LG GR-K243UG, GR-K24PS Service Manual
MODEL : GR-K24PS/GR-K243UG
CAUTION
PLEASE READ CAREFULLY THE SAFETY PRECAUTIONS OF THIS MANUAL
BEFORE CHECKING OR OPERATING THE REFRIGERATOR.
KIMCHI REFRIGERATOR
SERVICE MANUAL
http://biz.lgservice.com
1. Safety warnings and cautions.......................................................................................................................3
2. Product specification .....................................................................................................................................6
3. Product installation method ..........................................................................................................................7
4. Circuit diagram ...............................................................................................................................................8
5. MICOM function and circuit description.......................................................................................................9
6. Freezing cycle and refrigerant.....................................................................................................................32
7. General details about the product ..............................................................................................................34
8. Characteristics of each part ........................................................................................................................36
9. Cautions for disassembling the product....................................................................................................41
10. Assembly diagram and service parts list.................................................................................................42
1. First check if there is any electric leakage in the refrigerator unit.
2. Always unplug the refrigerator before handling any electricity 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 careful for thin objects (glass sheet, book).
7. When the refrigerating cycle is damaged, always request service to the major repair service agency.
(This is to prevent the house from getting dirty from the gas within the cycle.)
8. Always double check for repairs related to safety to ensure customer safety.
Safety regulations
Contents
- 2 -
Chapter 1. Safety warnings and cautions
u Always observe the 'Safety Warnings' and 'Cautions', which hare intended to ensure safety while repairing or operating
the product.
u Precautions are classified into 'Warning' and 'Caution', as explained below.
w Warning Warning means a dangerous condition which could result in significant damage, injury or death if
the instructions are not followed.
w Caution Caution means a condition which could 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
or electric shock.
Use a dedicated circuit.
Overloading circuits or outlets
could cause a fire.
Do not allow the consumer to repair ,
disassemble or modify the refrigerator .
Damaged power plug can
cause fire or electric
shock.
w Warning
Safety warnings and cautions
- 4 -
This product should always be
grounded, when needed.
If you think that there is a possibility of electricity
leakage by water or moisture, always ground the unit.
Do not store flammable liquid or gas in
the refrigerator such as ether , benzene,
alcohol, medicine, LP gas etc.
It can cause an explosion or a fire.
Do not store medicine or academic
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 refrigerator .
Items stored on the
refrigerator could fall
and cause injury.
When disposing the refrigerator ,
remove the rubber packing on the door
and do not leave it where children play.
A child can be
dangerously entrapped in
the refrigerator.
w Warning
Grounding screw
Grounding line
Copper plateCopper plate
More than 75cm
Academic
material
Medicine
Ether
Benzene
gas
Safety warnings and cautions
- 5 -
When using the refrigerator for low
temperature in freezer or refrigerator ,
do not store bottles.
Bottles can freeze and cause the bottles to crack,
which can cause an injury.
During repairs, be sure all connectors
are tight and wires are properly routed.
Make sure the connectors of the housing part are
properly connected.
During 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.
Always use exact replacement parts.
Make sure that the model name, voltage, current and
temperature ratings are correct for the electric part.
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.
