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9-1-2. Overload protection relay (O.L.P) structure and function

• The overload protection relay cuts the power to protest the motor when the temperature of the compressor rises

abnormally or when the overly high current is sent to the compressor motor.

• Overload protection relay structure is composed of the bi-metal element that cuts the power based on the temperature and

the heater that heats during an over-current. They are attached to the external surface of the compressor and detects the
temperature of the compressor. The composing circuit is connected to the compressor motor in direct connection.

• When the overload protection relay operates, you can here a "tak" sound and the operation contact point of the bi-metal

separates from the fixed contact point. When the heat of the heater is reduced or when the temperature of the compressor
is lowered after 3-5 minutes, the bi-metal connects the circuit with another "tak" sound to operate the compressor.

The overload protection relay detects and operates by both the temperature and the current. Therefore
even when the power is not connected, it can still operate when the temperature of the surface is high and
it can operate when there is an over-current even with low temperature on the surface. But even though
this will not happen in reality, just make sure that the relay operates by a combination of abnormal
temperature and current. (But the effect from the current is bigger than that from the temperature.)

After the overload protection relay operates and it recovers after 3-5 minutes when the heat is lowered, it
can still operate again if the surface temperature or current is high. In other words, repeated operation for
several hours can cause a customer claim. At this time, adequately cool the compressor and connect the
power. Also there is a case when the relay operates but immediately recovers to operate again. At this
time, exchange the relay.

9-1-3. Starter (P.T.C) function and operating principle

• The starter is directly connected to the supplementary coil of the

compressor to accelerate the compressor operation. It is
internally installed within the external case of the compressor
like the overload protection relay.

• The starter is generally composed of P.T.C material but in the

past there were ones in relay contact point type.
P.T.C stands for Positive Temperature Coefficient, referring to a
resistance that has a constant value initially (ex 33

) but when

the power is connected the resistance becomes infinite. To
understand the role of the starter you must understand the
operating principle of the single phase inductive motor and
simple AC circuit.

Characteristics of each part

- 45 -

(Overload relay structure)

Bi-metal

Operation contact point

Fixed contact point

Base (phenol)

Terminal

(a) Internal structure        (b) Electric circuit diagram
 

Caution

AC

CR

P.T.C 

(Motor circuit)

Supplementary

coil

Main coil

Содержание GR-K192UF

Страница 1: ...CAUTION PLEASE READ CAREFULLY THE SAFETY PRECAUTIONS OF THIS MANUAL BEFORE CHECKING OR OPERATING THE REFRIGERATOR KIMCHI REFRIGERATOR SERVICE MANUAL http biz lgservice com MODEL GR K192UF ...

Страница 2: ...ectricity conducting parts 3 When testing the refrigerator with the power on use insulated gloves for safety 4 When using measuring instruments check the rated current voltage and capacity 5 Do not allow water or moisture to get into the mechanical or electrical parts of the refrigerator 6 Remove all things on top of the refrigerator before tilting it during repairs to avoid spills Be especially c...

Страница 3: ...result in damage or injury if instructions are not followed 3 Safety warnings and cautions Use caution to prevent electric shock The control panel main PCB uses 310V When replacing PCB parts wait at least 3 minutes after unplugging Always unplug the refrigerator before repairing Make sure that the power plug is not pressed by the back of the refrigerator Power plug may be damaged and cause a fire ...

Страница 4: ... material etc in the refrigerator Store an object that requires precise temperature control can cause deterioration in quality or unexpected reaction to cause a dangerous situation Do not set items particularly flower vase cup cosmetic or medicine on top of the refrigerator It can cause fire and electric shock or cause an injury from dropping Do not stack items or carelessly store food on the refr...

Страница 5: ...ing repairs remove all dust and foreign material from the housing part connector part and check part It can prevent problems such as tracking or short circuit Do not bend modify bend pull or twist the power cord It can cause fire or electric shock Allow at least 5 minutes for resetting if you unplug the refrigerator If can cause an overload to the condenser operation and cause problems After 5 min...

Страница 6: ... 80W Resistance 605Ω 250VAC 10µF 200VAC 50µF Volume External dimensions Usable volume Left compartment Right compartment Width Depth Height Totalweight Motorpowerconsumption Coolingmethod Store Season Insulationmaterial Freshvegetablebasket Kimchirefrigeratorcontainer Lowtemperaturecatalyticdeodorizingsystem Compressor Evaporator Refrigerant amount Oil PTC OLP Fanmotorforcompressorcooling Leftcomp...

