LG Electronics GR-S552, GR-S592 User Manual

CAUTION

BEFORE SERVICING THE UNIT, READ THE "SAFETY PRECAUTIONS" IN THIS MANUAL.

MODEL: GR-S552 / GR-S592

REFRIGERATOR

SERVICE MANUAL

http://biz.lgservice.com

CONTENTS............................................................................................................................................................................. 2

SERVICING PRECAUTIONS.................................................................................................................................................. 3

SPECIFICATIONS................................................................................................................................................................... 4

PARTS IDENTIFICATION....................................................................................................................................................... 5

DISASSEMBLY.................................................................................................................................................................... 6-7

DOOR................................................................................................................................................................................... 6

DOOR SWITCH.................................................................................................................................................................... 6

FAN AND FAN MOTOR........................................................................................................................................................ 6

DEF' CONTROL ASM .......................................................................................................................................................... 7

LAMP.................................................................................................................................................................................... 7

CONTROL BOX-R................................................................................................................................................................ 7

ADJUSTMENT..................................................................................................................................................................... 8-9

COMPRESSOR.................................................................................................................................................................... 8

PTC-STARTER..................................................................................................................................................................... 8

OLP (OVER LOAD PROTECTOR)....................................................................................................................................... 9

CIRCUIT DIAGRAM................................................................................................................................................................ 9

TROUBLESHOOTING..................................................................................................................................................... 10-15

COMPRESSOR AND ELECTRIC COMPONENTS ........................................................................................................... 10

PTC AND OLP.................................................................................................................................................................... 11

ANOTHER ELECTRIC COMPONENT............................................................................................................................... 12

SERVICE DIAGNOSIS CHART.......................................................................................................................................... 13

REFRIGERATING CYCLE............................................................................................................................................ 14-15

DESCRIPTION OF FUNCTION & CIRCUIT OF MICOM ................................................................................................ 16-32

EXPLODED VIEW & REPLACEMENT PARTS LIST.......................................................................................................... 33-

Please read the followings before servicing your refrigerator.

1. Check if an electric leakage occurs in the 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 lower part with the upper door open, move with care to prevent head wound which may happen by hitting the upper door.

8. When sloping the set, remove any materials on the set, especially thin plate type. (ex.: glass shelf or books.)

9. When servicing evaporator part, wear cotton gloves without fail. It is to prevent wound by sharp fin of evaporator.

10. Leave a breakage of refrigerating cycle to a heavy service center. The gas in cycle inside may soil ambient air.

SAFETY PRECAUTIONS

CONTENTS

- 2 -

- 3 -

Air Recharging in Compressor

Test the refrigeration by connecting it electrically before refilling operation. It is necessary to ascertain the function of the motor-compressor and identify the defects immediately. If the defects have been found, empty the old system of eventual R-134a residue by breaking off the end of the extension piece at its narrow point. (Figure 1)

Replace the filter and any damaged components. Unsolder and pull off the piece remaining inside the service tube and then attach an extension completely with male Hansen and last, solder it to the same tube again. (Figure 2)

It is necessary to execute the soldering operation with valve open so that the fumes caused by oil residue can come out freely without blowholes between two tubes during heating the point to be soldered.

The extension fitted with the male Hansen is connected to the female fitting of the vacuum pump tube. (Figure 3)

Air evacuating from the system begins so soon as the pump starts. The refrigeration system must be kept under vacuum until the reading on the low-pressure gauge indicates vacuum (0 absolute, -1 atm., -760 mm hg) in any case it is advisable to keep the pump running for about 60 minutes. (Figure 3)

In case that a considerable leakage occurs and to stop the vacuum pump will be necessary and add a small quantity of Freon to the system, if vacuum should not be obtained (pressure gauge can't fall to 1 atmosphere), start the refrigeration unit and find the leakage with the special leakfinder. When the defective soldering point is visible, re-do it after opening the extension tube valve and reestablishing the normal outside pressure inside the group.

Because the melted alloy is sucked into the tubes and block them, the pressure must be rebalanced when vacuum is in the system in soldering. As soon as the

vacuum operation 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 the system. (Figure 5)

In addition, check the graduated scale on the cylinder for the quantity of R-134a to be added, for example, if we have 750 grams of Freon in the cylinder and must add 165 grams to the group, this amount will be reached when R-134a has dropped to 585 grams, remembering that the indicator shows a lower limit of meniscus. Do this after choosing the scale corresponding to the gas pressure different scales reported as the same gas pressure indicated by the pressure gauge on the top of the column.

To make R-134a flow into the system, open the valve placed at the base of the cylinder and connected to the filling tube. The amount of Freon cannot be added to the system all at once because it may cause a blocking of motor-compressor. Therefore, proceed by adding original quantity of about 20-30 grams and close the valve immediately.

