LG LM-4462C2T User manual

SERVICE MANUAL
Ceiling Cassette Multi
Air Conditioner
MODELS:LM-4462H2T
LM-4462C2T

Contents
Functions................................................................................................................................3
Product Specifications (Cooling & Heating)........................................................................ 5
Dimensions............................................................................................................................. 6
Refrigeration Cycle Diagram................................................................................................. 7
Wiring Diagram....................................................................................................................... 9
Operation Details ................................................................................................................. 11
Installation of Indoor, Outdoor Unit.................................................................................... 14
Test Running ........................................................................................................................ 26
Cycle...................................................................................................................................... 31
Cycle Troubleshooting Guide.............................................................................................. 34
Electronic Parts Troubleshooting Guide............................................................................ 35
Electronic Control Device.................................................................................................... 38
Schematic Diagram.............................................................................................................. 40
Exploded View and Replacement Parts List.......................................................................43
–2–

Functions
–3–
Indoor Unit
Operation ON/OFF by Remote controller
Sensing the Room Temperature
Room temperature control
Starting Current Control
Time Delay Safety Control
Indoor Fan Speed Control
Soft Dry Operation Mode
Airflow Direction Control
Auto Operation(Auto Change Over)
Deice (defrost) control (Heating)
Auto Restart
Hot-start Control (Heating) • The indoor fan stops until the evaporator piping tempera-
ture will be reached at 28°C.
Compact and light design • To install a unit is very convenient because of smaller size
than textile. ( 600 x 600 )
Low noise • The most advanced low-noise design.
• The adoption of turbo fan and round type heat exchanger
give the quietest operation.
Long life filter • Long life wrinkle(type) and washable and anti-bacteria filter
is adopted.
Plasma Air Purifying Filter
High head Drain pump • Built-in drain pump automatically drains water.
• A standard drain-head height of up to 700mm is possible.
High-Ceiling corresponding Function • According to the height of ceiling, the RPM of indoor fan
motor is selected to increase air reaching distance.
Central Control(Optional) •
It is operating individually or totally by central control function.
Group Control(Optional Wiring) •
Each controller can control 16 units and 8 controllers can be
connected.
• It operates maximum 16 units by only one wired remote con-
troller and each unit starts sequentially to prevent overcurrent.
• Room temperature sensor. (Thermistor)
• Maintains the room temperature in accordance with the Setting Temp.
• Indoor fan is delayed for 5 seconds at the starting.
• Restarting is inhibited for approx. 3 minutes.
• Jet, High, Med, Low
• Intermittent operation of fan at low speed.
• The louver can be set at swing up and down automatically.
• Although the air-conditioner is turned off by a power failure, it is restarted automati-
cally previous operation mode after power supply.
• The setting temperature and desired operation mode are auto-
matically set by fuzzy logic.
• Both the indoor and outdoor fan stops during defrosting.
• Hot start after defrost ends.

–4–
Remote Controller
Operation ON/OFF
Operation Mode Selection
Fan Speed Selection
Room Temperature Display
Temperature Setting
Setting the Timer
Weekly Timer
(Cooling
model only) (Heating
model only)
(Low) (Med) (High)
Cooling Operation Mode ( )
Heating Operation Mode ( ) Auto Operation Mode ( )
Soft Dry Operation Mode ( )
Fan Operation Mode
HIMEDLO
Program Holiday
SET/CLR
MinHour
Week
Timer CancelTimer Cancel
: High:39°CLOW:11°C
: Fan Operates without cooling & heating
Cooling Heating
Down to 18°C
Up to 30°CDown to 16°C Up to 30°C

