Toshiba RAS-18YKH-E User manual

SERVICE MANUAL
FILE NO. A00-0001
AIR-CONDITIONER
SUPPLEMENT
SPLIT WALL TYPE
PRINTED IN THAILAND, Apr.,2000
RAS-18YKH-E / RAS-18YAH-E
RAS-18YKH-A / RAS-18YAH-A

– 2 –
CONTENTS
1. SPECIFICATIONS....................................................................................... 3
2. CONSTRUCTION VIEWS............................................................................ 5
3. WIRING DIAGRAM ..................................................................................... 7
4. SPECIFICATIONS OF ELECTRICAL PARTS ............................................ 8
5. REFRIGERANT CYCLE DIAGRAM............................................................ 9
6. CONTROL BLOCK DIAGRAM ................................................................. 10
7. OPERATION DESCRIPTION .................................................................... 12
8. INSTALLATION PROCEDURE ................................................................. 16
9. TROUBLESHOOTING CHART ................................................................. 20
10. EXPLODED VIEWS AND PARTS LIST .................................................... 37

– 3 –
Model
Item
Capacity *1(kW)
Phase
Power source (V)
(Hz)
Power consumption (kW)
Power factor (%)
Running current Indoor (A)
Outdoor (A)
Starting current (A)
Moisture removal (lit/h)
Noise Indoor (H/M/L) (dB)
Outdoor (dB)
Refrigerant Name of refrigerant
Rated volume (kg)
Refrigerant control Gas side size (mm)
Connection type
Liquid side size (mm)
Interconnection pipe Connection type
Maximum length (of one way) *2(m)
Maximum height difference
Indoor unit (m)
Outdoor unit
Codensate drain pipe Outer diameter (mm)
INDOOR UNIT Height (mm)
Dimension Width (mm)
Depth (mm)
Net weight (kg)
Evaporator type
Indoor fan type High fan (m³/h)
Air volume Medium fan (m³/h)
Low fan (m³/h)
Fan motor output (W)
Air filter
OUTDOOR UNIT Height (mm)
Dimension Width (mm)
Depth (mm)
Net weight (kg)
Condenser type
Outdoor fan type
Airflow volume (m³/h)
Fan motor output (W)
Compressor Model
Output (W)
Safety device
Auto louver
Usable outdoor temperature range (°C)
1. SPECIFICATIONS
Specifications are subject to change without notice.
RAS-18YKH-E, RAS-18YAH-E RAS-18YKH-A, RAS-18YAH-A
Cooling Heating Cooling Heating
220–240V 240V
5,0 6,35–6,50 5,0 6,50
Single
220–240V 240V
50
2,03–2,20 2,33–2,52 2,20 2,52
91–81 92–85 81 85
0,28–0,30 0,28–0,30 0,30 0,30
9,82–11,00 11,22–12,10 11,00 12,10
60
2,0
44/41/38
54–56 55–57 56 57
R-22
1,45
Capillary tube
12,7
Flare connection
6,35
Flare connection
15
6
16
RAS-18YKH-E / RAS-18YKH-A
298
1050
180
12
Finned tube
Cross flow fan
750
650
550
31
Polypropylene net filter (Washable)
RAS-18YAH-E RAS-18YAH-A
690
880
310
65
Finned tube
Propeller
220V 240V 240V
3380 3560 3560
65
PH280X3-4MS
2000
Fuse, overload relay
Yes
11 to 43 –10 to 21 11 to 43 –10 to 21
↑
↓

– 4 –
Note : *1
• Capacity is based on the following temperature conditions.
Condition
Temperature
Indoor unit inlet air temperature (DB)
(WB)
Outdoor unit inlet air temperature (DB)
(WB)
JIS C9612-1994
Cooling Heating
27°C 20°C
19°C —
35°C 7°C
24°C 6°C
Notes : *2 CHARGELESS
• No additional refrigerant required.
• This air conditioner accepts a connection piping length of up to 15m and a head of up to 6m.
• There is no need to add the refrigerant as long as the total length of the connection piping is up to 15m.

– 5 –
2. CONSTRUCTION VIEWS
2-1. Indoor Unit
RAS-18YKH-E, RAS-18YKH-A
1050
1040
261 264 274 251
180
30
123
990
274 264
30
123402402
1050
298 248
30 40 10
15 40 20
298
47
450
59.6 5
55 16
112.8 136
Deodorizing filter
Air inlet
Indoor heat exchanger
Dust collecting filter
Air filter
Power cord (1,7m)
Air outlet
Hanger
Front panel
Rear plate
Hanger
Auxiliary pipe (0,49m)
Flare Ø6,35
Auxiliary pipe (0,39m)
Flare Ø12,7
Drain hose
0,60m
Anchor bolt hole
Ø8 ~ Ø10
Anchor bolt hole
Ø6
Detail of installing dimensions of the indoor unit
Minimum distance
from wall
Minimum distance
from wall
Minimum distance
from ceiling
Hanger
Ø65
Piping hole
Installation plate
Center line
Ø65
Piping hole
Wireless
remote control
Remote control holder
44 or more
80 or more 130 or more

– 6 –
2-2. Outdoor Unit
RAS-18YAH-E, RAS-18YAH-A
27
340
Ø12 x 18 hole
600
Detail Drawing
50
A
74 12
88
340
68 52
100 or more
100 or more 600 or more
600 or more
Mounting dimension of anchor bolt
600
Air inlet
Air inlet
Air outlet 4 x Ø12 x 18 for Ø8–Ø10 anchor bolt
Handle
Handle
690
340
63,8
880
310
340 (pitch)
364 12
23
Electric
Parts cover
Liquid side
(Flare Ø6,35)
Gas side
(Flare Ø15,88)
Service port
120
A
140
600
4–Ø12 x 18 hole
(for Ø8–Ø10 anchor bolt)
Ø25 Drain outlet

