LG LV-C3681CL_HL / LV-D4881CL_HL / LV-D6081CL_HL Service Manual ▷ View online
–25–
A filter drier - Should be installed just after the liquid line shut-off valve. This condition for the capillary tube has
installed at the indoor unit for our standard unit, capillary tube has installed at the outdoor unit, so it’s not neces-
sary to use. Do not use a receiver (a receiver is not provided with the unit and one should not be used.)
installed at the indoor unit for our standard unit, capillary tube has installed at the outdoor unit, so it’s not neces-
sary to use. Do not use a receiver (a receiver is not provided with the unit and one should not be used.)
Make piping flare connections
Both the suction and liquid connections of the units are equipped with flare connections which are closed off in the
factory and ready for connection. Use refrigerant grade tubing. Assemble flared joint by aligning the tubing with the
machined surface of the fitting. Start nut onto threads by backwards first and then forwards. Use correct size tubing
see table 1. And wrenches. Tighten nut securely. Leaks test the joint to ensure it is leak free.
factory and ready for connection. Use refrigerant grade tubing. Assemble flared joint by aligning the tubing with the
machined surface of the fitting. Start nut onto threads by backwards first and then forwards. Use correct size tubing
see table 1. And wrenches. Tighten nut securely. Leaks test the joint to ensure it is leak free.
Step 4 - Complete electrical connections
Power wiring - The unit is factory wired for the voltage shown on the nameplate. Provide an adequate fused dis-
connect switch within sight of unit, readily accessible, but out of reach of children. Provision for locking switch open
(off) is advisable to prevent power from being turned on while unit is being serviced. Disconnect switch, fuses, and
field wiring must comply with local code requirements. Use copper wire only between disconnect switch and unit.
Use minimum 60 deg.C wire for field power connection.
Route power wires through the opening in unit’s side panel and connect to the unit control box as shown on the
unit’s label diagram unit must be grounded. Control circuit wiring - The control voltage is 220 volts. See wiring dia-
gram and unit label. Route the control wires through the opening in the unit’s side panel to connect into the unit
control box.
connect switch within sight of unit, readily accessible, but out of reach of children. Provision for locking switch open
(off) is advisable to prevent power from being turned on while unit is being serviced. Disconnect switch, fuses, and
field wiring must comply with local code requirements. Use copper wire only between disconnect switch and unit.
Use minimum 60 deg.C wire for field power connection.
Route power wires through the opening in unit’s side panel and connect to the unit control box as shown on the
unit’s label diagram unit must be grounded. Control circuit wiring - The control voltage is 220 volts. See wiring dia-
gram and unit label. Route the control wires through the opening in the unit’s side panel to connect into the unit
control box.
Start-up
Preliminary checks
Preliminary checks
[1] Check that all internal connections are tight and that all barriers, covers and panels are in place.
[2] The field electrical power source must agree with the unit nameplate rating.
[3] All service valves must be open.
[4] Crankcase heater (where supplied) must be tight on the compressor crankcase.
Leak test field piping and fan coil by pressure method. Use R-22 at approximately 170 Kpa backed up with an
inert gas to a total pressure not to exceed 1690 Kpa.
Evacuation and dehydration of the field piping and fan coil is necessary service valves must be fully back-seated
to close the service port. There is no valve at the service portend failure to back-seat the valve could result in s
loss of the system charge or personal injury.
To start unit - Ensure that the crankcase heater ( where supplied) has been on for 24 hours, the field disconnect is
closed and the room thermostat is set below ambient temperature, the unit compressor will start after a 3 minute
delay. Operate the unit for 15 minutes, then check the system refrigerant charge. See refrigerant charging.
[2] The field electrical power source must agree with the unit nameplate rating.
[3] All service valves must be open.
[4] Crankcase heater (where supplied) must be tight on the compressor crankcase.
Leak test field piping and fan coil by pressure method. Use R-22 at approximately 170 Kpa backed up with an
inert gas to a total pressure not to exceed 1690 Kpa.
Evacuation and dehydration of the field piping and fan coil is necessary service valves must be fully back-seated
to close the service port. There is no valve at the service portend failure to back-seat the valve could result in s
loss of the system charge or personal injury.
