LG GR-267 Service Manual ▷ View online
3-5. Temperature sensor circuit, heater-sheet operation circuit.
The above circuits are freezer and refrigerator sensors to detect the set temperature of freezer and refrigerator, icemaking
sensor to detect water temperature, and defrost sensor which is fixed on the evaporator detects the temperature for defrost.
sensor to detect water temperature, and defrost sensor which is fixed on the evaporator detects the temperature for defrost.
The short or open condition of each sensor is as follows
*As Heater-Sheet is always on, 12V dc is applied to No.1 and No.2 terminals in CON10.
MICOM FUNCTION AND CIRCUITS
- 40 -
SENSOR
CHECK POINT
NORMAL(-30
°
C~50
°
C)
SHORT
OPEN
HOME BAR SENSOR(option)
POINT
a
Voltage
FREEZER SENSOR
POINT
b
Voltage
DEFROST SENSOR
POINT
c
Voltage
REFRIGERATOR SENSOR 2
POINT
d
Voltage
0.5V~4.5V
0V
5V
REFRIGERATOR SENSOR 1
POINT
e
Voltage
ICEMAKING SENSOR
POINT
f
Voltage
ROOM TEMPERATURE
POINT
g
Voltage
63
HEATER-SHEET
(DUCT-DOOR)
H-SENSOR
(HOME BAR-SENSOR)
F-SENSOR
(FREEZER-SENSOR)
R2-SENSOR
(REFRIGERATOR SENSOR 2)
R1-SENSOR
(REFRIGERATOR SENSOR 1)
CON10
CON7
P67
(AIN7)
P64
(AIN4)
P63
(AIN3)
P66
(AIN6)
P65
(AIN5)
CC14
104
R38
2K
RF7
26.1KF
1
IC1
(MICOM)
1
2
3
4
60
CC15
104
R44
2K
RF1
26.2KF
2
59
CC16
104
R45
2K
RF2
26.1KF
3
1
3
2
4
CON8
62
CC18
104
R48
2K
RF3
26.1KF
4
61
CC19
104
R49
2K
RF4
26.1KF
5
1
3
2
4
D-SENSOR
(DEFROST-SENSOR)
ICE MAKER
SENSOR
RT-SENSOR
P62
(AIN2)
CON9
58
CC27
104
R61
2K
RF6
16.7KF
RF5
10KF
6
2
1
P70
(AIN10)
CON6
1
CC28
104
R39
2K
7
13
14
3-6. Switch Input Circuit
The following is the input circuit to detect signals of test switch and electronic single motor damper reed switch to check
refrigerator.
refrigerator.
3-7. Option Designated Circuit (Model Classification Functions)
The above circuit is to designate option of classification for each model and inform to Micom. The designated option and
application standard for each model are as follows.
application standard for each model are as follows.
• This circuit is fixed correctly when the refrigerator is shipped from the factory. Do not add or remove options at your
discretion.
MICOM FUNCTION AND CIRCUITS
- 41 -
R40
4.7K
R53
2K
SINGLE MOTOR
DAMPER
REED S/W
R52
TEST S/W1
2K
CC21
104
P45
(SCK2)
46
P46
(S12)
47
IC1
(MICOM)
7
8
CON 8
40
OP1
OP2
41
P37
P40
IC1
(MICOM)
R25
R26
4. 7K
X
2
Classification
Connecting Conditions
Applicable Standards
Connection
Model with home bar
OP1
Cut
Model without home bar
Connection
Model with dispenser
OP2
Cut
Model without dispenser
3-8. Temperature Compensation and Overcooling and Less Cooling Compensation Circuits
1. Freezer Compartment, Refrigerator Compartment Temperature Compensation
• Temperature Compensation versus Compensation Resistance (the temperature difference compared to the present
temperature)
EX) If the compensation resistance (RCR1) of refrigerator compartment is changed from 10k
Ω
to 18k
Ω
(revised
resistance), the temperature of refrigerator compartment goes up by +1
°
C.