w Caution
Rated parts
After
After
After
minutesminutes
minutes
Chapter 2. Product specification
2-1. GR-K24PS/GR-K243UG
Product specification
- 6 -
Item GR-K24PS GR-K243UG
238Li 242.6Li
92Li 94.3Li
92Li 94.3Li
27Li 27Li
27Li 27Li
922mm 922mm
712mm 699mm
975mm 975mm
88kg 87kg
108W
Direct cooling
Electronic
Manual start, manual end
CYCLO PENTANE
1pc
8pcs
1pc
1pc
2pcs
MA57LAQF
PIPE ON SHEET
R134a(165g)
Freol 10G (220cc)
P6R8MA
4TM412RFBYY
ø110, 3blades attached
115V / 80W (Resistance: 165Ω)
115V / 80W (Resistance: 165Ω)
115V / 8W (Resistance: 1,653Ω)
115V / 6W (Resistance: 2,204Ω)
115V / 8W (Resistance: 1,653Ω)
CS: 160 VAC 100
µF
Volume
External
dimensions
Usable volume
Top left compartment
Top right compartment
Bottom left compartment
Bottom right compartment
Width
Depth
Height
Total weight
Motor power consumption
Cooling method
Store/Season
Icing removing method
Insulation material
Fresh vegetable basket
Kimchi storage container
Drawer storage container
Chungukjang fermenting container
Low temperature catalytic deodorizing system
Compressor
Evaporator
Refrigerant
Oil
PTC
Overload protection device
Fan motor for compressor cooling
Lid left compartment Kimchi seasoning heater
Lid right compartment Kimchi seasoning heater
Drawer left compartment Kimchi seasoning heater
Drawer left compartment Chungukjang seasoning heater
Drawer right compartment rice storage heater
Capacitor
Freeze cycle
Electrical part rating
Chapter 3. Product installation method
3-1. Method to adjust height of refrigerator
■ First adjust the level of the refrigerator.
(If the floor is uneven, the refrigerator may vibrate or cause noise.)
u Adjust the front to be leveled by turning the height adjustment screws under the front corners in the arrow direction.
3-2. Grounding method
1. In the following cases, you must always ground the refrigerator.
1) When using the refrigerator in the 110V region
2) When using the refrigerator in the 220V region where the power
outlet is not grounded to the side.
2. You must install a circuit breaker (rated current 15mA, rated
non-operating current 7.5mA) if it is difficult to ground the
refrigerator. For the circuit breaker, you can purchase and use the
one with plug and outlet.
3. For the grounding connector on back of the refrigerator, use a connecting line with a diameter of 1.6mm or longer or a
single core cord line with a nominal cross section area of 1.25mm or bigger. After soldering, bury the copper plate 75cm
or deeper from the ground.
u Size of copper plate: Thickness (0.7mm or more), area (90cm or more)
Do not ground the circuit in 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 exposition.
3. Phone line or lightning rod: If lightening strikes, dangerous voltage may be induced in the circuit.
Product installation method
- 7 -
Horizontal adjustment leg
(lower handle part)
Caution
GR-K24PS
Chapter 4. Circuit diagram
Circuit diagram
- 8 -
Chapter 5. MICOM function and circuit description
5-1. Function description
5-1-1. Display part
1. When the power is connected for the first time, it is set to “Lock”, “Left compartment-Cabbage Kimchi-Mid” and “Right
compartment-Cabbage Kimchi-Mid”.
2. During a power shut-down or when the power is reconnected, the refrigerator 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.
But even in the Lock status, if you press the “Compartment selection” button, it will operate in the order of “Lid left
compartment” ’ “Lid right compartment” ’ “Drawer right compartment” ’ “Drawer left compartment” to show you the
selected display.
MICOM function and circuit description
- 9 -
NOTCH
Cabbage/Radish/Mul Kimchi Vegetable/Fruit Light freezing Freezing food Rice Chungukjang
Min Mid Max Min Mid Max Min Mid Max Min Mid Max Min Mid Max Min Mid Max
Temperature 0°C -1.0°C -2.0°C 3.5°C 2.5°C 1.5°C -4.0°C -5.0°C -6.0°C -15°C -18°C -21°C 10.5°C 10°C 9.5°C 2.0°C 1.0°C 0°C
1) GR-K24PS
2) GR-K243UG
5-1-2. Food storage/seasoning function
(1) When selecting food type and storing temperature
1. Press the “Lock/Unlock” button for more than 2 seconds to switch to “Unlock” status.
2. Press the “Compartment selection” button to select the compartment to use.
3. Press the “Store” button to change the storing temperature to “Mid” ’ “Max” ’ “Min” ’ “Mid”. The food type changes as
follows. (“Cabbage Kimchi” ’ “Radish Kimchi” ’ “Mul Kimchi” ’ “Vegetable/Fruit” ’ “Light Freeze” ’ “Freeze” ’ “Old
Kimchi” ’ “Chungukjang” ’ “Rice”.) But the selected food type differs by the “Compartment selection”.
