LG GR-472 Service Manual Download Page 27

Page: 27 / 46

- 27 -

7-2-7 TEMPERATURE COMPENSATION & OVERCOOLING/UNDERCOOLING COMPENSATION CIRCUIT

1. Refrigerator Temperature Compensation

➧

Table of Temperature Compensation by adjusting the resistance (Difference with the current temperature)

E.g.) If the refrigerator compensation resistance (RCR1) is changed from 10K (the current resistance) to 18K

(the adjustment resistance), the temperature of the refrigerator rises +1 °C.

Refrigerator

Resistance

Temperature Remark

(RCR1)

Compensation

180 K

Ω

+2.5 °C

Compensation by

56 K

Ω

+2.0 °C

raising the

33 K

Ω

+1.5°C

temperature

18 K

Ω

+1.0 °C

12 K

Ω

+0.5 °C

10 K

Ω

0 °C

Standard Temperature

8.2 K

Ω

-0.5°C

Compensation by

5.6 K

Ω

-1.0°C

lowering the

3.3 K

Ω

-1.5 °C

temperature

2 K

Ω

-2.0 °C

470

Ω

-2.5 °C

Summary of Contents for GR-472

Page 1: ...CAUTION BEFORE SERVICING THE UNIT READ THE SAFETY PRECAUTIONS IN THIS MANUAL REFRIGERATOR SERVICE MANUAL COLOR SUPER WHITE http biz lgservice com MODEL GR R463JCA Ref No GR R522JQA ...

Page 2: ...set 2 To prevent electric shock unplug prior to servicing 3 In case of testing with power on wear rubber gloves to prevent electric shock 4 If you use any appliances check regular current voltage and capacity 5 Don t touch metal products in cold freezer with wet hand It may cause frostbite 6 Prevent water flowing to electric elements in mechanical parts 7 When you stand up during observing the low...

Page 3: ...ration is over add the quantity in grams of R 134a to the refrigerant system Remember that every system has an exact quantity of R 134a with a tolerance of 5 grams that can be added Figure 4 Before performing this operation if the vacuum pump and refilling cylinder are connected make sure that the valve placed between the vacuum pump and refilling tube are closed to keep the Freon for adding to th...

Page 4: ...nob Dial REFRIGERATOR Micom Control Full Automatic Heater Defrost OUT CASE Coated Steel Sheet INNER CASE A B S INSULATION Polyurethane Foam FREEZER 1 EA REFRIGERATOR 2 EA VEGETABLE TRAY Drawer Type EGG TRAY 1 Pieces ICE TRAY 1 Piece 2 ICE BANK 1 Piece COMPRESSOR P T C Starting Type EVAPORATOR Fin Tube Type CONDENSER Wire Condenser REFRIGERANT R134a 150g DEFROSTING DEVICE Heater l SHELF DEFROSTING ...

Page 5: ...ATOR Micom Control Full Automatic Heater Defrost OUT CASE Coated Steel Sheet INNER CASE A B S INSULATION Polyurethane Foam FREEZER 1 EA REFRIGERATOR 2 EA VEGETABLE TRAY Drawer Type EGG TRAY 2 Pieces ICE TRAY 1 Piece 2 ICE BANK 1 Piece COMPRESSOR P T C Starting Type EVAPORATOR Fin Tube Type CONDENSER Wire Condenser REFRIGERANT R134a 150g DEFROSTING DEVICE Heater l SHELF DEFROSTING SYSTEM TEMPERATUR...

Page 6: ...helves Plastic or Steel or Tempered Glass Multi Flow Duct Vitamin Vegetable Drawer Optional Lamp Egg Storage Rack Freezer Door Rack Refrigerator Door Rack Dairy Conner Leveling Screw Vegetable Partitioner Optional Wine Rack Option if steel shelf You can use this as Vodka rack in the Freezer Bottle Guide NOTE This guide covers several different models The refrigerator you have purchased may have so...

Page 7: ...ass Multi Flow Duct Vitamin Vegetable Drawer Optional Lamp Egg Storage Rack Freezer Door Rack Refrigerator Door Rack Dairy Conner Leveling Screw Vegetable Partitioner Optional Wine Rack Option if steel shelf You can use this as Vodka rack in the Freezer Bottle Guide Refrigerator Temperature Electronic Control Optional NOTE This guide covers several different models The refrigerator you have purcha...