The pressure rises and the motor-compressor must start, sucking the gas and making the pressure go down again. Regulate the valve again, maintaining the same manner until reaching to the quantity of R-134a established for the system being charged. When the system is running, the suction pressure must be stabilized between 0.10 to 0.4 atmosphere.

POINT TO BE BROKEN

CHARGE TUBE EXTENSION

FEMALE HANSEN

MALE HANSEN

SOLDERING POINTSERVICE TUBE EXTENSION

Figure 1 Figure 2

TO THE VACUUM PUMP

PRESSURE GAUGE

Figure 3

TO THE R-134a CYLINDER

TO THE REFRIGERATION SYSTEM

Figure 4

FILLING OR CHARGE TUBE

VALVE TO BE OPENED WHEN REFILLING

VALVE TO BE CLOSED AFTER VACUUM

TO THE VACUUM PUMP

TO THE REFRIGERATION SYSTEM

TO THE CHARGE CYLINDER

Figure 5

SERVICING PRECAUTIONS

- 4 -

ITEMS SPECIFICATIONS

FREEZER 114

NET CAPACITY

REFRIGERATOR 306 TOTAL 420

DIMENSIONS (mm) 755(W)

689(D)X1777(H) NET WEIGHT (kg) 79 COOLING SYSTEM Fan Cooling TEMPERATURE CONTROL Micom Control

Full Automatic

DEFROSTING SYSTEM

Heater Defrost OUT CASE Pre Coated Metal INNER CASE A B S INSULATION Polyurethane Foam

( l )

ITEMS SPECIFICATIONS

FREEZER 1 EA

REFRIGERATOR 2 EA VEGETABLE TRAY Drawer Type EGG TRAY 2 Pieces ICE TRAY 2 Pieces (Plastic) ICE BANK 1 Piece COMPRESSOR P.T.C Starting Type EVAPORATOR Fin Tube Type CONDENSER Wire Condenser REFRIGERANT R-134a (135g) DEFROSTING DEVICE HEATER

SHELF

1. SPECIFICATIONS

1-1 GR-S552

ITEMS SPECIFICATIONS

FREEZER 126

NET CAPACITY

REFRIGERATOR 334 TOTAL 460

DIMENSIONS (mm) 755(W)

719(D)X1777(H) NET WEIGHT (kg) 81 COOLING SYSTEM Fan Cooling TEMPERATURE CONTROL Micom Control

Full Automatic

DEFROSTING SYSTEM

Heater Defrost OUT CASE Pre Coated Metal INNER CASE A B S INSULATION Polyurethane Foam

( l )

ITEMS SPECIFICATIONS

FREEZER 1 EA

SHELF

1-2 GR-S592

- 5 -

2-1 FEATURE CHART

NOTE : This is a basic model. The shape of refrigerator is subject to change.

2. PARTS IDENTIFICATION

Egg Storage Rack

Freezer Door Rack

Freezer Temperature Control Dial

Leveling Screw

Vegetable Drawer

Used to keep fruits

and vegetables, etc.

fresh and crisp.

Shelves

Lamp

Fresh Meat

Base Cover

FREEZER

COMPARTMENT

Lamp

Shelf

Twisting Ice

Serve(Option)

General Type

Ice Making

Deodorizer

REFRIGERATOR

COMPARTMENT

Refrigerator

Temperature

Electronic Control

- 6 -

3-1 DOOR

● Freezer Door

1. Remove the hinge cover by pulling it upwards.

2. Loosen hexagonal bolts fixing the upper hinge to the body and lift the freezer door.

3. Pull out the door gasket to remove from the door foam Ass'y.

● Refrigerator Door

1. Loosen hexagonal bolts fixing the lower hinge to the body to remove the refrigerator door only.

2. Pull out the door gasket to remove from the door foam Ass'y.

3-2 DOOR SWITCH

1. To remove the door switch, pull out it with a '—' type driver as shown in (figure 9).

2. Disconnect the lead wire from the switch.

3-3 FAN AND FAN MOTOR

1. Remove the freezer shelf.

2. Remove the Cover Lamp-F and Case Lamp by loosening 1 screw fixed to ceiling of Inner Case.

3. Remove the Grille by pulling it out.

4. Pull out the Shroud and remove the Fan Motor Assy by loosening 2 screws.

5. Pull out the fan and, separate the Fan Motor, Brackets and the Guide Fan.

BOLT

HINGE

HINGE COVER

Figure 6

GASKET

Figure 7

LOWER HINGE

BOLT

Figure 8

Figure 9

3. DISASSEMBLY

GUIDE FAN

FAN

SHROUD

GRILLE

FAN MOTOR

Figure 12

Figure 11

- 7 -

3-4 DEF' CONTROL ASSY

Def control ASM consists of Defrost Sensor and FUSE–M. Defrost

Sensor

functions to defrost automatically and it is attached to the Evaporator and the metal side of the case senses Temp.

