PFC Micom and INV Micom Off 40 CT Sensor Open Short 4times CT Circuit Malfunction Off 41 INV D Pipe Th Error 4times 1times Open Short Off 43 High Pressure Sensor Error 4times 3times Open Short Off 44 Outdoor Air Th Error 4times 4times Open...

Page 44: ...ollow after shutting the power source down 2 Reset the power 3 Check that the Red LED of PCB is on during work The indoor unit is operated by force 4 Pump down during forced cooling operation CAUTION 1 Use pump down function within guaranteed temperature range IDU 20 32C ODU 0 40C 2 Make certain that IDU doesn t run with thermo off mode during operation 3 After the compressor is starting operation...

Page 45: ...gauge needle does not move approxima tely 5 minutes after turning off the vacuum pump 4 Disconnect the charge hose from the vacuum pump Vacuum pump oil If the vacuum pump oil becomes dirty or de pleted replenish as needed WARNING Use a vacuum pump or lnert nitrogen gas when doing leakage test or air purge Do not compress air or Oxygen and do not use Flammable gases Otherwise it may cause fire or e...

Page 46: ...h a little at a time approximately 150g each time while operating the air conditioner in the cooling cycle however one time is not suffi cient wait approximately 1 minute and then re peat the procedure pumping down pin 4 Immediately disconnect the charge hose from the 3 way valve s service port Stopping partway will allow the gas to be discharged If the system has been charged with liquid refrig e...

Page 47: ...rence between intake and discharge air depends on room air humidity When the room air humidity is relativery 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 in cooling mode 1 The suction pressure is usually 8 5 9 5kg cm2G Cooling at normal condition R410A 2 The temperatu...

Page 48: ... Remedy 1 Check the power outlet 2 Replace PCB Assembly 4 Replace PCB Assembly 5 Replace PCB Assembly Turn on the main power again Turn off the main power and wait for 10 seconds Yes No A Beeping sound is made from the indoor unit Check the voltage of power supply AC208 230V 60Hz and check for the following The voltage of main power supply The voltage applied to the unit The connecting method of I...

Page 49: ...n one of the Indoor temperature by 1 C at least 6 3 The Compressor Outdoor Fan are don t operate 6 2 The Product doesn t operate with the remote controller Turn on the main power Yes No A Beeping sound is made from the indoor unit Refer to 6 1 Check the voltage of power AC208 230V 60Hz Is it possible to turn on the unit by ON OFF button on display Yes No Is the remote controller working properly Y...

Page 50: ...emperature 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 AC208 230 Check the related circuit of relay in Outdoor PCB Ass y Check Point Between Micom No 19 and GND DC 5V DC 0V DC 12V DC 1V Between IC01M No 10 and GND Comp ON Comp OFF Check the Relay RY PWR...

Page 51: ...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...

Page 52: ... 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 of CN U D CN0L R and GND Confirm that there is a soldering short at following terminals Between 1 2 3 and 4 of MICOM Between 17 18 19 and 20 of MICOM Between 4 5 6 and 7 of IC01M Between 5 6 7 and 8 of IC01M 6 5 When the louver do...

Page 53: ...h 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 6 6 Troubleshooting Indoor Error 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 So...

Page 54: ...on 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 Repair or Change the main PCB 4 Check the installation of wired remote controller Noise interference Adjust the state of installation 03 Communication Wired R C Open Short Wrong connection Connection of wire Main PCB Volt DC12V Noise...

Page 55: ...e Drain pump Float switch Drain pump power input 230V 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 Che...

Page 56: ...nother Unit operate heating At the same time this model cannot use cool and heating mode Display code Title Cause of error Check point Normal condition Check Point 1 Check another indoor model operation mode 2 Operating the same mode with the first operated indoor unit 3 Clearing the CH07 Press the on off button or mode change button and matching the indoor unit mode same as the first operated ind...

Page 57: ...or 1 Check the poor soldering 2 Check the insertion condition of the EEPROM 3 Check the PCB Connection Display code Title Cause of error Check point Normal condition Check Point 1 Check the EEPROM Direction 2 If the EEPROM value the Program value are not matched the Code is Displayed 3 After Checking the connection and Insertion replace the PCB or Option PCB EEPROM Direction Check Point ...

