Download Mitsubishi Mr.Slim MS24WN Service manual

OB311--1.qxp
04.1.13 9:53 AM
Page 1
Revision:
● PARTS LIST have been partially modified.
● Please void OB311.
SPLIT-TYPE, AIR CONDITIONERS
No. OB311
REVISED EDITION-A
SERVICE MANUAL
Wireless type
Models
MS24WN (W)
· MU24WN
CONTENTS
1. FEATURES ·························································3
2. PART NAMES AND FUNCTIONS······················4
3. SPECIFICATION·················································6
4. DATA···································································8
5. OUTLINES AND DIMENSIONS ·······················12
6. WIRING DIAGRAM ··········································14
7. REFRIGERANT SYSTEM DIAGRAM ··············15
8. MICROPROCESSOR CONTROL ····················16
9. SERVICE FUNCTIONS ····································25
10. TROUBLESHOOTING······································27
11. DISASSEMBLY INSTRUCTIONS·····················40
12. PARTS LIST······················································44
13. OPTIONAL PARTS ······················BACK COVER
INDOOR UNIT
Indication of model name
MS24WN
Remote
controller
OUTDOOR UNIT
Indication of model name
MU24WN
The Slim Line.
From Mitsubishi Electric.
TM
C
L IST ED
US
OB311--1.qxp
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Page 2
Revision:
• Parts No. has been changed due to the color change of outdoor unit parts. WHITE➔NEW WHITE (Brighter)
• Capillary tube has been added to parts list.
Model
Page
MU24WN
47
Part name
CAPILLARY TUBE (TAPER PIPE)
[0.14X[0.09X1-31/32
Part number
E02 784 936
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Page 3
FEATURES
MS24WN
MU24WN
LCD wireless
remote controller
Model
Cooling capacity
SEER
MS24WN
22,800 Btu/h
10.5
“I FEEL CONTROL” IN OUR LCD WIRELESS REMOTE CONTROLLER WITH ON/OFF PROGRAM TIMER
Mitsubishi Electric’s new wireless remote controller incorporates a number of advanced features that provide even greater control and ease-to-use. It has a liquid crystal display which indicates such information as mode, fan speed and temperature
selected as well as the programmed ON/OFF timer. It is also equipped with “I Feel Control”, a unique Mitsubishi Electric feature that allows the user to adjust the temperature to exactly the level he or she wants simply by tapping the button that
describes present conditions : “Too Cool” or “Too Warm”. The optimum temperature set this way is then memorized for immediate recall whenever the air conditioner is used again.
Select desired air flow direction.
REMOTE-CONTROL OPERATION MODE
Using the remote controller, you can select from five airflow settings to match room layout and the location of people. Also, you
can set the vane to swing automatically.
SWING
SWING
AUTO-RESTART FUNCTION
The auto restart function restarts the equipment automatically
when power is restored following an outage. Operation resumes in
the mode in which the equipment was running just before the outage.
HIGH PERFORMANCE ROTARY COMPRESSOR
The advanced design of Mitsubishi Electric’s powerful and energy
efficient rotary compressor results in lower operating costs and
longer service life.
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PART NAMES AND FUNCTIONS
INDOOR UNIT
MS24WN
Grille
Air inlet
Deodorizing filter (option)
(Gray sponge type)
Air cleaning filter (option)
(White bellows type)
Front panel
Remote control
receiving section
Horizontal vane
Air filter
Remote controller
Vertical vane
Display section
Operation section
(When the grille is opened)
Operation indicator lamp
Operation Indicator
Emergency operation switch
Receiving section
ACCESSORIES
MS24WN
1
2
3
4
5
6
7
Installation plate
Installation plate fixing screw 4 x 25 mm(0.16 x 0.98 in.)
Remote controller holder
Fixing screw for 3 3.5 x 16 mm(0.14 x 0.63 in.) (Black)
Battery (AAA) for remote controller
Wireless remote controller
Felt tape (Used for left or left-rear piping)
OUTDOOR UNIT
MU24WN
4
1
7
1
2
2
1
1
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REMOTE CONTROLLER
MS24WN
Signal transmitting section
Operation display section
PM
OPERATE/ STOP
(ON/ OFF)button
AM
TOO
ON/OFF WARM
TOO
COOL
TEMPERATURE buttons
Open the front lid.
CLOCK
PM
AM
TOO
ON/OFF WARM
VANE button
(Horizontal vane button)
TOO
COOL
FAN
STOP
VANE
START
OFF-TIMER button
I FEEL COOL
FAN
FAN SPEED CONTROL button
DRY
ON-TIMER button
MODE WIDE VANE
HR.
