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Troubleshooting Guide

- 63 -

Copyright © 2018 LG Electronics Inc. All rights reserved.
Only training and service purposes.

251

Input Voltage high/low

Error

No.

Error Type

Error Point

Main Reasons

Input voltage is over limited
value of the product (173V
or less, 289V or more)

1. Input voltage abnormal (R-N)
2. Compressor Module Inv. PCB damage

(input voltage sensing part)

3. N phase line disconnection

n

Error Diagnosis and Countermeasure Flow Chart

Yes 

Yes 

Recheck power and installation condition

Yes

Are there any power wire 

connections normal?

No 

Yes 

1. Check R/S/T/N wiring conditions

 Rewire them if abnormality found.

Is input voltage normal?

No 

Check
R~S/S~T/T~R phase voltage is 380V 10%
R~N/S~N/T~N phase voltage is 220V 10%

 Check connection condition and wiring if power is 

 abnormal 

Is Inv. PCB

bridge diode joining condition normal?

No 

Check joining condition of Inv. PCB and bridge diode

 joining again if abnormality found

Yes 

Is DC_Link Wire connection

condition normal?

No 

1.Check Inv. PCB P,N connector
   connection condition
2.Check Inv. PCB P,N connector
   connection condition
3. Check wire disconnection and wiring

 Reassemble if abnormality found

Inv. PCB LED display error

No 

Replace Inv. PCB

Summary of Contents for ARNU07GCEA4

Page 1: ...R410A CAUTION Before Servicing the unit read the safety precautions in General SVC manual Only for authorized service personnel CONFIDENTIAL Copyright 2018 LG Electronics Inc All rights reserved Only training and service purposes ...

Page 2: ...aining and service purposes Air Conditioner Service Manual TABLE OF CONTENTS Safety Precautions 3 Part 1 General Information 7 Model Names 8 External Appearance 9 Nomenclature 11 Part 2 MULTI V M 12 Part 3 PCB Setting and Test Run 32 Part 4 Trouble shooting guide 37 ...

Page 3: ... 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...

Page 4: ...igerant 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 ca...

Page 5: ...of capacity When installting the unit in a hospital communication station or similar place provide sufficient protection against noise The inverter equipment private power generator high frequency medical equipment or radio communication equipment may cause the air conditioner to operate erroneously or fail to operate On the other hand the air conditioner may affect such equipment by creating nois...

Page 6: ...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 frost...

Page 7: ... rights reserved Only training and service purposes Part 1 General Information 1 Model Names 8 1 1 Indoor Unit 8 1 2 MULTI V M 8 2 External Appearance 9 2 1 Indoor Unit 9 2 2 MULTI V M 10 3 Nomenclature 11 3 1 Indoor Unit 11 3 2 MULTI V M 11 ...

Page 8: ... 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 30k 9 0 36k 10 6 42k 12 3 48k 14 1 Wall Mounted Unit Standard SJ O SK SV O O ARTCOOL Mirror SB O SC Gallery SF Ceiling Cassette 1 Way TU TT 2 Way TS 4 Way TR O TQ O TP O TN O O O TM O Ceiling Concealed Duct High Static BG BR B...

Page 9: ...U24GTP 4 ARNU28GTP 4 ARNU30GTP 4 ARNU36GTN 4 ARNU42GTMC4 ARNU48GTM 4 ARNU54GTM 4 A Basic C Plasma Wall Mounted Unit Standard ARNU05GSJ 4 ARNU07GSJ 4 ARNU09GSJ 4 ARNU12GSJ 4 ARNU30GSVA4 ARNU15GSJ 4 ARNU18GSK 4 ARNU24GSK 4 A Basic N Ionizer ARNU36GSVA4 Ceiling Mounted Cassette 4 Way 2 ARNU07GTNA4 ARNU09GTNA4 ARNU12GTNA4 ARNU15GTNA4 ARNU18GTNA4 ARNU24GTMA4 ARNU28GTMA4 ARNU36GTMA4 ARNU42GTMA4 r o r r ...

Page 10: ... 10 Copyright 2018 LG Electronics Inc All rights reserved Only training and service purposes External Appearance 2 2 MULTI V M Chassis Model Name External Appearance K4 ARNU050LMC0 B8 ARNU050GME0 ...