Fuse-M is a kind of safety device for preventing overheating of the Heater when defrosting.

At the temperature of 77°C, it stops the emission of TEMP from 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)

3-5 LAMP

3-5-1 Freezer room lamp

1. Unplug the power cord from the outlet.

2. Remove the room lamp lid by taking down while pulling it forward with your hand after inserting finger into the inside hole as shown in (figure 16).

3. Remove the lamp by turning it counterclockwise.

4. Assemble in reverse order of disassembly. Replacement bulb must be the same specication as original.

3-5-2 Refrigerator room lamp

1. Unplug the power cord from the outlet.

2. Remove refrigerator shelves.

3. Remove the room lamp lid by taking down while pulling forward with your hands as shown in (figure 17).

4. Turn the lamp counterclockwise.

5. Assemble in reverse order of disassembly. Replacement bulb must be the same specification as original.

3-6 CONTROL BOX-R

1. First, remove all shelves in the refrigerator and Control Box-R by loosening 1 screw.

2. Loosen 2 screws fixing the Control Box-R to the Inner Case after detaching the cap screw.

3. Remove the Control Box-R by pulling it downward.

SHROUD-F

Figure 13

FAN

DEF CONTROL ASM

Figure 14

FREEZER ROOM LAMP REFRIGERATOR ROOM LAMP

Figure 16

Figure 17

MULTI FLOW DUCT

Figure 18

- 8 -

4-1 COMPRESSOR

4-1-1 Role

The compressor inhales low temperature and low pressure gas evaporated from Evaporator of the Refrigerator, and condenses this gas to high temperature and high pressure gas, and then plays delivering role to Condenser.

4-1-2 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 (OLP) 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.

4-1-3 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.

4-2 PTC-STARTER

4-2-1 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

(2) The higher the temperature is, the higher resistance

value becomes . These features are used as starting device of Motor.

4-2-2 Role of PTC-Starter

(1) PTC is attached to Hermetic Compressor used for

Refrigerator, 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 subcoil. 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 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 operate again.

4-2-5 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 PTC is not cooled, Compressor Motor is worn away and causes circuitshort and fire. Therefore, use a proper fixed OLP without fail.

4-2-6 Note to Use PTC-Starter

(1) Be careful not to allow 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 it 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.

PTC STARTER

HERMETIC TERMINAL

COMPRESSOR MOTOR

PTC

OVERLOAD PROTECTOR

RSIR

Figure 20

4. ADJUSTMENT

- 9 -

4-3 OLP (OVER LOAD PROTECTOR)

4-3-1 Definition of OLP

(1) OLP (OVER LOAD PROTECTOR) is attached to

Hermetic Compressor and protects Motor by cutting off current in Compressor Motor by Bimetal in the OLP in case of over-rising temperature.

(2) When over-voltage flows to Compressor motor, Bimetal

works by heating the heater inside OLP, and OLP protects Motor 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)

5. CIRCUIT DIAGRAM

CONTACTING POINT

COVER

BIMETAL

CONTACTING POINT

HEATER

TERMINALS

ADJUST SCREW

HEATER

BIMETAL

Figure 21

NOTE : 1. This is a basic diagram and specifications vary in different localities.

- 10 -

6-1 COMPRESSOR AND ELECTRIC COMPONENTS

6. TROUBLESHOOTING

4 5

YES

Power Source.

Remove the PTC-Starter from the Compressor and measure the voltage between Terminal C of Compressor and Terminals 5 or 6 of PTC.

No Voltage.

(Rating Voltage ±10%)?

Replace OLP.

Reconnect.

Replace PTC-Starter.

Replace OLP.

O.K.

Check connection condition.

OLP disconnected?

Advise 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 regular OLP.

Measure minimum starting voltage after 5 min. for balancing cycle pressure and cooling the PTC.

Check the resistance of Motor Compressor.

Check the resistance of PTC-Starter.

Check OLP.

Check starting state.

- 11 -

6-2 PTC AND OLP

YES

Normal operation of Compressor is impossible or poor.

Separate the PTC from Compressor and measure the resistance between No. 5 and 6 (only RSIR Type) or No. 4 and 5 of PTC with a Tester 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 : 47Ω ± 30% 220 - 240V/50Hz : 47Ω ±30% 110 -115V/60Hz : 6.8Ω ± 30% 220V/60Hz : 47Ω ± 30% 127V/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 23

Figure 22

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