LG AK-C3608H00, Installation Manual

Page: 21 / 38

TROUBLE SHOOTING
21
ENGLISH
Symptom Causes Check & Corrective measure
Compressor runs, but
short cycling
1. Safety circuit open due to :
a) Low suction pressure
b) High discharge pressure
c) Overload protector
2. Thermostat in cold location
3. High thermostat setting
1. a) Verify the reason for low suction
pressure (refer to symptom for "low
suction pressure").
b) Verify the reason for high discharge
pressure (refer to symptom for "high
discharge pressure").
c) Check dome temperature. RLA each
phase. Verify the reason.
2. Check and relocate as required.
3. Lower the temperature setting to 21°C for
test.
Thermostat shows
faulty indication
1. Safety circuit open due to :
a) Low suction switch
b) High discharge switch
c) Overload protector
1. a) Verify the reason for low suction
pressure (refer to symptom for "low
suction pressure").
b) Verify the reason for high discharge
pressure (refer to symptom for "high
discharge pressure").
c) Check comp. RLA against nameplate for
each phase, check comp, dome
temperature, etc. & correct it.
Low suction pressure
1. Less Freon
2. Loose belt
3. Variable pulley wiely open
4. Dirty filter
5. Dirty cooling coil
6. Return air restricted
7. Improper expansion valve bulb
installation / location
8. Restriction in expansion valve /
filter dryer
1. Check for gas leak & charge freon as
required.
2. Adjust it. Check belt tension.
3. Adjust the pulley.
4. Clean it.
5. Clean it.
6. Check return air girlle sizes, etc. against
design.
7. Verify and correct it.
8. Check and correct / replace it.
High suction pressure
1. Excess freon charge
2. Excess air quantity
3. High room temperature
condition
4. Undersize unit (serving large
open)
5. Expansion valve widely open
6. Defective compressor valve
1. Verify and adjust it.
2. Adjust air quantity.
3. Check & verify. Isolate the area to be
cooled & observe.
4. Check design / unit selection.
5. Check superheat & adjust it, if required.
6. Check and replace compressor.
High discharge
pressure
1. Condenser fan motor not
working properly
2. Excess freon charge
3. Dirty condenser
4. High ambient condition /
Air in condenser obstructed
5. Defective fan motor capacitor
6. Defective fan motor
1. Fan blade stuck with ventury. Check &
correct it.
2. Check freon and adjust it, if necessary.
3. Clean it.
4. Verify the reason and correct it.
5. Check and replace it.
6. Check and replace it.