OPERATION SELECT button
LONG
MIN.
HR. button
MIN. button
(TIME SET button)
RESET CLOCK
CLOCK SET button
WIDE VANE button
(Vertical vane button)
LONG button
RESET button
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Page 6
SPECIFICATION
Model
Item
❈1
Cooling capacity
Btu/h
Power consumption ❈1
W
EER ❈1 [SEER] ❈2
INDOOR UNIT MODEL
External finish
Power supply
Max. fuse size (time delay)/ Disconnect switch
A
Min. ampacity
A
Fan motor
F.L.A
FAN Dry
CFM
Airflow Low—Med.—High
COOL Dry(Wet)
CFM
pt./h
Moisture removal
Sound level Low-Med.-High
dB(A)
in.
Cond. drain connection O.D.
W
in.
Dimensions
D
in.
H
in.
Weight
lb.
OUTDOOR UNIT MODEL
External finish
Power supply
Max. fuse size (time delay)
A
Min. ampacity
A
Fan motor
F.L.A
Model
Winding resistance (at 68˚F) Ω
Compressor
R.L.A
L.R.A
Refrigerant control
Sound level
dB(A)
W
in.
Dimensions
D
in.
H
in.
Weight
lb.
REMOTE CONTROLLER
Control voltage (by built-in transformer)
REFRIGERANT PIPING
Pipe size
Liquid
in.
(Min. wall thickness)
Gas
in.
Indoor
Connection method
Outdoor
Between the indoor
Height difference
ft.
& outdoor units
Piping length
ft.
Refrigerant charge (R22)
oz.
Refrigerant oil (Model)
MS24WN
22,800
2,170
10.5 (10.5)
MS24WN
White
115V 60Hz 1[
15
1.1
0.82
431-491-565
402(346)-484(417)-565(487)
7.6
39-43-47
5/8
43-5/16
8-15/16
12-13/16
40
MU24WN
Munsell 5Y7/1
208/230V 60Hz 1[ 3 wires
25
22
0.87
PH33NPBT
C-R 0.84 C-S 2.09
16
58
Linear expansion valve
55
34-1/4
11-5/8
33-1/2
152
Wireless type
12V DC
Not supplied (optional parts)
3/8 (0.0285)
5/8 (0.0315)
Flared
Flared
Max. 25
Max. 50
4 Ib. 5 oz.
27.9 (MS32N1)
Notes : Test conditions are based on ARI 210/240
❈1 : Rating conditions (cooling) — Indoor : 80˚FDB, 67˚FWB, Outdoor : 95˚FDB, (75˚FWB)
❈2 : Rating conditions (cooling) — Indoor : 80˚FDB, 67˚FWB, Outdoor : 82˚FDB, 65˚FWB
Operating Range
Cooling
Maximum
Minimum
Indoor intake air temperature Outdoor intake air temperature
95˚FDB, 71˚FWB
115˚FDB
67˚FDB, 57˚FWB
67˚FDB
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MAX. REFRIGERANT PIPING LENGTH & MAX. HEIGHT DIFFERENCE
Piping size : in.
Additional piping
Max. length : ft.
A
Model
MS24WN
MU24WN
50
Gas
Length of connecting pipe : in.
Liquid
Minimum
Outside Minimum Outside
Wall
Wall
diameter thickness
diameter
thickness
[ 5/8
0.0315
[ 3/8
0.0285
Indoor unit
Outdoor unit
Gas : 16-15/16
Liquid : 19-11/16
Gas : 0
Liquid : 0
MAX. HEIGHT DIFFERENCE
Indoor
unit
w Height difference
should be within
25ft. regardless of w Max. Height
which unit, indoor
difference 25ft.
or outdoor
position is high.
Additional Piping
Max. length
A
Outdoor unit
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DATA
4
4-1. PERFORMANCE DATA
1) COOLING CAPACITY
MS24WN MU24WN
(208V/ 230V)
Indoor air
Model
IWB
(˚F)
MS24WN
Outdoor intake air DB temperature(˚F)
85
75
95
105
115
TC
SHC
TPC
TC
SHC
TPC
TC
SHC
TPC
TC
SHC
TPC
TC
SHC
TPC
71
27.9
13.9
1.93
26.1
13.0
2.12
24.5
12.2
2.28
22.8
11.3
2.40
21.0
10.4
2.50
67
26.4
16.7
1.82
24.6
15.5
2.01
22.8
14.4
2.17
21.2
13.4
2.30
19.5
12.3
2.41
63
24.9
19.0
1.74
23.0
17.6
1.92
21.4
16.4
2.07
19.5
14.9
2.21
17.8
13.6
2.30
Notes 1. I WB : Intake air wet-bulb temperature.