Page 8: ...ype Ice Making Optional Freezer Shelf REFRIGERATOR COMPARTMENT Deodorizer Optional Fresh Zone Lamp Shelves Plastic or Steel or Tempered Glass Multi Flow Duct Vegetable Drawer Lamp Temperature Control Dial Wine Rack Option if steel shelf You can use this as Vodka rack in the Freezer NOTE This guide covers several different models The refrigerator you have purchased may have some or all of the featu...

Page 9: ...emove the Cover Lamp R by the use of type driver inserting in the low holes of the cover 2 Loose 2 screw 3 Pull the Control Box R 4 Disconnect the Housing of lead wire 5 Separate the INSU Multi Duct and Control Box R 6 Separate the Thermistor and Control Box R 7 Separate the Thermistor and Display PCB 3 4 FAN AND FAN MOTOR 1 Remove the freezer shelf 2 Separate the twist by pulling right 3 Loosen 1...

Page 10: ... the Defrost Heater 1 Pull out the shroud F after removing the Grille Fan Figure 13 2 Separate the connectors connected with the Def Control ASM and replace the Def Control ASM after cutting the Tie Wrap Figure 14 3 6 LAMP 3 6 1 Freezer room lamp 1 Pull forward the lamp cover F hole 2 Remove the lamp F by turning 3 6 2 Refrigerator room lamp 1 Remove the cover lamp R by pulling with a type driver ...

Page 11: ...For normal operation of single phase induction motor in the starting operation flows in both main coil and sub coil After the starting is over the current is cut off in subcoil The proper features of PTC play the above all roles So PTC is used as a starting device of motor 4 2 3 PTC Applied Circuit Diagram According to Starting Method of Motor 4 2 4 Motor Restarting and PTC Cooling 1 For restartin...

Page 12: ... by cutting off current which flows to Compressor Motor 4 3 2 Role of OLP 1 OLP is attached to Hermetic Compressor used to Refrigerator and Show Case and prevents Motor Coil from being started in the Compressor 2 Do not turn the Adjust Screw of OLP in any way for normal operation of OLP Composition and connection Diagram of OLP CONTACTING POINT COVER BIMETAL CONTACTING POINT HEATER TERMINALS ADJUS...

Page 13: ...u u GR S472 S522 u u GR 472 522 NOTE 1 This is a basic diagram and specifications vary in different localities 13 ...

Page 14: ...vise the customer to use a regular Trans Replace Compressor OLP works within 30 sec in forcible OLP operation by turning instant power on and off Components start in the voltage of Rating Voltage 10 below Applied voltage isn t in the range of Rating Voltage 10 Check the resistance among M C S C and M S in Motor Compressor Check the resistance of two terminals in PTC Starter Check if applying a reg...

Page 15: ...ster or Whistone Bridge Figure 22 Separate the OLP from Compressor and check resistance value between two terminals of OLP with a Tester Figure 23 Observation value is 220V 50Hz 22Ω 30 115V 60Hz 6 8Ω 30 240V 50Hz 33Ω 30 127 220V 60Hz 22Ω 30 The resistance value is 0 or several hundreds Ω The value is Check another electric components Replace OLP Check another electric components Replace PTC Figure...

Page 16: ...ressor Replace the compressor Replace each component Raise the voltage Replace each component Cause Check if current flows to starting devices Check current flowing in sub coil of Compressor Check capacity of OLP The items described above are normal Cooling ability is poor Fan motor doesn t run Much frost are sticked to the EVAPORATOR Poor contacting Coil is shorted Shorted Replace each component ...

Page 17: ...ten or check if the door is closed up it firmly Dew forms Check if ambient temperature and humidity Wipe dew with a dry cloth This happening in the Out Case of surroumcling air are high is solved in low temperature and humidity naturally Is the gap in the door packed Fill up the gap Abnormal Is the set positioned in a firm and even place Adjust the Adjust Screw and position noise generates in the ...

Page 18: ...re Normal cooling is possible don t get cold formed when injecting Refrigerant at all of regular amount PARTIAL Freeze room and Flowing sound of Refrigerant A little high Normal discharging of CLOG Refrigerator is heard and frost forms more than refrigerant don t get cold in inlet only ambient The capillary tube is faulty normally temperature WHOLE Freezer and Flowing sound of Refrigerant Equal to...