Page 11: ... Ionizer G Low Static K High Sensible Heat U Floor Standing without Case SE S8 SJ SK R Mirror V Silver B Blue ART COOL Type Panel Color SF E Red V Silver G Gold 1 Kiss Photo changeable Q Console Z Fresh Air Intake Unit Nomenclature Additional information Serial number is refer to the bar code on the product Model Name ARU N 050 L M S 0 No 1 2 3 4 5 6 7 No Signification 1 MULTI V System Outside Uni...

Page 12: ... 12 Copyright 2018 LG Electronics Inc All rights reserved Only training and service purposes Part 2 MULTI V M ...

Page 13: ... 13 Copyright 2018 LG Electronics Inc All rights reserved Only training and service purposes Function 14 ARU Series ...

Page 14: ... Defrost control 19 2 3 Stop operation 20 3 Protection control 21 3 1 Pressure protection control 21 3 2 Discharge temperature control 22 3 3 Inverter protection control 22 3 4 Phase detection 22 3 5 Pressure switch 22 4 Other control 23 4 1 Initial setup 23 4 2 Pump Down 26 4 3 Night Low Noise Function 27 4 4 Vacuum Mode 28 4 5 Static pressure compensation mode 28 4 6 Cool Heat selector 29 4 7 Cy...

Page 15: ...ing 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 4 way valve Subcooling Indoor Unit EEV EEV Fuzzy control Fuzzy control Full open OFF Fuzzy control Superheat fuzzy control Fuzzy control Subcooling fuzzy control Fuzzy control Fuzzy control Fuzzy control ON Cooling ope...

Page 16: ... 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...

Page 17: ...dition Every 8 hours operate n Oil return process ends if compressor protection control starts OFF 40 pulse Normal control Normal control Ending ON 400 pulse Normal control Normal control Running OFF 40 pulse Normal control Normal control Starting Oil return signal Thermo off unit EEV Thermo on unit EEV Fan Component MULTI V M Indoor Unit OFF Min pulse Max pulse Normal control 30Hz Ending OFF Min ...

Page 18: ...tarts Indoor Unit 1200 ơ 600 ơ 60 100 pulse 1200 ơ 600 ơ Normal Control Normal control Ending 400 800 pulse 400 800 pulse Running 60 100 pulse Normal control Normal control Normal control Starting Thermo off unit EEV Thermo on unit EEV Fan Component MULTI V M 4way valve Subcooling EEV Main EEV Fan Inverter compressor Component ON Min pulse Min pulse Min pulse Normal control OFF OFF 30Hz Starting M...

Page 19: ...0 800 pulse 400 800 pulse Running 60 100 pulse Normal control Normal control Normal control Starting Thermo off unit EEV Thermo on unit EEV Fan Component Function 2 2 Defrost Defrost operation eliminates ice accumulated on heat exchanger recovering performance of heat exchanger Each cycle component operates as following table during defrost operation n Ending condition 1 All heat exchanger pipe te...

Page 20: ...eration on cooling mode Note OFF Min pulse Min pulse Stop 0Hz Operation 4way valve Subcooling EEV Main EEV Fan Inverter compressor Component 1 hour after stop outdoor temp 30 C Note 4way valve Subcooling EEV Main EEV Fan Inverter compressor Component OFF ON ơ OFF Min pulse Min pulse Stop 0Hz Operation 2 3 2 Stopping operation on heating mode ...

Page 21: ...ecrease 3 Protection control Pressure Range Compressor Fan Ps 98 kPa 1 minute later operation Stop Ps 124 kPa 15Hz 10 s 100RPM 10 s Pressure Range Compressor Fan Pd 3846 kPa Stop Pd 3513 kPa 15Hz 10 s 50RPM 10 s Pd 3317 kPa Frequency holding 50RPM 10 s Pd 3115 kPa Frequency holding RPM holding Pd 3115 kPa Normal control Pressure Range Compressor Fan Ps 98 kPa 1 minute later operation Stop Ps 124 k...

Page 22: ...and power relay The state of pressure sensing switch is normally on It has small electric current from 220V AC Never touch the connecting terminal with hand nor short two wires directly Temperature Range Compressor Sub cooling EEV IDU EEV Tdis 115 OFF Min pulse Min pulse Tdis 110 5Hz 10 s SC_SH decrease control SH decrease control Tdis 108 5Hz 30 s 108 Tdis 105 no increase 105 Tdis 100 3Hz or less...