4. Press the “Lock/Unlock” button to complete the selection of food type and storing temperature. At this time, if a minute
passes without pressing the “Lock/Unlock” button, it will automatically switch to Lock status and end the food type and
storing temperature selection mode.
(2) When selecting food type and rhythm fermenting (seasoning)
1. Press the “Lock/Unlock” button for more than 2 seconds to switch to “Unlock” status.
2. Press the “Compartment selection” button to select the compartment to use.
3. Press the “Ferment” button to change the seasoning stage to “Seasoning” ’ “Seasoning+>” ’ “Mature seasoning” ’
“Underground fermenting” ’ “Fresh seasoning” ’ “Fresh seasoning+>” ’ “Seasoning”. The food type changes as follows
as the seasoning degree changes from “Fresh seasoning+>” ’ “Seasoning”. (“Cabbage Kimchi” ’ Radish Kimchi” ’ Mul
Kimchi” ’ “Old Kimchi” ’ ”Chungukjang”.). But the seasoning stage for old Kimchi and Chungukjang changes from
“Seasoning” ’ “Mature seasoning” ’ “Fresh seasoning” ’ “Seasoning”, and the underground fermenting only works for
the cabbage Kimchi in the lid right compartment. Also selected food type differs by the “Compartment selection”.
4. Press the “Lock/Unlock” button to complete the rhythm fermenting. At this time, if a minute passes without pressing the
“Lock/Unlock” button, it will automatically switch to Lock status and end the rhythm ferment (seasoning) selection mode.
5. When the rhythm fermenting selection is completed, the remaining time is indicated and when seasoning is done, the
remaining time will be “0 hours”. And the storing temperature will automatically be 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. Press the “Compartment selection” button to select the compartment to use.
3. At this time, press the “Flavor keeping” button to select or cancel the flavor keeping function. (But the flavor keeping
function only applies to the Cabbage Kimchi, Radish Kimchi and Mul Kimchi in the lid left and right compartment.)
4. Press the “Lock/Unlock” button to end the flavor keeping selection mode. At this time, if a minute passes without pressing
the “Lock/Unlock” button, it will automatically switch to Lock status and end the flavor keeping selection mode.
5. If you select flavor keeping during seasoning process, it will immediately end the seasoning and switch to flavor keeping.
At this time the storing temperature will automatically be set to “Mid”.
6. If you select the flavor keeping function, the refrigerator will lower the temperature to maintain the current Kimchi flavor.
(-1 degrees for “Min”, -0.5 degrees for “Mid” and -0 degrees for “Max”.)
7. During flavor keeping operation, a cold shock operation is done every 12 hours.
8. If you select rhythm fermenting during flavor keeping, the flavor keeping function will be canceled.
MICOM function and circuit description
- 10 -
5-1-3. When selecting power on/off function
1. Press the “Lock/Unlock” button for more than 2 seconds to switch to “Unlock” status.
2. Press the “Compartment selection” button to select the compartment.
3. At this time, press the “Power” button for more than 2 seconds to turn the power off.
4. At this time, all the LEDs in the display will be turned off with the power off LED turning on.
5. If you press the “Power” button when the power is off, it will turn on the power and recover to “Cabbage Kimchi” and
“Mid”.
6. When the power is turned off, the heater of the applicable compartment is turned off and the valve will be closed.
5-1-4. Rhythm fermenting control pattern diagram
1. The fermenting control pattern varies, depending on the temperature of the Kimchi when it is 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.
4. If a failure occurs, such as a sensor error during seasoning, the storage will default to Cabbage Kimchi storage status.
