Heat Controller DMC24CA-1 User manual

Ceiling Cassette Type
Single-Zone
Air Conditioning
DMC24CA-1
DMC36CA-1
Beforeservicingtheunit,readthe
“safetyprecautions”inthismanual.
Onlyforauthorizedservicepersonnel.

2Ceiling Cassette Air Conditioner
TABLE OF CONTENTS
Table of contents Page
1. Safety Precautions...........................................................................................................3
2. Feature & Benefits ...........................................................................................................7
3. List of Functions.............................................................................................................10
4. Function of Remote Control...........................................................................................11
5. Specifications.................................................................................................................13
6. Dimensional Drawings ...................................................................................................15
7. Wiring Diagrams.............................................................................................................18
8. Refrigerant Cycle Diagrams...........................................................................................20
9. Installation......................................................................................................................21
10. Trouble Shooting Guide................................................................................................31
11. (3-Way)Valve................................................................................................................47
12. Electronic Control Device.............................................................................................51

Service Manual 3
Safety Precautions
To prevent injury to the user or other people and property damage, the following instructions must
be followed.
■Incorrect operation due to ignoring instruction will cause harm or damage. The seriousness is
classified by the following indications.
■Meanings of symbols used in this manual are as shown below.
This symbol indicates the possibility of death or serious injury.
This symbol indicates the possibility of injury or damage to properties only.
■Installation
Be sure not to do.
Be sure to follow the instruction.
Do not use a defective or under-
rated circuit breaker. Use this
appliance on a dedicated circuit.
• There is risk of fire or electric
shock.
Always ground the product.
• There is risk of fire or electric
shock.
Install the panel and the cover
of control box securely.
• There is risk of fire or electric
shock.
Always install a dedicated cir-
cuit and breaker.
• Improper wiring or installation may
cause fire or electric shock
Use the correctly rated break-
er or fuse.
• There is risk of fire or electric
shock.
Do not modify or extend the
power cable.
• There is risk of fire or electric
shock.
Safety Presautions

4Ceiling Cassette Air Conditioner
■Operational
Do not install, remove, or re-
install the unit by yourself
(customer).
• There is risk of fire, electric shock,
explosion, or injury.
Be cautious when unpacking
and installing the product.
• Sharp edges could cause injury.
Be especially careful of the case
edges and the fins on the con-
denser and evaporator.
For installation, always con-
tact the dealer or an
Authorized Service Center.
• There is risk of fire, electric shock,
explosion, or injury.
Do not install the product on a
defective installation stand.
• It may cause injury, accident, or
damage to the product.
Be sure the installation area
does not deteriorate with age.
• If the base collapses, the air condi-
tioner could fall with it, causing
property damage, product failure,
and personal injury.
Do not let the air conditioner
run for a long time when the
humidity is very high and a
door or a window is left open.
• Moisture may condense and wet or
damage furniture.
Do not touch(operate) the
product with wet hands.
• There is risk of fire or electrical
shock.
Do not place a heater or other
appliances near the power
cable.
• There is risk of fire or electric
shock.
Do not let electric parts of the
product get wet.
• There is risk of fire, failure of the
product, or electric shock.
Safety Presautions

Service Manual 5
■Installation
Do not open the inlet grill of the product during
operation. (Do not touch the electrostatic filter,
if the unit is so equipped.)
• There is risk of physical injury, electric shock, or prod-
uct failure.
Be cautious that water could not enter the
product.
• There is risk of fire, electric shock, or product damage.
Always check for gas (refrigerant) leakage after
installation or repair of product.
• Low refrigerant levels may cause failure of product.
Install the drain hose to ensure that water is
drained away properly.
• A bad connection may cause water leakage.
Do not store or use flammable gas or com-
bustibles near the product.
• There is risk of fire or failure of product.
If strange sounds, or small or smoke comes
from product. Turn the breaker off or discon-
nect the power supply cable.
• There is risk of electric shock or fire.
Gasolin
Safety Presautions