Page 23: ...nitial setup steps before running All DIP switch setting must be completed before initial setup 1 Step 1 factory setting value display Factory setting value is displayed in 7 segment on PCB for 24 s All dip switches must be set properly before step 1 4 Other control Power is on Master model code is displayed 3 s In case of 5HP 05 Blank 6 s Total capacity including sub units is displayed 2 s Heat p...

Page 24: ...n DISPLAY PCB is pressed for 6 s During auto addressing 7 segment on DISPLAY PCB displays 88 After auto addressing the number of indoor units is displayed in 7 segment for 30 s The address of each indoor unit is displayed on each wired remote controller Push address red button for 3 s Auto address starts Auto address is in progress max 15 min The number of indoor units is displayed for 30 s 10 ind...

Page 25: ...ation oFF op1 op3 selected the option change the set value blank save in EEPROM Night low noise oFF op1 op15 selected the option change the set value blank save in EEPROM ODU address 0 254 set the value change the set value blank save in EEPROM Snow removal rapid defrost oFF op1 op3 selected the option change the set value blank save in EEPROM Target pressure adjusting op1 op6 selected the option ...

Page 26: ...link Note 1 Note 2 Yes Low pressure 229kpa IDU ODU OFF Power reset after Dip switch off Pump down completed Press the red button SW01C Satisfy low pressure target ODU SVC V V Setting ODU SVC V V Setting Note If low pressure become under 307kPa blink close the gas SVC V V of all ODU immediately If low pressure descends below 229 kPa the system turns off automatically Close the gas SVC V V immediate...

Page 27: ...ot used set the dip S W OFF and reset the power If ODU Hz and RPM change cooling capacity may go down RPM Time Settings Master unit PCB DIP switch on No 5 Select the mode using Button Func Push the button Select the Function using Button Fn3 Push the button Select the Option using Button op1 op13 Push the button Start the Night low noise function Save the selected option value in EEPROM Step Judgm...

Page 28: ...V open Vacuum mode setting method Vacuum mode cancellation method Push the reset button on Master unit PCB Select the mode using ȯ ȭ Button SVC Push the button Select the Function using ȯ ȭ Button Se3 Push the button Master unit PCB DIP switch on No 5 Select the mode using ȯ ȭ Button Func Push the button Select the Function using ȯ ȭ Button Fn2 Push the button Select the Option using ȯ ȭ Button op...

Page 29: ... op1 op2 Push the button Cool Heat Selection mode is set Switch up Switch down Left side Right side mode setting method mode setting method Switch control Function Switch up Switch down oFF op1 mode op2 mode Right side on Left side off Not operate Cooling Cooling Right side on Right side on Not operate Heating Heating Left side off Not operate Fan mode Off CAUTION Ask an authorized technician to s...

Page 30: ...ta view fuction Display the cycle data value selected from the Segment No Title 7 seg Example Seg_1 Seg_2 Seg_3 Seg_4 1 Current High Pressure P1 4321 kPa 4 3 2 1 2 Current Low Pressure P2 1234 kPa 1 2 3 4 3 Inv Comp H1 120 Hz 1 2 0 4 Fan1 H3 110 RPM 1 1 0 5 Fan2 H4 110 RPM 1 1 0 6 Superheating degreee T1 53 5 3 0 7 Subcooling degreee T2 4 5 4 5 8 ODU temp T3 10 1 0 0 9 Suction temp T4 43 4 4 3 4 1...

Page 31: ...tion mode Refrigerant noise reduction mode setting method Master unit PCB DIP switch on No 5 Select the mode using ȯ ȭ Button SVC Push the button Select the Function using ȯ ȭ Button Se 8 Push the button Start the refrigerant noise reduction mode On Normal mode Fast cooling Fast heating Off Save the selected option value in EEROM ...

Page 32: ... 32 Copyright 2018 LG Electronics Inc All rights reserved Only training and service purposes Part 3 PCB Setting and Test Run ...

Page 33: ... main power supply and energizing the crankcase heater for more than 6 hours will cause the refrigerant to evaporate increasing the insulation resistance Check if high low pressure common pipe liquid pipe and gas pipe valves are fully opened NOTE Be sure to tighten caps Check if there are any problems in automatic addressing or not Check and confirm that there are no error messages in the display ...