– 7 –
COLOR
IDENTIFICATION
BRW : BROWN
RED : RED
WHI : WHITE
YEL : YELLOW
BLU : BLUE
BLK : BLACK
GRY : GRAY
PNK : PINK
ORN : ORANGE
GRN &YEL :GREEN &
ORANGE
Buzzer
parts
Fan motor
Thermal fuse
164˚C
Indication parts
Infrared rays
receive parts
654321
6 5 4 3 2 1
4 5 6 7 8 9321 4 5 6 7 8 9321
4 5 6 7 8 9321 4 5 6 7 8 9321
Louver
motor
BLU
PNK
YEL
WHI
RED
BLK
WHI
BRW
GRY
YEL
Transformer
MCC-629
T01
RED
CN32
C26
Running
capacity
CN13
CN10CN24
C27
C28
TNR
R106
F01 Fuse
T5A
250V
L01
Filter
CN15
CN16 CN25
TNR R98
TRIAC D04
CR01
CN07
TH01
PTH CN12
CN01
CN22CN05CN04
CN26
CN17
CN03
Grand
terminal
CN30
PJ18
CN11
CN11
CN33
GRY
BLU
BLK
BLK
BLU
YEL
RED
WHI
BLK
BLK
WHI
RED
GRY
BLU
YEL
BLK
Coil for
4-way valve
BLK
BLU
ORN
RED
BRW
WHI
WHI BLU BLU
5
3
11 22 33
1
5
3
1
33
1
3
1
3
1
1
2
3
1
31
33
211
Switch parts
12 3
123
123
1 2 3
1 2 3
3 5
53
1
1
2
1
321
31 2 3
1 2 3
1 2
1 2
1 2
Heat exchanger
sensor
Discharge
temperature
sensor (TD)
21 21
Thetmo.
sensor
21 21
Thermal fuse
77˚C
Transformer
Indoor terminal block
Outdoor terminal block
Power supply
18YAH-E : 220–240V ~, 50Hz
18YAH-A : 240V ~, 50Hz
Ferrite core
GRN &YEL GRN &YEL
Chassis
BLK RED
RED
BLK
BLK
BLK RED
Crank case
heater Fuse
3A
Fuse
3A
RED
WHI
BLK BLK
PNK WHI RED
RED
Capacitor Capacitor
Compressor
Magnetic
relay
Fan motor
21 21
ORN
RED
ORN
BLK BLK BLK BLK
WHI
BLU
2
1 1
3 3
2
1 1
3 3
1 1
3 3
CN02
CN03
CN11
CN04
CN01
CN05
CN06 MAIN P.C. BOARD (MCC-1275)
MAIN P.C. BOARD (MCC-1293)
CR12
RY05
RY07
TNR R96
IC07
CR11
1 1
3 3
5 5
7 7
9 9
1 1
3 3
5
1 1
1 1
2 2
3 3
1 1
3 3
1 1
3
BLK
BLK
Heat
exchanger
sensor (TE)
2
1 1
3 3
L
TNR
R73
TNR R74 DSA
T5A, 250V AC
52C
6T3
5L3
4T2
3L2
2T1
1L1
A2
A1
22
21
BRW BRW BRW BRW BRW BRW BRW BRW
BLK WHI
GRN
&
YEL
RED
IC
WHI
BLK
N
3. WIRING DIAGRAM

– 8 –
No. Parts name Type Specifications
Output (Rated) 31W, 2poles, DC35V, 19W
1 Fan motor (for indoor) AFP-220-31-4B Winding resistance (Ω)Red-Black White-Black
(at 20°C) 267,8 147,7
2 Thermo. sensor (TA-sensor) (microprocessor) 10kΩat 25°C
3 Transformer (T01) TTZ MCC-629
4 Microcomputer TMP87CK40AN
5 Heat exchanger sensor (microprocessor) 10kΩat 25°C
(TC-sensor)
6 Line filter (L01) 25mH, AC 0,7A
7 Diode (DB01) KBP06M
8 Capacitor (C01) ECAIEHG222E 220µF, 25V
9 Fuse (F01) MT3 T5A, 250V
10 Varistor (R98, R106) 15G431K 430V
11 PTH (TH01) 82Ω
12 Louver motor MP35EA7 Output (Rated) 2W, 10poles, 1phase DC12V
No. Parts name Type Specifications
Output (Rated) 2000W, 2poles, 1phase, 220–240V, 50Hz
1 Compressor PH280X3-4MS Winding resistance (Ω)Red-Black White-Black
(at 20°C) 1,35 2,68
Output (Rated) 65W, 6poles, 1phase, 220–240V, 50Hz
2 Fan motor (for outdoor) MMF-230-65C Winding resistance (Ω)Red-Black White-Black
(at 20°C) 71,2 139,0
3 Running capacitor (for fan motor) SK45FMP AC 450V, 3,5µF
4 Running capacitor SK42CMP45U1 AC 420V, 45µF
(for compressor)
5 Solenoid coil (for 4-way valve) LB60012 AC 200/240V
6 Thermo. sensor TE, TD 10kΩat 25°C
7 Case heater 240V, 28W
8 Magnetic switch FC2S 3a1b
9 Transformer FT67 220–240V
10 Microcomputer TMP470840
11 Varistor (R73, 74, 86) 15G471K 470V
12 Fuse (F01) MT3 T5A, 250V
4. SPECIFICATIONS OF ELECTRICAL PARTS
4-1. Indoor Unit
RAS-18YKH-E, RAS-18YKH-A
4-2. Outdoor Unit
RAS-18YAH-E, RAS-18YAH-A

– 9 –
Mark ( ) means check points of Gas Leak
Cooling
Heating
INDOOR UNIT A
T1
Indoor heat
exchanger
Cross flow fan
P
Accumulator
Compressor
PH280X3-4MS
Packed valve
(Ø12,7)
Gas container connection (Reinstall etc.)
(Note)
Maximum pipe length is 15m
Maximum pipe head is 6m
Packed valve
(Ø6,35)
Capillary tube
Ø1,2 x 700
Capillary tube
Ø1,7 x 600
Liquid tank
550cc
Heating
Heating
4-way valve
Cooling
Cooling
Heating
Cooling
O.D. : 12,7mm O.D. : 6,35mm
Outdoor heat exchanger
Propeller fan Refrigerant
R-22 1,45kg
OUTDOOR UNIT
0,39m
(Connecting pipe)
Ø12,7
0,49m
(Connecting pipe)
Ø6,35
5. REFRIGERANT CYCLE DIAGRAM
Standard pressure Surface temp. of heat
50Hz P exchanger interchanging Fan speed
(kg/cm²G) pipe T1 (°C) (indoor)
18YAH-E, A 18YKH-E, A
Standard 21,0 53,0 High
Heating High temperature*1 20,5 to 25,5 52,0 to 61,0 Low
Low temperature 17,0 45,0 High
Standard 3,0 9,0 High
Cooling High temperature 3,5 11,0 High
Low temperature 2,5 1,5 Low
Ambient temp.
conditions DB/WB
(°C)
Indoor Outdoor
20/– 7/6
27/– 21/15
20/– –10/–10
27/19 35/24
32/23 43/26
21/15 21/15
Note :
• Measure the heat exchanger temperature at the center of U-bend.(By means ofTC sensor.)
*1 • During heating overload, the high temperature limit control operation is included.