MICOM FUNCTION AND CIRCUITS
- 42 -
R19
10K
RCR1
10K
R20
10K
Refrigerator Compartment
Temperature Compensation
56
57
RCF1
10K
IC1
(MICOM)
P60
(AIN0)
(AIN0)
P61
(AIN1)
(AIN1)
Freezer Compartment
Temperature Compensation
Freezer Compartment
Refrigerator Compartment
Resistance
Temperature
Resistance
Temperature
Remarks
(RCF1)
Compensation
(RCF1)
Compensation
180k
Ω
+5
°
C
180k
Ω
+2.5
°
C
Compensate to be
56k
Ω
+4
°
C
56k
Ω
+2.0
°
C
warmer
33k
Ω
+3
°
C
33k
Ω
+1.5
°
C
18k
Ω
+2
°
C
18k
Ω
+1.0
°
C
12k
Ω
+1
°
C
12k
Ω
+0.5
°
C
10k
Ω
0
°
C
10k
Ω
0
°
C
Standard temperature
8.2k
Ω
-1
°
C
8.2k
Ω
-0.5
°
C
5.6k
Ω
-2
°
C
5.6k
Ω
-1.0
°
C
3.3k
Ω
-3
°
C
3.3k
Ω
-1.5
°
C
2k
Ω
-4
°
C
2k
Ω
-2.0
°
C
Compensate to be
470
Ω
-5
°
C
470
Ω
-2.5
°
C
cooler
The temperature compensation for refrigerator compartment is in the following Table.
• The adjustment method for the freezer temperature is the same as that for the refrigerator. The temperature compensation
in the freezer are twice as much as that in the refrigerator.
• This circuit is aimed to input the necessary temperature compensation values into the MICOM in order to adjust the
refrigerator temperature which is different in each model.
MICOM FUNCTION AND CIRCUITS
- 43 -
Revised resistance
470
Ω
2k
Ω
3.3k
Ω
5.6k
Ω
8.2k
Ω
10k
Ω
12k
Ω
18k
Ω
33k
Ω
56k
Ω
180k
Ω
Present resistance
No
0.5
°
C
1
°
C
1.5
°
C
2
°
C
2.5
°
C
3
°
C
3.5
°
C
4
°
C
4.5
°
C
5
°
C
470
Ω
change
Up
Up
Up
Up
Up
Up
Up
Up
Up
Up
0.5
°
C
No
0.5
°
C
1
°
C
1.5
°
C
2
°
C
2.5
°
C
3
°
C
3.5
°
C
4
°
C
4.5
°
C
2k
Ω
Down Change
Up
Up
Up
Up
Up
Up
Up
Up
Up
1
°
C
0.5
°
C
No
0.5
°
C
1
°
C
1.5
°
C
2
°
C
2.5
°
C
3
°
C
3.5
°
C
4
°
C
3.3k
Ω
Down
Down
Change
Up
Up
Up
Up
Up
Up
Up
Up
1.5
°
C
1
°
C
0.5
°
C
No
0.5
°
C
1
°
C
1.5
°
C
2
°
C
2.5
°
C
3
°
C
3.5
°
C
5.6k
Ω
Down
Down
Down
Change
Up
Up
Up
Up
Up
Up
Up
2
°
C
1.5
°
C
1
°
C
0.5
°
No
0.5
°
C
1
°
C
1.5
°
C
2
°
C
2.5
°
C
3
°
C
8.2k
Ω
Down
Down
Down
Down
Change
Up
Up
Up
Up
Up
Up
Refrigerator
2.5
°
C
2
°
C
1.5
°
C
1
°
C
0.5
°
C
No
0.5
°
C
1
°
C
1.5
°
C
2
°
C
2.5
°
C
(R2)
10k
Ω
Down
Down
Down
Down
Down Change
Up
Up
Up
Up
Up
3
°
C
2.5
°
C
2
°
C
1.5
°
C
1
°
C
0.5
°
C
No
0.5
°
C
1
°
C
1.5
°
C
2
°
C
12k
Ω
Down
Down
Down
Down
Down
Down
Change
Up
Up
Up
Up
3.5
°
C
3
°
C
2.5
°
C
2
°
C
1.5
°
C
1
°
C
0.5
°
C
No
0.5
°
C
1
°
C
1.5
°
C
18k
Ω
Down
Down
Down
Down
Down
Down
Down
Change
Up
Up
Up
4
°
C
3.5
°
C
3
°
C
2.5
°
C
2
°
C
1.5
°
C
1
°
C
0.5
°
C
No
0.5
°
C
1
°
C
33k
Ω
Down
Down
Down
Down
Down
Down
Down
Down
Change
Up
Up
4.5
°
C
4
°
C
3.5
°
C
3
°
C
2.5
°
C
2
°
C
1.5
°
C
1
°
C
0.5
°
C
No
0.5
°
C
56k
Ω
Down
Down
Down
Down
Down
Down
Down
Down
Down
Change
Up
5
°
C
4.5
°
C
4
°
C
3.5
°
C
3
°
C
2.5
°
C
2
°
C
1.5
°
C
1
°
C
0.5
°
C
No
180k
Ω
Down
Down
Down
Down
Down
Down
Down
Down
Down
Down
Change