Page 34: ...oor heat exchanger part Low pressure error or discharge temper ature error Motor insulation broken Strainer clogged Oil leakage Motor insulation failure R S T misconnection Motor failure bad ventilation around outdoor heat exchanger Bad connector contact Coil failure EEV clogged EEV clogged Check resistance between terminals and chassis Change strainer Check Oil level after opening oil port Check ...

Page 35: ...onics Inc All rights reserved Only training and service purposes Test Run n Location of setting Switch 3 DIP Switch Setting SW04C X cancel SW03C ȯ forward DIP SW01 7 Segment SW02C ȭ backward SW01C Ɨ confirm SW01D reset Display PCB ...

Page 36: ...ting of Compressor Module Checking according to dip switch setting You can check the setting values of the Master Compressor Module from the 7 segment LED The dip switch setting should be changed when the power is OFF Checking the initial display The number is sequentially appeared at the 7 segment in 5 seconds after applying the power This number represents the setting condition For example repre...

Page 37: ... 37 Copyright 2018 LG Electronics Inc All rights reserved Only training and service purposes Part 4 Trouble shooting guide ...

Page 38: ...ecking Method for Key Components 40 2 1 Compressor 40 2 2 Fan Motor 41 2 3 Electronic Expansion Valve 42 2 4 Phase Bridge Diode Checking Method 45 2 5 Inverter IPM Checking Method 46 2 6 Pressure Sensor High Low Pressure Sensor 47 2 7 Outdoor Fan 47 2 8 4 way Valve 48 2 9 Temperature Sensor 48 3 Self diagnosis function 19 Trouble shooting guide ...

Page 39: ...r switching ON the power supply Heating failure frozen outdoor heat exchanger part Low pressure error or discharge temper ature error Motor insulation broken Strainer clogged Oil leakage Motor insulation failure R S T misconnection Motor failure bad ventilation around outdoor heat exchanger Bad connector contact Coil failure EEV clogged EEV clogged Check resistance between terminals and chassis Ch...

Page 40: ... of the inverter occurred 2 You can use rectification voltmeter if using commercial frequency tester when measuring output values of the inverter when measuring absolute values Accurate measuring values cannot be obtained with a gen eral movable tester For analog and digital mode 1 2 Is how long power on during operation Does failure appears again when starting operation Method to measure insulati...

Page 41: ...ng wiring Modify connection status in front of or at the rear of the breaker or if the power terminal console is at frosting condition Modify the power supply voltage is beyond speci fied scope For following wiring 1 Check connection status 2 Check contact of the connector 3 Check that parts are firmly secured by tightening screws 4 Check connection of polarity 5 Check short circuit and grounding ...

Page 42: ...ate motor will not operate smoothly and start vibrating EEV valve operation ø1 ON ON OFF ON ø2 ON ON ON OFF ø3 OFF OFF ON OFF ø4 OFF OFF OFF ON Output ø No Output state 1 2 3 4 Valve open Angle close pulse open Full open 1950 pulses At power ON open angle signal of 1400 pulses out put and valve position is set to ⓐ If valve operates smoothly no noise and vibration occurs and if valve is closed noi...

Page 43: ...purposes EEV Coil and body MULTI V M Remove and assemble the coil Lead wire Coil Body Body Body Grip the A part tightly and pull up coil part upward When the coil part is removed or assembled be careful not to bend the pipe of the body Assemble Remove Checking Method for Key Components ...

Page 44: ...terminal red white red yellow red orange red blue 2 If the estimated resistance value is in 52 3 then the EEV is normal Replace EEV 1 Check the resistance between coil terminal brown white brown yellow brown orange brown blue 2 If the estimated resistance value is in 150 10 then the EEV is normal Replace EEV Indoor unit 1 Operate indoor unit with FAN mode and operate another indoor unit with COOLI...

Page 45: ...istance mode and measure If the value is small 0 Ω or high hundreds M Ω PCB needs to be replaced Red and black are the measuring terminals of multi tester Internal circuit diagram Appearance R red 0 4 V 0 7 V S red 0 4 V 0 7 V T red 0 4 V 0 7 V R black 0 4 V 0 7 V S black 0 4 V 0 7 V T black 0 4 V 0 7 V Diode terminal terminal black terminal red Tester terminal R S T չ ո S R Q CAUTION Check the el...