– 10 –
Infrared Rays Signal Receiver
Functions
ECONO.
Louver Direction Setting
Louver AUTO Swing
OFF TIMER Setting
ON TIMER Setting
Fan Speed Selection
Thermo. Setting
Operation Mode Selection
AUTO, COOL, DRY, FAN ONLY
Operation (START/STOP)
Clock Frequency
Oscillator Circuit
8MHz
Heat Exchanger Sensor
Infrared
Rays Initializing Circuit
M.C.U
Indoor Unit Control Panel
From Outdoor Unit
CLOCK FREQUENCY 36,864kHz
Remote Control
Operation
Display
Timer
Display
ECONO.
Sign Display
PRE DEF.
Sign Display
Indoor
Fan Motor
Louver ON/OFF Signal
Louver Driver Louver
Motor
Power Supply
Circuit
Temperature Sensor • Louver Control
• 3-minute Delay at Restart for Compressor
• Motor Revolution Control
• Processing
(Temperature Processing)
• Timer
• Serial Signal Communication
Serial Signal Transmitter/Receiver
Transformer Serial Signal Communication (outdoor unit)
Photo Triac
Noise Filter
6. CONTROL BLOCK DIAGRAM
6-1. Indoor Unit

– 11 –
C.P.U
Discharge
Temperature
Sensor
TD
TE
Heat
Exchanger
Sensor
Serial Signal
Communication
(Indoor Unit)
Serial Signal
Transmitter/
Receiver
• Compressor Control
• 4-Way Valve Control
• Outdoor Fan Control
• Defrost Operation
• Serial Signal Communication
4-Way Valve
ON/OFF Signal
Compressor
Compressor
ON/OFF Signal
Outdoor Fan
ON/OFF Signal
4-Way
Valve
Magnetic
Switch
Power
Supply
Outdoor
Fan Motor
Relay
Driver
Photo
Coupler
Relay
RY05
Relay
RY07
Triac
Initializing Circuit
Power Supply Circuit
Clock frequency
Oscillator Circuit
Transformer
RAS-18YAH-E : AC220–240V, 50Hz
RAS-18YAH-A : AC240V, 50Hz
(for Indoor Unit)
6MHz
6-2. Outdoor Unit

– 12 –
(Room temp. –
Set temp.)
+1
0
Set
temp.
ON
OFF
4-way valve
Outdoor fan
OPERATION
display
ON
OFFOFFON ON
Compressor
Common relay
HIGH
MED
LOW(+)
LOW
LOW
28
27
26
25
24
Room temp.
7. OPERATION DESCRIPTION
7-1. FAN ONLY Operation
(MODE of the remote control :FAN ONLY)
(1) Fan speed setting
1) When the FAN is set to AUTO, the indoor fan
motor operates as shown in Fig 7-1-1.
2) When the FAN is set to LOW, MED, or HIGH,
the indoor fan motor operates with a constant
in volume as listed in Table 7-1-1.
Fig. 7-1-1 Auto setting of air volume
Table 7-1-1 Manual setting of FAN SPEED
Indication of HIGH Air volume
FAN SPEED (m3/h)
LOW 550
MED 650
HIGH 750
(2) Once the setting is made, the operation mode is
memorized in the microcomputer so that the
same operation can be effected thereafter
simply by pushing the START/STOP button.
7-2. COOL Operation
(MODE of the remote control : COOL)
(1) Compressor, 4-way valve, outdoor fan and
operation display are controlled as shown in Fig.
7-2-1.
Fig. 7-2-1
(2) A cool operation is carried out when the indoor
microcomputer sends the operation signal to the
outdoor microcomputer.
1) When the FAN is set to AUTO, the indoor fan
motor operates as shown in Fig 7-2-2.
2) When the FAN is set to LOW, MED, or HIGH,
the indoor fan motor operates with a constant
in volume as listed in Table 7-1-1.
Fig. 7-2-2
(3) Once the setting is made, the operation mode is
memorized in the microcomputer so that the
same operation can be effected thereafter
simply by pushing the START/STOP button.
7-2-1. Louver Control
(1) By pushing the SET button of the remote control
during the operation, the louver can be set to the
desiredposition.
And the louver position is stored in the micro-
computer, the louvers will be set to the position
automatically at the next operation.
(2) When the AUTO button is pushed, the louver
vertically swings within range of 25deg.
(Room temp. – Set temp.)
MED (+)
MED
LOW (+)
LOW
+1,5
+1,0
+0,5
+0
–0,5
RY01 OFF
Set
temp.
Manual
FAN
According
to the set
position
HIGH
AUTO

– 13 –
(Room temp. – Set temp.)
10,5
0
–0,5
–1,0
–1,5
Set
temp.
HIGH
RY01 OFF
MED (+)
MED
LOW (+)
LOW
FAN
Manual
AUTO
According
to the set
position
0
–1 ON
OFF
ON
OFF
ON
ON ON
(Room temp. – Set temp.)
4-way valve
Outdoor fan
OPERATION
display
Compressor
Common relay
7-3. HEAT Operation
(MODE of the remote control :HEAT)
(1) Compressor, 4-way valve, outdoor fan and
operation display are controlled as shown in Fig.
7-3-1.
Fig. 7-3-1
(2) A heat operation is carried out when the indoor
microcomputer sends the operation signal to the
outdoor microcomputer. The indoor fan motor
operates as shown in Fig.7-3-2, when the FAN
is set to AUTO.
The motor operates with a constant air volume
as listed in Table 7-1-1, when the FAN is set to
LOW, MED, or HIGH.
Fig. 7-3-2
(3) Once the setting is made, the operation mode is
memorized in the microcomputer so that the
same operation can be effected thereafter
simply by pushing the START/STOP button.
7-3-1. Louver Control
(1) By pushing the SET button of the remote control
during the operation, the louver can be set to the
desired position.
(2) When the AUTO button is pushed, the louver
vertically swings within range of 25deg.
And the louver position is stored in the micro-
computer, and at the next operation, the louvers
will be set to the stored position automatically at
the next operation.
7-3-2. Cool Airflow Control
(1) If the indoor heat-exchanger temperature
detected by the indoor heat-exchanger sensor is
16°C or below, the indoor fan stops and if the
temperature rises to 26°C or above, the fan is
restarted.
Details are in 7-8.