Страница 7: ...d into a 115V grounded outlet If you are unsure of the voltage or grounding integrity consult a qualified electrician Take care not to ground the circuit at one of the following places 1 Water pipe If there is a plastic piping within the system the ground may not be valid 2 Gas pipe There is a danger of fire or explosion 3 Phone line or lightning rod If lightning strikes dangerous voltage may be i...

Страница 8: ...Chapter 4 Circuit diagram Circuit diagram 8 ...

Страница 9: ...ator maintains the prior display But in case of a power shut down or power reconnection during rhythm fermenting the temperature returns to Mid for the applicable food type 3 In Lock status you will not hear a buzzer even when you press the buttons and the functions will not work MICOM function and circuit description 9 Notch Temperature Kimchisrore Vegetable Fruit Light freezing Freezing food Min...

Страница 10: ...t seasoning selection mode 4 When Rhythmic fermentation is terminated the remaining time is displayed and when the fermentation is completed 0 hour is displayed as the remaining time and the storing temperature is automatically set to Mid 3 When selecting flavor keeping 1 Press the Lock Unlock button for more than 2 seconds to switch to Unlock status 2 Select Kimchi store as storing type Flavor ke...

Страница 11: ...placed into the storage the type of Kimchi being made and the degree of the seasoning selected 2 In the 1st seasoning cycle if the Kimchi is at room temperature the cold control operates 3 During the seasoning cycle if the Kimchi is cold the seasoning heater is turned on and if the Kimchi is warm the seasoning heater is turned off Only 1st seasoning and 2nd seasoning 4 If a failure occurs such as ...

Страница 12: ...of COMP and 3 Way valve operation 5 1 6 Buzzer sound When you press a button on the front display you will hear a varying buzzer sound depending on the type and function Refer to Buzzer operating circuit in p21 5 1 7 Power failure compensation function 1 When the power is restored after an outage the refrigerator performs the setting originally programmed except for Error status and Test mode 2 If...

Страница 13: ...temperature of the left and right compartments Operation in response to the ambient temperature In general operation Season Spring Summer Autumn Winter Operation status Operating order Remarks Initial power up Temperature of the left of right sensor is 45 C Temperature of the left of right sensor is 45 C When returning to normal status in test mode The3 wayvalveis openedtoboth compartmentsfor3 min...

Страница 14: ... holding Kimchi store button on the left chamber and Kimchi store button on the right chamber together for one second or longer If the outside temperature sensor is normal all LEDs are turned ON but if abnormal all LEDs are turned ON with the remaining time display on the right chamber OFF MICOM function and circuit description 14 Error code display NO Item Error code display At the remaining ferm...

Страница 15: ...button on the left chamber and Kimchi store button on the right chamber together for one second or longer When these buttons are released the LED returns to the previous state MICOM function and circuit description 15 TEST1 TEST2 TEST3 TEST4 Recover to initial status TEST S W Press once Mode Operation Comp Fan motor Valve L R ferment heater Display LED At the L R remaining fermentation time displa...

Страница 16: ...to dissipate There is a danger of electric shock 5 2 2 Oscillation circuit The oscillation circuit provides the clock signal for synchronization and calculation of time in relation to the logic elements of microprocessor IC1 MICOM OSC1 must always use the original rated parts because if the specification changes the timing generated will not be correct causing erratic functioning of the microproce...

Страница 17: ...rcuit description 17 Type of load COMP fan motor Left seasoning heater Right seasoning heater Measuring point IC7 13 10 11 Status ON Within 1V OFF 12V LED MODULE TYPE Ex Lock Ding D Dong sound Ex Lock Ding D Dong sound Off IC101 Pin 3 61 5V IC101 Pin 2 62 0V Measuring point Status 45ms 1046 5Hz 1174 7Hz 1318 5Hz 45ms 45ms45ms 70ms 750ms 5V 0V 5V 0V 45ms 1568 0Hz 1318 5Hz 1046 5Hz 45ms 45ms45ms 70m...