Page 46: ...w table 5 In case the measured value is different from the table set multi tester to resistance mode and measure If the value is small 0Ω or high hundreds MΩ PCB needs to be replaced 6 In case that IGBTM is damaged check if comp is needed to be replaced Red and black are the measuring terminals of multi tester P N Inverter PCB U V W 3 1 8 9 Checking Method for Key Components P terminal black N ter...

Page 47: ...placed 4 The composition of pressure sensor The pressure sensor is composed like the circuit picture shown above If DC 5V voltage flows on red and black wire voltage would be made between the white and black wire The pressure which is equivalent to the pressure output is shown in the table above 1 The outdoor fan is controlled by the inverter motor which can control the number of rotations 2 The o...

Page 48: ... Insulation resistance in the state of connecting the valve to coil should be over 100mΩ when measure it with DC mega tester DC 500V 1 Outdoor temperature sensor TH1 2 Discharge pipe D pipe temperature sensor TH2 1 Check the condition of installation and the contact of temperature sensor 2 Check whether the connector contact of temperature sensor is normal 3 Measure the resistance of temperature s...

Page 49: ...ive wired remote controller signal in indoor unit PCB 0 4 Drain pump Malfunction of drain pump 0 5 Communication error Compressor Module indoor unit Failing to receive Compressor Module signal in indoor unit PCB 0 6 Outlet pipe temperature sensor of indoor unit Outlet pipe temperature sensor of indoor unit is open or short 0 9 Indoor EEPROM Error In case when the serial number marked on EEPROM of ...

Page 50: ...r Module Heat Exchanger Temperature Sensor Front side open or short 4 6 Compressor Module Suction Temperature Sensor Fault Compressor Module Suction Temperature Sensor open or short 5 0 Omitting connection of R S T power of Compressor Module Omitting connection of Compressor Module 5 1 Excessive capacity of indoor units Excessive connection of indoor units compared to capacity of Compressor Module...

Page 51: ...4 Compressor Module Subcooling Inlet Temperature Sensor Error Compressor Module Subcooling Inlet Temperature Sensor Error 1 1 5 Compressor Module Subcooling Outlet Temperature Sensor Error Compressor Module Subcooling Outlet Temperature Sensor Error 1 5 0 Compressor Module Discharge Superheat not satisfied Compressor Module Compressor Discharge Superheat not satisfied during 5 Min 1 5 1 Failure of...

Page 52: ... open or less than 100Ω short Error occurs Refer Resistance value maybe change according to temperature of temp sensor It shows according to criteria of current temperature 5 margin Normal Air temp sensor 10 C 20 7kΩ 25 C 10kΩ 50 C 3 4kΩ Pipe temp sensor 10 C 10kΩ 25 C 5kΩ 50 C 1 8kΩ n Error diagnosis and countermeasure flow chart Is sensor properly connected to PCB Is the resistance value of sens...

Page 53: ... No Error Type Error Point Main Reasons The remote controller did not receive the signal from indoor unit during specific time 1 Remote controller fault 2 Indoor unit PCB fault 3 Connector fault Wrong connection 4 Communication cable problem n Error diagnosis and countermeasure flow chart If there is no remote controller to replace Use another unit s remote controller doing well Check cable Contac...

Page 54: ... with condensate water half level of float switch Is drain pump working Sound drain noise contact etc Replace float switch Replace Indoor PCB or reconnect the connector Yes Yes No No Is Float switch short On measuring its resistance No Yes Drain pump blocked by foreign particles Yes No In indoor unit PCB Does the terminal voltage for drain pump has 220V output Replace indoor unit PCB Replace Drain...

Page 55: ...tronics Inc All rights reserved Only training and service purposes Indoor PCB drain pump connector Check input of 220V Marked as CN DPUMP float A Point to check rotating Float switch Housing CN FLOAT Standard of drain pipe head height slope MAX 450 ...

Page 56: ... No Outdoor PCB fault Replace after checking Re connect communication cable No Yes Indoor PCB fault Replace after checking Note1 communication from IDU is normal if voltage fluctuation 9V 9V exists when checking DC voltage of communication terminal between IDU and ODU Is total number of indoor units connected displayed after auto addressing No END If the DC voltage between communication terminal A...

Page 57: ...e micro processor and the EEPROM on the surface of the PCB 2 ERROR due to the EEPROM damage Error No Error Type Error Point Main Reasons Error occur in EEPROM of the Indoor PCB Indoor unit EEPROM error n Error diagnosis and countermeasure flow chart Replace the indoor unit PCB and then make sure to perform Auto addressing and input the address of central control ...

