LG Gr P227 Ytqa Service Manual
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TROUBLE DIAGNOSIS - 101 - Problems Symptom Causes Checks Measures Remarks Defective Buzzer rings Trouble mode indication. Check trouble diagnosis function. Repair troubles Refer to mode display button. but key doesindication in not sense evenfunction button is explanations. pressed. Door Buzzer Buzzer Defective connecting lead wire from Check lead wire associated with door Repair lead wire. Check model continuously main PCB to door switch. switch. with dispenser. rings or door Defective freezer compartment door Refer to door switch in parts repair Replace Freezer opening alarm switch parts. guide. compartment door does not work.switch. Bad water/ice Ice and water Defective connecting lead wire from Check Lead Wire associated with lever Repair lead wire. dispenser. are not Main PCB to lever switch. switch with a tester. dispensed. Defective lever switch parts Refer to door switch in parts repair guide. Replace lever switch. Defective photo coupler IC parts. Check voltage change at photo coupler Replace photo output terminals with lever switch coupler IC or PCB. pressed. It is OK if voltage change is between 0V - 5V. Defective relay associated with ice Check relay with a tester. Replace defective dispense (geared motor, cube and relay. dispenser solenoid). Defective parts associated with ice Check resistance of parts with a tester. Replace defective dispense (geared motor, cube and parts. dispenser solenoid). Defective relay associated with water Check relay with a tester Replace defective dispense.relay. Defective parts associated with water Check resistance of parts with a tester. Replace defective dispenser.parts.
3. Cooling Cycle Heavy Repair 3-1. The Heavy Repair Standards for Refrigerator with R134a Refrigerant NOTE)Please contact Songso company on +82-53-554-2067 if you have inquiry on heavy repair special facility. TROUBLE DIAGNOSIS - 102 - NO. Items Unit Standards Purposes Remarks 1 Pipe and piping Min. Pipe:within 1 hour. To protect The opening time should be reduced to a system opening time. Comp:within Moisture half of the standards during rain and 10 minutes. Penetration. rainy seasons (the penetration of water Drier:within into the pipe is dangerous). 20 minutes. 2 Welding. Nitrogen Weld under To protect - Refet to repair note in each part. Pressure. Nitrogen oxide scale - R134a refrigerant is more susceptible to atmosphere formation. leaks than R12 and requires more care (N 2pressure: during welding. 0.1~0.2 kg/cm2) - Do not apply force to pipes before and after welding to protect pipe from cracking. 3N 2sealed parts. Confirm N2Confirm air leaking To protect - In case of evaporator parts, if it doesnt leak. sounds when moisture noise when removing rubber cap blow removing rubber penetration. dry air or N 2gas for more than 1 min cap. use the parts. Sound:usable No sound:not usable 4RefrigerationEvacuationMin. More than To remove Cycle. time 40 minutes. moisture. Vacuum Torr Below 0.03(ref) Note:Only applicable to the model degree equipped with reverse flow protect plate. Vacuum EA High and low Vaccum efficiency can be improved by Pressure sides are operating compressor during evacuation. evacuated at the same time for models above 200 Vacuum EA Use R134a To protect The rubber pipes for R12 refrigerant shall piping exclusive mixing of be melted when they are used for R134a manifold. mineral and refrigerant(causes of leak). ester oils. Pipe EA Use R134a To protect coupler cxclusive. R12 Refri- gerant mixing. Outlet R134a exclusive. (Socket) Plug R134a exclusive 5 Refrigerant weighing. EA Use R134a Do not mix - Do not weight the refrigerant at too hot or exclusively. with R12 too cold an area.(25°C is adequate.) Weighing refrigerant. - Use copper bombe allowance:±5g Socket:2SV Plug: 2PV R134a Note:Winter:-5g Note:Do not burn O-ring (rubber) during Summer:+5g welding. 6 Drier replacement. - Use R134a exclusivelyTo removefor R134a refrigeratorthe moisture - Use R12 exclusivelyfrom pipe.for R12 refrigerator-Replace drier whenever repairing refrigeratorcycle piping. 7 Leak check. -Do not use soapy Detect -Check oil leak at refrigerant leak area. water for check. refrigerant Use electronic leak detector if oil leak is it may be sucked leak area. not found. into the pipe by. -The electronic leak detector is very sensitive to halogen gas in the air. It also can detect R141b in urethane. Please practice, therfore, many times before use.