6Ceiling Cassette Air Conditioner
Keep level even when installing the product.
• To avoid vibration or water leakage.
Use two or more people to lift and transport
the product.
• Avoid personal injury.
Use a soft cloth to clean. Do not use harsh
detergents, solvents, etc.
• There is risk of fire, electric shock, or damage to the
plastic parts of the product.
Do not touch the metal parts of the product
when removing the air filter. They are very
sharp!
• There is risk of personal injury.
Do not step on or put anyting on the product.
(outdoor units)
• There is risk of personal injury and failure of product.
Do not insert hands or other objects through
the air inlet or outlet while the product is oper-
ated.
• There are sharp and moving parts that could cause
personal injury.
90˚
Wax
Thinner
■Operational
Safety Presautions

Service Manual 7
Features & Benefits
Environment Friendly Refrigerant :
- LG Ceiling Cassette Air Conditioners uses environ-
ment friendly refrigerant, which don't do any harm to
the environment.
Plasma Air Purifier :
- It removes not only microscopic contaminants &
dust, but also house mites, pollen, and pet fur to help
preventing allergic diseases like asthma.It provides
odor free, dust free and allergy free air.
Group Control :
- It enables to control as much as 16 units with the
help of one wired remote controller. All the units will
follow same setting of temperature & other sub func-
tions.
Central Control :
- It enables to control 16 x 8 = 128 units with the help
of 8 controllers. All units can be put on and off from
one Central Room. For Setting Temperature, Fan
Speed and other sub functions, access the respec-
tive LCD wired remote controller of each unit.
Jet Cool :
-In this mode, quick and fast cooling is done. Cold and
high velocity air is supplied to the room till the indoor
temperature reaches 18°C(64°F). The unit will contin-
ue to run in jet cool mode till the Indoor temperature
reaches 18°C(64°F).
1216........
........
IonizerPre-filter
Dust particles
dusts
Odour
Dust
electrode
discharge
Odor molecule
+6.5KV
discharge
aluminum coated
electrode(-)
(3.25KV discharge)
Generating
plasma
++
++
+
Dusts Collection
Polluted
Air Purified
fresh Air
Main
PCB
Controller
# 1 Controller # 2 Controller # 8
M
1
Sub
1
M
2
Sub
2
M
16
Sub
16
M
17
Sub
17
M
18
Sub
18
M
128
Sub
128
Features & Benefits

8Ceiling Cassette Air Conditioner
Swirl Swing
- It is the function for comfort cooling/heating operation.
- The diagonal two louvers are opened the
more larger than the other louvers.
After one minute, it is opposite.
Space Control
Vanes angle can be controlled by pair, considering its
installation environment.
- For example direct drafts can be annoying, leading
to discomfort and reduced productivity vane control
helps to eliminate this problem.
- Easily controlled by wired remote control.
- Air Flow can be controlled easily regarding any
space environment.
Auto Restart Operation :
- Whenever there is electricity failure to the unit, and after resumption of the power, unit will start in the same
mode prior to the power failure. Memorized condition are on / off condition, operating mode, set temperature
and fan speed.The unit will memorize the above conditions and start with same memorized condition.
Two Thermistor Control :
- There may be a significant difference between the temperature taken at the installed product and indoor tem-
perature. Two thermistor control provides option to control temperature by referring any of the two tempera-
tures. With the help of the slide switch at the back of the LCD wired remote controller, selection of the desired
thermistor for controlling the unit can be done. One thermistor is in the Indoor unit & the other one is in the
LCD wired remote.
Features & Benefits
71
Vane 2
Swirl Swing(New)4- Open(Conventional)
Swirl Swing(New)4- Open(Conventional)
2.4% 4.8%100% Improved
Comparison of Air Flow Types
Comparison of Floor
Temp. Distribution(20°C)
Vane 1 Close OpenOpen
Open
Open
Open
Close CloseOpen
Vane 3 Close Open Close CloseOpen
OpenOpen Close CloseOpen
Vane 2
OpenOpen
Time
Close CloseOpen
Vane 4
Vane 1
Vane 3
Vane 2
Time
Vane 4
Vane 3
Vane 4
Vane 1