TC : Total Capacity (x103 Btu/h), SHC : Sensible Heat Capacity (x103 Btu/h)
TPC : Total Power Consumption (kW)
2. SHC is based on 80˚F of indoor intake air DB temperature.
2) COOLING CAPACITY CORRECTIONS
Refrigerant piping length (one way)
Model
MS24WN
25ft. (std.)
40ft.
50ft.
1.0
0.954
0.923
4-2. PERFORMANCE CURVE
MS24WN
MU24WN
Cooling
SHF at rating condition = 0.63
Airflow = 487CFM
Bypass Factor = 0.16
30
Total power consumption (kW)
Total capacity ( ✕10 Btu/h)
28
26
24
22
208V/230V
Ind
oor
inta
ke
air
WB
tem
per
20
atu
18
re (
°F)
71
67
63
16
2.6
208V/230V
2.4
2.2
re
2.0
1.6
ke
or
ndo
inta
)
(°F
p
em
Bt
1.8
tu
era
71
67
63
W
air
I
1.4
65 70 75 80 85 90 95 100 105 110 115
Outdoor intake air DB temperature (°F)
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4-3. Condensing pressure
Data is based on the condition of indoor humidity 50%.
Air flow should be set at High.
MU24WN
(PSIG)
300
86
80
75
70
(PSIG)
100
260
re
90
atu
r
pe
240
B
rD
tem
Suction pressure
Condensing pressure
280
oo
Ind
220
200
180
160
68 70
mperature
Indoor DB te
80
86
80
70
75
70
60
50
75
80
85
90
95
100
40
68 70
104(°F)
Outdoor ambient temperature
9
75
80
85
90
95
Outdoor ambient temperature
100
104(°F)
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Page 10
4-4. STANDARD OPERATION DATA
Model
MS24WN
Unit
Cooling
Btu / h
22,800
SHF
—
0.63
Input
kW
2.17
Item
Capacity
Total
INDOOR UNIT MODEL
MS24WN
Power supply
115V 60Hz 1[
Input
kW
0.071
A
0.62
Fan motor current
Electrical
circuit
OUTDOOR UNIT MODEL
MU24WN
Power supply
208/230V 60Hz 1[
Input
kW
2.099
A
9.36/ 8.30
Comp. current
Fan motor current
A
0.67/0.71
Condensing pressure
PSIG
250
Suction pressure
PSIG
71
˚F
174
Refrigerant Condensing temperature
circuit
Suction temperature
˚F
115
˚F
48
Comp. shell bottom temp
˚F
158
Ref. pipe length
ft.
25
Refrigerant charge (R22)
—
4 Ib. 5 oz.
DB
˚F
80
WB
˚F
67
DB
˚F
51
WB
˚F
50
Fan speed (High)
rpm
1,280
Airflow (High)
CFM
487(Wet)
DB
˚F
95
WB
˚F
—
Fan speed
rpm
750/820
Airflow
CFM
1,589/1,765
Discharge temperature
Intake air temperature
Indoor
unit
Discharge air temperature
Intake air temperature
Outdoor
unit
POWER SUPPLY
MS24WN
✻ Control voltage
•Both wirings can be applied.
INDOOR UNIT
115V 60Hz 1[,
2wires
INDOOR UNIT
Disconnect switch
OUTDOOR UNIT
SIGNAL WIRE
2 wires 12V DC
OUTDOOR UNIT
SIGNAL WIRE
2 wires 12V DC
115V 60Hz 1[,
2 wires
115V
208/230V
60Hz 1[, 3 wires
208/230V
60Hz 1[, 3 wires
10
Power supply voltage to
serial signal circuit is 12V DC.
Voltage between 1 + and 3 -on in-out terminal block will be
12V DC peak.
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4-5. OPERATING RANGE
(1) POWER SUPPLY
Model
Rating
Guaranteed Voltage
Indoor unit
MS24WN
115V 60Hz 1[
Outdoor unit
MU24WN
208/230V 60Hz 1[
Min. 103V
115V Max. 127V
Min. 198V 208V 230V Max. 253V
(2) OPERATION
Intake air
temperature
Function
Outdoor
Indoor
DB (˚F)
WB (˚F)
DB (˚F)
WB (˚F)
Standard temperature
80
67
95
—
Maximum temperature
95
71
115
—
Minimum temperature
67
57
67
—
Condition
Cooling
—
78%
Maximum humidity
4-6. OUTLET AIR SPEED AND COVERAGE RANGE
Model
Mode
Function
MS24WN
FAN
COOL
Dry
Wet
Air flow
(CFM)
565
487
Air speed Coverage
(ft./sec.) range (ft.)