Product Specifications
Model Name
Item Unit
Cooling Capacity Btu/h(kcal/h)
Heating Capacity Btu/h(kcal/h)
Moisture Removal l/h
Power Source Ø, V, Hz
Air Circulation Indoor m3/min
Outdoor
Input Cooling W
Heating
Running Current Cooling A
Heating
E.E.R. Btu/h-W
COP W/W
Dimensions Indoor
(W x H x D) Panel mm
Outdoor
Net. Weight Indoor kg
Outdoor
Refrigerant (R-22) g
Airflow Direction Control (Up & Down)
Remocon Type
Service Valve & Liquid
Connecting Tube Gas
Drain Hose
Connecting Wire
Main Power Cable Air-Flow Direction Control
Heating Operation Mode
Fan Speeds (steps)
Auto Operation (Changeover)
Forced Operation
Jet Cool
Soft Dry Operation
Timer Delay Safety Function
Feature Air Deflection (Way)
Self Diagnosis
Hot start
Auto Restart
Air refresh (Hole)
High Ceiling
Group Control (Optional wiring)
Central Control
Wired remote controller
(with weekly Program)
Plasma A/Cleaner
LM-4462H2T LM-4462C2T
A or B A or B
A + B A + B
–5–
22,000 44,000 22,000 44,000
21,500 43,000 - -
2.7 5.4 2.7 5.4
1Ø, 220-240V, 50Hz
15
88
2,400 4,500 2,400 4,500
2,400 4,850 - -
11 21 11 21
11 22 - -
9.17 9.78 9.17 9.78
9 8.9 - -
570 x 570 x 269
670 x 670 x 30
900 x 1,225 x 370
19(16.5+2.5)
106 103
1,740 x 2 1,630 x 2
O
Wired Remocon, Wireless remocon (Option)
3/8" (9.52)
5/8" (15.88)
O
0.75mm2
8.0mm2
OO
OX
44
OO
OO
OO
OO
OO
44
OO
OX
OO
OO
OO
OO
Optional Optional
OO
XX

Dimensions
Indoor Unit
900
1,225
370
269
67055
570
269
190.5
160
52
90 90
120.4 30 521
670
570
450
40
110 110
670
670
CLOSE OPEN OPEN CLOSE
–6–
Outdoor Unit

Refrigeration Cycle Diagram
LM-4462H2T
(■Rated performance for refrigerant line length of: 7.5m)
For installation over rated distance, 70g of refrigerant should be added for each meter in Heat pump Model.
For installation over rated distance, 50g of refrigerant should be added for each meter in Cooling only Model.
ex) When installed at a distance of 15m, 525g of refrigerant should be added in Heat pump Model.
(15-7.5) x 70g = 525g
When installed at a distance of 15m, 375g of refrigerant should be added in Cooling only Model.
(15-7.5) x 50g = 375g
Pipe size(Diameter: ø) Piping length(m) Elevation(m)
Gas Liquid Rated Max. Rated Max.
5/8" 3/8" 7.5 50 7.5 30
–7–
INDOOR A-UNIT
INDOOR B-UNIT
OUTDOOR UNIT
HEAT
EXCHANGER
HEAT
EXCHANGER
HEAT
EXCHANGER
A-COMPRESSOR
GAS SIDE
LIQUID SIDE
COOLING
HEATING
A-REVERSING
VALVE
CAPI
CAPI
CAPILLARY TUBE
HEAT
EXCHANGER
B-COMPRESSOR
GAS SIDE
LIQUID SIDE
B-REVERSING
VALVE
CAPILLARY TUBE

–8–
LM-4462C2T
(■Rated performance for refrigerant line length of: 7.5m)
For installation over rated distance, 70g of refrigerant should be added for each meter in Heat pump Model.
For installation over rated distance, 50g of refrigerant should be added for each meter in Cooling only Model.
ex) When installed at a distance of 15m, 525g of refrigerant should be added in Heat pump Model.
(15-7.5) x 70g = 525g
When installed at a distance of 15m, 375g of refrigerant should be added in Cooling only Model.
(15-7.5) x 50g = 375g
Pipe size(Diameter: ø) Piping length(m) Elevation(m)
Gas Liquid Rated Max. Rated Max.
5/8" 3/8" 7.5 30 7.5 15
INDOOR A-UNIT
INDOOR B-UNIT
OUTDOOR UNIT
HEAT
EXCHANGER
A-COMPRESSOR
GAS SIDE
LIQUID SIDE
B-COMPRESSOR
CAPILLARY TUBE
HEAT
EXCHANGER
GAS SIDE
LIQUID SIDE CAPILLARY TUBE
CAPI

