LG LRTBC2025T precautio Servicing Precautions

SERVICING PRECAUTIONS

AIR RECHARGING IN COMPRESSOR
Test the refrigeration system connecting it electrically before

refilling operation. It is necessary to ascertain the function
of the motor-compressor and identify the defects

immediately. Ifdefects have been found, empty the old
system of possible 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 complete extension with male Hansen and

at last, solder itto the same tube again. (Figure 2)

POINT TO BE BROKEN CHARGE TUBE FEMALE

EXTENSION HANSEN

,_ MALE HANSEN

SERVICE TUBE EXTENSION SOLDERING POINT

Figure 1 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 blowhetes between two tubes

during the heating the of 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)

GAUGE

Figure 3

Air evacuating from the system begins as 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 30
minutes. (Figure 3)

If considerable leakage occurs, it will be necessary to stop
the vacuum pump and to add a small quantity of Freon to
the system. If vacuum should not be obtained (pressure
gauge can't fall to f atmosphere), start the refrigeration
unit and find the leakage with special leak-finder. When the

defective soldering point is visible, repair 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

blocks them, the pressure must be rebalanced when
vacuum is in the system when soldering. As soon as the

vacuum operation is over, add the quantity in grams of

R-134a to the refrigeration system. Remember that every
system has an exact quantity of R-134a that can be added
with a tolerance of +5 grams. (Figure 4)

TO THE R-134a CYLINDER

_,, _ TO THE REFRIGERATION

SYITEM 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 the refilling tube is
closed in order to keep the Freon for addition to the system.
(Figure 5)

FILLING OR VALVE TO BE OPENED
CHARGE TUBE WHEN REFILLING

TO THE REFRIGERATION TO THE CHARGE

SYSTEM CYLINDER

VALVE TO BE CLOSED
AFTER VACUUM

TO THE

VACUUM _ Figure 5
PUMP

In add:tion, 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 140
grams to the group, this amount will be reached when
R-134a has dropped to 610 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 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 the original

quantity of about 20-30 grams and close the vane
immediately.

The pressure rises and the motor compressor must start

sucking the gas and lowering the pressure again. Open 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 0.30 to 0.6 (0.10 to 0.4)

atmosphere.

-3-

2. PARTS IDENTIFICATION

FREEZER

COMPARTMENT

Freezer Shelf

Automatic Ice Maker

tce Cube Box

Freezer Temperature

Control Dial

REFRIGERATOR
COMPARTMENT

Temperature

Control Dial

Lamp

Shelves

Egg Box

Snack Corner

Crisper

Used to keep fruits

and vegetables

fresh and cdsp,

Base Grille

Push the grille toward

the refdgerator

until it snaps

into place.

Lamp

Freezer Door Bin

Door Cooling
On the refrigeratordoor,
the cold air passageway is
installedto supply

coldair tothe doorsideof

the refrigerator
compartment.

Egg Tray

Can Server

Dairy Corner
Can Storage

Adjustable
Door Bin

Refrigerator Door
Rack

Leveling Screw
(Inside)

-5-

3. DISASSEMBLY

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.

HINGE COVER

BOLT

HINGE

Figure 6

3. Pull out the door gasket to remove from the door foam

assembly.

GASKET

Figure 7

• Refrigerator Door
1, Loosen hexagonal bolts attaching the lower hinge to the

body to remove the refrigerator door only.

3-2 DOOR SWITCH

1. To remove the door switch, pull out it with a slotted type

driver as shown in (figure 9).

2. Disconnect the lead wire from the switch.

LEAD WIRE

DOOR SWITCH

Figure 9

3-3 THERMOSTAT

1. Remove Control Bc_-R by loosening 2 screws attached to

ceilingof Reffigerator comparb_ent (Figure 10)
Separate the thermostat and dial knob F.

Remove the thermostat by disconnecting the lead wire.

Figure 10

<_ LOWER HINGE

BOLT

Figure 8

2. Pun out the door gasket to remove from the door foam

assembly.

-6-

3-4 FAN AND FAN MOTOR

1. Remove the freezer shelf, (If your refrigerator have an

Ice Maker, disassemble the Ice maker first)

2. Remove the grille by pulling it out and by loosening a

screw,

3. Remove the Fan Motor assembly by loosening 4 screws

and disassemble the shroud.

4. Pull out the fan and separate the Fan Motor and Bracket.

SHROUD

Figure 12

3-5 DEFROST CONTROL ASSEMBLY

Defrost control assembly consists of Defrost Thermostat

and FUSE-M.
Defrost Thermostat functions to defrost automatically and it

is attached to metal side of the Evaporator and senses
Temp.

Fuse-M is a safety device for preventing over-heating of the
Heater when defrosting.

At the temperature of 77°C, it stops the emission of heat
from the Heater.