To start unit - Ensure that the crankcase heater ( where supplied) has been on for 24 hours, the field disconnect is
closed and the room thermostat is set below ambient temperature, the unit compressor will start after a 3 minute
delay. Operate the unit for 15 minutes, then check the system refrigerant charge. See refrigerant charging.
Service
Before performing recommended maintenance, be sure the unit main power switch is turned off failure to do so
may result in an electric shock or injury from the rotating fan blade.
A high pressure relief valve is located in the compressor. The relief valve opens at a pre-set pressure differential
between suction (low side) and discharge (high side) to allow pressure equalization.
The internal current and temperature sensitive overload resets automatically when the internal compressor
motor temperature drops to a safe level (overload may require up to 45 minutes to reset).
When an internal overload is suspected of being open, check by using an ohm-meter for continuity test. If neces-
sary, refer to your local distributor for complete information.
Pump-down procedure - The system may be pumped down in order to make repairs on the low side without los-
ing the complete refrigerant charge.
[1] Attach a pressure gauge to suction service valve gauge port.
[2] Frontseat (close) the liquid lines valve.
[3] Start unit and run until suction pressure reaches 35 Kpa.
[4] Shut unit off and frontseat (close) suction valve.
[5] Vent remaining pressure.
may result in an electric shock or injury from the rotating fan blade.
A high pressure relief valve is located in the compressor. The relief valve opens at a pre-set pressure differential
between suction (low side) and discharge (high side) to allow pressure equalization.
The internal current and temperature sensitive overload resets automatically when the internal compressor
motor temperature drops to a safe level (overload may require up to 45 minutes to reset).
When an internal overload is suspected of being open, check by using an ohm-meter for continuity test. If neces-
sary, refer to your local distributor for complete information.
Pump-down procedure - The system may be pumped down in order to make repairs on the low side without los-
ing the complete refrigerant charge.
[1] Attach a pressure gauge to suction service valve gauge port.
[2] Frontseat (close) the liquid lines valve.
[3] Start unit and run until suction pressure reaches 35 Kpa.
[4] Shut unit off and frontseat (close) suction valve.
[5] Vent remaining pressure.
–26–
TABLE 1 : CHARGING TABLE
High-pressure switch, located on the discharge line, protects against high discharge pressure caused by such
events as overcharge, condenser fan motor failure, system restriction, ect. it opens at a preset pressure rise. If the
system pressures go above the setting during abnormal conditions, the switch opens.
Service valve - The service valves in the condensing unit come from the factory closed. This means the refriger-
ant charge is isolated from the line side of the connection ports.
The service valves must be open (turned counter clockwise until seated) before the service port caps can be
removed and the hoses of the gauge manifold connected. in this position, the refrigerant has access from and
through the outdoor and indoor unit. The service valve can not be field repaired, there fore only a completed valve
or valve system and service caps are available for replacement Defrost control The control consists of a defrost
thermostat (and optional control board, depending on the type of remote control supplied). It Interrupts the normal
system heating operation to defrost the outdoor coil if the coil saturated suction temperature indicates freezing
temperatures
events as overcharge, condenser fan motor failure, system restriction, ect. it opens at a preset pressure rise. If the
system pressures go above the setting during abnormal conditions, the switch opens.
Service valve - The service valves in the condensing unit come from the factory closed. This means the refriger-
ant charge is isolated from the line side of the connection ports.
The service valves must be open (turned counter clockwise until seated) before the service port caps can be
removed and the hoses of the gauge manifold connected. in this position, the refrigerant has access from and
through the outdoor and indoor unit. The service valve can not be field repaired, there fore only a completed valve
or valve system and service caps are available for replacement Defrost control The control consists of a defrost
thermostat (and optional control board, depending on the type of remote control supplied). It Interrupts the normal
system heating operation to defrost the outdoor coil if the coil saturated suction temperature indicates freezing
temperatures
Defrost control simultaneously stops the outdoor and indoor fans and energizes the reversing valve solenoid to
return the system to the cooling cycle (outdoor unit as a condenser, indoor unit as evaporator). The defrost timer
(optional) limits defrosting. Normally the frost is removed and the defrost thermostat contacts open to terminate
defrosting before the maximum allowable time has elapsed. When defrosting is terminated, the outdoor and indoor
fan motors are energized, and the reversing valve solenoid is de-energized returning the unit to the heating cycle.
return the system to the cooling cycle (outdoor unit as a condenser, indoor unit as evaporator). The defrost timer
(optional) limits defrosting. Normally the frost is removed and the defrost thermostat contacts open to terminate
defrosting before the maximum allowable time has elapsed. When defrosting is terminated, the outdoor and indoor
fan motors are energized, and the reversing valve solenoid is de-energized returning the unit to the heating cycle.