3-2. Summary Of Heavy Repair TROUBLE DIAGNOSIS - 103 - Process Contents Tools - Cut charging pipe ends and discharge refrigerant from Filter, side cutters drier and compressor. - Use R134a oil and refrigerant for compressor and drier Pipe Cutter, Gas welder, N 2gas - Confirm N 2sealing and packing conditions before use. Use good one for welding and assembly. - Weld under nitrogen gas atmosphere.(N 2gas pressure: 0.1-0.2kg/cm 2). - Repair in a clean and dry place. - Evacuate for more than forty minutes after connecting Vacuum pump(R134a manifold gauge hose and vacuum pump to high (drier) exclusively), Manifold gauge. and low (compressor refrigerant discharging parts) pressure sides. - Evacuation Speed:113l/min. - Weigh and control the allowance of R134a bombe in a R134a exclusive bombe(mass vacuum conditions to be ±5 g with electronic scales and cylinder), refrigerant(R134a) charge through compressor inlet manifold gauge, electronic (Charge while refrigerator operates). scales, punching off flier, - Weld carefully after inlet pinching. gas welding machine - Check leak at weld joints. Electronic Leak Detector, Minute leak: Use electronic leak detector Driver(Ruler). Big leak: Check visually or fingers. Note:Do not use soapy water for check. - Check cooling capacity ➀Check radiator manually to see if warm. ➁Check hot line pipe manually to see if warm. ➂Check frost formation on the whole surface of the evaporator. - Remove flux from the silver weld joints with soft brush Copper brush, Rag, Tool box or wet rag.(Flux may be the cause of corrosion and leaks.) - Clean R134a exclusive tools and store them in a clean tool box or in their place. - Installation should be conducted in accordance with the standard installation procedure.(Leave space of more than 5 cm from the wall for compressor compartment cooling fan mounted model.) Trouble diagnosis Remove refrigerant Residuals Parts replacement and welding Compressor compartment and tools arrangement Transportation and installation Check refrigerant leak and cooling capacity Vacuum Refrigerant charging and charging inlet welding
3-3. Precautions During Heavy Repair TROUBLE DIAGNOSIS - 104 - Items Precautions 1. Use of tools. 1) Use special parts and tools for R134a. 2. Removal of retained 1) Remove retained refrigerant more than 5 minutes after turning off a refrigerator. refrigerant. (If not, oil will leak inside.) 2) Remove retained refrigerant by cutting first high pressure side (drier part) with a nipper and then cut low pressure side. (If the order is not observed, oil leak will happen.) 3. Replacement of drier. 1) Be sure to replace drier with R134a only when repairing pipes and injecting refrigerant. 4. Nitrogen blowing 1) Weld under nitrogen atmosphere in order to prevent oxidation inside a pipe. welding. (Nitrogen pressure : 0.1~0.2 kg/cm 2.) 5. Others. 1) Nitrogen or refrigerant R134a only should be used when cleaning inside of cycle pipes inside and sealing. 2) Check leakage with an electronic leakage tester. 3) Be sure to use a pipe cutter when cutting pipes. 4) Be careful not the water let intrude into the inside of the cycle. 1 2 Compressor Low pressure sideCondenser High pressure side DrierEvaporator
3-4. Practical Work For Heavy Repair TROUBLE DIAGNOSIS - 105 - Items Precautions 1. Removal of residual refrigerant. 1) Remove residual refrigerant more than 5 minutes later after turning off the refrigerator. ( If not, compressor oil may leak inside.) 2) Remove retained refrigerant slowly by cutting first high pressure side (drier part) with a nipper and then cut low pressure side. 2. Nitrogen blowing welding. When replacing a drier: Weld and parts by blowing nitrogen(0.1~0.2kg/cm 2) to high pressure side after assembling a drier. When replacing a compressor: Weld and parts by blowing nitrogen to the low pressure side. Note) For other parts, nitrogen blowing is not necessary because it does not produce oxidized scales inside pipe because of its short welding time. 3. Replacement of drier. Inserting a capillary tube Measure distance with a ruler and put a mark(12 +3/-0)on the capillary tube. Insert tube to the mark, and weld it KEYPOINTING Observe the sequence for removal of refrigerant. (If not, compressor oil may leak.) KEYPOINTING Welding without nitrogen blowing produces oxidized scales inside a pipe, which affect on performance and reliability of a product. KEYPOINTING Be sure to check the inserted length of capillary tube when it is inserted. (If too much inserted, a capillary tube is clogged by a filter.) CompressorLow pressure side CondenserHigh pressure sideDrierEvaporator Release Refrigent IntakeSuction 121 2 Evaporator Drier High pressure side Condenser Refrigent Intake 12+3-0 Filter* Unit : mm
