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—29—
COMPLAINT
CAUSE
REMEDY
If not running, determine the cause. Replace if
required.
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.
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.
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.
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.
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.
not to contact cabinet, compressor, shroud, and
barrier.
Fan motor
Condenser air flow
restriction
restriction
Condenser fins
(damaged)
(damaged)
Capacitor
Wiring
Refrigerating system
Air filter
Exhaust damper door
Unit undersized
Blower or fan
Copper tubing
Compressor cycles on
overload(Cont’d)
overload(Cont’d)
Insufficient cooling
Excessive noise.
—21—
4.3 TROUBLESHOOTING GUIDE
In general, possible trouble is classified in two kinds.
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.
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.
Unit runs but poor cooling.
Ineffective Cooling
Check outdoor coil
(heat exchanger) & the fan
operation.
(heat exchanger) & the fan
operation.
Check gas leakage.
Repair gas leak.
Replacement of unit if the
unit is beyond repair.
unit is beyond repair.
Satisfactory operation with
temperature difference of
inlet & outlet air ;
44~50
temperature difference of
inlet & outlet air ;
44~50
°
F(7~10
°
C)
Check heat load
increase.
increase.
Clean condenser.
Not on separate circuit.
Check inside gas
pressure.
pressure.
Adjusting of refrigerant
charged.
charged.
Malfunction of compressor.
Replacement of
compressor.
compressor.
Check cold air circulation
for smooth flow.
for smooth flow.
Dirty indoor coil
(Heat exchanger)
(Heat exchanger)
Stop of auto air-swing
Correct above trouble
Check clogging in refrigera-
tion circuit.
tion circuit.
Repair clogging in refrigera-
tion circuit.
tion circuit.
Obstruction at air outlet
Clogged of air filter.
Malfunction of fan
—22—
Fails to Start
Check circuit breaker
and fuse.
and fuse.
Gas leakage of feeler bulb
of thermostat
of thermostat
Check of control switch.
Fan only fails to start.
Improper wiring.
Defect of fan motor
capacitor.
capacitor.
Irregular motor resistance
( ).
Irregular motor insulation
( ).
( ).
Irregular motor insulation
( ).
Replacement of fan motor.
Regular but fails to start.
Replacement of compressor
(locking of rotor, metal).
(locking of rotor, metal).
Improper thermostat setting.
Loose terminal connection.
Improper wiring.
Irregular motor resistance ( )
Irregular motor insulation ( )
Replacement of compressor
(Motor damaged)
(Motor damaged)
Drop of power voltage.
Capacitor check.
Replacement
Compressor only fails to
start.
start.
Defect of compressor
capacitor.
capacitor.
Check of power source.
Check of control switch
setting.
setting.
—23—
• Check the Fuse.
• Check the wiring diagram.
• Check the wiring diagram.
Is the Trans input power
AC 115V?
Is the Trans output power
about AC 14V?
Is shorted the Trans. output?
Is output Voltage of IC01D
DC 12V?
Is output Voltage of IC02D
DC 5V?
Is the voltage No.20 of Micom
DC 5V?
Exchange Main PCB Ass'y.
Is the
connection between
Main and Display
all right?
Is the reset circuit all right?
(The No.16 of
Micom is 5V.)
• Check the Fuse.
• Check the wiring diagram.
• Check the wiring diagram.
• Check the Main
PCB pattern.
PCB pattern.
• Exchange the Trans.
• Exchange D02D~D05D.
• Exchange IC01D.
• Exchange IC01D.
• Exchange IC02D.
• Exchange IC01A, C02A.
• Connect connector
exactly.
exactly.
• Check the PCB
pattern.
pattern.
NO
NO
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES
YES
NO
YES
■
ELECTRICAL PARTS TROUBLESHOOTING GUIDE: LWG0760PCG, LWG0760QCG
LWG0960PCG, LWG0960QCG
LWG0820PCG, LWG0720NCG
LWG0820PCG, LWG0720NCG
Possible Trouble 1
The unit does not operate.
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