Page 58: ...nnection proper Yes No Connect properly Is fan motor normal Replace indoor unit fan motor It is normal when check hall sensor of indoor fan motor as shown below Yes No k Replace indoor unit PCB Checking connection state of fan motor connector 1 4 5 6 7 1 5 6 7 4 4 4 4 Each termainl with the tester Tester Chassis hundreds kΩ hundreds kΩ hundreds kΩ hundreds kΩ Normal resistance 10 Replace the indoo...

Page 59: ...ables 2 Check insulation resistance between compressor terminal and pipe over 50m Replace compressor if abnormality found Are there any power wire connections normal No Yes 1 Check R S T N Wiring Condition Rewire them if abnormality found Is Inv PCB normal No Check Inv PCB IPM normality Replace Comp PCB assembly if abnormality found Is compressor Wire connection condition normal No 1 Check Inv PCB...

Page 60: ...bridge diode joining condition normal No Check joining condition of Inv PCB and bridge diode joining again if abnormality found Yes Is input voltage normal No Check R S S T T R phase voltage is 380V 10 R N S N T N phase voltage is 220V 10 Check connection condition and wiring if power is abnormal Yes Is Inv PCB normal No Check Inv PCB IPM normality Replace Inv PCB Are the resistance Between each p...

Page 61: ...ge is 220V 10 Check connection condition and wiring if power is abnormal Are there any power wire connections normal No Yes 1 Check R S T N wiring conditions Rewire them if abnormality found Is Inv PCB normal No Check Inv PCB IPM normality Replace Inv PCB if abnormality found Is bridge diode normal No 1 Check joining condition of bridge diode and heatsink 2 Check bridge diode joining again or repl...

Page 62: ...or off due to the high pressure switch in Compressor Module Excessive rise of discharge pressure in outdoor compressor 241 Is high pressure switch connector connected to PCB No Note 1 Note 2 Note 2 Connect securely Is high pressure switch connector short during off time Yes No Is this error appeared again after reset Yes No Is SVC valve open Yes Re check momentary problem or not Replace connecting...

Page 63: ...e there any power wire connections normal No Yes 1 Check R S T N wiring conditions Rewire them if abnormality found Is input voltage normal No Check R S S T T R phase voltage is 380V 10 R N S N T N phase voltage is 220V 10 Check connection condition and wiring if power is abnormal Is Inv PCB bridge diode joining condition normal No Check joining condition of Inv PCB and bridge diode joining again ...

Page 64: ...efrigerant pressure Reassemble or manage if abnormality found 1 Check resistance between each terminal of compressor Refer to the right side tables 2 Check insulation resistance between compressor terminal and pipe over 50m Replace compressor if abnormality found Are the resistance Between each phase and insulation resistance of Inverter compressor normal No Yes No Yes 1 Check Inv PCB U V W connec...

Page 65: ...s and Countermeasure Flow Chart Is input voltage normal No Yes Recheck power and installation condition Check R S S T T R phase voltage is 380V 10 R N S N T N phase voltage is 220V 10 Check connection condition and wiring if power is abnormal Is Inv PCB normal No Yes Replace Inv PCB 1 Check R S T N wiring conditions 2 Check Noise filter wiring conditions Rewire them if abnormality found No Yes Rep...

Page 66: ...f abnormality found Are the resistance Between each phase and insulation resistance of Inverter compressor normal No Yes 1 Check resistance between each terminal of compressor Refer to the right side tables 2 Check insulation resistance between compressor terminal and pipe over 50m Replace compressor if abnormality found Is compressor Wire connection condition normal No Yes 1 Check Inv PCB U V W c...

Page 67: ...ectric component part Replace Compressor Module EEV Does liquid injection corresponded operate normally Check liquid injection corresponded Is there pipe strainer etc clogging Check another components and operation conditions Take measures Replace strainer No Yes No Yes No Yes No Yes No Yes Resistance value of discharge temperature sensor 10C 362k 25C 200k 50C 82k 100C 18 5k Error No Error Type Er...