Service Manual 9
Features & Benefits
High Ceiling Operation
- According to the height of ceiling installation, it pro-
vides variability of indoor fan motor rpm. If the height
of installation is low then you can adjust low rpm of
indoor fan motor. On the other hand if the height of
the installation is high you can adjust high rpm of
indoor fan motor. Selection of speed can be done by
slide switch at the back of the LCD wired remote.
ex:
Water Drain Pump :
- In some of the places natural drainage is not possi-
ble. For such places drain pump is very useful. It
removes condensed water from the unit.
Time Delay Safety Function :
- It delays restarting of the compressor by three min-
utes thereby preventing damage to the compressor.
Zero Standby Power:
- Due to SMPS (Switching Modulation Power Supply)
technology, there is almost zero power consumption
in the standby mode.
Child Lock Function:
-It prevents the children or others from tampering the
control buttons. Unit can be controlled by the wireless
remote controller. This can be easily set by pressing
timer key & Min key simultaneously. After child lock is
set, pressing any key will displaye CL on the LCD for
3 seconds and all the keys will be ineffective.
Self Diagnosis Function:
- This function provides diagnosis of the unit. An
error code will be displayed on the LCD wired
remote controller & diagnosis can be done as per
the code indication. The same is also printed on
key cover of the LCD wired remote controller.
30m
30m
5~6W
Others LG
0.5W
CHILD LOCK
-Display
Selection Height RPM
Lower 2.4m(7.9ft) 700/600/500
Standard 2.7m(8.9ft) 750/650/550
Higher 3.0m(9.8ft) 800/700/600

10 Ceiling Cassette Air Conditioner
List of Functions
• Ceiling Cassette
List of Functions
Air supply outlet
Airflow direction control (left & right)
Airflow direction control (up & down)
Auto swing (left & right)
Air flow Auto swing (up & down)
Airflow steps(Fan / Cool / Heat)
CHAOS swing
CHAOS wind (Auto wind)
Jet cool (Power wind)
Swirl wind
Deodorizing filter
Air purifying Plasma air purifier
Prefilter(Washable)
Drain pump
Installation E.S.P. control
Electric heater (Operation)
High ceiling operation
Hot start
Reliability Self diagnosis
Soft dry operation
Auto changeover
Auto cleaning
Auto operation(Artificial intelligence)
Auto restart operation
Convenience Child lock
Forced operation
Group control
Sleep mode
Timer (On/Off)
Timer (weekly)
Two thermistor control
Standard wired remote controller
Deluxe wired remote controller
Individual Control Simple wired remote controller
Wired remote controller(for hotel use)
Wireless remote controller(simple)
Wireless LCD remote controller
General central control(Non LGAP)
CAC Network Dry contact
Function Simple central control(LGAP)
PDI(Power Distribution Indicator)
PI 485
Special Function Kit CTIE
Zone control
Others Thermistor
44
XX
Auto Auto
XX
OO
3/4/- 3/4/-
XX
XX
OO
OO
XX
OO
OO
OO
--
--
OO
XX
OO
OO
XX
XX
OO
OO
OO
OO
Option Option
--
OO
OO
OO
OO
--
--
--
--
PQWRHSF0 PQWRHSF0
Option Option
Option Option
Option Option
Option Option
Option Option
XX
XX
--
FunctionCategory
DMC24CA-1 DMC36CA-1
Note :
O : Applied, X : Not applied, –: No relation
Option: Model name & price are different according to options, and assembled in factory with main unit.
Accessory: Installed at field, ordered and purchased separately by the corresponding model name, supplied with separate package.