Page 19: ...ge without fail 1 gauge of charging M C vacuum Perform vacuum operation until a proper 1 degree is within 1 Torr vacuum degree is built up 2 If the vacuum degree of the cycle inside is If a proper vacuum degree isn t built up 2 10 Torr below for low pressure and 20 Torr check the leakage from 2 for high pressure it says no vacuum the Cycle Pipe line part and 2 leakage state Quick Coupler Connectin...

Page 20: ...is plugged in it is set to Medium Each time the button is pushed it is set to Medium Medium High High Low Medium Low Medium in order 2 When the power is initially applied or restored after a power failure it is automatically set to Medium 7 DESCRIPTION OF FUNCTION CIRCUIT OF MICOM 20 Temp Control Medium Medium Low Low Medium High High TEMP C 6 4 3 2 0 ROOM REFRIGERATOR GR R472 R522 GR S472 S522 GR...

Page 21: ... circuited wire the defrosting will not be performed 7 1 3 SEQUENTIAL OPERATION OF ELECTRIC COMPONENTS The electric components such as the comp defrosting heater and cooling fan start sequentially to avoid the noise and damage to the part which may result from the simultaneous start of various components on turning the power on or after the completion of a test Condition of Operation Operating Seq...

Page 22: ...he refrigerator temp indication LED on the display of the refrigerator while the remaining LEDs are off 22 GR R472 R522 GR S472 S522 R1 R2 R3 R4 NO Error Error Code Display Cause State of Operation with Error R1 R2 R3 R4 Comp Cooling fan Defrostingheater ON OFF 1 2 3 Faulty refrigerator R sensor on the control box of the refrigerator Faultydefrostingsensor Defrosting failure Cut or short circuited...

Page 23: ...MICOM and IC 5Vdc The voltage for each part is as follows VA1 is a part for preventing the over voltage and noise When 385V or higher power is applied the inside elements are short circuited and broken resulting in the blowout of the fuse in order to protect the elements of the secondary part of the TRANS 23 PART VA 1 CE 2 CE3 VOLTAGE 220 Vac 12 Vdc 5 Vdc ...

Page 24: ... is changed 7 2 3 RESET CIRCUIT The RESET circuit is for allowing all the functions to start at the initial conditions by initializing various parts including the RAM inside the MICOM IC1 when the power is initially supplied or the power supply to the MICOM is restored after a momentary power failure For the initial 10ms of power supply LOW voltage is applied to the MICOM RESET terminal During a n...

Page 25: ...7 2 4 LOAD DRIVE CIRCUIT 1 Load Drive Condition Check 25 Load Type Measurement Location IC5 No 13 No 10 ON 1V or below Condition OFF 12V Comp Freezer Fan Motor Defrosting Heater ...

Page 26: ...MICOM OPENING or SHORT state of each TEMPERATURE SENSOR are as follows 7 2 6 DOOR OPEN DETECTING CIRCUITS 26 SENSOR CHECK POINT NORMAL 30 C 50 C SHORT CIRCUITED OPEN Refrigerator Sensor POINT Voltage 0 5 V 4 5 V 0 V 5 V Defrosting Sensor POINT Voltage A B MEASURING POINTS Freezer Refrigerator Door CLOSED OPEN IC1 Pin No 8 5 V 0 V ...

Page 27: ...mpensation resistance RCR1 is changed from 10K the current resistance to 18K the adjustment resistance the temperature of the refrigerator rises 1 C 65 13 Refrigerator Resistance Temperature Remark RCR1 Compensation 180 KΩ 2 5 C Compensation by 56 KΩ 2 0 C raising the 33 KΩ 1 5 C temperature 18 KΩ 1 0 C 12 KΩ 0 5 C 10 KΩ 0 C Standard Temperature 8 2 KΩ 0 5 C Compensation by 5 6 KΩ 1 0 C lowering t...

Page 28: ... DISPLAY LIGHT ON CIRCUIT The circuit shown above is to determine whether a function control key on the operation display is pushed and to turn on the corresponding function indication LED The drive type is the scan type 28 ...

Page 29: ...emperature This postponing is necessary because of perceiving speed Measure the F SENSOR SUPER FROST SENSOR R1 R2 SENSOR after disconnect CON5 of PWB ASSY MAIN TEMPERATURE SENSOR RESISTANCE OF REFRIGERATOR DEFROST SENSOR 20 C 77 KΩ 15 C 60 KΩ 10 C 47 3 KΩ 5 C 38 4 KΩ 0 C 30 KΩ 5 C 24 1 KΩ 10 C 19 5 KΩ 15 C 15 9 KΩ 20 C 13 KΩ 25 C 11 KΩ 30 C 8 9 KΩ 40 C 6 2 KΩ 50 C 4 3 KΩ ...

