LG LT-C1260CL User manual

Ceiling Cassette
Air Conditioner
SERVICE MANUAL
MODELS: LT-C1260CL
LT-C1260HL
LT-C1262HL

Contents
Functions .................................................................................................................................3
Product Specifications (Cooling & Heating)..........................................................................5
Dimensions ..............................................................................................................................7
Refrigeration Cycle Diagram ..................................................................................................8
Wiring Diagram ........................................................................................................................9
Operation Details ...................................................................................................................10
Installation of Indoor, Outdoor Unit .....................................................................................13
2-way, 3-way valve..................................................................................................................29
3-way Valve ............................................................................................................................31
Cycle Troubleshooting Guide ...............................................................................................36
Electronic Parts Troubleshooting Guide .............................................................................37
Electronic Control Device .....................................................................................................40
Schematic Diagram ...............................................................................................................41
Exploded View and Replacement Parts List .......................................................................42
–2–

Functions
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
–3–
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 size because of smaller
than fextile size. ( 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 type(wrinkle) and wastable and anti-bacteria filter
is adopted.
Plasma Air Purifying Filter(2HL Only)
High head height Drain pump • Built-in drain pump automatically drains water.
• A standard drain-head height of up to 700mm is possible.
High-Ceilingcorresponding Function • According to the height of ceiling, the RPM of indoor fan
motor is selectable 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 connect.
•
It operates maximum 16 units by only one wired remote con-
troller and each unit starts random 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 rule.
• 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 Program
(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
HI JET AUTOMEDLO
Program Holiday
SET/CLR
MinHour
Week
Timer CancelTimer Cancel
: High:39°C ↔LOW:11°C
: Fan Operates without cooling & heating
Cooling Heating
Down to 18°C
Up to 30°CDown to 16°C Up to 30°C

Power Supply ø, V, Hz
Capacity Cooling kcal/h(W)
Btu/h
Heating kcal/h(W)
Btu/h
Input Cooling W
Heating W
Running Current Cooling A
Heating A
Starting Current Cooling A
Heating A
E.E.R kcal/h(W)
C.O.P W/W
Air Circulation Indoor m3/min
Outdoor m3/min
Moisture Removal l/ h
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
Central Control
Air purifying filter
Wired remote controller (with weekly Program)
Refrigerant(R-22) Charge g
Dimensions Indoor mm
(W x D x H) Panel mm
Outdoor mm
Net Weight Indoor kg
Outdoor kg
Main Power Cord AWG#:P*mm2
Connection Cable AWG#:P*mm2
Service Valve Liquid inch(mm)
Gas inch(mm)
Installation Pipe Length (m)
Elevation (m)
Insulation(material/thickness)
Drain Hose(I.D/O.D) mm
Product Specifications (Cooling & Heating)
–5–
1, 220-240, 50
3,024(3,516)
12,000
-
-
1,200
-
5.5
-
22
-
2.52
-
10
25
1.5
O
X
4
O
O
O
O
O
1
O
X
O
O
O
O
Optional
O
X
800
860 x 390 x 180
1050 x 480 x 30
770 x 540 x 245
17 (14+3)
31
14:3*2.5
18:4*0.75
1/4(6.35)
1/2(12.7)
15
7
FoamPE/5mm
ø25/32
1, 220-240, 50
3,024(3,516)
12,000
3,024(3,516)
12,000
1,200
1,100
5.5
5.0
22
21
2.52
3.19
10
25
1.5
O
O
4
O
O
O
O
O
1
O
O
O
O
O
O
Optional
O
X
850
860 x 390 x 180
1050 x 480 x 30
770 x 540 x 245
17 (14+3)
31
14:3*2.5
18:6*0.75
1/4(6.35)
1/2(12.7)
15
7
FoamPE/5mm
ø25/32
1, 220-240, 50
3,024(3,516)
12,000
3,024(3,516)
12,000
1,200
1,100
5.5
5.0
22
21
2.52
3.19
10
25
1.5
O
O
4
O
O
O
O
O
1
O
O
O
O
O
O
Optional
O
O
850
860 x 390 x 180
1050 x 480 x 30
770 x 540 x 245
17 (14+3)
31
14:3*2.5
18:6*0.75
1/4(6.35)
1/2(12.7)
15
7
FoamPE/5mm
ø25/32
Model LT-C1260CL LT-C1260HL LT-C1262HL