Страница 18: ... sensor to detect the outside ambient temperature and sensors in the left and right compartments for storing and seasoning Kimchi The status of each sensor whether open or shorted is shown below MICOM function and circuit description 18 Sensor Check point Normal 30 C 50 C Shorted Open Left compartment sensor POINT Voltage Right compartment sensor POINT Voltage 0 5V 4 5V 0V 5V Ambient temp sensor P...

Страница 19: ...e motor and the coil wrapped around each stator 5 2 8 Power failure compensation circuit located on display PCB u The power failure compensation circuit recalls the temperature range of the right and left compartments and maintains these levels if power if interrupted briefly The IC for power failure compensation EEPROM delivers to and maintains the information in MICOM through the serial interfac...

Страница 20: ...CUP 4 CUP 4 5 CUP 5 CUP 2KΩ 0 5 CDOWN Nochange 0 5 CUP 1 CUP 1 5 CUP 2 CUP 2 5 CUP 3 CUP 3 5 CUP 4 CUP 4 5 CUP 3 3KΩ 1 CDOWN 0 5 CDOWN Nochange 0 5 CUP 1 CUP 1 5 CUP 2 CUP 2 5 CUP 3 CUP 3 5 CUP 4 CUP 5 6KΩ 1 5 CDOWN 1 CDOWN 0 5 CDOWN Nochange 0 5 CUP 1 CUP 1 5 CUP 2 CUP 2 5 CUP 3 CUP 3 5 CUP 8 2KΩ 2 CDOWN 1 5 CDOWN 1 CDOWN 0 5 CDOWN Nochange 0 5 CUP 1 CUP 1 5 CUP 2 CUP 2 5 CUP 3 CUP 10KΩ 2 5 CDOWN...

Страница 21: ...on and circuit description 21 JCL1 JCL2 JCR1 JCR2 CUT 1 C CUT 1 C CUT 1 C CUT 1 C CUT CUT 0 C CUT CUT 0 C 0 C Factory default 0 C Factory default Left compartment cut compensation Left compartment storing temperature compensation Right compartment storing temperature compensation Under cool compensation Over cool compensation Under cool compensation Right compartment cut compensation Over cool com...

Страница 22: ...ain PCB and the MICOM of the display PCB If there is no communication between these boards for 30 seconds a communication error occurs MICOM function and circuit description 22 DISPLAY PCB MAIN PCB MAIN MICOM MICOM for LED control DC 12V GND Receive Notch status Send Error status PWB PCB ASSEMBLY MAIN PWB PCB ASSEMBLY DISPLAY ...

Страница 23: ... Button input and display part illumination circuit This circuit determines which buttons are pressed and drives the LED display whose driving method is a scan method MICOM function and circuit description 23 ...

Страница 24: ...argin of error u For left and right sensor measure both sensor ends of the connector after separating the connectors of CON2 and 3 of PWB PCB assembly and main part For the outside sensor measure end of 2 and 5 of CON5 MICOM function and circuit description 24 Measuring temperature C Left sensor right sensor outside 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 1...

Страница 25: ... PCB parts diagram and parts list 5 4 1 PWB PCB assembly and main parts diagram The parts diagram can slightly change according to the situation MICOM function and circuit description 25 E B R 3 2 8 7 2 2 ...

Страница 26: ...5 4 2 PWB PCB assembly and main parts list g The parts list can slightly change according to the situation MICOM function and circuit description 26 ...

Страница 27: ...5 4 3 PWB PCB assembly and display parts diagram and parts list g The parts list can slightly change according to the situation MICOM function and circuit description 27 ...

Страница 28: ...5 5 PCB circuit diagram 5 5 1 PWB PCB assembly and main circuit diagram g PCB circuit diagram can slightly change according to the situation MICOM function and circuit description 28 ...

Страница 29: ...MICOM function and circuit description 29 ...

Страница 30: ...ssembly and display circuit diagram EBR381171 g The circuit diagram can slightly change according to the situation g This includes the PWB PCB assembly and sub circuit diagram MICOM function and circuit description 30 ...

Страница 31: ...rounding us This requires an insulated space refrigerant R134a to absorb the heat and the circulation circuit compressor condenser evaporator etc to operate the phase change of the refrigerant 6 1 2 Refrigerant gas circulation diagram 1 Compressor 2 Wire condenser 2 1 Hot line pipe 3 Drier 4 3 way valve 5 Capillary tube left 6 Capillary tube right 7 Evaporator left 8 Evaporator right 9 Suction pip...