20.1
34.2
17.2
29.4
● The air coverage range is the figure up to the position where the air speed is 1 ft./sec., when air is blown out horizontally from
the unit properly at the High speed position.
The coverage range should be used only as a general guideline since it varies according to the size of the room and furniture
arranged in the room.
4-7. ADDITIONAL REFRIGERANT CHARGE (R22(oz.))
Model
MS24WN MU24WN
Outdoor unit
precharged
(up to 25ft.)
25ft.
30ft.
35ft.
40ft.
45ft.
50ft.
4 lb. 5 oz.
0
0.81
1.62
2.43
3.24
4.05
Refrigerant piping length (one way)
CALCULATION : Xoz. = 0.81/ 5oz./ft. x (Additional Piping Length-25) ft.
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Page 12
OUTLINES AND DIMENSIONS
MS24WN
Unit: inch
INDOOR UNIT
3-7/8
6-13/16
16-5/16
1-7/8
16-5/16
3-7/8
1/8
1-7/8
10-1/16
42-1/16
6-13/16
Wall hole [ 2-15/16
8-7/8
3/16
43-5/16
12-13/16
Installation plate
{
Air in
2-3/16
31-1/8
9-15/16
Air out
3/4
6-3/8
2-5/16
Wireless remote controller
12
8-15/16
Liquid line [
Gas line [
Insulation [
[
3/8 19-11/16
3/4 16-15/16
1-15/16 O.D
1-1/4 I.D
Drain hose [ 5/8
(Connected part O.D)
Insulation [ 1-1/8
5/16
Indoor unit
12-3/8
Installation plate
Page 13
MU24WN
OUTDOOR UNIT
Unit: inch
Outdoor Unit-Necessary surrounding clearance
7-7/8
1-9/16 1-1/16
13
14-1/4
Air intake
Air intake
Front opening
9/16
Air outlet
Note:Allow adequate
13/32 upper clearance
13/32
Terminal block for power line
34-1/4
13/32
Terminal block for indoor and outdoor unit connection
11-7/8
19-11/16
5-29/32
7-9/32
19-11/16
11/16
7-9/32
19-11/16
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Service space
Outlet guide
installation hole
Handle for moving
Service panel
Handle for moving
4-1/8
1-5/16
2-1/16
Refrigerant-pipe flared
connection [3/8
Knock out hole
for front piping
(refrigerant,drainage
and wiring)
2-3/8
2-1/2o7/8 Oval holes
(standard bolt M10)
Refrigerant-pipe flared
connection [5/8
1-3/4
33-1/2
21-3/4
17-17/32
20-5/8
1-5/8
1-3/4
1-9/16
17-23/32
18-7/18
20-5/8
7-1/18
17-3/8
A
2-3/8
4-3/4
Knock out holes for
power line 2-[1-1/16
Knock out hole
for right piping
(refrigerant,drainage
and wiring)
Drain hole [1-5/16
Bottom
piping hole
2-U-shaped
notched
holes
Drain hole [1-5/16
9/32
A
Handle
for moving
11-5/8
15/16
Side air intake
Conduit hole
Rear fresh
air intake
R1
Outdoor Unit-Necessary surrounding clearance
(Concentrated installation)
The upper side must be open.
3/
3-1/8
16
/4
11/16
13/32
7-7/8
4
R1
1/2
For 10 units or less
39-3/8
13
1 max.
Rear piping hole
3-3/4
3/1
6
15/16
1-5/16
5-7/16
NOTE: Do not wire12V DC and
115V AC in same conduit hole.