TROUBLE DIAGNOSIS - 106 - Items Precautions 4.Vacuum degassing. Pipe Connection Connect a red hose to the high pressure side and a blue hose to the low pressure side. Vacuum Sequence Open , valves and evacuate for 40 minutes. Close valve . 5.Refrigerant charging. Charging sequence 1) Check the amount of refrigerant supplied to each model after completing vacuum degassing. 2) Evacuate bombe with a vacuum pump. 3) Measure the amount of refrigerant charged. - Measure the weight of an evacuated bombe with an electronic scale. - Charge refrigerant into a bombe and measure the weight. Calculate the weight of refrigerant charged into the bombe by subtracting the weight of an evacuated bombe. KEYPOINTING - If power is applied during vacuum degassing, vacuum degassing shall be more effective. - Operate compressor while charging refrigerant. (It is easier and more certain to do like this.) KEYPOINTING - Be sure to charge the refrigerant at around 25°C. - Be sure to keep -5g in the winer and +5g in summer the amount of refrigerant charged= a weight after charging - a weight before charging (a weight of an evacuated cylinder)Calculation of amount of refrigerant charged 21 3 Compressor Low pressure Condenser High pressure DrierEvaporator Red Yellow Blue Vaccum PumpSuction pipe R134a Indicate the weight of an evacuated bombe
3-5. Standard Regulations For Heavy Repair TROUBLE DIAGNOSIS - 107 - Items Precautions 4) Refrigerant Charging Charge refrigerant while operating a compressor as shown above. 5) Pinch a charging pipe with a pinch-off plier after completion of charging. 6) Braze the end of a pinched charging pipe with copper brazer and take a gas leakage test on the welded parts. 6. Gas-leakage test * Take a leakage test on the welded or suspicious area with an electronic leakage tester. 7. Pipe arrangement Check each pipe is placed in its original in each cycle place before closing a cover back-M/C after completion of work. Particularly control the size of Joint Drain Pipe Compressor CondenserDrier Evaporator Bombe Rubber 1) Observe the safety precautions for gas handling. 2) Use JIG (or wet towel) in order to prevent electric wires from burning during welding. (In order to prevent insulation break and accident.) 3) The inner case shall be melted and insulation material (polyurethane) shall be burnt if not cared during welding inner case parts. 4) The copper pipe shall be oxidized by overheating if not cared during welding. 5) Not allow the aluminum pipes to contact to copper pipes. (In order to prevent corrosion.) 6) Observe that the inserted length of a capillary tube into a drier should be 12 mm. 7) Make sure that the inner diameter should not be distorted while cutting a capillary tube. 8) Be sure that a suction pipe and a filling tube should not be substituted each other during welding. ( High efficiency pump.) 12 mm+3-0 Drier Molecular Pipe Molecular Sieves +3 -0
3-6. Brazing Reference Drawings PIPE ASSEMBLY JOINT PIPE ASSEMBLY HOT LINE (Refrigerator)PIPE ASSEMBLY HOT LINE (Freezer) PIPE ASSEMBLY JOINT CONDENSER ASSEMBLY WIRE PIPE ASSEMBLY SUCTIONDRIER ASSEMBLY CAPI - TUBE Copper BrazerCopper(Silver) Brazer Silver Brazer Copper Brazer Copper Brazer Copper Brazer Coppper BrazerSilver Brazer Silver Brazer PIPE ASSEMBLY JOINT PIPE ASSEMBLY HOT LINE (Freezer) PIPE ASSEMBLY JOINT CONDENSER ASSEMBLY WIRE PIPE ASSEMBLY SUCTIONDRIER ASSEMBLY CAPI - TUBE Copper BrazerCopper(Silver) Brazer Silver Brazer Copper Brazer Copper Brazer Copper Brazer Coppper BrazerSilver Brazer 1) Type A 2) Type B TROUBLE DIAGNOSIS - 108 -
