LG LM-1966C2L_M / LM-1966H2L_M / LM-2166H2L_M / LM-2065C3L_M Service Manual ▷ View online
(1) Pumping down
•
Procedure
1. Confirm that both the gas side and liquid side
valves are set to the open position.
- Remove the valve stem caps and confirm that
the valve stems are in the raised position.
- Be sure to use a hexagonal wrench to operate
the valve stems.
2. Operate the unit for 10 to 15 minutes.
3. Stop operation and wait for 3 minutes, then con-
nect the manifold gauge to the service port of
the gas side valve.
the gas side valve.
- Connect the hose of the gauge with the push
pin to the service port.
4. Air purging of the charge hose.
- Open the Low-handle valve on the gauge
slightly to air purge from the hose.
5. Set the liquid side valve to the closed position.
6. Operate the air conditioner at the cooling cycle
and stop it when the gauge indicates 1kg/cm
2
g.
7. Immediately set the gas side valve to the closed
position.
- Do this quickly so that the gauge ends up indi-
cating 1kg/
g.
8. Disconnect the charge set, and mount the liquid
side and gas side valve caps and the service
port nut.
port nut.
- Use torque wrench to tighten the service port
nut to a torque of 1.8kg.m.(4.2kg.m/5.5kg.m)
- Be sure to check for gas leakage.
9. Apply steps from 1 to 8 to each unit (A-unit, B-
unit) by the same method.
- 42 -
Indoor unit
Outdoor unit
Liquid side
Close
Gas side
2-Way
valve
Open
3-Way
valve
manifold gauge
Hi- handle
(CLOSE)
Low-handle
(CLOSE)
(2) Evacuation
(All amount of refrigerant leaked)
• Procedure
1. Confirm that both the liguid side valve and gas
side valve are set to the opened position.
2. Connect the vaccum pump to the center hose of
the manifold gauge.
3. Connect the service port of the gas side valve to
the low side of the gauge.
4. Evacuation for approximately one hour.
- Confirm that the gauge needle has moved
toward-76 cmHg (vacuum of 4 mmHg or less).
5. Close the Low handle of the gauge turn off the
vacuum pump, and confirm that the gauge nee-
dle does not move(approximately 5 minutes
after turning off the vacuum pump).
dle does not move(approximately 5 minutes
after turning off the vacuum pump).
6. Disconnect the charge hose from the vacuum
pump.
- Vacuum pump oil.
If the vacuum pump oil becomes dirty or deplet-
ed,replenish as needed.
ed,replenish as needed.
7. Mount the valve caps and the service port caps.
8. Apply steps from 1 to 7 to each unit (A-unit, B-
unit) by the same method.
- 43 -
Indoor unit
Outdoor unit
Liquid side
Close
Gas side
2-Way
valve
Open
3-Way
valve
manifold gauge
Vacuum pump
Hi- handle
(CLOSE)
Low-
handle
(OPEN)
(3) Gas Charging
(After Evacuation)
• Procedure
1. Connect the gauge to the charging cylinder.
- Connect the charge hose which you disconnect-
ed from the vacuum pump to the valve at the
bottom of the cylinder.
bottom of the cylinder.
- If you are using a gas cylinder, also use a scale
and reverse the cylinder so that the system can
be charged with liquid.
be charged with liquid.
2. Purge the air from the charge hose.
- Open the valve at the bottom of the cylinder and
press the check valve on the charge set to
purge the air. (Be careful of the liquid refriger-
ant). The procedure is the same if using a gas
cylinder.
purge the air. (Be careful of the liquid refriger-
ant). The procedure is the same if using a gas
cylinder.
3. Open the low handle on the gauge and charge
the system with liquid refrigerant.
- If the system can not be charged with the speci-
fied amount of refrigerant, it can be charged
with a little at a time (approximately 150g each
time) while operating the air conditioner in the
cooling cycle; however, one time is not suffi-
cient, wait approximately 1 minute and then
repeat the procedure(pumping down-pin).
with a little at a time (approximately 150g each
time) while operating the air conditioner in the
cooling cycle; however, one time is not suffi-
cient, wait approximately 1 minute and then
repeat the procedure(pumping down-pin).
4. Immediately disconnect the charge hose from
the gas side valve's service port.
- Stopping partway will allow the gas to be dis-
charged.
- If the system has been charged with liquid
refrigerant while operating the air conditioner
turn off the air conditioner before disconnecting
the hose.
turn off the air conditioner before disconnecting
the hose.
5. Mount the valve stem nuts and the service port
nut.
- Use torque wrench to tighten the service port
nut to a torque of 1.8 kg.m.(4.2kg.m/5.5kg.m.)
- Be sure to check for gas leakage.
6. Apply steps from 1 to 5 to each unit (A-unit, B-
unit) by the same method.
- 44 -
Indoor unit
Outdoor unit
Liquid side
Close
Gas side
2-Way
valve
Open
3-Way
valve
manifold gauge
Charging
cylinder
Hi- handle
(CLOSE)
Low-handle
(OPEN)
Check valve
This is different from previous procedures.
Because you are charging with liquid refrigerant
from the gas side, absolutely do not attempt to
charge with larger amounts of liquid refrigerant
while operating the air conditioner.
Because you are charging with liquid refrigerant
from the gas side, absolutely do not attempt to
charge with larger amounts of liquid refrigerant
while operating the air conditioner.
Trouble analysis
1. Check temperature difference between intake and discharge air and operating current.
All amount of refrigerant leaked out.
Check refrigeration cycle.
Check refrigeration cycle.
Refrigerant leakage
Clog of refrigeration cycle
Defective compressor
Clog of refrigeration cycle
Defective compressor
Excessive amount of refrigerant
Normal
Notice:
Temperature difference between intake and discharge air depends on room air humidity. When the room air
humidity is relativery higher, temperature difference is smaller. When the room air humidity is relatively lower
temperature difference is larger.
Temperature difference between intake and discharge air depends on room air humidity. When the room air
humidity is relativery higher, temperature difference is smaller. When the room air humidity is relatively lower
temperature difference is larger.
2. Check temperature and pressure of refrigeration cycle.
Notice:
1. The suction pressure is usually 4.5~6.0 kg/cm
1. The suction pressure is usually 4.5~6.0 kg/cm
2
G at normal condition.
2. The temperature can be measured by attaching the thermometer to the low pressure tubing and wrap it with
putty.
- 45 -
Cycle Troubleshooting Guide
Temp. difference
: approx. 0°C
Current
: less than 80% of
rated current
Temp. difference
: approx. 8°C
Current
: less than 80% of
rated current
Temp. difference
: less than 8°C
Current
: over the rated
current
Temp. difference
: over 8°C
Temp. Difference
Operating Current
Suction pressure
Temperature
(Compared with
(Compared with
Cause of Trouble
Description
the normal value)
the normal value)
High
Defective compressor
Current is low.
Defective 4-way reverse valve
Normal
Excessive amount of
High pressure does not quickly
refrigerant
rise at the beginning of operation.
Insufficient amount of
Current is low.
Lower
Higher
refrigerant(Leakage)
Clogging
Clogging
Current is low.
Higher
Click on the first or last page to see other LM-1966C2L_M / LM-1966H2L_M / LM-2166H2L_M / LM-2065C3L_M service manuals if exist.