MICOM function and circuit description
- 11 -
: Seasoning heater ON/OFF
: Seasoning heater OFF
Time
Seasoning completeSeasoning start
Kimchi sensor temperature
Mul Kimchi (10 )
Storage operation
When the Kimchi placed
in the refrigerator is cool
When the Kimchi placed
in the refrigerator is
at room temperature
1st seasoning 5th seasoning2nd seasoning 3rd seasoning 4th seasoning
5-1-5. Temperature contr ol method
1. The compressor runs or stops and the 3-way valve opens or closes depending on the temperature sensed by each
sensor.
2. If the temperature in either compartment is unsatisfactory, the compressor is turned on and the 3-way value is opened to
the affected compartment.
3. If the temperatures in several compartments are unsatisfactory, the compressor is turned on and runs until both
compartments become satisfactory. The 3-way valve is opened and closed for each compartment until the temperature is
satisfactory.
4. During the seasoning cycle, if the temperature is low, the heater is turned on and if the temperature is high, the
compressor is turned on and the 3-way value is opened.
5-1-6. Buzzer sound
When you press a button on the front display, you will hear “ding dong” sound. (Refer to 5-2-4. (2) Buzzer operating circuit).
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 the power fails during the seasoning process, there is not power outage compensation function and the storage defaults
to previously set Kimchi type and temperature of “Mid”. (to protect excessive seasoning)
5-1-8. Operation in response to ambient temperature
The storage senses the ambient temperature and adjusts the temperature in the compartments accordingly. This keeps the
storage from being too cold or too warm because of seasonal variations and maintains exact temperatures in the
compartments.
MICOM function and circuit description
- 12 -
Storage
temperature
Operation in response to the ambient temperature
In general operation
Season Spring Summer Autumn Winter
5-1-9. Sequential operation of components
Components (compressor, 3-way valve, lid left compartment seasoning heater, lid right compartment seasoning heater,
drawer left compartment heater and drawer right compartment heater) are operated in a specific order to prevent damage
and noise caused by simultaneous operation of all parts when the unit is started and after completing the self-test routine.
g Operation order may slightly vary depending on temperature setting.
MICOM function and circuit description
- 13 -
Operation status Operating order Remarks
Initial power-up
Temperature of
the left of right
sensor is >10°C
Temperature of
the left of right
sensor is <10°C
When returning to
normal status in test
mode
Power
on
3-way
valve
open
3-way
valve
left
open
Compressor
on
Immediately 3 min 10 sec
Power
on
Compressor
on
Lid left
compartment
seasoning
heater on
Lid left
compartment
seasoning
heater off
3-way
valve
open
All
loads
off
Compressor
on
3-way
valve
open
3-way
valve left
open
3-way
valve lid right
compartment
open
Lid right
compartment
seasoning
heater on
Lid right
compartment
seasoning
heater off
Drawer left
compartment
seasoning
heater on
Drawer left
compartment
seasoning
heater off
Drawer right
compartment
seasoning
heater on
Drawer right
compartment
seasoning
heater off
Immediately 0.5 sec 5 sec 0.5 sec
0.5 sec 0.5 sec 0.5 sec 0.5 sec
0.3 sec 3 min 10 sec
0.3 sec 3 min
7 min
The 3-way valve is
opened to both
compartments for
3 minutes; then it is
opened to lid
left/right
compartment or
drawer left/right
compartment.
5-1-10. Error diagnosis function
1. The error diagnosis function is the function to support SVC in case of an error that can affect the performance of the
product.
2. If an error occurs, the control panel button will not work.
3. If an error occurs and is resolved, the refrigerator will default to the normal status. (The unit is reset.)
4. The error codes are shown in segment for the remaining seasoning time display of the right compartment, and all LEDs,
except for failure code, are turned off.
Note 1) A. For display 1) ,press the “compartment selection” and “store” button simultaneously, all LED’s will turn on except the
remaining fermentation time displaying LED’s.
B. For display 2) , press the left lid compartment store button and right lid compartment store button together all LED’s will turn
on except right lid compartment remaining fermentation time display LED’s.