– 14 –
+2
+1
Set temp.
1H 2H TIME0H
(˚C)
ECONO. button
is pushed
Set temp.
is changed
Set temp.
is changed
-1
-2
Set temp.
1H 2H TIME0H
(˚C)
ECONO. button
is pushed
Set temp.
is changed
Set temp.
is changed
Cooling mode
Heating mode
(The same cooling mode as the room temperature control is set at set temp. –3˚C)
(The same heating mode as the room temperature control is set at set temp. +3˚C)
(Room temp. – Set temp.)
+3
–3
7-4. AUTO Operation
(MODE of the remote control : AUTO)
(1) One of the 3 modes, Cooling, Fan only and
Heating is selected according to room tempera-
ture at which operation is to start, as shown in
Fig.7-4-1. The Fan mode will continue until
room temperature reaches a level at which
another mode is selected.
7-4-1. Temporary Auto
When theTEMPORARY button is pushed, the set
temperature is fixed at 24°C and controlled in
accordance with the chart shown in Fig.7-4-1.
Fig. 7-4-1
7-5. ECONO. Mode
When the ECONO. button is pushed, during COOL,
HEAT and AUTO operation, the OPERATION display
is turned off and the ECONO.display is lit and the
indoor unit operates quietly and mildly with control-
ling airflow.
7-5-1. Cooling
(1) In the ECONO. mode, the set temp. by the
remote control is changed automatically as
shown in Fig.7-5-1.
(2) Fan speed →LOW
Fig. 7-5-1
7-5-2. Heating
(1) In the ECONO. mode, the set temp.by the
remote control is changed automatically as
shown in Fig.7-5-2.
(2) Fan speed →LOW
Fig. 7-5-2

– 15 –
60
54
52
(˚C)
Compressor,
Outdoor fan
OFF
ON
* 1 ····· Only outdoor fan is turned off.
* 1
Heat exchanger
temperature
Compressor
Less than 2˚C continues
for 6 minutes
OFF
ON
Outdoor fan
12
Heat exchanger
temperature
2
(˚C)
According to the
set position
Indoor fan speed
30
26
20
16
Heat exchanger
temperature
(˚C)
OFF
L (Low)
7-6. High-Temperature Limit Control
(Heating Operation)
The microprocessor detects the indoor heat ex-
changer temperature so as to prevent exceeding the
condensate pressure.
Control is performed as shown in Fig.7-6-1.
Fig. 7-6-1
7-7. Low-Temperature Limit Control
(Cooling Operation)
The microprocessor detects the indoor heat ex-
changer temperature so as to prevent freezing up
the indoor heat exchanger.
Control is performed as shown in Fig.7-7-1.
Fig. 7-7-1
7-8. Cool Airflow Prevention Control
(Heating Operation)
(1) During the heating operation, the indoor fan
speed is controlled automatically in accordance
with the indoor heat exchanger temperature to
prevent blowing the cool air.
Control is performed as shown in Fig.7-8-1.
Fig. 7-8-1
(2) As soon as the defrost operation starts, the
indoor fan stops.
7-9. Defrost Operation
During heat operation, if the temperature (Evaporat-
ing temperature) detected by the outdoor heat
exchange sensor (TE :Defrost) lowers by the set
degree less than the temperature detected at start
time, the operation enters the defrost operation.In
this time, the 4-way valve relay and the outdoor fan
are turned off.The indoor fan is turned off by the
cool air blow-out preventing control of the indoor
microcomputer at the indoor side, and "PRE.-DEF."
on the remote control goes on.
The defrost operation is automatically reset to the
normal operation when the temperature detected by
the above-mentionedTE sensor rises up to the set
value, or when Max.12 minutes of the operation
time has passed.

– 16 –
8. INSTALLATION PROCEDURE
8-1. Safety Cautions
CAUTION To Disconnect the Appliance from the Mains Supply.
This appliance must be connected to the mains by means of a circuit breaker or a switch with a
contact separation of at least 3 mm.
If this is not possible, a power supply plug with earth must be used. This plug must be easily
accessible after installation. The plug must be disconnected from the power supply socket in order
to disconnect the appliance completely from the mains.
DANGER
• FOR USE BY QUALIFIED PERSONS ONLY.
• TURN OFF MAIN POWER SUPPLY BEFORE ATTEMPTING ANY ELECTRICAL WORK. MAKE
SURE ALL POWER SWITCHES ARE OFF. FAILURE TO DO SO MAY CAUSE ELECTRIC
SHOCK.
• CONNECT THE CONNECTING CABLE CORRECTLY. IFTHE CONNECTING CABLE IS
CONNECTED BY WRONG WAY, ELECTRIC PARTS MAY BE DAMAGED.
• CHECK THE EARTH WIRE IS NOT BROKEN OR DISCONNECTED BEFORE INSTALLATION.
• DO NOT INSTALL NEAR CONCENTRATIONS OF COMBUSTIBLE GAS OR GASVAPORS.
FAILURE TO FOLLOWTHIS INSTRUCTION CAN RESULT IN FIRE OR EXPLOSION.
• TO PREVENT OVERHEATING THE INDOOR UNIT AND CAUSING A FIRE HAZARD, PLACE
THE UNIT WELL AWAY (MORE THAN 2M.) FROM HEAT SOURCES SUCH AS RADIATORS,
HEAT REGISTORS, FURNACE, STOVES, ETC.
WARNING
• Never modify this unit by removing any of the safety guards or by by-passing any of the safety
interlock switches.
• Do not install in a place which cannot bear the weight of the unit.
Personal injury and property damage can result if the unit falls.
• Before doing the electrical work, attach an approved plug to the power supply cord.
And make sure the equipment to be earthed.
• Appliance shall be installed in accordance with national wiring regulations.
CAUTION
• Exposure of unit to water or other moisture before installation will result in an electrical short.
Do not store in a wet basement or expose to rain or water.
• After unpacking the unit, examine it carefully for possible damage.
If you detect any damage, do not install the unit. Contact your Toshiba dealer immediately.
• Do not install in a place that can increase the vibration of the unit. Do not install in a place that can
amplify the noise level of the unit or where noise and discharged air might disturb user’s neighbors.
• To avoid personal injury, be careful when handling parts with sharp edges.
• Please read the installation manual carefully before installing the unit. It contains further
important instructions for proper installation.
REQUIREMENT OF REPORT TO THE LOCAL POWER SUPPLIER
Please make sure certainly that the installation of this air conditioner will be reported to the local
power supplier before installation.
If you have any obscure problems (or if the power supplier does not accept the installation) of this
appliance, service agency will take adequate countermeasures.
For general public use
Power supply cord of parts of appliance for outdoor use shall be more than polychloroprene
sheathed flexible cord (design H05 RN-F), or cord designation 245 IEC 57.
8-2. Installation Diagram of Indoor and Outdoor Units
8-2-1. Optional Installation Parts
Part code Parts name Q’ty
Refrigerant piping
A Liquid : Ø6,35 Each one
Gas side : Ø12,7
BPipe insulating material 1
(Polyethylene foam, 6mm thick)
C Putty, PVC tapes Each one
5
2
Wireless remote control
Batteries
Cover
Before installing the wireless remote control
Clip anchor
(local part)
Air filters
(for both sides)
Saddle
Mounting
screw
Purifying
filter
8
• Secure the outdoor unit with the
anchor bolts if the unit is likely to
be exposed to a strong wind.
• Use Ø8 or Ø10 anchor bolts.
• If it is necessary to drain the
defrost water from the outdoor
unit, base pan attach the
9
drain nipple to the outdoor unit
before installing it.
The drain outlet is located as
shown above.
• With the remote control
cover opened, load the
supplied batteries correctly,
observing their polarity.
Anchor bolt arrangement of
outdoor unit
44mm or more
80mm or more 130mm
or more
Installation
plate
1
6
Deodorizing
filter
7
Pan head
wood screws
4
Remote control
holder
3
Wireless remote
control
Vinyl tape
Apply after carrying
out a drainage test.
2
Electric
parts
cover
600mm or more
100mm or more
600mm or more
100mm
or more
600mm
or more
Extention drain hose
(Option : RB-821SW)
600 mm
340 mm
120 mm
Air intlet
Air outlet
64 mm
Drain outlet
During piping installation
Insert the remote control holder cushion
between the indoor unit and wall, and lift
the indoor unit to make work easier.
Wall
Drainage
Do not allow the drain hose
to get slack.
The auxiliary piping can be
connected to the left, rear or down.
Cut the piping hole
sloped slightly
Make sure to run the drain hose sloped
downward.
Down
Rear
Rear left Left
6 mm thick heat resisting
polyethylene foam
Insulation of refrigerant pipes insulates
the pipes separately, not together.
Separately sold or
market available
drain hose.
Drain
nipple
Bottom
plate
Ø25
• Install the provided drain nipple in the
hole of the bottom plate of the outdoor
unit. (See figure at left.)
• Perform proper drainage processing
using a separately sold or market
available drain hose.
(16 mm inner diameter.)
• Do not use an ordinary hose available
at the market, since it tend to get flat,
resulting in a clog of drain water.
9
Loop the connective cable
(about 100 mm in diameter and 300 – 350 mm long).