1. Pull out the grille assembly.

2. Separate the connector connected with the Defrost

Control assembly and replace the Defrost Control
assembly after cutting the Tie Wrap. (Figure 14)

SHROUD-F

Figure 13

DEF-THERMO

FUSE-M

HOLDERFUSE Figure 14

3-6 LAMP

REFRIGERATOR ROOM LAMP

Figure 16-1

3-6-1 Refrigerator room lamp

1. Unplug the power cord from the outlet.

2. Remove refrigerator shelves.

3. Release the hooks on both ends of the lamp shield and
pull the shield downward to remove it.

4. Turn the lamp counterclockwise.

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

(Max 40 W)

FREEZER ROOM LAMP

Figure 16-2

3-6-2 Freezer room lamp

1. Unplug refrigerator or disconnect power.

2, Reach behind light shield to remove bulb.

3. Replace bulb with a 25-watt appliance bulb,

4. Plug in refrigerator or reconnect power,

3-7 CONTROL BOX-R

1. First, remove all shelves in the refrigerator and Control
Bax-R by loosening 2 screws,

CONTROL BOX-

COVER LAMP_ Figure 17

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

3. Disconnect the lead wire on the right position and
seperate timer, themostat, Lamp socket, etc.

-7-

4. ADJUSTMENT

_1 COMPRESSOR

4-1-1 Role
The compressor intakes 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 includes overload protection. The PTC
starter and OLP (overload protector) are outside the

compressor. Since the compressor is manufactured to
tolerances of I micron, and is sealed in a dust - and

moisture - free environment, use extreme caution when
repairing it.

4-%3 Note for Usage

(1) Be careful not to allow over-voltage and over-current.
(2) No Strike

If applying forcible power or strike (dropping or careless

handling), 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, the result may be poor operation

and poor contact may cause.

(5) Be careful that dust, humidity, and welding flux don't

contaminate the compressor inside when replacing the

Compressor. Dust, humidity, and flux due to welding
which contaminates the cylinder may cause leskage

and noise.

4-2 PTC-STARTER

4-2-1 Composition of PTC-Starter
(1) PTC (Positive Temperature Coefficient) is a no-centact

semiconductor starting device which uses ceramic
material consisting of BaTiO3.

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

value. These ,features are used as starting device for

the Motor,

4-2-2 Role of PTC-Starter
(1) PTC is attached to Hermetic Compressor used for

Refrigerator, Show Case, and starting Motor,

(2) Compressor for household refrigerator applies to

single-phase induction Motor.
For normal operation of the single-phase induction

motor, in the starting operation flows in both main coil
and sub-coil. After the starting is over, the current in

subcoil is cut off. The proper features of PTC play aft
the above roles. So, PTC is used as a motor starting
device.

4-2°3 PTC-Applied Circuit Diagram

• According to Starting Method for the Motor

OVERLOAD PROTECTOR(O.L.P)

F- -c-q F COMPRESSOR

.....

PTC STARTER HERMETIC

TERMINAL

RSIR

Figure 19

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 rain. for pressure balance of Refrigerating Cycle and
PTC cooling.

(2) During normal operation of the Compressor Motor, PTC

elements generate heat continuously. Therefore,
if PTC iso't cooled for a while after the power has been

shut oft, the motor will not restart.

4-2-5 Relation of PTC-Starter and OLP

(1) If the power is off during operation of Compressor and

the power is on before the PTC is cooled, (instant shut-
off within 2 rain. or unplugging and reconnecting), the

PTC isn't cooled and a resistance value grows. As a
result, current can't flow to the sub-ceil, the Motor can't

operate, and the OLP operates by flowing over current
in only in the main-cofi.

(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 cimuit*
short and fire. Therefore, always use a properly

attached OLR

4-2-6 Note to Use PTC-Starter

(1) Be careful not to allow over-voltage and over-current.
(2) Do not strike

Don't apply a forcible power or strike.

(3) Keep apart from any liquid.

If liquid, such as oil or water away enters the PTC,
PTC materials may Faildue to insulation breakdown of

the materiel itself.

(4) Don't change PTC at your convenience.

Don't disassemble PTC and case. If the exterior to the
PTC-starter is damaged, resistance value is altered and
it may cause poor starting of the compressor motor may

cause.

(5) Use a propedy attached PTC.

-8-

4-30LP (OVERLOAD PROTECTOR)
4-3-1 Definition of OLP

(1) OLP (OVERLOAD PROTECTOR) is attached to the

Compressor and protects the Motor by catting 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

Bimetat works by heating the heater inside the OLR

and the OLP protects Motor by catting off currant which
flows to the Compressor Motor.

4-3-2 Role of the OLP

(1) The OLP is attached to the Hermetic Compressor used

for the Refrigerator 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 OLR
(Composition and connection diagram of OLP)

5. CIRCUIT DIAGRAM

CONTACTING
POINT

COVER

__BIMETAL

BIMETAL

ADJUST

SCREW

Figure 21

HEATER

10.5=
9se(

lOse
11se
t2se

13se
14s_
15se

SWn_H0FF 2 3

SWI SW2SW3

3854JD1046C

-9-

6. TROUBLESHOOTING

6-1 COMPRESSOR AND ELECTRIC COMPONENTS

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.