Страница 32: ...the refrigerant from low pressure 0kg cm2 to high pressure 8 12kg cm2 High pressure gas refrigerant exhausts heat and becomes liquid refrigerant There is an absorbent that absorbs the moisture within the circulation circuit Moisture absorption device This is the long narrow pipe where high pressure refrigerant passes to reduce the pressure Low pressure liquid refrigerant absorbs heat to change to ...

Страница 33: ...locker This is effective in high frequency area Using sound absorber This method is similar to the blocking method but uses Styrofoam and glass wool in the transmission path to absorb the sound This is effective in low frequency area Vibration reduction This method blocks the mechanical vibration from the operating part so that it does not reach other parts using vibration reduction rubber etc Dyn...

Страница 34: ... device noise Wire condenser noise vibration noise u The installation floor surface is not hard enough u The refrigerator is not leveled u Wing sound u Woong Woong sound u Poor balance of the compressor u Contacting sound of the surrounding pipe of the compressor part u Contact sound from the OLP contact point during compressor operation u Woong Woong sound u Ching sound Reinforce the floor hardne...

Страница 35: ...netration of mineral oil and ether oil Prevent mixed penetration of R12 refrigerant Prevent mixed penetration of R12 refrigerant Prohibit mixed use of R12 refrigerant Prohibit mixed use of R12 refrigerant Remove moisture existing within the piping Detect refrigerant leakage part for reference Specially manage to half or lower of the prior standard during rain or rainy season Especially the water p...

Страница 36: ...he naked eye or finger to check the oil from the compressor g Caution Do not use soap water for the leakage parts Cooling performance check 1 Check whether the heat emitter is warm by hand 2 Check if the moisture is formed evenly around the evaporator surface within the refrigerator The flux of the silver welding part should be removed with soft brush or wet cloth etc Flux can accelerate rusting a...

Страница 37: ... piping repair and inserting the refrigerant always use the drier for R134a 1 To prevent the oxidization scale from forming within the pipe weld it while substituting the nitrogen with a constant pressure within the piping nitrogen pressure 0 1 0 2kg cm2 1 Internal cleaning and sealing within the cycle pipe should be done with nitrogen gas or R134a refrigerant 2 When checking for leakage use the e...

Страница 38: ...r Blow the nitrogen gas to the low pressure side and then do the welding on part 1 and 2 Note The heating time during welding for other parts is very short and the possibility of forming an internal oxidization scale is very low Exclude the nitrogen blowing for other parts 1 Removing residual refrigerant 2 Nitrogen blowing welding Welding nitrogen substitute Item Caution 2 1 3 Way Valve Condenser ...

Страница 39: ... in the bombe calculate and measure the weight 4 Vacuuming 5 Refrigerant charging Item Caution 3 1 2 3 Way Valve Condenser Hot Line Pipe Vacuum pump Evaporator Compressor Drier High pressure side Low pressure High pressure Blue Yellow Red Indicates the weight of empty bombe Room temperature must be around 25 C during the operation Control the refrigerant charging amount as follow 5g in winter and ...

Страница 40: ...e compressor and charge the refrigerant with the charging pipe 5 When the charging is complete pinch the charging pipe using the pinch off plier 6 After welding the end of the pinched charging pipe with copper test for gas leakage on the welding part Using an electric weight test for leakage on welded parts and other parts that you think can leak gas out When the work is done check whether all pip...

Страница 41: ...6 17 22 24 10 26 7 3 25 3 Way Hot Line Pipe Valve Accumulator Suction Pipe Evaporator Evaporator Condenser Drier 20 21 14 13 Left compartment Right compartment Welding classification Applied parts Remarks Copper 1 2 3 7 10 13 14 17 20 21 22 24 25 26 27 Silver 4 5 6 8 9 16 LOKRING 11 12 18 19 ...

Страница 42: ...disconnected Valve problem Welding part leaking Check leaking part Heat emitter leaking Valve housing not inserted Capillary tube clogged Main PWB housing not inserted Valve L wire disconnected Valve problem Welding part leaking Check leaking part Heat emitter leaking Poor operation of 3 way valve Refrigerant leaking Left side cycle clogged Poor operation of 3 way valve Refrigerant leaking Right s...