Wiring Diagram
LM-4462H2T
• Indoor Unit
• Outdoor Unit
–9–
INDOOR WIRING DIAGRAM
INDOOR
MOTOR DRAIN
PUMP STEP MOTOR
TEMP.
THERMISTOR
PIPE
THERMISTOR
REMOTE
CONTROL
FLOAT S/W
CN -DISP
DISPLAY PCB
TERMINAL
BLOCK
TO OUTDOOR UNIT
3854A20126L
BR
YL
BK
OR
BL
BL
BR
GN/YL
RD
BK
BL
COMP
4 WAY
3(L)4(N)5 6 7
FUSE T3.15A
S
CR
B-MOTOR A-MOTORB-COMPA-COMP
Capacitor
OR
YL
S
CR
OR
OR OR
OR
BL
Capacitor Capacitor
OR
BK BK
YL
BK
BK
BK
WH
BL
WH
BR
TB1
TB4
TB5
TB2
TB6
TB3
WH WH
BK
BK
BK
BK
BK
WH BK BK
BK
YL
RD
BL
GN/YL
POWER INPUT
CN-COMP CN-FAN CN-SV
CN-COM CN-POWER
CN-TH1
CN-TRAMS
A-INDOOR B-INDOOR
65 564(N)
4(N)3(L)3(L)
BK
BK
REVERSING
A-COIL
MOTOR
RELAY
B-COMP
POWER
RELAY
A-COMP
POWER
RELAY
POWER
TRANS
12
34
56
78
REVERSING
B-COIL
A-THERMISTOR
B-THERMISTOR
P/No: 3854A20135B
YL
S
CR
BL
WH
BK
S
CR
BR
Capacitor
BR
RD
BK WH
BR
810 642 810
642
INDOOR
EARTH

–10–
LM-4462C2T
• Indoor Unit
• Outdoor Unit
810 642
810 642
12
34
56
78
12
34
56
78
P/No: 3854A20075Z
RD
S
CR
A-COMP
RELAY
B-COMP
RELAY
A-MOTOR
RELAY
LOW Ambient PCB
B-MOTOR
RELAY
BK
WH YL YL
BR
BR
BR BR
RD YL
YL
YL
YL
BL
BL BK
BK OR
OR
OR
OR
BK
BK
OR OR
OR
1
2
3
4
5
6
7
8
9
BK
BK
WH YL BK
WH
GN/YL
YL
BK
BK
TEMP.
THERMISTOR
BK
BK
WH
BK
BK BK
BL
BLBL BL
BK
YL
WH
RD
TB7
3(L)
POWER INPUT
INDOOR
EARTH
DIAGRAM WIRING A-INDOOR
TB5
TB8
B-INDOOR
4(N) 3(L)4(N)5(A)3(L)4(N)5(B)
TB6
TB4
A-COMP
S
CR S CR
TB3
TB2
TB1
B-COMP A-MOTOR
S
CR
B-MOTOR
WH
OR

–11–
Operation Details
(1) The function of main control
1. Time Delay Safety Control
•3min The compressor is ceased for 3minutes to balance the pressure in the refrigeration cycle.
(Protection of compressor)
•5sec Vertical air flow direction control louvers open in 5 seconds to prevent noise between louvers and wind.
•30sec The 4-way valve is ceased for 30sec. to prevent the refrigerant-gas abnormal noise when the Heating
operation is OFF or switched to the other operation mode while compress is off.
While compressor is running, it takes 3~5 seconds to switch.
2. Auto Swing Control
•This function is to swing the louver up and down automatically.
3. Air-Filter Checking Control
•'Filter' will display in the remote controller display and main body display when an air-filter is polluted. Then clean
the air-filter for reference to Owners Manual.
4. Soft-Dry Operation
•The indoor fan speed is automatically set to the low, so the shift of the indoor fan speed is impossible because of
already being set to the best speed for Dry Operation by Micom Control.
5. Cooling Mode Operation
•When selecting the Cooling( ) Mode Operation, the unit will operate according to the setting by the remote con-
troller and the operation diagram is as following
Intake Air temp.
SET TEMP.+0.5°C
(COMP. ON)
SET TEMP. -0.5°C
(COMP. OFF) More than More than
3 minutes 3 minutes
Selecting Selecting Selecting
fan speed fan speed fan speed
COMPRESSOR ON OFF ON OFF ON
INDOOR FAN Low Low