Reversing valve in heat pumps, the change-over between heating and cooling modes is accomplished with a
valve that reverses the flow of refrigerant in the system. The reversing valve solenoid can be checked when the
power is off with an ohm-meter. Check for continuity and shorting to ground. With the control circuit (220-240V)
power on, check for the correct voltage at the solenoid coil. Check for a burned or overheated solenoid. With the
unit operating, other items can be checked, such as frost or condensate water on the refrigerant lines. Using a
remote measuring device. check the inlet and outlet line temperatures. Do not touch the line. If the reversing valve
is operating normally, the inlet and outlet temperatures on the appropriate lines should be close Any difference
would be due to heat loss or gain across the valve body. Temperatures are best checked with a remote reading
electronic-type thermometer with multiple probes. Figures 14 and 15 show test points (tp) on the reversing valve
for recording temperatures. insulate points for a more accurate reading. It the valve is defective; shut-off all power
to the unit and remove all charge from system. Remove the valve using a tubing cutter.
Wrap the new valve with a wet rag to prevent overheating while brazing.
valve that reverses the flow of refrigerant in the system. The reversing valve solenoid can be checked when the
power is off with an ohm-meter. Check for continuity and shorting to ground. With the control circuit (220-240V)
power on, check for the correct voltage at the solenoid coil. Check for a burned or overheated solenoid. With the
unit operating, other items can be checked, such as frost or condensate water on the refrigerant lines. Using a
remote measuring device. check the inlet and outlet line temperatures. Do not touch the line. If the reversing valve
is operating normally, the inlet and outlet temperatures on the appropriate lines should be close Any difference
would be due to heat loss or gain across the valve body. Temperatures are best checked with a remote reading
electronic-type thermometer with multiple probes. Figures 14 and 15 show test points (tp) on the reversing valve
for recording temperatures. insulate points for a more accurate reading. It the valve is defective; shut-off all power
to the unit and remove all charge from system. Remove the valve using a tubing cutter.
Wrap the new valve with a wet rag to prevent overheating while brazing.
After the valve is brazed in, check for leaks, evacuate and charge system, Operate the system in bath heat and
cool modes several times to be sure the valve functions properly.
cool modes several times to be sure the valve functions properly.
RECOMMENDED PIPE SIZE
Suction
Liquid
36K Btu
3/4"
3/8"
48K Btu
3/4"
1/2"
60K Btu
3/4"
1/2"
MODEL
To accumulator
From indoor coil via
service valve on
outdoor coil
service valve on
outdoor coil
From compressor
discharge line
discharge line
Fig. 14 - Reversing valve
(cooling mode or defrost mode, solenoid energized)
To outdoor coil
TP-4
TP-3
TP-2
TP-1
To accumulator
To indoor coil via
service valve on
outdoor coil
service valve on
outdoor coil
Insulate
for accurate
reading
for accurate
reading
Insulate
for accurate
reading
for accurate
reading
Fig. 15 - Reversing valve
(heating mode, solenoid de-energized)
From compressor
discharge line
discharge line
From outdoor coil
TP-4
TP-3
TP-2
TP-1
ELECTRIC WIRE SIZE
**REMARK**
* If an air conditioner is a model for both cooling and heating.
Cooling when the room temperature at the start of operation is above 23°C.
Heating when the room temperature at the start of operation is less 23°C.
Heating when the room temperature at the start of operation is less 23°C.
–27–
Refrigerant Charging
To prevent personal injury, wear safety glasses and gloves when handling refrigerant. Do not overcharge
system. This can cause compressor flooding.
