LG LRTPC2031NI, LRTPC1831NI Owner’s Manual

SERVICING PRECAUTIONS

AIR RECHARGING IN COMPRESSOR
Test the refrigeration system connecting itelectrically before

refilling operation, it is necessary to ascertain the function
of the motor.compressor and identify the defects
immediately, if defects 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 it to the same tube again. (Figure 2)

POINT TO BE BROKEN

SERVICE TUBE EXTENSION

Figure 1

It is necessary to execute the soldering operation with

vane open so that the fumes caused by oil residue can

come out freely without blowholes between two tubes

during the heating the of the point to be soldered.
"me extension fitted with the male Hansen is connected to
the female fitting of the vacuum pump tube. (Figure 3)

CHARGE TUBE FEMALE
EXTENSION HANSEN

,_ MALE HANSEN

SOLDERING POINT

Figure 2

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 -+5grams. (Figure 4)

TO THE R-134a CYLINDER

_, _ TOTHE REFRIGERATION

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 Fraon for addition to the system.
(Figure 5)

FILLING OR VALVE TO BE OPENED
CHARGE TUBE WHEN REFILLING

SYSTEM

I Figure 4

iS=

GAUGE

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 arm., -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 1 atmosphere), start the refdgeration

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

TO THE REFRIGERATION TO THE CHARGE
SYSTEM CYLINDER

VALVE TO BE CLOSED
AFTER VACUUM

TO THE
VACUUM _ Figure 5

PUMP

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 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 mater-

compressor. Therefore, proceed by adding the 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 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-

160/120

CIRCUITDIAGRAM _su._._lcomoL

_,_.._'_ERMOSTAT DEFRC_,TIMER

_: , _ fl"_nIhewal =eJet.

• I. U. __,.

8 I I i- -- _ _ / =: _'Jli_ SW1 SW2 8W3 TIME

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I-J , I_ _clli_l = =r---- ---, OFF ON ON 14sec

L_4=.Fp_t I I , 'RD 3 ; , C

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BK:BIJ_ BN:BROWNPR:PURPLE_:F1NK GN:GR_N 3854JD1046C

_. D _ i BK

......... , -_ : _ , ON ON ON 15see

,"_ :Reue unptuothepo_r cord

$W1 _ SWI

2. PARTS IDENTIFICATION

FREEZER

COMPARTMENT

Freezer Shelf

Automatic Ice Maker

tce Cube Box

Lamp

Freezer Door Bin

Freezer Temperature

Control Dial

REFRIGERATOR

COMPARTMENT

Temperature

Control Dial

Lamp

Shelves

Egg Box

Snack Corner

Crisper

Used to keep fruits

and vegetables

fresh and crisp.

Base Grille

Push the gdlle toward

the refngerator

untilit snaps

intoplace.

Door Cooling

On the refrigerator door,

the cold air passageway is

installedto supply
coldair to the doorsideof

the refrigerator

compa_ment.
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 boltsfixing the upper hinge to the

body and liftthe freezer door.

HINGE COVER

BOLT

HINGE

Figure 6

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

assembly.

3-2 DOOR SWITCH

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

Disconnect the lead wire from the switch.

LEAD WIRE

Figure 9

3-3 THERMOSTAT
1, Remove Control Box-R by loosening 2 screws attach_l to

ceiling of Refrigeratoroompartrnent (Figure 10)

2. Separate the thermostat and dial knob F,

3. Remove the thermostat by disconnecting the lead wire.

_ GASKET

Figure 7

• Refrigerator Door

1. Loosen hexagonal bolts attaching the lower hinge to the

body to remove the refrigerator door only.

LOWER HINGE

Figure 8

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

assembly.

Figure 10

-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.

3-6 LAMP

REFRIGERATOR ROOM LAMP

Figure 16-1

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 770C, 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

DEF-THERMO

3-6-1 Refrigerator room lamp

1. Unplug the power cord from the outlet.

2. Remove refrigerator shelves.

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

4. Turn the lamp eeuntemlockwise.

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 d_sconnect 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 Cor_rel
Box-R by loosening 2 screws.

Figure 13

FUSE-M

HOLDER FUSE Figure 14

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

4.1COMPRESSOR

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 end 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 1 micron, and is sealed in a dust - and

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

4-1.3 Note for Usage

(1) Be careful not to allow over-vottage 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 iockage
and noise.

4-2 PTC-STARTER

4-2-1 Composition of PTC-Starter

(1) PTC (Positive Temperature Coefficient) is a no-contact

semiconductor starting device which uses ceramic

matedal consisting of BaTiO3.