/ Applied voltage isn't

-}P,_in the range of Rating
/ Voltage +-10%.

_}_ (Rating Voltage I+-10%)?

-_ OLP disconnected?

YES }l_[_

_ Replace OLR

Check connection t_ 1

condition.

L-_ Reconnect. I

H Advise the customer I [_

to use a regular }_
transformer.

[_ heck the

resistance of

Motor

Compressor.

[_ Check the

resistance of
PTC-Starter,

[_ [ Check OLR

[_ [ sChartieCnkgstate.

i_ heck the resistance

among M-C, S-C and
M-S in Motor

Compressor.

--_ heck the resistance
of two terminals in
PTC-Starter.

N_O YES }__

Replace Compressor.

I

YES

NO }_ Replace

PTC-Starter.

YES

_1 Check if applying I.__ OLP works within "I YES .[_

a regular OLR I-_ 130 sec. in forcible OLPI _ I

I I Ioperation by turning _ Replace OLR

I -'

NO

t_ Measure minimum I--_

starting voltage after 5 I r I
min. for baiencing cycle I I

pressure and cooling the _ I

PTC. I I

Componentsstartin I_ o.K. I

the voltage of Rating
Voltage +_10%

below. NO }1-[_

-10-

6-2 PTC AND OLP

I Normal operationof

Compressor is

impossibleor poor.

6-3 DEFROST TIMER

Separate the PTC-

Sl_rter from
Compressor and

measure the
resistance between

' No. 5 and 6 of PTC-

Starter with a Tester or
Wheatstone Bridge.

(Figure 21)

Observationvalue is
220V/5OHz: 22_:_30%
115V/6OHz ;6.8_.__+30%
240V/50Hz ;33(_±30%
127, 220V/60Hz : 22_
±30%

The resistance value
is 0 or several

hundred Q.

The value is _.

Check another
electric components.

Replace OLR

Separate the OLP fmm_ YES_ _

"_' Compressor and check I

the resistance value I I

between two terminals

I ,

of OLP with a Tester. NLN0_

(Figure 22)

.._ Check another I

electric components. I

I
I

(_Figure 21_igure 22

Normal operation of

the Defrost Timer is

impossible.

No defrosting.

Poorcooling.

fl Position the Cam Shaft to

"_ the point of first click

sound and check the
current flowing between

terminals No. t(brown)
and No. 2(bright orange).

F Next, position the Cam

Shaft to the point of

second click sound and
check the current flowing

between terminals

___ No. 1 (brown) and

No. 4 (black)
(Figure 23).

- Turn the Cam Shaft.

Shake about 3 times

"-_ with holding the Cam

Shaft and Body softly.

--_ The resistance is _o.

__The resistance is

OQ or variable.

__The resistance is about

220VISOHz:20K_
1t 5V/6OHz :7.8K3.2

I "°

Loud click sound.

H

-I

Replace the
Defrost Timer.

Replace the I

Defrost Timer.

i

Check the another I

i

electric components. I

Replace the I

Defrost Timer.

Replace the I

Defrost Timer.

-11 -

Figure 23

6-4 OTHER ELECTRIC COMPONENTS

• Cooling is impossible

Compressor I

doesn't ran. I:_

Check ff cuwentflowsto

the following

component.

I

a. Thermostat

b. Starting devices

Cause

I

Poor contacting and

gas leakage.

,._Shorted or broken.

Poorsenta_ing

c. OLP _ orshorted.

d. Compressor coil

_Coilshorted.

e. Defrost Timer _ Poor contacting
f. Circuit parts ____-_--_"or shorted.

I

_ Replace

indicated component. I

J Compressor runs

poorly.

_ heck a starting _{ Low voltage.voltage.

.}_ Check if currant flows t._ Poor oontecting

to starting devices, and broken.

_ heckcum_nt flo_ng ___ Shorted.

in sub-coil of
Compressor.

• Cooling ability is poor

I Fan motor

doesn't run.

Much frost is built upon
the EVAPORATOR. I---

Check capacity of OLR

The items described
above are normal.

Lack of capacity.

_,_ oil of motorCompressor.

i I

Check current flowing _._

of the door S/W. Poor contacting.

Check current flowing _ Coil is

shorted.

in the Fan Motor.

I -I

Check the running _ Running is poor.
condition of Timer. I rl (Coil is shorted.)

Check current flowing I _l

of the following _ Shorted.

components.

• Defrost Thermostat

i • Fuse-M

Check current flowing I
of the following

I

components.

• L-cord

• TE-Piate Heater

Raise the voltage. I

_'-- }_ iRndiP_t6_dcemp°ne_" I

_ Replece

the compressor. I

Replace I

indicated component.

Replace I

indicated component.

Replace

indicated component. I

-12-