Page 58: ...Voltage is about input voltage x 1 414 if the Voltage does not come with the above Voltage Check the power input Replace the PCB Motor 2 Check the Voltage Black line to White the Voltage is DC 15V Check the Power input Replace the motor Check the Motor 1 Check the shaft if the shaft is not turn smoothly the Motor Power IC is defected replace the motor 2 Check the motor resistance if the shaft is t...

Page 59: ...r 2MΩ Replace compressor if abnormality found Are the resistance Between each phase and insulation resistance of Inverter compressor normal No Yes 1 Check inverter PCB assembly U V W connector connection condition 2 Check wire disconnection and wiring 3 Check compressor terminal connection condition bad contact Reassemble if abnormality found Is compressor Wire connection condition normal No Yes C...

Page 60: ...tage is discharged after main power off 2 Pull out V V W COMP connector 3 Set multi tester to resistance mode 4 If the value between P and N terminal of IPM is short 0Ω or open hundreds MΩ PCB needs to be replaced IPM damaged 5 Set the multi tester to diode mode 6 In case measured value is different from the table PCB needs to be replaced PCB damaged 27 26 25 24 23 22 21 P U V W Nu Nv Nw 0 4 0 6 V...

Page 61: ...CN N connectors and U V W COMP Connector 3 Set multi tester to resistance mode 4 If the value between P and N terminal of IPM is short 0Ω or open hundreds MΩ PCB needs to be replaced IPM damaged 5 Set the multi tester to diode mode 6 In case measured value is different from the table PCB needs to be replaced PCB damaged 0 3 0 5 V Black Red 25 26 P W V U ں ڹ ڸ 13 15 11 12 8 9 IGBTM check U V W 36 4...

Page 62: ...isconnection wiring again if abnormality found Yes Is input voltage normal No Check L1 L2 phase is 230V 15 Check connection condition and wiring if power is abnormal Yes Is inverter PCB assembly normal No Check inverter PCB assembly IPM normality Replace inverter PCB assembly Are the resistance Between each phase and insulation resistance of Inverter compressor normal No 1 Check resistance between...

Page 63: ...r source 230V 15 2 Check the fan operation is right 3 Check the current 4 Check the install condition 5 Check the CT Sensor Output signal 18 24 30 kBtu h class Check output the CT Sensor DC 2 5 0 2V 36 42 kBtu h class Check output pin 1 2 of the CT Sensor 5V Vdc 2 5V I_IN I_IN GND GND Red Black CT Sensing Check Point Inverter PCB 36 42kBtu h class 18 24 30kBtu h class ...

Page 64: ...Error Diagnosis and Countermeasure Flow Chart Is Inverter PCB assembly Power connection normal No Check connection from terminal block to Inverter PCB assembly CN L CN N Yes Is input voltage normal No Yes Is Inverter PCB Normal No Replace inverter PCB assembly Recheck power and installation condition Yes Check L1 L2 Voltage is 230V 15 WARNING Before checking PCB or each outdoor electric parts wait...

Page 65: ...2 Measure the voltage as shown in figures 3 If the measurements are significantly different from the levels shown in the figures the PFCM is deemed to be damaged IN OUT OUT Red Black Vdc Sequence of Measurement Measurement Normal Standards Sequence of Measurement Measurement Normal Standards 1 C E 0 3V 0 5V 2 C E 0 3V 0 5V ڹ ڸ 0 3 0 5 V IGBT ڸ ڹ ڸ ڹ C Collector E Emitter 1 A C 0 3V 0 5V 2 A C 0 3V...

Page 66: ...Part 5 Trouble Shooting 66 Copyright 2017 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only Measuring input voltage N L Inverter PCB 36 42kBtu h class ...

Page 67: ...t voltage 2 5Vdc 10 25 Input voltage Abnormal Input voltage 140Vac 300Vac Check the power source Check the components Display code Title Cause of error Check point Normal condition Is Inverter PCB Normal No Replace inverter PCB assembly Is input voltage normal No Check L1 L2 Voltage is 230V 15 Yes Recheck power and installation condition Yes Input Power Source Check Point L1 L2 n Error Diagnosis a...

Page 68: ...for training and service purposes LGE Internal Use Only CT Sensing Check Point GND INPUT V 18 24 30kBtu h class Vdc 2 5V GND Red Black INV_Cur INV_Current ent INV_Current GND GND INPUT V INPUT V INPUT V GND Inverter PCB Input Voltage Sensing Check Point 36 42kBtu h class Vdc GND INPUT V ...