Service Manual 11
Function of Remote Control
1. Wireless LCD Remote Control
Function of Remote Control
Cooling Operation
Auto Operation
Healthy Dehumidification Operation
Operation Mode
ON OFF
CANCEL
SET
°C/°F
AUTO CLEAN
1
3
5
4
9
10
12
18
16
7
2
8
13
15
11
6
Flip-up door
(opened)
Signal transmitter
17
14
1. START/STOP BUTTON
Operation starts when this button is pressed and
stops when the button is pressed again.
2. OPERATION MODE SELECTION BUTTON
Used to select the operation mode.
3. ROOM TEMPERATURE SETTING BUTTONS
Used to select the room temperature.
4. INDOOR FAN SPEED SELECTOR
Used to select fan speed in four steps
low, medium and high.
5. JET COOL
Used to start or stop the speed cooling.(speed cooling
operates super high fan speed in cooling mode.)
6. AUTO SWING BUTTON
Used to stop or start louver movement and set the
desired up/down airflow direction.
7. ON/OFF TIMER BUTTONS
Used to set the time of starting and stopping opera-
tion.
8. TIME SETTING BUTTONS
Used to adjust the time.
9. TIMER SET/CANCEL BUTTON
Used to set the timer when the desired time is
obtained and to cancel the Timer operation.
10. SLEEP MODE AUTO BUTTON
Used to set Sleep Mode Auto operation.
11. AIR CIRCULATION BUTTON
Used to circulate the room air without cooling.
12. ROOM TEMPERATURE CHECKING BUTTON
Used to check the room temperature.
13. PLASMA AIR CLEAN BUTTON
Used to start or stop the plasma-purification func-
tion.
14. HORIZONTAL AIRFLOW DIRECTION CONTROL
BUTTON (OPTIONAL)
Used to set the desired horizontal airflow direction.
15. RESET BUTTON
Used prior to resetting time.
16. 2nd F Button
Used prior to using modes printed in blue at the bot-
tom of buttons.
17. AUTO CLEAN (OPTIONAL)
Used to set Auto Clean mode.
18. °C/°F SWITCH BUTTON
Used to switch temperature reading from Centigrade
to Fahrenheit.
❈The wireless remote controller do not operate the swirl mode.❈The wireless remote controller do not operate the swirl mode.

12 Ceiling Cassette Air Conditioner
Function of Remote Control
Timer Cancel 2ndF
Program Week
Hour Min
Holiday
Set/Clr
RESET
Plasma
Operation unit
Humidify
AUTO SWING OPERATION FAN SPEED
Program set
SUB FUNCTION SET TEMP
Room Temp
HI
MED
LO
Heater
Defrost
Filter
Preheat
Out door
Time
Timer
On
Set no. Time
Off 01 03 05 07 09 11 13 15 17 19 21 23
3
10
12
14
15
11
13
18
16
2
6
1
5
4
8
9
7
17
1234
ZONE
2ndF
No Func
AUTO
JET
SLo
1 Operation display
Displays the operation conditions.
2 On/Off Button
Operation starts when this button is pressed, and
stops when the button is pressed again.
3 Set Temperature Button
Used to set the temperature when the desired tem-
perature is obtained.
4 FAN Operation Button
Used to circulate room air without cooling.
5 Fan Speed & Jet Cool Button
Used to set the desired fan speed and select jet
cool mode.
6 Operation Mode Selection Button
Used to select the operation mode.
•Auto Operation Mode
•Cooling Operation Mode
•Soft Dry Operation Mode
7 Auto Swing Button
Used to swing up and down.
8 Room Temperature Checking Button
Used to check the room temperature.
9 Plasma Air Clean Button
Used to start or stop the plasma-purification function.
10 Timer Cancel Button
Used to cancel the timer.
11 Timer Set Button
Used to set the timer when the desired time is
obtained.
12 Week Button
Used to set a day of the week.
13 Program Button
Used to set the weekly timer.
14 Holiday Button
Used to set a holiday of the week.
15 Time Set Button
Used to set the time of the day and change the
time in the weekly timer Function.
16 Set and Clear Button
Used to set and clear the weekly timer.
17 Swirl Button
Used to select swirl swing mode.
18 Reset Button
Used to set the current time and clear the setting
time.
2. Wired LCD Remote Control

