DOWNLOAD LG LWG0760AHG_AHN_AHE Service Manual ↓ Size: 2.87 MB | Pages: 60 in PDF or view online for FREE

—25—

If not running, determine the cause. Replace if required.

Remove the cabinet. inspect the interior surface of the
condenser; if restricted, clean carefully with a vacuum cleaner
(do not damage fins) or brush. Clean the interior base before
reassembling.

If condenser fins are closed over a large area on the coil
surface, head pressures will increase, causing the
compressor to overload. Straighten the fins or replace the
coil.

Test capacitor.

Check the terminals. If loose, repair or replace.

Check the system for a restriction.

If restricted, clean of replace.

Close if open.

Determine if the unit is properly sized for the area to be
cooled.

Check the set screw or clamp. If loose or missing, correct. If
the blower or fan is hitting air guide, rearrange the air
handling parts.

Remove the cabinet carefully and rearrange tubing not to
contact cabinet, compressor, shroud, and barrier.

Check the voltage at outlet. If none, correct.

Check the teminals. If loose, repair or replace.

Check for continuity, refer to the wiring diagram for teminal
identification. Replace the switch if the circuit is open.

Check setting. Turn to warmest position.

Check the position of knob. If not at the warmest setting,
advance knob to this setting. Check continuity of the
thermostat. Check continuity of control by removing lead from
terminal, turn the selector switch to heat, and check between
common terminal and H terminal. (NOTE: Room temperature
should be 30°C(86°F) or lower when testing the temperature
control.) If no continuity exists, replace thermostat.

Selecter switch must be in the HEAT (      ) mode.

Check continuity of the switch. Continuity should be between
terminals identified on wiring diagram when the switch is in
heat mode. 

Check continuity of the reverse valve coil.
Continuity should be between two lead wires.
If none, check the reverse valve body.
Replace the part which is defective.

Fan motor

Condenser air flow
restriction

Condenser fins
(damaged)

Capacitor

Wiring

Refrigerating system

Air filter

Exhaust damper door

Unit undersized

Blower or fan

Copper tubing

No power

Wiring

Rotary switch

Temperature control position

Thermostat
(Temperature control)

Selector switch position

Selector switch

Reverse valve

Compressor cycles on
overload(Cont’d)

Insufficient cooling or
heating

Excessive noise.

No heat.

—17—

Following is a brief description of the important components and their function in the refrigeration system. 
Refer to figure 30 to follow the refrigeration cycle and the flow of the refrigerant in the cooling cycle.

MOTOR

COMPRESSOR

OIL

(LIQUID REFRIGERANT)

CAPILLARY TUBE 

OUTSIDE COOLING
AIR FOR REFRIGERANT
PASS THROUGH

SUCTION LIME
COOL LOW PRESSURE VAPOR

COOLED
AIR

COMPLETE LIQUID
BOIL OFF POINT

LIQUID
PRESSURE
DROP

ROOM AIR HEAT LOAD

VAPOR INLET

HOT
DISCHARGED
AIR

LIQUID OUTLET

HIGH PRESSURE VAPOR

LIQUID PEFRIGERANT

LOW PRESSURE VAPOR

ROOM AIR CONDITIONER

EVAPORATOR COILS

CONDENSER COILS

CYCLE OF REFRIGERATION

CAPILLARY  TUBE

COMPRESSOR

BLOWER

EVAPORATOR  COIL

CONDENSER  COIL

FAN

MOTOR

:  COOLING CYCLE
:  HEATING CYCLE

—18—

In general, possible trouble is classified in two causes.
The one is called Starting Failure which is caused from an electrical defect, and the other is Ineffective Air
Conditioning caused by a defect in the refrigeration circuit and improper application.

Check of outdoor coil
(heat exchanger) & the fan
operation

Check gas leakage.

Repair gas leak.

Replacement of unit if the
unit is beyond repair.

Satisfactory operation with
temperature difference of
inlet & outlet air ;
COOLING :   7~10

°

C

HEATING  : 15~17

°

C

Check heat load increase in
cooling operation.

Unexpected residue

Added heat load

Check of inside gas
pressure

Adjusting of refrigerant
charge

Malfunction of compressor

Replacement of
compressor

Check of cold (warm) air cir-
culation for smooth flowing

Dirty indoor coil
(Heat exchanger)

Malfunction of fan

Clogged of air filter

Obstruction at air outlet

Countermeasure against
above trouble.

Check clogging in refrigera-
tion circuit.

Repair clogging in refrigera-
tion circuit.

—19—

Check of circuit breaker
and fuse

Gas leakage of feeler bulb
of thermostat

Check of control switch

Only fan fails to start.

Improper wiring

Defect of fan motor
capacitor

Irregular motor resistance
(      )
Irregular motor insulation
(      )

Replacement of fan motor

Regular but fails to start.

Replacement of compressor
(locking of rotor, metal)

Improper thermostat setting

Loose terminal connection.

Improper wiring

Irregular motor resistance (    )

Irregular motor insulation (    )

Replacement of compressor
(Motor damaged)

Drop of power voltage

Capacitor check

Replacement

Only compressor fails to
start.

Defect of compressor
capacitor

Check of power source

Check of control switch
setting