– 17 –
8-3. Indoor Unit
8-3-1. Installation Place
• A place which provides the spaces around the
indoor unit as shown in the above diagram.
• A place where there is no obstacle near the air inlet
and outlet.
• A place which allows an easy installation of the
piping to the outdoor unit.
• A place which allows the front panel to be opened.
CAUTION
• Direct sunlight to the indoor unit wireless
receiver should be avoided.
• The microprocessor in the indoor unit should
not be too close to r-f noise sources.
(For details, see the owner's manual.)
Remote control
• A place where there are no obstacles such as a
curtain that may block the signal from the indoor
unit.
• Do not install the remote control in a place exposed
to direct sunlight or close to a heating source, such
as a stove.
• Keep the remote control at least 1 m apart from the
nearestTV set or stereo equipment.
(This is necessary to prevent image disturbances or
noise interference.)
• The location of the remote control should be
determined as shown below.
Fig. 8-3-1
8-3-2. Installation Parts
Part with an asterisk (*) is packaged with outdoor unit.
Deodorizing filter x 1
Purifying filter x 1
Name
Owner’s manual
Installation manual
1
5
9
2
6
3
7
4
8
Name of parts (Q'ty)
Part
No.
Name of parts (Q'ty)
Part
No.
Installation plate x 1
Wireless remote control x 1
Remote control holder x 1
Pan head wood screw
Ø3,1 x 16 x 2
Batteries x 2
Mounting screw Ø4x 25 x 8
Drain nipple
*
x 1
Others
(Top view)
Indoor unit
5m
5m
45˚
45˚
Remote
control
Reception
range
*
: Axial distance
Remote
control
Reception
range
7m
Indoor unit
(Side view)
*
7m
75˚
8-3-3. Cutting a Hole and Mounting
Installation Plate
Cutting a hole
47mm
100mm
Refrigerant pipe hole
Ø65mm
Indoor unit outline
Hooking
section
Center of pipe hole is located
on the line indicated by the
arrow and 100 mm apart from
the pipe hole center line.
Fig. 8-3-2
When installing the refrigerant pipes from the rear.
Determine the pipe hole position using the installation
plate, and drill the pipe hole Ø65 mm slightly downward.
NOTE
When using the drill to pierce the wall that contains a
metal lath, wire lath or metal plate, be sure to use a
pipe hole brim ring sold separately.
Mounting the installation plate
For installation of the indoor unit, use the paper
pattern on the back.
Fig. 8-3-3
When the installation plate is directly
mounted on the wall
100mm
44mm
or more
40mm 130mm
or more
450mm
Anchor
bolt hole
Refrigerant pipe hole
Ø65mm
1 Installation plate
Refrigerant
pipe hole
Ø65mm
Indoor unit
outline
Thread
Weight
100mm 47mm
4mm
40mm
21mm
80mm
or more
1. Securely fit the installation plate onto the wall by
screwing it in the upper and lower parts to hook up
the indoor unit.
2. To mount the installation
plate on a concrete wall with
anchor bolts, utilize the
anchor bolt holes as
illustrated in the above figure.
3. Install the installation plate
horizontally in the wall.
Installation plate
(Keep horizontal direction)
Fig. 8-3-4
CAUTION
Failure to firmly install the unit may result in
personal injury and property damage if the unit falls.
1. Adjust the lateral position of the installation plate
without changing the height, so that each screw hole
in the plate comes in the center of a pillar or stud.
2. Make pilot holes with a bit to prevent the studs
from cracking, and then drive the screws into the
holes and tighten.
CAUTION
When installing the installation plate with
mounting screw, do not use the anchor bolt hole.
Otherwise the unit may fall down and result in
personal injury and property damage.
• In the case of a reinforced concrete wall
(1) In the selected area on the reinforced concrete wall,
bore holes at intervals of 450 mm, and drive
clip anchors or hole in anchors into them.
(2) Attach the installation plate to the wall by
screwing bolts or nuts into the anchors.
However, in the case where hole in
anchors are used, the depth of the
holes should be adjusted so that the nut-
heads extend no more than 15 mm. Fig. 8-3-5
Anchor
bolt
Projection
15mm
or less
• There may be a wire conduit embedded in the wall.
Confirm on the blue prints or ask the builder.
• Install the installation plate using 4 to 8 pieces of
mounting screw securing four corners with screws.
• Make sure of the proper installation of the
installation plate before mounting the indoor unit.
Concrete wall Concrete wall
Installation
plate
Hole in anchor
Bolt
Hole in anchor Installation plate
Nut with threaded
hole 8 mm dia.
Less than 15 mm
Fig. 8-3-6
• In the case of the pipe on the back
Using the pattern, position the pipe hole, and bore the
hole slightly downward.
8-3-4. Electrical Work
Important items of indoor unit wiring
1. For electrical works the wiring and cables must be
performed in compliance with national wiring
standard or regulation. If incorrect and incomplete
wiring is carried out, it will cause an electrical fire
or electrical shock.
2. Do not use the inter-connecting cable.
Never execute the connection of electrical wiring
with other method than the approved one.
(exp. use the terminal block etc.)
3. Prepare the interior power supply cord capacity
sufficient for starting and usage current of air
conditioner.
4. Connect the connecting cable to the terminal as
identified with their respective matched numbers
on the terminal block of outdoor unit.
5. Fix the cable securely with the cord clamps to the
specified position.
6. Do not damage or scratch the conductive core &
inner insulator of power supply and inter
connecting cables when peeling them.
7. Do not deform or smash the surface of the cables.
Do not press or fix the cord and cables firmly with
staples, etc.
How to connect the cable
1. Remove the side panel. (2 screws)
2. Remove the electric parts cover and cord clamp.
3. Insert the connecting cable fully into the terminal
block and secure it by screw tightly.
Tightening torque : 1,2 N•m (0,12 kgf•m)
4. Secure the con-
necting cable with
the cord clamp.
5. Fix the electric
parts cover and
side panel.
How to open the screw cap
• Place your finger on the
lower part and push up to
open the screw cap.
Fig. 8-3-7
CAUTION
• Be sure to refer the wiring system diagram
labeled inside the side panel.
• Check local electrical codes and also any
specific wiring instruction or limitation.
How to remove the front panel
Fig. 8-3-8
(1) Open the screw caps and remove three front
panel fixing screws.
(2) Put the screw caps back as they were.
(3) Press the part saying “PUSH” on the air inlet grille
to open the air inlet grille.
Remove three black front panel fixing screws.
(4) Close the air inlet grille.
(5) Manually open the vertical air flow louver directly
below.
(6) Open the front panel lower portion until it comes in
contact with the vertical air flow louver. Lift up the
front panel upper portion in a forward diagonal
direction to unhook the clicks inside the front
panel upper portion.
(7) After unhooking the nails inside the main unit
upper portion, rotate the front panel upper portion
towards you to remove the front panel from the
unit body.
(6) Screws
(6)
(7) (7)
(1) (2) (1) (2) (1) (2) Screw caps and screws
(5)
(3) (4) (3) (4)
Fig. 8-3-9
Stripping length of connecting cable
Front panel Rear plate
Rear plate
bushing
Electrical component
box cover
Screws
Cord clamp
Wiring cover Screw
Fig. 8-3-10
NOTE
• Use standard wire only
• Wire type : More than H05 RN-F (1,3 mm² or more)
• Insert the connecting cable fully into the terminal
block and secure it by screw tightly.
• Tightening torque : 1,2 N•m (12 kgf•cm)
• Secure the connecting cable with the cord clamp.
• Fix the wiring cover, rear plate bushing and front
panel on the indoor unit.
3
2
1
10 mm
220 mm
50 mm
60 mm

