GR-122SJ — LG Refrigerator Service Manual (repair manual)

Model
GR-122SJ
Pages
13
Size
246.69 KB
Type
PDF
Document
Service Manual
Brand
Device
Refrigerator
File
gr-122sj.zip
Date

View LG GR-122SJ Service Manual online

Ref. : Because this refrigerator is designed to electric starting method, connect the power cord to the outlet 5 min. after
unpluging the power cord for no abnormal sound and normal operation.
5. CIRCUIT DIAGRAM
- 9 -
NOTE : This is a basic circuit diagram and the specifications vary in different localities.
5. DEFROST THERMOSTAT
1. After removing the fan grill, unfasten the tie wrap.
2. Disconnect 2 lead wires connected to the defrost
thermostat. (Figure 12)
6. LAMP
1. Remove all shelves in the refrigerator.
2. Remove the lamp, in the grill part of the control box-R,
by turning it counterclockwise. (Figure 13)
1. COMPRESSOR
Role
The compressor inhales low temp. and low pressure gas
evaporated from Evaporator of the refrigerator, and
condenses this gas to high temp. and high pressure gas,
and then plays delivering role to Condenser.
Composition
The compressor is Composed of Compressor Apparatus
compressing gas, Compressor Motor moving Compressor
Apparatus and Case protecting Compressor Apparatus
and Motor.
There are PTC-Starter, and Over Load Protector in the
Compressor outside.
On the other hand, because the Compressor consists of
1/1000mm processing precision components and is sealed after
producing without dust or humidity, deal and repair with care.
Note to use
(1) Be careful not to allow over voltage and over current.
(2) No strike 
If applying forcible power or strike (dropping or careless
dealing), poor operation and noise may occur.
(3) Use proper electric components appropriate to the
compressor.
(4) Note to Keep Compressor.
If Compressor gets wet in the rain and rust in the pin of
Hermetic Terminal, poor operation and poor contact
may cause.
(5) Be careful that dust, humidity, and flux due to welding
don't inflow in Compressor inside in replacing
Compressor. Dust, humidity, and flux due to welding
which inflows to Cylinder may cause lock and noise.
4. ADJUSTMENT
- 7 -
LAMP
Figure  13
DEFROST THERMOSTAT
TIE WRAP
Figure  12
2. PTC-STARTER
Composition of PTC-Starter
(1) PTC (Positive Temperature Coefficient) is no-contact
semiconductor starting device which uses ceramic
material and the material consists of BaTiO
3
.
(2) The higher the temperature is, the higher resistance
value becomes . These features are used as starting
device of motor.
Role of PTC-Starter
(1) PTC is attached to hermetic Compressor used to
refrigerator and show case and starts motor.
(2) Compressor for household refrigerator applies single-
phase induction motor.
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
sub coil. The proper features of PTC play the above all
roles. So, PTC is used as a starting device of motor.
PTC Applied Circuit Diagram
According to Starting Method of Motor
Motor Restarting and PTC Cooling
(1) For restarting after power off during normal
Compressor Motor operation, plug the power cord after
5 min. for pressure balance of refrigerating cycle and
PTC cooling.
(2) During normal operation of Compressor Motor, PTC
elements generate heat continuously. Therefore, 
if PTC isn't cooled for a while after power off, Motor
can't start operation again.
Relation of PTC-Starter and OLP
(1) If power off during operation of Compressor and power
on before PTC is cooled(instant shut-off within 2 min. or
reconnect a power plug due to misconnecting), 
PTC isn't cooled and a resistance value grows. As a
result, current can't flow to the sub-coil and motor can't
operate and OLP operates by flowing over current in
only main-coil.
(2) While the OLP repeats on and off operation about 3-5
times, PTC is cooled and Compressor Motor performs
normal operation. If OLP doesn't operate when PTL is
not cooled, Compressor motor is worn away and
causes circuit-short and fire.
Therefore, use a proper fixed OLP without fail.
Note to use PTC-Starter
(1) Be careful to over voltage and over current.
(2) No Strike
Don't apply a forcible power or strike.
(3) Keep apart from any liquid.
If liquid such as oil or water inflows into PTC, 
PTC materials may break due to insulation breakdown
of material itself.
(4) Don't change PTC at your convenience.
Don't disassemble PTC and mold. If damaging to
outside of PTC-starter, resistance value alters and poor
starting of Compressor motor may cause.
(5) Use a properly fixed PTC.
3. OLP (OVERLOAD PROTECTOR)
Definition of OLP
(1) OLP (OVERLOAD PROTECTOR) is attached to the
Compressor and protects the Motor by cutting the
current to the Motor if the temperature rises and
activates the bimetal spring in the OLP.
(2) When over-voltage flows to Compressor motor, the
Bimetal works by heating the heater inside the OLP, 
and the OLP protects Motor by cutting off current which
flows to the Compressor Motor.
Role of the OLP
(1) The OLP is attached to the Hermetic Compressor used
for the Refrigerator and Show Case and prevents the
Motor Coil from being started in the Compressor.
(2) Do not turn the Adjust Screw of the OLP in any way for
normal operation of the OLP.
(Composition and connection Diagram of OLP)
- 8 -
CONTACTING
POINT
HEATER
TERMINALS
BIMETAL
COVER
CONTACTION
POINT
ADJUST
SCREW
BIMETAL
HEATER
Figure  15
OVERLOAD PROTECTOR
PTC
3
5
6
C
S
M
S
M
MOTOR
HERMETIC
TERMINAL
PTC STARTER
RSIR
COMPRESSOR
Figure  14
1. DOOR
Freezer Door
1. By taking out two screws attaching in lower hinge,
disassemble the freezer door. (Figure 6)
Refrigerator Door
1. Disassemble the sheet hinge assembly by remove two
screws attaching the sheet hinge assembly to the body.
(Figure 7)
2. DOOR SWITCH
1. Remove the assembly and the control box located on
the upper right hand side of the freezer, and take out the
switch. Remove lead socket from the switch.
2. Pull out the lead socket.
3. THERMOSTAT
Take out the knob from the control box assembly and
detach the thermostat. (Figure 9)
4. FAN AND FAN MOTOR
1. Detach fan grill with minus driver. 
Be careful not to destroy the fan grill. (Figure 10)
2. Detach the hook connected between the fan grill and the
shroud. Disassemble the shroud. (Figure 11)
3. Take out fan motor assembly by removing two screws
that attached to the shroud. Pull out the fan from the fan
motor assembly.
3. DISMANTLE
- 6 -
Figure  6
Figure  7
Contro box
Door switch
Lead socket
Figure  8
Figure  9
Figure  10
Figure  11
Page of 13
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Here you can view online or download LG GR-122SJ Service Manual in pdf. This Service Manual can help you recover, restore, fix, disassemble and repair LG GR-122SJ Refrigerator. Information contained in LG GR-122SJ service manual (repair manual) typically includes:

  • Disassembly, troubleshooting, programming, maintenance, remote, adjustment, installation and setup instructions.
  • Schematics, wiring and block diagrams.
  • Printed wiring boards (PWB) and printed circuit boards (PCB).
  • Parts list (bill of materials).