–12–
Intake Air temp.
Setting temp.+3°C
(Compressor OFF)
Setting temp.
(Compressor ON)
INDOOR FAN
COMPRESSOR ON OFF ON OFF
A point; While the indoor Heat-Exchanger temperature is higher than 40°C fan operates at low speed, when
it becomes lower than 40˚C fan stops.
B point; When the indoor Heat-Exchanger temperature is higher than 42°C, fan operates at selected fan
speed, when it becomes lower than 39°C, the fan operates at low speed.
6. Heating Mode Operation
The unit will operate according to the setting by the remote controller and the operation diagram is shown as follows.
(Hot Start)
Low
OFF
Selected
Fan Speed
minimum 3min
Selecting fan
speed
LowLowLow OFF OFF
minimum
10sec.
1min
AA
minimum
1min.
minimum
10sec.
B
7. Hot-Start Control
•The indoor fan stops until the evaporator piping temperature reaches to 25°C.
•If the evaporator piping temperature drops below 22°C, indoor fan stops again.
•The operation diagram is as follows.
PIPING
TEMPERATURE 1min
COMPRESSOR
INDOOR FAN
ON
OFF LOW Selected
fan speed
22°C
25°C

–13–
8. Defrost Control
•Defrost operation is controlled by timer and sensing temperature of outdoor pipe.
•The first defrost starts only when the outdoor pipe temperature falls below -6°C after 45 minutes passed from
starting of heating operation and more than 9 minutes operation of compressor.
•Defrost ends after 9 minutes passed from starting of defrost operation or after the outdoor fan operates within
max. 2 minutes 30 seconds when the outdoor pipe temperature rises over 12°C even it before 9 minutes.
•The second defrost starts only when the outdoor pipe temperature falls below -6°C after 45 minutes passed from
ending of the first defrost and more than 9 minutes operation of compressor.
Out door pipe
temperature
45MIN. (over 10min.operation of comp.) 10MIN.
Outdoor pipe
temperature
12.0˚C
8.0˚C
-6.0˚C
COMP. ON
FAN(OUT)
4 WAY ON
OFF OFF OFF ON ON
ON ON ONOFF
9. Self-diagnosis Function
•'CHECK' will flash in the remote controller display when a problem occurs. Then please contact your dealer.
•Correct the accident point as shown in the table below before restarting operation.
•During the normal operation 'CHECK' won't be displayed in the remote controller.
Remote controller LCD FAULT MESSAGES
CH 01 Indoor room temperature thermistor error
CH 02 Indoor piping thermistor error
CH 03 Indoor main body / Remote controller unit communication error
CH 04 Water level float switch error

–14–
Installation of Indoor, Outdoor Unit
1. Selection of the best location
1) Indoor unit
•There should not be any heat source or steam near
the unit.
•There should not be any obstacles to prevent the air
circulation.
•A place where air circulation in the room will be
good.
•A place where drainage can be easily obtained.
•A place where noise prevention is taken into consid-
eration.
•Do not install the unit near the door way.
•Ensure the spaces indicated by arrows from the
wall, ceiling, or other obstacles.
•The indoor unit must keep the maintenance space.
2) Outdoor unit
•If an awning is built over the unit to prevent direct
sunlight or rain exposure, be careful that heat radia-
tion from the condenser is not restricted.
•There should not be any animals or plants which
could be affected by hot air discharged.
•Ensure the spaces indicated by arrows from the
wall, ceiling, fence or other obstacles.
More than 30cm More than 30cm
More than 70cm
Unit:cm
Ceiling
Ceiling Board Ceiling Board
30 or more
Above 250 300 or less
100 or more
50 or
more
50 or
more
30 or less
Floor