Страница 43: ...nge the 3 way valve assembly If you have to weld it for a specific reason cover the body with a wet towel and minimize the heat transmission below 100 C 2 Valve exchange service valve problem You must do the service operation in the same method as above 3 Other cautions 1 You must insert the capillary tube by 13 for welding This is to prevent the clogging of the tube during welding 2 Be careful no...

Страница 44: ... connected to the external heat emitter u The compressor for service is supplied with nitrogen gas charged and the rubber cap sealed This is to prevent internal oxidization and the prevent moisture in the atmosphere from penetrating When removing the cap for exchanging the compressor you can hear a pik sound with nitrogen gas emitting which means it is a normal product If the nitrogen gas is emitt...

Страница 45: ...rates by a combination of abnormal temperature and current But the effect from the current is bigger than that from the temperature u After the overload protection relay operates and it recovers after 3 5 minutes when the heat is lowered it can still operate again if the surface temperature or current is high In other words repeated operation for several hours can cause a customer claim At this ti...

Страница 46: ...ator 2 Operating structure Characteristics of each part 46 Compressor Refrigerant valve CAPILLARY TUBE Left compartment CAPILLARY TUBE Right compartment Evaporator Left compartment Evaporator Right compartment Suction pipe Valve body External structure Operating circuit Internal structure Operating coil Pipe inlet Pipe outlet Valve coil ...

Страница 47: ...e rotor 4 Operating characteristics Characteristics of each part 47 Left Right compartment open STEP 0 Right compartment open STEP 54 Left Right compartment open STEP 36 Left compartment open STEP 18 Closed area Valve Left side outlet Right side outlet Initial control Power reset Left Right Left compartment open Right compartment open Clockwise rotation Counter clockwise rotation ...

Страница 48: ...As shown below it is a 2 pole device with one pole composed of 2 parts On the small pole called the shading pole wire is connected shorted called the shading coil In accordance with the characteristics of the AC motor the motor switches between and to operate but because in the 2 pole device the N and S pole changes within both poles without left and right rotation the device cannot rotate without...

Страница 49: ...se is generated from the shading coil to reduce the velocity shifting the center of the magnetic field to the main pole In b zone the change in current is minimal and the negative effect of shading coil is minimal to have the center of the magnetic field in the middle as shown in Fig 2 In c zone the velocity of the main pole decreases but with the negative effect increasing the velocity from the s...

Страница 50: ...tion Applied part Function Resistance value Remarks Problem parts Symptom Check method Resolution 1 Heat wire disconnected connecting wire disconnected 2 Poor terminal contact Kimchi not seasoned 1 Measure the resistance of both ends of the heater with a tester to see if it is Ω 2 Measure the resistance of both ends of the heater with a tester to see if it fluctuates 1 Exchange the product 2 Prope...

Страница 51: ...e multiplier rate to maximum within the resistance measuring range measure while switching the terminals Characteristics of each part 51 A electrode Dielectric material B electrode Problem parts Symptom Check method Resolution Disconnected open Shorted Normal 1 Compressor does not work 2 Compressor is heated 3 OLP is operating 4 Power fuse is disconnected Immediately after exchanging or frequently...

Страница 52: ...PCB assembly main located in the mechanical room be careful so that the lead wires do not touch the edge part If the lead wire coating is disconnected or the coating is damaged it can cause a short circuit 10 2 Frame assembly display Cautions for disassembling the product 52 Case U Deco Case Frame Display ...

Страница 53: ... Assembly diagram and service parts list 53 203A 243A 243A 501A 410H 502B 323B 310B 317A 307A 314A 308A 309A 312A 315C 619A 411A 319A 319C 420A 329C 327A 315D 315A 315B 304A 310A 281B 222A 233A 233A 281B 221A 233A 200A 233A 200B 230A 230B 283D 327B 243A 243A 203A 604A 641H 604A 641H ...

Страница 54: ...Assembly diagram and service parts list 54 249G 249D 248A 249B 212D 102A 102A 248D 147C 147A 270A 212G ...

Страница 55: ...P No MFL31842103 FEB 2008 Printed in Korea ...

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