Dimensions
–6–
694.5
1050
480
846
860
328.430.8 390
893.4
931.6
16.7
50
42.7
7
430
130
Ø80
Ø55
180
91.6
155
97.7
37
116.3
141.8
180
164
194.4
91.6
180
(1) Indoor Unit

(2) Outdoor Unit
–7–
WL2
L3
L1
D
H
L4
L5
Gas side
(3-way valve)
Liquid side
(2-way valve)
MODEL 12K Btu Series
DIM unit
W mm 770
H mm 540
D mm 245
L1 mm 287
L2 mm 64
L3 mm 518
L4 mm 10
L5 mm 100

Refrigeration Cycle Diagram
•Rated performance for refrigerant line length of: 7.5m
•If 12K Capacity is installed at a distance of 15m, 225g of refrigerant
should be added ....................................................(15-7.5) x 30g
–8–
INDOOR UNIT OUTDOOR UNIT
HEAT
EXCHANGE
(EVAPORATOR)
HEAT
EXCHANGE
(CONDENSER)
COMPRESSOR
ACCUMU
LATOR
GAS SIDE
3-WAY VALVE
LIQUID SIDE
2-WAY VALVE
CAPILLARY TUBE
CHECK VALVE
(Heating Model only)
COOLING
HEATING
REVERSING
VALVE
(Heating Model Only)
12K Btu/h 1/2" 1/4" 7.5 15 5 7 30
Capacity
GAS LIQUID
Elevation (m)
Length (m) * Additional
refrigerant
(g/m)
Pipe Size
Rated Rated
Max. Max.

–9–
Wiring Diagram
HEAT PUMP
COOLING ONLY
OUTDOOR WIRING DIAGRAM INDOOR WIRING DIAGRAM
FAN
MOTOR COMP
CSR
OLP
YLYL BLBL RDRD
BR RD
BL
BL
BR
GN/YL
BL
BL
BL
RD BK
BK
BL
BR BR RD BLBL
CAPACITOR
3854A20072K
FCH
PTC
48
61 0
2
45 789
TERMINAL
BLOCK
TO INDOOR UNIT
POWER
RELAY
REVERSING
VALVE
TB
CAPACITOR
TEMP
THERMISTOR PIPE THERMISTOR FLOAT S/W
MAIN PCB ASSY
STEP
MOTOR
REMOTE
CONTROL
CN-STEP/MCN-REMO
CN-POWER
CN-CC
CN-DISP
DISPLAY PCB ASSY
CN-ROOM CN-PIPE CN-FLOAT
CN-MOTOR
CN-D/PUMP
INDOOR
MOTOR
BR
BR
BK
OR
YL
BR
BL
BL
RD
BK YL
GN/YL
TERMINAL
BLOCK
POWER
INPUT
TO OUTDOOR UNIT
1(L) 2(N) 4 5
DRAIN
PUMP
3854A20072N
FUSE T3.15A
789
GN/YL
GN/YLGN/YL
4WAY
OUT FAN
OUTDOOR WIRING DIAGRAM INDOOR WIRING DIAGRAM
FAN
MOTOR COMP
CSR
OLP
YLYL BLBL RDRD
BR RD
BL
BL
BR
GN/YL
BL
BL
BL
RD
BL
BR BR RD BLBL
CAPACITOR
3854A20072M
FCH
PTC
48
61 0
2
45 789
TERMINAL
BLOCK
TO INDOOR UNIT
POWER
RELAY
TB
CAPACITOR
TEMP
THERMISTOR PIPE THERMISTOR FLOAT S/W
MAIN PCB ASSY
STEP
MOTOR
REMOTE
CONTROL
CN-STEP/MCN-REMO
CN-POWER
CN-CC
CN-DISP
DISPLAY PCB ASSY
CN-ROOM CN-PIPE CN-FLOAT
CN-MOTOR
CN-D/PUMP
INDOOR
MOTOR
BR
BR
BK
OR
YL
BR
BL
BL
RD
GN/YL
TERMINAL
BLOCK
POWER
INPUT
TO OUTDOOR UNIT
1(L) 2(N) 4 5
DRAIN
PUMP
3854A20072L
FUSE T3.15A
789
GN/YL
GN/YLGN/YL

–10–
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