–15–
Indoor unit
Outdoor unit
B
A
•Rated performance for refrigerant line length of: 7.5m
NOTE:
• Thoroughly study the following installation locations:
1. In such places as restaurants and kitchens, considerable amount of oil steam and flour adhere to the
turbo fan, the fin of the heat exchanger and the drain pump, resulting in heat exchange reduction,
spraying, dispersing of water drops, drain pump malfunction, etc.
In these cases, take the following actions:
• Make sure that the ventilation fan for smoke-collecting hood on a cooking table has sufficient
capacity so that it draws oily steam which should not flow into the suction of the air conditioner.
• Make enough distance from a cooking room to install the air conditioner in such a place where it
may not suck in oily steam.
2. Avoid installing air conditioner in such circumstances where cutting oil mist or iron powder is in sus-
pension in factories, etc.
3. Avoid places where inflammable gas is generated, flows in, is stored or vented.
4. Avoid places where sulfurous acid gas or corrosive gas is generated.
5. Avoid places near high frequency generators.
3) Piping length and the elevation
Use the ventilation fan
for smoke-collecting
hood with sufficient
capacity.
Cooking table
Air conditioner
Take enough
distance
MODEL
GAS LIQUID
Cooling Model 5/8" 3/8" 7. 53051550
Heat pump Model 5/8" 3/8" 7.
55053070
Elevation B(m)
Length A(m) * Additional
refrigerant
(g/m)
Pipe Size
Rated Rated
Max. Max.

–16–
•The dimensions of the paper model for installing are
the same as those of the ceiling opening dimen-
sions.
•Select and mark the position for fixing bolts and pip-
ing hole.
•Decide the position for fixing bolts slightly tilted to
the drain direction after considering the direction of
drain hose.
•Drill the hole for anchor bolt on the wall.
Level gauge
Ceiling
Ceiling board
Unit:mm
570 Unit size
570 Unit size
450 (Hanging bolt)
7575
600 (Ceiling opening)
600 (Ceiling opening)
521(Hanging bolt) 39.5
39.5
•This air-conditioner uses a drain pump.
•Horizontly install the unit using a level gauge.
•During the installation, care must be taken not to
damage electric wires.
CAUTION
2. Ceiling opening dimensions and hanging bolt location

3. The Indoor Unit Installation
•The following parts is option.
Hanging Bolt - W 3/8 or M10, length 650 mm
Nut - W 3/8 or M10
Spring Washer - M10
Plate Washer - M10
•Drill the piping hole on the wall slightly tilted to the out-
door side using a Ø70 hole-core drill.
–17–
Set screw of
paper model (4 pieces)
Paper model
for installation
Ceiling board
100mm
Adjust the same height
Ceiling board
Ceiling
Flat washer for M10
(accessory)
Keep the length of the bolt
from the bracket to 40mm
Open the ceiling board
along the outer edge of the
paper model
Flat washer for M10
(accessory)
Hanging bolt
(W3/8 or M10)
Nut
(W3/8 or M10)
Nut
(W3/8 or M10)
Spring washer
(M10)
Air Conditioner body
Wall
5~7mm
Indoor Outdoor
•
Tighten the nut and bolt to prevent unit falling.
CAUTION
4. Remote Controller Installation
•Although the room temperature sensor is in the indoor unit, the remote control box should be installed in such
places away from direct sunlight and high humidity.
Installation of the remote control box
•Select places that are not splashed with water.
•Select control position after receiving customer approval.
•The room temperature sensor of the thermostat for temperature control is built in the indoor unit.
•This remote controller equipped with liquid crystal display. If this position is higher or lower, display is difficult to see.(The
standard height is 1.2 ~ 1.5m high)
Routing of the remote control cord
•Keep the remote control cord away from the refrigerant piping and the drain piping.
•To protect the remote control cord from electrical noise, place the cord at least 5cm away from other power cables (audio
equipment, television set, etc.)
•If the remote control cord is secured to a wall, provide a trap at the top of the cord to prevent water droplets from running.