Service Manual 13
Specifications
Specifications
Note :
1. Capacities are based on the following conditions:
Cooling: - Indoor Temperature 26.7°C(80°F) DB /19.4°C(67°F) WB
- Outdoor Temperature 35°C(95°F) DB /23.9°C(75°F) WB
Piping Length - Interconnecting Piping Length 7.5m(25ft)
- Level Difference of Zero.
Conversion Formula
kW = Btu/h ×0.0002931
CFM = CMM ×35.3
Power supply Phase/Volts/Hz
Cooling capacity kW
Btu/h
Heating capacity kW
Btu/h
Current Nominal running current A
Fan Motor Type
Fan Type
Motor Output(W) * number of units
Air flow rate (H/M/L) cmm
cfm
Capacitor mF/V
Drive
Coil Row * stages * FPI mm
Dimensions Body mm(inch)
(W*D*H) Decorative Panel mm(inch)
Net Weight Body kg(lbs)
Decorative Panel kg(lbs)
Gross Weight Body kg(lbs)
Decorative Panel kg(lbs)
Air filter
Sound Level (H/M/L) dB(A)+3
Piping Connections Liquid mm(inch)
Gas mm(inch)
Drain OD/ID mm(inch)
Dehumidification rate l/h(pts/h)
Safety Devices
Temperature sensor
Refrigerant
Refrigerant control
Connectable outdoor Unit
Power and Transmission interunit cable
No.* mm2 (No. AWG)
Model DMC24CA-1 DMC36CA-1
Indoor unit type Ceilling Cassette - 4way
1 / 208-230 / 60 1 / 208-230 / 60
7.03 9.96
24,000 34,000
--
--
1.0 1.0
BLDC BLDC
Turbo Fan Turbo Fan
50.6 * 1 50.6 * 1
18.4/17.0/15.6 24.1/22.7/21.2
650/600/550 850/800/750
--
DC DC
2R * 9C * 18 2R * 9C * 18
840 * 840 * 225(331/16 * 331/16 * 87/8) 840 * 840 * 225(331/16 * 331/16 * 87/8)
950 * 950 * 30(3713/32 * 3713/32 * 13/16) 950 * 950 * 30(3713/32 * 3713/32 * 13/16)
26(57.3) 26(57.3)
3(6.61) 3(6.61)
30(66) 30(66)
4(9) 4(9)
Long Life filter Long Life filter
38/35/32 40/37/34
6.35(1/4) 6.35(1/4)
12.7(1/2) 15.88(5/8)
32/25(1.26/0.98) 32/25(1.26/0.98)
3.0(6.3) 3.7(7.8)
Fuse, Thermal protector for Fan motor
Thermistor Thermistor
R410A R410A
EEV EEV
Single Single
4 * 2.1(14) 4 * 2.1(14)

14 Ceiling Cassette Air Conditioner
Specifications
Rated Capacity Cooling kW
Btu/h
Heating kW
Btu/h
Rated Input Cooling kW
Heating kW
Energy Label
Testing combination
Running current Cooling A
Heating A
Starting current (Cooling/Heating) A
Power supply Phase / Volts / Hz
Power supply Cable(outdoor) No. * mm
2
(No. AWG)
Power and transmission cable No. * mm
2
(No. AWG)
Dimensions W * H * D mm(inch)
Net weight kg(lbs)
Gross weight kg(lbs)
Maximum number of connectable unit
Compressor Type
(constant) Qty * model
Motor Type
Oil charge volume cc
Oil type
Refrigerant Charge(at 7.5m(25ft)) g(oz)
Type
Control
Heat Exchanger Rows * Column * FPI
Defrosting method
Fan Capacitor mF/Vac
Drive
Discharge Direction Side / Top
Air flow rate cmm(cfm)
Noise level(H) Sound press, 1m db (A) + 3
Piping connections Liquid mm(inch)
Gas mm(inch)
Max. piping length Main piping m(ft)
Max. elevation Indoor unit - Outdoor unit m(ft)
7.03 9.96
24,000 34,000
--
--
2.5 3.6
--
--
--
11.5 17
--
24 38
1 / 208-230 / 60 2 / 208-230 / 60
3 * 2.1(14) 3 * 3.3(12)
4 * 2.1(14) 4 * 2.1(14)
870 * 800 * 320(341/2* 311/2* 1219/32) 900 * 1160 * 370(357/16 * 4511/16 * 149/16)
73(160) 86(190)
78(172) 93(205)
11
ROTARY ROTARY
2*GK120KAA GJ151KAA + GJ208KAA
Induction Induction
700 1200
PVE PVE
2100(74.1) 2500(88.2)
R410A R410A
EEV EEV
2R * 36C * 20 2R * 52C * 18
- -
6 / 370 6 / 370
Direct Drive Direct Drive
Side discharge Side discharge
51(1801) 105(3708)
55 58
6.35(1/4) 6.35(1/4)
12.7(1/2) 15.88(5/8)
30(100) 35(115)
15(50) 20(66)
DMC24CA-1 DMC36CA-1
Outdoor Unit
Note :
1. Capacities are based on the following conditions:
Cooling: - Indoor Temperature 26.7°C(80°F) DB /19.4°C(66.9°F) WB
- Outdoor Temperature 35°C(95°F) DB /23.9°C(75°F) WB
Piping Length - Interconnecting Piping Length 7.5m(25ft)
- Level Difference of Zero.
Conversion Formula
kW = Btu/h ×0.0002931
CFM = CMM ×35.3