4. HOW TO DEAL WITH CLAIMS 4-1. Sound TROUBLE DIAGNOSIS - 109 - Problems Checks and Measures Whizz soundsExplain general principles of sounds. • All refrigerator when functioning properly have normal operating sound. The compressor and fan produce sounds. There is a fan in the freezer compartment which blows cool air to freezer and refrigerator compartments. Whizz sounds are heard when the air passes through the narrow holes into the freezer and refrigerator compartments. Cooling Fan sound in the compressor compartment. • There is a fan on the back of the refrigerator, which cools the compressor compartment. If there is a small space between the refrigerator and the wall, the air circulation sounds may be noticeable. Noise of Compressor. • This operating sound happens when the compressor compresses the refrigerant. The compressor rotates at 3600RPM. The sound of compressor operation becomes louder as the refrigerator capacity increases. Click soundsExplain the principles of temperature change. • The sounds happens when pipes and internal evaporator in the refrigerator compartment expand and contract as the temperature changes during the refrigerator operation. This sound also happens during defrosting, twice a day, when the ice on the evaporator melts. Clunk soundExplain that it comes from the compressor when the refrigerator starts. • When the refrigerator operates, the piston and motor in the compressor rotate at 3600RPM. This sound is caused by the vibration of motor and piston when they start and finish their operation. This phenomena can be compared with that of cars. When the car engine ignites and starts to rotate, the loud sound becomes gradually quiet. When the engine stops, it stops with vibration. Vibration soundCheck the sound whether it comes from the pipes vibration and friction. • Insert rubber or leave a space between pipes to avoid the noise. • Fix the fan blade if the noise is due to the collision of fan and shroud. • Fix the drip tray if it is loosened. Sound depends on the installation location. • Sound becomes louder if the refrigerator is installed on a wooden floor or near a wooden wall. Move it to the another location. • If the refrigerator is not leveled properly, a small vibration can make a loud sound. Please adjust the level of the refrigerator.
TROUBLE DIAGNOSIS - 110 - Problems Checks and Measures Sounds of water flowingExplain the flow of refrigerant. • When the refrigerator stops, the water flowing sound happens. This sound happens when the liquid or vapor refrigerant flows from the evaporator to compressor. Click soundsExplain the characteriistics of moving parts. • This noise comes from the MICOM controllers switch on the top of the refrigerator when it is turned on and off. Noise of ice maker operationExplain the procedure and principles of ice maker operation. (applicable to model with ice maker).• Automatic ice maker repeats the cycle of water supplying ➝icemaking ➝ice - Noise produced by ice dropping ejection. When water is supplied, the water supply valve in the machine room and hitting ice bank. makes sounds like “Whizz” and water flowing also makes sound. When water - Noise from motor sounds “Whizz”. freezes to ice, freezing sounds such as “click, click” are heard. When ice is being ejected, sounds like “Whizz” produced by a motor to rotate an ice tray and ice dropping and hitting ice bank sounds are also heard. Noise when supplying water.Explain the principles of water supplied to dispenser. • When the water supply button in the dispenser is pressed, the water supply valve in the compressor compartment opens and let the water flow to the water tank in the lower part of the refrigerator compartment. The water is dispensed by this pressure. When this happens, motor sound and water flowing sound are heard. Noise when supplying ice.Explain the principles of ice supply and procedure of crushed ice making in a dispenser. • When ice cube button is pressed, ice stored in the ice bank is moved by a Helix Pusher and dispensed. If crushed ice button is pressed, the cube ice is crushed. When this happens, ice crushing and hitting ice bank sounds are heard.