MICOM function and circuit description
- 14 -
NO Item
Error code display
Error contents Remarks
Failure of lid left
compartment sensor
Failure of lid right
compartment sensor
Failure of drawer left
compartment sensor
Failure of drawer right
compartment sensor
Failure of outside
temperature sensor
Communications error
Lid left compartment sensor disconnected
or short circuited
Lid right compartment sensor disconnected
or short circuited
Drawer left compartment sensor
disconnected or short circuited
Drawer right compartment sensor
disconnected or short circuited
Outside temperature sensor disconnected
or short circuited
When communication is not working
continuously for 30 sec
* Check the connection
of each sensor
The connector could be pulled out.
Poor TR in communications part
1
2
3
4
5
6
E1
E2
E3
E4
CO
Note 1)
1) GR-K24PS
2) GR-K243UG
5-1-11. Test function
1. The test function checks the functions of the PCB and the refrigerator, searching for errors in parts.
2. The test switch on the PCB operates the test mode. The refrigerator reverts to the normal mode after 2 hours if you forget
to end it manually.
3. When the test mode is active, the buttons on the control panel are disabled but the buzzer still sounds a ding if one is
pressed.
4. When the test mode is completed, unplug the refrigerator briefly and plug it in again to reset it and allow normal
operation.
5. If a sensor failure or other failure is detected during the test mode, release the test mode to display the failure code.
6. During the display of the error code, test mode does not work even if you press the Test switch.
MICOM function and circuit description
- 15 -
Mode Operation Contents Remarks
Test 1
(lid left
compartment
cooling
power
mode)
Test 2 (lid
right
compartment
cooling
power
mode)
Test 3
(drawer
left
compartment
cooling
power
mode)
Test 4
(drawer
right
compartm
ent cooling
power
mode)
Normal
recovery
Press the test
switch once
Press the test
switch once when
Test 1 indicates it is
completed.
Press the test
switch once when
Test 2 indicates it is
completed.
Press the test
switch once when
Test 3 indicates it is
completed.
Press the test
switch once when
Test 4 indicates it is
completed.
1) Compressor ON.
2) 3-way valve open
3) Heater all off
4) Display “11”
1) Compressor ON.
2) 3-way valve open
3) Heater all off
4) Display “22”
1) Compressor ON.
2) 3-way valve open
3) Heater all off
4) Display “33”
1) Compressor ON.
2) 3-way valve open
3) Heater all off
4) Display “44”
Returns to initial status (COMP 7 min delay)
g The system recovers to
the initial status after a
maximum of 2 hours.
g The system recovers to
the initial status after a
maximum of 2 hours.
g The system recovers to
the initial status after a
maximum of 2 hours.
g The system recovers to
the initial status after a
maximum of 2 hours.
5-2. Circuit description
5-2-1. Power circuit
The power circuit consists of the noise attenuation part and the SMPS (Switch Mode Power Supply) part. The SMPS
consists of the rectifier (BD1 & CE1) to convert AC voltage to DC voltage, switching part (IC3) to switch the converted DC
voltage, transformer to transmit energy of the first side of the switching end to the second side, the secondary power to
supply power to MICOM and IC, and the feedback part (IC4) to feedback the secondary voltage to the first side of the
transformer in order to maintain the secondary voltage constant.
: High voltage (DC 310V) is maintained in this circuit. Wait at least 3 minutes after unplugging to allow the
current 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 microprocessor.
5-2-3. Reset circuit
The reset circuit allows the entire process to be
started from the initial status by resetting the
various elements within the MICOM (IC1), such as
RAM, whenever power is applied to the unit. Low
voltage is applied to the reset terminal for 10ms at
the beginning of the power input. The reset
terminal has a voltage of 5 V during general
operation. (If the reset operation fails, the
microprocessor will not operate.)
MICOM function and circuit description
- 16 -
Caution
OSC1
CSTLS4M00G53
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