When re-charging is necessary during the heating season, weigh in the total charge as indicated in the charging
table. Remove any refrigerant remaining in the system before re-charging. If the system has lost the complete
charge, evacuate and re-charge by weight. Service port connection.Are provided on the liquid and suction line ser-
vice valves.
system. This can cause compressor flooding.
When re-charging is necessary during the heating season, weigh in the total charge as indicated in the charging
table. Remove any refrigerant remaining in the system before re-charging. If the system has lost the complete
charge, evacuate and re-charge by weight. Service port connection.Are provided on the liquid and suction line ser-
vice valves.
Maintenance
Before performing the recommended maintenance, be sure the unit’s main power switch is turned off. Failure to do
so may result in electric shock or injury from the rotating fan blade.
Cleaning coils - The coil should be washed-out with water, or blown-out with compressed air. Clean the coil annu-
ally, or as required by the location or outdoor air conditions. Inspect the coil monthly and clean as required. Dirt
and debris may pass through the first coil section, then become trapped between the rows of fine and restrict the
condenser air flow. Use a flashlight to determine if any dirt or debris has collected between the coil sections. Clean
coil as follows.
[1] Turn off unit power.
[2] Using a water-hose, or any other suitable equipment, flush the coil from the outside to remove dirt. Be sure to
so may result in electric shock or injury from the rotating fan blade.
Cleaning coils - The coil should be washed-out with water, or blown-out with compressed air. Clean the coil annu-
ally, or as required by the location or outdoor air conditions. Inspect the coil monthly and clean as required. Dirt
and debris may pass through the first coil section, then become trapped between the rows of fine and restrict the
condenser air flow. Use a flashlight to determine if any dirt or debris has collected between the coil sections. Clean
coil as follows.
[1] Turn off unit power.
[2] Using a water-hose, or any other suitable equipment, flush the coil from the outside to remove dirt. Be sure to
flush all dirt and debris from the drain holes in the base of the unit.
FAN MOTOR
CONDENSER COIL
COMPRESSOR
TOP VIEW
FRONT VIEW
RIGHT SIDE VIEW
LIQUID VALVE
SUCTION VALVE
FAN
36K Btu
10A / 250V
0.5A / 250V
30A / 3P.
-
6
48K/60K Btu
10A / 250V
0.5A / 250V
50A / 3P.
-
6
MODEL
OUTDOOR
FUSE
CONTROL
INDOOR FUSE
CONTROL
CIRCUIT
BREAKER
ON THE
GROUND 60
°
C
IN PIPE
75
°
C
ELECTRIC WIRE SIZE (SQMM)
MORE THAN 23
°
C
26
°
C
CONTINUOUS
AUTO
COOL
LESS THAN 23
°
C
23
°
C
CONTINUOUS
AUTO
HEAT
ROOM
TEMPERATURE
DESIGNATED
TEMPERATURE
TIMER
MODE
AIR FLOW
SPEED
OPERATION
MODE
–28–
3-way Valve
1. Pumping down
• Procedure
(1) Confirm that both liquid side and gas side
valves are set to the open position.
– Remove the valve stem caps and confirm that
– 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
connect the charge set to the service port of
the 3-way valve.
– Connect the charge hose to the service port.
the 3-way valve.
– Connect the charge hose to the service port.
(4) Air purging of the charge hose.
– Open the low-pressure valve on the charge set
slightly to air purge from the charge hose.
(5) Set the liquid side valve to the closed
position.
(6) Operate the air conditioner in cooling mode
and stop it when the gaug e indicates
1kg/cm
1kg/cm
2
g.
(7) Immediately set the 3-way valve to the closed
position.
– Do this quickly so that the gauge ends up
– Do this quickly so that the gauge ends up
indicating 3 to 5kg/cm
2
g.
(8) Disconnect the charge set, and mount the 2-
way and 3-way valve’s stem nuts and the
service port nut.
– Use torque wrench to tighten the service port
service port nut.
– Use torque wrench to tighten the service port
nut to a torque of 1.8 kg.m.
– Be sure to check for gas leakage.
Lo
Closed
Purge the air
Outdoor unit
Indoor unit
Liquid side
Gas side
CLOSE
Open
3-Way
valve
valve
3-Way
valve
valve
CLOSE
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