Page 69: ...ation resistance between compressor terminal and pipe over 2MΩ Replace compressor if abnormality found Are the resistance Between each phase and insulation resistance of Inverter compressor normal No Yes 1 Check inverter PCB assembly U V W connector connection condition 2 Check wire disconnection and wiring 3 Check compressor terminal connection condition bad contact Reassemble if abnormality foun...

Page 70: ...70 Copyright 2017 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only Measuring resistance between each terminal of compressor Compressor wire connection U V W ȯ 36 42kBtu h class ...

Page 71: ...ormal operation 4 Check refrigerant pressure Reassemble or manage if abnormality found Is installation condition normal Is compressor Wire connection condition normal 1 Check inverter PCB assembly U V W connector connection condition 2 Check wire disconnection and wiring 3 Check compressor terminal connection condition bad contact Reassemble if abnormality found Is AC input Wire connection conditi...

Page 72: ... Is input voltage normal No Check L1 L2 phase is 230V 15 Check connection condition and wiring if power is abnormal Yes Is inverter PCB assembly normal No Check inverter PCB assembly IPM normality Replace inverter PCB assembly Are the resistance Between each phase and insulation resistance of Inverter compressor normal No 1 Check resistance between each terminal of compressor 0 438 0 628 7 2 Check...

Page 73: ...ficient Poor INV Comp Dis charge sensor LEV connector displaced poor LEV assembly Check outdoor fan constraint screened flow structure Check refrigerant leakage Check if the sensor is normal Check the status of EEV assembly CN DISCHARGE BLACK 3Pin Connector Replace the Thermistor Yes CN_TH3 RED 4Pin Connector WARNING Before checking PCB or each outdoor electric parts wait for 3 minutes after the p...

Page 74: ...ed Open service valve Are communication cable piping normal Yes No Is amount of refrigerant normal refer refrigerant part Yes No Adjust the amount of refrigerant Additive charge check communication piping correction Is strainer Ok No Replace the strainer No Replace the pressure sensor Yes Yes Check indoor outdoor unit LEV Check Indoor unit PCB Check indoor outdoor unit installation conditions Yes ...

Page 75: ...ween PFC Micom and INV Micom 1 Micom defect Circuit defect 2 Different Micom S W Version 3 ODU inverter PCB assembly damage Display code Title Cause of error Check point Normal condition n Error Diagnosis and Countermeasure Flow Chart Is Inverter PCB assembly normal No Replace inverter PCB assembly Is PFC Micom INV Micom S W Program normal No Upgrade Micom Program Yes Yes Recheck power and install...

Page 76: ...on condition Yes Input Power Source Check Point L1 L2 n Error Diagnosis and Countermeasure Flow Chart 40 C T Sensor Error Initial current error Malfunction of current detection circuit Open Short Check CT Sensor output voltage 2 5Vdc 5 Display code Title Cause of error Check point Normal condition WARNING Before checking PCB or each outdoor electric parts wait for 3 minutes after the power is off ...

Page 77: ...ronics Inc All right reserved Only for training and service purposes LGE Internal Use Only Inverter PCB CT Sensing Check Point 36 42kBtu h class Vdc 18 24 30kBtu h class CT Sensing Check Point Vdc 2 5V GND Red Black INV_Cur INV_Current ent INV_Current ...

Page 78: ... Short Soldered poorly Internal circuit error 1 Bad connection of thermistor connector 2 Defect of thermistor connector Open Short 3 Defect of outdoor PCB 48 Condenser Out pipe sen sor Open Short Soldered poorly Internal circuit error 1 Bad connection of thermistor connector 2 Defect of thermistor connector Open Short 3 Defect of outdoor PCB Ω Check Point 1 Estimate the resistance of each sensor U...

Page 79: ... connector PCB Bad connection high pressure connector Defect of high pressure connector Open Short Defect of connector PCB Open Short Defect of outdoor main PCB Is sensor connected to PCB correctly Connect sensor to PCB correctly Replace corresponding pressure sensor Yes No Replace the pressure sensor Yes No No Yes END After replacement of outdoor unit main PCB is the system also abnormal Is press...