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

value. These features ere 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

sfagio-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
subooil is cut off. The proper features of PTC play all
the above roles. So, PTC is used as a motor starting

devise.

4-2-3 PTC-Applied Circuit Diagram

• According to Starting Method for the Motor

OVERLOAD PROTECTOR(O L.P)

@ c

I- -_-C- q = _"_ COMPRESSOR
' ' "_ MOTOR

PTC STARTER HERMETIC

RSIR

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 isn't cooled for a while after the power has been
shut off, the motor witi not restart.

42-5 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 tufa. or unplugging and reconnecting), the

PTC isn't cooled and a resistance value grows. As a

result, current can't flow to the sub-coil, the Motor can't
operate, and the OLP operates by flowing over currant

in only in the 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 DIP doesn't operate when PTC is not cooled,

Compressor Motor is worn away and causes circuit-
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 fail due to insutation breakdown of

the material 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.

TERMINAL

Figure 19

-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 cutting the
current to the Motor if the temperature dses 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.

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

CIRCUITDIAGRAM

"iI_E_OSTAT DEFFIOST.TIMER

CONTACTING
POINT

ADJUST

SCREW

COVER

BIMETAL

BIMETAL

HEATER

WATERSUPPLYI_"riMECONTROLoPnoN ]

Figure 21

-9-

S_TCHNO

SWITCHOFF 2 3

SW1 SW2SW3

TIME

10.5s<
9se(

10se

11se
12se

13se
14s_

15se

3854,,ID1046C

6. TROUBLESHOOTING

6-1 COMPRESSOR AND ELECTRIC COMPONENTS

Remove the PTC-

[_ Power Source.

Starter from the
Compressor and

measure the voltage
between Terminal C of

Compressor and
Terminals 5 or 6 of PTC.

__ (Rating Voltage YES

±10%)? I "[_

]_No Voltage.

Applied voltage isn't

-]_| in the range of Rating
L Voltage ±10%.

Check the I-_ Check the resistance

Motor M-S in Motor

resistance of I-[ among M-C, S-C and

Compressor. Compressor.

Check the _ Check the resistance

PTC-Starter. PTC-Starter.

resistance of I [ of two terminals in

[_ a regular OLR _, 130 sec. in forcible OLP

Check OLR

1= £

I--_[ Check if applying _'_ OLP works w_hin __O._ YEs i _[_

,_ OLP disconnected?

to use a regular
Advise the customer I • [_

transformer.

,Es

NO • Replace

YES

I I I operation by turning Replace OLR

I I instant power on and

Replace OLR

C°%ceonect nh

L_ Reconnect. I

PTC-Starter.

1I°" f

NO

starting state, starting voltage after 5 the voltage of Rating

[5_ Check _ Measure minimum _ C°mponents start in _ O'K" I

min. for balancing cycle Voltage ±10%
pressure and cooling the below. • r_

PTC. NO

-10-

6-2 PTC AND OLP

Normal operation of In -_,

Compressor is

impossible or poor.

/

Separate the PTC- _1
Star_er from

Compressor and
measure the

resistance between
No. 5 and 6 of PTC-
Starter with a Tester or

(Figure 21)

r

Observation value is ,_1

220VI50Hz : 22_)±30%
115V/6OHz : 6.8_+-30%
240V/50Hz : 33_2+-30%

127,220VI6OHz : 22{_

±30%

The resistance value _.=1
is 0 or several

hundred Q.

/

-I

r

Check another I

electric components. I

Starter

Replace PTC- I

6-3 DEFROST TIMER

Normal operation of

the Defrost Timer is

impossible.

I No defrosting.

I Poor cooling.

Wheatstone Bridge.

.J Separate the OLP from I YES_[

")'[ Compressor and check I "1

the resistance value

between two terminals I I
| of OLP with a Tester.
/ (Figure 22)

the point of tirst click

r Position the Cam Shaft to

F Next, position the Cam

F No. 1 (brown) and

sound and check the
current flowing between

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

Shaft to the point of
second click sound and

check the current flowing
between terminals

No. 4 (black)
(Figure 23).

The value is =o.

electric components.

Check another I

Replace OLF_

F_Figure

21_igure 22

--_ The resistance is _,.

0_2orvariable.

._The resistanceis

220V/50Hz : 20K.q

._The resistance is about

115VI60Hz : 7.8K.Q

_ Replacethe

DefrostT_mer. I

_ Replace the

Defrost Timer. I

I_t Check the another I

electric components, I

--}_ Turn the Cam Shaft.

"_ with holding the Cam

Shake about 3 times

Shaft and Body softly.

-11 -

> Replace the

Defrost Timer. I

t--H I

Figure 23