Page 68: ... times successive compressor off due to over increase of high pressure by high pressure sensor Over increase of discharge pressure of compressor 341 Is service valve opened No Open service valve Are communication cable pipe connection normal Yes No Is refrigerant amount normal refer refrigerant part Yes No Is fan normal Indoor fan during heating Outdoor fan during cooling Yes No Yes Adjust refrige...

Page 69: ...e opened Open service valve Are communication cable piping normal Yes No Is amount of refrigerant normal refer refrigerant part Yes No Is fan normal in heating outdoor fan in cooling indoor fan Yes Adjust the amount of refrigerant Additive charge check communication piping correction Check and replace related parts Is strainer Ok No Replace the strainer No Replace the pressure sensor Yes Yes Check...

Page 70: ... sensing part n Error Diagnosis and Countermeasure Flow Chart Is input voltage normal No Yes Recheck power and installation condition Check R S S T T R phase voltage is 380V 10 R N S N T N phase voltage is 220V 10 Check connection condition and wiring if power is abnormal Is Inv PCB assembly normal No Yes Replace Inv PCB assembly Measuring input voltage Inv PCB assembly 1 Check R S T N wiring cond...

Page 71: ...rresponding sensor Error is generated if the resistance is more than 5M open and less than 2k short Note Standard values of resistance of sensors at different temperatures 5 variation 10C 362k 25C 200k 50C 82k 100C 18 5k Check the resistance inverter compressor discharge temperature sensor Error No Error Type Error Point Main Reasons 411 Compressor1 discharge pipe temperature sensor error Sensor m...

Page 72: ...igh pressure connector 2 Defect of high pressure connector Open Short 3 Defect of outdoor PCB Error No Error Type Error Point Main Reasons Abnormal value of sensor Open Short Abnormal value of sensor Open Short Sensor error of low pressure Sensor error of high pressure 421 431 Is sensor connected to PCB correctly Connect sensor to PCB correctly Yes No No After replacement of Compressor Module main...

Page 73: ... Abnormal value of sensor Open Short Abnormal value of sensor Open Short Sensor error of outdoor air temperature Piping temperature sensor error of heat exchanger in master slave heat exchanger module heat exchanger A B Compressor suction temperature sensor error 441 461 451 Is sensor connected to PCB correctly Is sensor value correct Connect sensor to PCB correctly Replace sensor Yes No No Yes If...

Page 74: ...oltage Noise filter wiring Field Fault Case R Phase Terminal Changed Color Is input voltage normal No Yes Recheck power and installation condition Yes Check R S S T T R phase voltage is 380V 10 R N S N T N phase voltage is 220V 10 Check connection condition and wiring if power is abnormal Are there any power wire connections normal No Yes 1 Check R S T N wiring conditions Rewire them if abnormalit...

Page 75: ...um of indoor unit capacity exceed Compressor Module capacity specification Over Capacity Sum of indoor unit capacity is more than outdoor capacity 511 n Error diagnosis and countermeasure flow chart Is capacity sum of indoor units less than 130 of Compressor module capacity at LGMV No Yes Are quantity and capacity of indoor units installed same as the data of LGMV Yes Adjust the capacity of indoor...

Page 76: ...unication error between Inv PCB Main PCB 521 n Error diagnosis and countermeasure flow chart Is communication LED Yellow of Inv PCB on No Re connect communication cable Is communication cable connected correctly Yes No Re connect communication cable Is Main PCB normal Yes No Replace Main PCB Replace Inv PCB The method of checking Main PCB and Inv PCB If normal communication LED blinks Yes No Turn ...

Page 77: ...ED blinking Replace communication PCB 3 Auto addressing after replace Communication PCB Check outdoor Main PCB Is communication cable connected correctly No Yes Supply power Is power supplied to indoor PCB No Yes Are quantity of indoor Units installed same as The data of LGMV In case of CH53 almost happened with CH05 the indoor units not operated actually are normal so check with same method of CH...

Page 78: ...Troubleshooting Guide 78 Copyright 2018 LG Electronics Inc All rights reserved Only training and service purposes Communication Part in Main PCB Wiring Fault Case Remark IDU A IDU B ...

Page 79: ...rter signal at main PCB of Compressor module Communication error Main PCB Inv PCB 571 n Error diagnosis and countermeasure flow chart Are there any communication wire connections normal Is Inv PCB assembly normal Is there any error when power reset Recheck power and installation condition 1 Check communication wiring conditions 2 Check connector conditions Rewire them if abnormality found 1 Replac...