Page 80: ...indoor unit capacity 2 Check the combination table Display code Title Cause of error Check point Normal condition 51 Over capacity Over capacity Combination Check the indoor unit capacity Check the combination table Model Gross max capacity Max single indoor unit capacity A2UW18GFH0 24k 15k A3UW24GFH0 33k 24k A4UW30GFH0 40k 24k A5UW36GFH0 48k 24k A6UW42GFH0 56k 36k ...

Page 81: ...th other parts 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 If one indoor unit is operated normally outdoor PCB is no proble...

Page 82: ...Chart Is EEPROM insertion normal No Yes Recheck power and installation condition 1 Check EEPROM insert direction connection condition 2 Check EEPROM Check SUM Replace if abnormality found Is inverter PCB assembly normal No Yes Replace inverter PCB assembly Yes MAIN PCB assembly normal No Replace MAIN PCB assembly Check Point Check the EEPROM Check sum Direction 18 24 30kBtu h class EEPROM WARNING ...

Page 84: ...d EEV connector displaced poor EEV assembly Poor Cond Pipe sensor assembly burned Check outdoor fan constraint screened flow structure Check if refrigerant overcharged Check the status of EEV assembly Check the status of sensor assembly burn CN C PIPE Violet 3Pin Connector Replace the Thermistor Yes WARNING Before checking PCB or each outdoor electric parts wait for 3 minutes after the power is of...

Page 85: ...Outdoor Indoor Unit 3 Check EEV Connector Assemble Condition Normal Operation 4 Check Refrigerant Pressure 5 Check Power Wire Connection Condition Reassemble or Manage if abnormality Found 1 Check Inv PCB Screw Connection Condition Reassemble or Manage if abnormality Found No Inv PCB IGBTM Connection Condition Normal Yes 1 Check Outdoor Unit Fan Motor Operation or Lock Reassemble or Manage if abno...

Page 86: ...17 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only Check Screw Connection Condition 36 42kBtu h class 18 24 30kBtu h class PFCM Measuring resistance between No 19 20 pin Red Black 10 9 11KΩ ...

Page 87: ... 4 Check pipe distortion and abnormality 5 Check service valve is opened Eliminate causes for abnormal condition Check resistance between NO 19 pin and NO 20 pin of PFC module Check resistance between NO 24 pin and NO 25 pin of PFC module 7KΩ 10 at 25 C Replace PCB if abnormality found Is assemble condition of INV PCB heatsink normal Is PCB temperature sensing part normal No No Yes Check assemble ...

Page 88: ...king Reassemble or replace if abnormality found Is ODU Fan Motor normal No Yes 1 Set the multi tester to diode mode 2 Check voltage between 1pin and 4pin of Fan Motor 1Ţ0 2V 3 Replace Inverter PCB if abnormality found Is wire connection of ODU Fan Motor wire normal No Yes Check wiring between OUD fan motor and Inverter PCB Check if Hall Senor and Motor output terminal color is matched Reassemble i...

Page 89: ...aining and service purposes LGE Internal Use Only Inverter PCB 36 42kBtu h class 18 24 30kBtu h class Tester Fan motor connector Check voltage betwen 1pin and 4pin of fan motor Checking wire terminals for possible short Tester ԟ ۼ ५HᴦQPEI ڸ ڻ ᴬ ᴬ ڼ ڻ d Ẹ Ẹ d Ẹ Ẹ d Ẹ Ẹ d Ẹ Ẹ ڽ ڻ ᴬ ᴬ ھ ڻ ڸ ھڽڼڻ ...

Page 90: ...Indoor Outdoor Unit 3 Check EEV connector assemble condition normal operation 4 Check refrigerant pressure Reassemble or manage if abnormality found Is installation condition normal Is compressor Wire connection condition normal 1 Check inverter PCB assembly U V W connector connection condition 2 Check wire disconnection and wiring 3 Check compressor terminal connection condition bad contact Reass...

Page 91: ...2017 LG Electronics Inc All right reserved Only for training and service purposes LGE Internal Use Only Input Power Source Check Point Main PCB wiring Check Point Noise Filter wiring Check Point OUT IN 18 24 30kBtu h class IN OUT OUT L1 L2 ...

Page 92: ...ght reserved Only for training and service purposes LGE Internal Use Only Noise Filter wiring Check Point Main PCB wiring Check Point Input Power Source Check Point Inverter PCB wiring Check Point L2 L2 L1 L2 L2 L1 L1 L1 36 42kBtu h class L1 L2 L2 L1 L2 L1 L1 L2 L1 L2 ...

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