– 18 –
Fig. 8-3-11
8-3-5. Piping and Drain Hose Installation
Left-hand connection with piping
• After scribing slits of the rear
panel by a knife or a marking-
off pin, cut them by a pair
of nippers or the like.
Grounding
wire
Connecting
cable
Terminal block
Screw
Cord clamp
Wiring cover
Screws
TEMPORARY
AUTO
TEST RUN
(COOL)
REMOTECONTROL
21
Slit (rear panel)
Fig. 8-3-12
Bend the connecting pipe so that it is laid within 52
mm above the wall surface. If the connecting pipe is
laid exceeding 52 mm above the wall surface, the
indoor unit may unstably be set on the wall.
When bending the connecting pipe, make sure to use
spring bender so as not to crush the pipe.
Bend the connecting pipe within a radius of 40 mm.
NOTE
If the pipe is bent incorrectly, the indoor unit would be
unstably set on the wall and the air conditioner might
be raised.
1. When the piping runs to the left, remove the left
side body bushing of the rear panel.You may need
the body bushing when you relocate the unit, so
be sure to make customer keep it in a safe place.
2. After passing the connecting pipe through the pipe
hole, connect the connecting pipe to the auxiliary
pipes and wrap facing tape around them.
Fig. 8-3-13
Outward form of indoor unit
R 40mm (Use polisin (polyethylene core)
or the like for bending pipe.)
52 mm
Use the handle of screwdriver,etc.
80˚
Underside connection with piping
1. Cut out the knock-out piece from the right below of
the rear plate with a knife, etc. Smooth the cut
edges.
Fig. 8-3-14
CAUTION
• Bind the auxiliary pipes (two) and connecting
cable with facing tape tightly. In case of leftward
piping and rear-leftward piping, bind the
auxiliary pipes (two) only with facing tape.
Slit part
Pipe holder
Pipe holder Rear plate
Fig. 8-3-15
• Carefully arrange pipes so that any pipe does
not stick out of the rear plate of the indoor unit.
• Carefully connect the auxiliary pipes and
connecting pipes to each other and cut off the
insulating tape wound on the connecting pipe to
avoid double-taping at the joint, moreover, seal
the joint with the vinyl tape, etc.
• Since dewing results in a machine trouble,
make sure to insulate both the connecting
pipes.(Use polyethylene foam as insulating
material.)
• When bending a pipe, carefully do it not to
crush it.
8-3-6. Indoor Unit Fixing
1. Pass the pipe through the hole in the wall, and
hook the indoor unit on the installation plate at the
upper hooks.
2. Swing the indoor unit to right and left to confirm
that it is firmly hooked up on the installation plate.
3. While pushing the indoor unit onto the wall by the
lower part, hook it up on the installation plate by
the lower part.
Pull the indoor unit
toward you by the
lower part to confirm
that it is firmly
hooked up on the
installation plate.
Indoor unit
Connecting
cable
Installation
plate
Auxiliary
pipes
1Installation
plate
Hook here
Hook here
1
2
Space for pipes
Wall
Drain
guide
Fig. 8-3-16
This air conditioner has the
structure designed to drain
water collected from dew,
which forms on the back of the
indoor unit, to the drain pan.
Therefore, do not store the
power cord and other parts
at a height above the drain
guide. Fig. 8-3-17
8-3-7. Drainage
1. Run the drain hose sloping downwards.
NOTE
• Hole should be made at a slight downward slant to
the outdoor side.
50 mm
or more
Do not rise the drain hose. Do not form the drain hose
into the waved shape.
Do not put the
drain hose end
into water.
Do not put the drain
hose end in the
drainage ditch.
Fig. 8-3-18
2. Put water in the drain pan and make sure that the water
is drained out of doors.
3. When connecting extension drain hose, insulate the
connecting part of extension drain hose with shield
pipe.
Fig. 8-3-19
CAUTION
Arrange the drain pipe for proper drainage from the
unit. Improper drainage can result in dew-dropping.
How to install the front panel on the indoor unit
Install the front panel through the opposite order of “How
to remove the front panel”.
When the panel is removed and mounted again, take the
following action :After fastening the 6 screws, be sure to
hook the inside clicks , , and of the front panel
shown in the diagram, right gap is between the front panel
and the rear plate.
• If cooling (dry) operation is made without pushing the air
outlet, dew can be deposited on the front panel surface.
In addition, a gap between the front panel and the body
will become wider, spoiling the appearance.
Shield pipe
Extension drain hose
Inside the room
Drain hose
312
Push Push Push
Fig. 8-3-20
8-3-8. Gas LeakTest
• Check the flare nut connections, valve stem cap
connections and service
cap connections for gas
leak with a leak detector
or soap water.
Fig. 8-3-21
Flare nut
connections
(indoor unit)
Electric parts
cover
Flare nut
connections
(Outdoor unit) A
B
C
D
Valve stem cap connection
Valve stem
cap connection
Service cap
connection
8-3-9. Check andTest Operation
¨1. Check the unit is firmly hooked up on the
installation plate.
¨2. Check the connecting pipes tightened
securely.
Confirm that there is no gas leakage.
¨3. Confirm that all connecting cables are
secured and correct.
¨4. Check the pipe insulation.
¨5. Check the drainage.
¨6. Connection of the grounding wire.
¨7. To switch theTEST RUN (COOL) mode,
turn the switch on.
TEMPORARY
AUTO
TEST RUN
(COOL)
REMOTE CONTROL
Fig. 8-3-22
Make sure to return the TEMPORARY switch
to REMOTE CONTROL.
Three-minutes protection feature
A protection feature prevents the air
conditioner from being active for about 3
minuets when it is restarted immediately
after operation.
¨8. Operate the unit at cooling operation
mode for fifteen minutes or more.
Measure the temperature of the intake
and discharge air.Ensure the difference
between the intake temperature and the
discharge one is more than 8°C.
NOTE: Three-minutes protection feature
A protection feature prevents the air
conditioner from being activated for
about 3 minutes when it is restarted
immediately after operation.
¨9. Check the remote control operation when
it is at fixed position.
When finished the check and test operation,
make sure to return the TEMPORARY switch
to REMOTE CONTROL.
¨10. Explain to the customer on the correct
usage of air conditioner with simple
layman’s terms.