Page 80: ...fect wrong insertion 2 Different EEPROM Version 3 ODU Inv PCB assembly damage n Error Diagnosis and Countermeasure Flow 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 Inv PCB normal No Yes Replace Inv PCB Inv EEPROM inserting point Right inserting directio...

Page 81: ...EEV Defect Ref Overcharge Is Installation Condition Normal No 1 Check Pipe Clogging Distortion 2 Check Covering 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 IPM...

Page 82: ...Ω below short will generate error Note Temperate sensor resistance vary with temperature So compare temperature sensor resistance value according to Compressor module temperature by referring below table 5 tolerance Air temperature sensor 10 C 20 7kΩ 25 C 10kΩ 50 C 3 4kΩ Pipe temperature sensor 10 C 10kΩ 25 C 5kΩ 50 C 1 8kΩ Error No Error Type Error Point Main Reasons 651 Compressor module liquid ...

Page 83: ...ition Check Heat Exchanger Module Fan Motor assemble condition and fan locking Reassemble or replace if abnormality found Is Heat Exchanger Module Fan Motor normal No Yes 1 Check resistance between each phase U V W of Heat Exchanger Module fan motor terminal 16 8Ω 5 at 75 2 Check insulation resistance between Heat Exchanger Module fan motor terminal U V W Replace fan motor if abnormality found Is ...

Page 84: ... Voltage is abnormal T N 2 ODU Inv PCB damage CT sensing part Are there any power wire Connections normal No 1 Check R S T N wiring conditions 2 Check noise filer wiring conditions Rewire them if abnormality found Check R S S T T R phase voltage 380V 10 R N S N T N phase voltage 200V 10 Check connection condition and wiring if power is abnormal No Is input voltage normal Yes 1 Replace Inv PCB No I...

Page 85: ...in Reasons EEPROM Access Error Main PCB EEPROM 861 n Error Diagnosis and Countermeasure Flow Chart Reset after checking EEPROM assemble condition Replace Correct EEPROM EEPROM Insertion Same direction both socket hole and EEPROM hole Yes No Yes No Is EEPROM assemble condition normal Correct check sum Recheck power and installation condition Note Replace after power off EEPROM Main PCB ...

Page 86: ...re sensor resistance value according to Compressor module temperature by referring below table 5 tolerance Air temperature sensor 10 C 20 7kΩ 25 C 10kΩ 50 C 3 4kΩ Pipe temperature sensor 10 C 10kΩ 25 C 5kΩ 50 C 1 8kΩ Error No Error Type Error Point Main Reasons 1131 Compressor module liquid pipe condenser temperature sensor error Abnormal sensor resistance value Open Short 1 Defective temperature ...

Page 87: ...100 Ω below short will generate error Note Temperate sensor resistance vary with temperature So compare temperature sensor resistance value according to Compressor module temperature by referring below table 5 tolerance Air temperature sensor 10 C 20 7kΩ 25 C 10kΩ 50 C 3 4kΩ Pipe temperature sensor 10 C 10kΩ 25 C 5kΩ 50 C 1 8kΩ Error No Error Type Error Point Main Reasons 1141 Compressor module Su...

Page 88: ...as pipe direct connection N T S R T S R Measuring input voltage Noise filter wiring R L1 S L2 T L3 N 1 Ref leakage much Both Pipe in pipe out temp is under 10 during unit is off EEV 40pls Also big refrigerant flow noise occured n Error diagnosis and countermeasure flow chart Error No Error Type Error Point Main Reasons 1501 Discharge superheat low Discharge superrheat is under 3 liquid back Check ...

Page 89: ...ion are properly connected No Reconnect it After reset can we check supply voltage at PCB when starting heating mode operation No Is 4 way valve coil connected to 4 way valve normally ø No Is 4 Way valve coil resistance normal Change 4 Way valve coil No Yes Refer to CH 51 make measure Yes Is compressor working normally No Check and replace compressor Magnet switch corresponding PCB refer electric ...

Page 90: ...nfirm the 4way valve coil is inserted to the end Measure the resistance of 4way valve Check the output voltage of terminal socket during heating operation 90 Troubleshooting Guide Copyright 2018 LG Electronics Inc All rights reserved Only training and service purposes ...

Page 91: ...P NO MFL42395744 Copyright 2018 LG Electronics Inc All rights reserved Only training and service purposes ...

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