Page 30: ...OMPRESSOR lock or Replace COMPRESSOR blocked OLP PTC is poor Replace OLP PTC COMPRESSOR RELAY is Replace MAIN PWB RY1 poor THE CONNECTING WIRE Certify the black wire of MAIN is poor PWB CONNECTOR CON1 2 Whether refrigerant leaks or Measure the amount of frost Refrigerant leakage Remedy the leaking part leaks or not sticking on EVA and the and reaching Refrigerant surface temperature of condenser p...

Page 31: ...G is poor DEFROSTING is NO DEFROSTING 1 HEATER emit heat Check the MAIN PCB HEATER disconnection Replace HEATER poor TEMPERATURE FUSE Replace TEMPERATURE disconnection FUSE Connection is poor Certify EVA connection and wire of MAIN PWB CONNECTOR CON1 DEF SENSOR is poor Replace DEF SENSOR HEATER RELAY is poor Replace RY3 of MAIN PWB 2 DRAIN PIPE blocking Certify DRAIN PIPE DRAIN PIPE blocking Remov...

Page 32: ...7 5 MAIN PWB ASSEMBLY AND PARTS LIST 7 5 1 MAIN PWB ASSEMBLY u u GR R472 R522 32 ...

Page 33: ...7 5 2 MAIN PWB ASSEMBLY u u GR S472 S522 33 ...

Page 34: ...7 5 3 REPLACEMENT PARTS LIST u u GR R472 R522 34 ...

Page 35: ...7 5 4 REPLACEMENT PARTS LIST u u GR S472 S522 35 ...

Page 36: ...7 5 5 PWB ASSEMBLY DISPLAY AND PARTS LIST u u GR R472 R522 36 ...

Page 37: ...7 5 6 PWB ASSEMBLY DISPLAY AND PARTS LIST u u GR S472 S522 37 ...

Page 38: ...7 6 1 PWB DIAGRAM u u GR R472 R522 38 ...

Page 39: ... 39 ...

Page 40: ...7 6 2 PWB DIAGRAM u u GR S472 S522 40 ...

Page 41: ... 41 REF TEMP CONTROL ...

Page 42: ...04E 328B 401A 309A 308A 249 103B 103A 409B 158C 158F 501A 501F 411A 501K 410J 410G 410H 281B 120A 120A 158C 409B 120G 110A 120E 120B 120C 281A 281A 105A 301A 418A 109B 103C 407A 42 8 EXPLODED VIEW 8 1 The parts of refrigerator and the shape of each part are subject to change in different localities Capacitors and fuse are optional parts EV ...

Page 43: ...u u GR R472 522 GR S472 522 43 149A 110B 125A 131A 125J 125H 405C 404A 329A 405A 332A 154A 149C 151A 149C 155B 149C 140A 149B 149C 136A 136B 136A 136B 136D 136C 152B 152A 149D EV 330B ...

Page 44: ... 241A 241D 205A 249B 205A 233A 230A 203A 200A 210A 210B 231A 231A 231A 231A 201A 201A 212G 212C 212A 233B 243A 243B 244C 244A 244C 212G 212C 212A 241C 212G 201A 201A 212G 210A 210B 503B 503C 243A 243B 212A 212C 244C 212A 244A 244A 244A EV ...

Page 45: ... 136A 136B 136A 136B 203A 200A 210A 210B 201A 201A 235A 212G 212C 212A 205A 205A 241D 241A 241D 241A 136D 136C 149A 110B 125A 131A 125J 125H 330B 405C 404A 329A 405A 332A 149D 210A 210B 212G 212A 212C 233A 230A 231A 231A 243A 243B 244A 244C 243A 243B 244A 244C EV ...

Page 46: ...P No 3828JD8605W JUN 2005 Printed in Korea ...

Search results

Summary of Contents for GR-472

Reviews:

Related manuals for GR-472

Brands by name

Popular brands

LG GR-472, Service Manual

Search results

Summary of Contents for GR-472

Reviews:

Related manuals for GR-472

Brands by name

Popular brands