– 19 –
Outer dia.
A (mm) Thickness
(mm) Imperial Rigid (mm)
6,35 1,3 0,7 0,8
12,7 1,8 1,0 to 1,1 1,0
8-4. Outdoor Unit
8-4-1. Installation Place
• A place which provides the spaces around the outdoor
unit as required above in the diagram.
• A dry sunny place. If the place is exposed to direct
sunlight use an awning for protection.
•
A place which can bear the weight of the outdoor unit and
does not allow an increase in noise level and vibration.
• A place where the operation noise and discharged air
do not disturb your neighbors.
• A place which is not exposed to a strong wind.
• A place free of a leakage of combustible gases.
• A place which does not block a passage.
• When the outdoor unit is to be installed in an elevated
position, be sure to secure its feet.
• A place where the drain water does not raise any problem.
• An allowable length of the refrigerant piping is up to 15 m.
• An allowable heat level is up to 6 m.
CAUTION
1. Install the outdoor unit without anything blocking
the air discharging.
2. When the outdoor unit is installed in a place
exposed always to a strong wind like a coast or
on a high story of a building, secure the normal
fan operation using a duct or a wind shield.
3. Specially in windy area, install the unit to
prevent the admission of wind.
4. Installation in the following places may result
trouble. Do not install the unit such places.
• A place full of machine oil.
• A saline-place such as coast.
• A place full of sulfide gas.
• A place where high-frequency
waves are likely to be
generated as from
audio equipment,
welders, and
medical
equipment. Fig. 8-4-1
Strong
wind
8-4-2. Refrigerant Piping Connection
Flaring
Die Pipe
A
Fig. 8-4-3
Tightening Connection
Align the centers of the connecting pipes and tighten
the flare nut as far as possible with your fingers Then
tighten the nut with a spanner and torque wrench as
shown in the figure.
CAUTION
(Unit : N•m)
Outer dia. Tightening Additional
(mm) torque tightening torque
6,35 16 (1,6 kgf•m) 18 (1,8 kgf•m)
12,7 49 (5,0 kgf•m) 54 (5,5 kgf•m)
Fig. 8-4-4
8-4-3. Evacuating
AIR PURGE
Evacuate the air in the connecting pipes and in the
indoor unit using vacuum pump. Do not use the
refrigerant in the outdoor unit.
For details, see the manual of vacuum pump.
Use of vacuum pump
1. Connect the charge hose (A) from the manifold valve
to the charge inlet of the gas side packed valve.
2. Connect the charge hose (B) to the port of vacuum
pump.
3. Open fully the low pressure side handle of the
manifold valve.
4. Operate the vacuum pump.
5. Close the low pressure side handle of manifold valve
after evacuating and stop the vacuum pump.
Continue evacuating more than 15 minutes and check
the pressure gage indicates –0,1 MPa (–76 cm Hg).
6. Open the stems of packed
valves A and B1 all the way.
7. Securely tighten the stem
cap to each of the packed
valve stems.
Half union Flare nut
Externally
threaded side Internally
threaded side
Use a wrench to secure. Use a torque wrench to tighten.
VP
Outdoor unit
Charge
hose (B)
Service port
Packed
valve
A
B
1
C
D
Gas
(Ø12,7)
Liquid
(Ø6,35)
Indoor unit
Lo Hi
High
pressure
side
handle
Pressure
gage Manifold valve
Low pressure
side handle
Charge
hose (A)
Fig. 8-4-5
CAUTION
• KEEP IMPORTANT 4 POINTS FOR PIPINGWORK
(1)Take away dust and moisture
(Inside of the connecting pipes.)
(2)Tight connection (between pipes and unit)
(3)Evacuate the air in the connecting pipes using
VACUUM PUMP.
(4)Check gas leak (connected points)
PackedValve Handling Precautions
• Open the valve stem all the way out; so not try to
open it beyond the stopper.
• Securely tighten the valve stem cap torque is as follows;
Gas pipes side (ø12,7 mm) : 49 N•m (5,0 kgf•m)
Liquid pipe side (ø6,35 mm) : 16 N•m (1,6 kgf•m)
Hexagon wrench is required.
Fig. 8-4-6
5mm
Flare nut
Stopper
Valve body
Valve stem Valve stem cap
8-4-4. Electrical Work
How to connect the power cord
For the air conditioner that has no power cord,
connect a power cord to it as mentioned below.
• Remove the electric parts cover from the outdoor
unit. (4 screws)
• After removing the electric parts cover, remove
the cord clamp.
• Connect and secure the power supply cord.
Fig. 8-4-7
Stripping length of power cord
LN
123
Screw
Screw
Terminal block
Earth line
Cord
clamp Cord
clamp
Power
supply
cord Connecting
cable
Earth line
Terminal block
Earth line
90mm
10mm
10mm 80mm
L
N
Fig. 8-4-8
WARNING
To plug the cable in the plug receptacle, take
the following precaution.
THIS APPLIANCE MUST BE EARTHED.
IMPORTANT
THE WIRES IN THIS MAINS LEAD ARE
COLORED IN ACCORDANCE WITH THE
FOLLOWING CODE :
Fig. 8-4-9
As the colors of the flexible cord of this
appliance may not correspond with the colored
markings, to identify terminals in your plug, as
follows :
Connect BROWN colored core to plug terminal
marked letter “L”.
Connect BLUE colored core to plug terminal
marked letter “N”.
Connect GREEN andYELLOW colored core to
plug terminal marked Earth symbol “ ”.
The installation of the cables has to be done in
such a way that the basic insulated wires for the
infrared sensor can not be touched.
Use the power supply cord/cables with
thickness, type, and protective devices
specified in the installation manual.
Prepare the interior power supply cord and
cables wiring with current capacity sufficient for
starting and usage of air conditioner.
L
N
L
N-LIVE
-NEUTRAL
-EARTH
: Brown
: Blue
: Green and Yellow
NOTE
• Use standard wire only.
• Wire type : 3,5 mm² or
more AWG-12.
Model RAS-18YAH-E RAS-18YAH-A
(RAS-18YKH-E) (RAS-18YKH-A)
Power source 50 Hz ~, 220 – 240V 50 Hz ~, 240V
Maximum running current 16,8 A
Plug socket & fuse rating 20 A
Wiring 3,5 mm² (AWG-12) or more
CAUTION
If incorrect/incomplete wiring is carried out, it
will cause an electrical fire or smoke.
Prepare the power source for exclusive use with
the air conditioner.
This product can be connected to the mains.
Connection to fixed wiring :
A switch or circuit breaker which disconnects all
poles and has a contect separation of at least 3
mm must be incorporated in the fixed wiring.
An approved short circuit breaker or switches
must be used.
8-4-5. Wiring Connection
1. Remove the electric parts cover from the
outdoor unit. (4 screws)
2. Connect the connecting cable to the terminal as
identified with their respective matched numbers
on the terminal block of indoor and outdoor unit.
(1,3 mm² AWG-16 or more)
3. When connecting the connecting cable to the
outdoor unit terminal, make a loop as shown
installation diagram, to prevent water coming in
the outdoor unit.
4. Insulate the unused cords (conductors) with
strip the sheath of connecting cable to prevent
the shortage or electric leakage.
Process them so that they do not touch any
electrical or metal parts.
Stripping length of connecting cable
Fig. 8-4-10
CAUTION
1. Wrong wiring connection may cause some
electrical parts burn out.
2. Be sure to use the cord clamps and the
electric parts cover to the specified positions
with attached to the product.
Mount the electrical parts cover for cables of
connecting section firmly with the screws.
3. Do not damage or scratch the conductive
core and inner insulator of power supply and
inter connecting cables when peeling them.
4. Be sure to comply with local cords on running
the wire from indoor unit to outdoor unit (size
of wire and wiring method etc.) Wire type :
More than H05 RN-F
5. Use the power supply cord and inter-connecting
cable with specified thickness, specified type,
and protective devices specified.
6. No wire should touch refrigerant piping,
compressor of any moving parts.
60mm
3
2
1
123
10mm
10mm50mm Connecting
cable
Screws
Terminal
block
Terminal
screw
Cord clamp
Earth line
Fig. 8-4-2
2. Insert a flare nut into the pipe, and flare the pipe.
• Do not apply excess torque.
Otherwise, the nut may crack depending on the conditions.
90˚ Obliquity Roughness Warp
1. Cut the pipe with a pipe cutter.