Service Manual 15
225(8.9)
950(37.4)
950(37.4)
840(33.1)
7
76(3.0)
135(5.3)
4
5
225(8.9)
6
806(31.7)
840(33.1)
840(33.1)
688(27.1)
950(37.4)
30(1.18)
950(37.4)
R35(1.4)
3
2
1
900(35.4) (ceiling opening)
688(27.1) (hanging bolt)
840(33.1)
900(35.4) (ceiling opening)
950(37.4)
806(31.7) (hanging bolt)
840(33.1)
Drain pipe connection
Air suction grille
Part Name
Decoration panel
Air discharge grille
Liquid pipe connection
Gas pipe connection
6
5
No.
2
4
3
1Remark
7Power supply connection
* mm(inch)
Dimensional Drawings
1. Indoor Units
Model No.: DMC24CA-1 / DMC36CA-1
Dimensional Drawings

16 Ceiling Cassette Air Conditioner
870(34.3)
546(21.5)
54.6(2.1)
333(13.1)
Ø531(20.9)
10(0.4)
808(31.8)
782.5(30.8)
392(15.4)
25.5(1.0)
80(3.1) 50(2.0)
320(12.6)
320(12.6)
340(13.4)
360(14.2)
160(6.3)
*mm(inch)
Dimensional Drawings
Model No.: DMC24CA-1
2. Outdoor Units

Service Manual 17
Dimensional Drawings
Model No.: DMC36CA-1
Gas pipe connection
Part Name
Air discharge grille
Liquid pipe connection
Earth screw
Power & transmission connection
5
No.
2
4
3
1Remark
5
1135(44.7)
1165(45.9)
308(12.1)
565(22.2)
273(10.7)
520(20.5)
80(3.1)
124(4.9)
900(35.4)
550(21.7)
370(14.6)
395(15.6)
15(0.6)
175(6.9)
3
2
65(2.6)
4
370(14.6)
1
*mm(inch)

18 Ceiling Cassette Air Conditioner
Wiring Diagrams
1. Indoor Unit
DMC24CA-1 / DMC36CA-1
Wiring Diagrams
Connector Number Location
CN-POWER AC power supply
CN-MOTOR BLDC fan motor output
CN-DPUMP Drain pump output
CN-DISP Display
CN-FLOAT Float switch input
CN-REMO Remote control
CN-CC Dry-contact
CN-ROOM Room sensor
CN-PIPE1 In-pipe thermistor
CN-PIPE2 Out-pipe thermistor
CN-GRILL Elevation grille
CN-HVB HVB Ass'y (Air cleaner)

Service Manual 19
Wiring Diagrams
DMC24CA-1
DMC36CA-1
2. Outdoor Unit
Notes:
BL
RD
YL
BLUE
RED
YELLOW
BK
OR
GN/YL
BLACK
ORANGE
GREEN/YELLOW
BR
WH BROWN
WHITE
FIELD WIRING
Notes:
BL
RD
YL
BLUE
RED
YELLOW
BK
OR
GN/YL
BLACK
ORANGE
GREEN/YELLOW
BR
WH BROWN
WHITE
FIELD WIRING

20 Ceiling Cassette Air Conditioner
Refrigerant Cycle Diagrams
1. Cooling Only Models
INDOOR UNIT
H/EX
LIQUID SIDE
Gas Side
GAS SIDE
Capillary Tube
OUTDOOR UNIT
Thermistor
(Air)
E.E.V.
Accumulator
Heat
Exchanger
Check
Valve
Constant
Compressor 1
Constant
Compressor 2
Check
Valve
Thermistor
Thermistor
High
pressure
S/W
Thermistor
24k
34k
Gas Liquid Rated Max. Rated Max.
Pipe Size(Diameter:Ø) inch Piping length (ft.) Elevation (ft.)
Capacity
Additional
Refrigerant
(oz/ft)
1/4
1/4 1/2 5/8 25 100
115 50 66
16
16
Refrigerant Cycle Diagrams
0.22
0.32