–18–
•Fix the under plate on the wall
•Separate the under plate from Remote control box.
•Fix the cord clamps on the wall by ø3 tapping
screws (accessory).
•Fix the remote control cord.
Remote control
box body
Cord clamp
(accessory)
Lever carefully
the box open
using a screw
driver, etc.
Front case
The lower part
Face of wall
Under plate
Screw (accessory)
Remove the battery cover from the remote con-
troller.
• Pull out the cover according to the arrow direction.
Insert the two batteries.
•Be sure that the (+) and (-) directions are correct.
•Be sure that both batteries are new.
Re-attach the cover.
•Slide it back into position.
WIRED REMOTE CONTROL INSTALLATION
REMOTE CONTROL PREPARATION(OPTIONAL)
DISASSEMBLING
ELECTRICAL WIRING
HOW TO MOUNT ON A WALL
HOW TO INSERT BATTERIES
Make sure that wire and teminal
numbers are matched on unit side and
remote controller side.
The maximum length of the cord is 100m.
If the length of the cord exceeds 50m,
use a wire size greater than 0.5mm2.
Remote controller
(Main board)
CN REMO
•Do not use rechargeable batteries,
such batteries different from standard
dry cells in shape, dimensions, and
performance.
•Remove the batteries from the remote
controller if the air conditioner is not
going to be used for long time.
HOW TO INSERT BATTERIES

–19–
5. Wiring Connection
•Open the control box cover and connect the Remote controller cord and Indoor power wires.
Make sure that the screws of the terminal are free from looseness.
WARNING
CAUTION
8.5mm
20mm
GN/YL
7.5mm
20mm
GN/YL
NORMAL
CROSS-SECTIONAL
AREA 0.75mm2
NORMAL
CROSS-SECTIONAL
AREA 8.0mm2
Terminal Block of Indoor Unit
A-Unit
3(L) 4(N) 5 6 7
Terminal Block of Indoor Unit
B-Unit
3(L) 4(N) 5 6 7
3(L)4(N) 6 5 4(N) 3(L) 5 6
Terminal Block of Outdoor Unit
Terminal Block of
Outdoor Unit
Power Cord
Terminal Block of Indoor Unit
A-Unit
3(L) 4(N) 5 6 7
Terminal Block of Indoor Unit
B-Unit
3(L) 4(N) 5 6 7
3(L) 4(N) 3(L) 4(N)5(A) 3(L) 4(N) 5(B)
Terminal Block of Outdoor Unit
Terminal Block of
Outdoor Unit
Power Cord
LM-4462H2T
LM-4462C2T
[Air inlet side view]
Control box cover
Indoor
power cord
Remote
controller
cord Control box cover
fitting screw(2 units)
If the supply cord is damaged, it must be replaced by a special cord or assembly available from the
manufacturer or its service agent.
The power cord connected to the outdoor unit should be complied
with the following specifications (Rubber insulation, type H05RN-F
approved by HAR or SAA).
The connecting cable connected to the indoor and outdoor unit
should be complied with the following specifications (Rubber
insulation, type H05RN-F approved by HAR or SAA).

–20–
1. All wiring must comply with LOCAL REGULATIONS.
2. Select a power source that is capable of supplying the current required by the air conditioner.
3. Feed the power source to the unit via a distribution switch board designed for this purpose.
4. The terminal screws inside the control box may be loose due to vibration during transport.
Check the screws for loose connection.
(Running the air conditioner with loose connection can overload and damage electrical components.)
5. Always ground the air conditioner with a grounding wire and connector to meet the LOCAL REGULATION.
Main power source
Switch box
Circuit Breaker
Use a 50A circuit breaker or time delay fuse.
Refrigerant pipe
ELECTRICAL WIRING