– 20 –
9. TROUBLESHOOTING CHART
Troubleshooting Procedures :
• Following details of “What to be pre-checked
first”, make sure of the basic items.
• When there is no trouble corresponding to
above, check in detail the faulty parts follow-
ing “How to judge faulty parts by symptoms”
later.
9-1. What to be Prechecked First
9-1-1. Power Supply Voltage
The line voltage must be AC 220–240V (RAS-
18YKH-E, RAS-18YAH-E), 240V (RAS-18YKH-A,
RAS-18YAH-A). If the line voltage is not within this
range, this air conditioner may not work normally.
9-1-2. Incorrect Cable Connection between
Indoor and Outdoor Units
The indoor unit is connected to the outdoor unit with
4 cables. Make certain that the indoor and outdoor
units have been connected properly, with terminals
assigned the same numbers wired to each other.
If the connectors are not connected as specified, the
outdoor unit will not operate normally, or OPERA-
TION lamp andTIMER lamp will flash (5Hz).
9-1-3. Misleading but Good Operations
(Program Controlled Operation)
The microcomputer performs the operations listed in
Table 9-1-1 to control the air conditioner. If a claim
is made on the operation, check whether it corre-
sponds to the contents in theTable 9-1-1.
If it does, it is an indispensable operation for the
control and maintenance of the air conditioner:it is
not a failure of the unit.
Table 9-1-1
No.
1
2
3
4
5
6
7
8
9
Operation of air-conditioner
When the breaker is turned on, the
OPERATION lamp on the setting
indication part flashes.
Fan speed remains unchanged in the
dry mode.
Room temperature is in the range
under which the compressor is turned
off, but the compressor will not stop.
The compressor will not switch on or
off even when the thermo control is
operated in the dry operation.
The PRE-DEF.lamp comes on when
the heating operation is started.
The outdoor fan stops once in the
while during the heating operation.
Compressor does not work though
room temperature is in the range of
turning the compressor on.
During automatic operation, the
operation mode changes.
During automatic operation mode, the
fan only operation continues.
Description
The OPERATION lamp flashes, indicating that power is
turned on. If this happens, push the START/STOP button
once to cause the lamp to stop flashing. A power outage
also causes the lamp to flash.
Fan speed is automatically controlled in the dry mode.
The compressor will not stop while the compressor on hold
timer (3-minutes timer) is actuated.
In the dry mode, the compressor goes on and off at regular
intervals, independent of the thermo control.
The PRE-DEF.lamp comes on during defrost operation and
when the indoor heat exchanger temperature is low when the
heating operation is started. At this time, the indoor fan is
stopped to prevent cold air from drifting into the room.
• When the indoor heat exchanger temperature is high, the
outdoor fan may be stopped by the high-temperature limit
control operation.
Compressor does not work while the compressor restart
delay (3-min.) timer is active. The same is true after power is
turned on, as the time is still active.
After selection of the cooling and heating operation, the
operation mode is selected again when the compressor off
mode continues for 15 min. according to the room tempera-
ture.
When the room temperature is within setting temperature ±
1°C the fan only mode is selected.