R1
OB311--1.qxp
Standard bolt length
2-9/16
Front right piping holesdetail figures
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Page 14
WIRING DIAGRAM
MS24WN
INDOOR UNIT
(
MODEL WIRING DIAGRAM
4
3
2
1
CN201
TO OUTDOOR
UNIT
CONNECTING
WIRES
12V DC
FROM OUTDOOR
UNIT
CONNECTING
WIRES
POWER
SUPPLY
115V
1 phase
60Hz
TO OUTDOOR
UNIT
CONNECTING
WIRE
TB
3+
ORN
w
1-
VLT
N
BLK
L1
)
HIC1
1
2
3
4
CN
151
CN
102
15
MV2 MV2 MV1
CN
101
SR141
CN211
CN
3
3
DISPLAY
P.C.BOARD
RECEIVER
P.C.BOARD
NAME
REMOTE
CONTROLLER
SYMBOL
NAME
SYMBOL
MV1
VANE MOTOR(HORIZONTAL)
RT12
INDOOR COIL THERMISTOR(MAIN)
FUSE(3.15A)
MV2
VANE MOTOR(VERTICAL)
RT13
INDOOR COIL THERMISTOR(SUB)
DC/DC CONVERTER
NR11
VARISTOR
INDOOR FAN MOTOR (INNER PROTECTOR)
RT11
ROOM TEMPERATURE THERMISTOR
C11
INDOOR FAN CAPACITOR
F11
HIC1
MF
MF
RT11
ELECTRONIC CONTROL P.C. BOARD 111
w A disconnect may be required by local code.
SYMBOL
1
3
4
C11
TAB12
BLK
GRY
YLW
BRN
WHT
RED
3
CN
121
TRANS
RED
RT12
CN112
NR11
F11
RT13
NAME
SOLID STATE RELAY
SR141
TERMINAL BLOCK
TB
NOTE:1. About the outdoor side electric wiring, refer to the outdoor unit electric wiring diagram for servicing.
2. Use copper conductors only.(For field wiring)
3. Symbols below indicate;
: Terminal block,
: Connector
LEV
CN662
1
-
X52
2
CN724
1
1 RED
ORN
C2
3 CN711
2
SR61
TAB52
X52
BLK
L1
NO
F61
1
3
NR61
T61
CN730 5
OUTDOOR ELECTRONIC CONTROL P.C. BOARD
N
RED
WHT
1
BLU
GRN/YLW
GROUND
7
ORN
VLT
BLU
RED
BLU
NAME
3
COM
L2
SYMBOL
4
N
TB1
L1
POWER
SUPPLY
208/230V
1 phase 60Hz
5
BLK
WHT
+
RED
TO INDOOR UNIT
CONNECTING
WIRES
115V
1 phase 60Hz
6
6
TB2
3
BLU
FROM INDOOR UNIT
CONNECTING WIRE
FROM INDOOR UNIT
CONNECTING WIRES
12V DC
MF
RT62 RT63
BLK
WHT
ORN
RED
MU24WN
MODEL WIRING DIAGRAM
OUTDOOR UNIT
SG79J618H02
RED
A2
DSAR
SYMBOL
52C
NAME
52C
C1
A1
SYMBOL
C
2
RED
S
MC
R
BLK
NAME
C1
COMPRESSOR CAPACITOR
MF
OUTDOOR FAN MOTOR(INNER PROTECTOR)
TB2
TERMINAL BLOCK
C2
OUTDOOR FAN CAPACITOR
NR61
VARISTOR
T61
TRANSFORMER
SURGE ABSORBER
RT62
DISCHARGE TEMPERATURE THERMISTOR
X52
COMPRESSOR AUXILIARY RELAY
F61
FUSE(3.15A)
RT63
AMBIENT TEMPERATURE THERMISTOR
52C
COMPRESSOR CONTACTOR
LEV
EXPANSION VALVE COIL
SR61
MC
COMPRESSOR(INNER PROTECTOR)
DSAR
TB1
SOLID STATE RELAY
TERMINAL BLOCK
NOTE:1. About the indoor side electric wiring, refer to the indoor unit electric wiring diagram for servicing.
2. Use copper conductors only.(For field wiring)
3. Symbols below indicate;
: Terminal block,
: Connector
14
SG79J606H02
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Page 15
REFRIGERANT SYSTEM DIAGRAM
Unit: inch
MS24WN
INDOOR UNIT
MU24WN
OUTDOOR UNIT
Refrigerant pipe [5/8
(with heat insulator)
Indoor
heat
exchanger
Indoor coil
thermistor
RT12(main)
Strainer
#100
Stop valve
(with service port)
Flared connection
Indoor coil
thermistor
RT13(sub)
SERVICE
PORT
Discharge
temperature
thermistor
RT62
SERVICE
PORT
Outdoor
heat
exchanger
FUSIBLE
PLUG
Room temperature
thermistor
RT11
Accumulator
Compressor
Capillary tube
O.D.0.16✕I.D.0.09✕7-7/8
(Upper path)
Strainer
#50
Flared connection
LEV
Stop valve
Ambient
temperature
thermistor
RT63
Capillary tube
O.D.0.16✕I.D.0.09✕3-15/16
(Lower path)
Strainer
#100
Capillary tube
O.D.0.14✕I.D.0.09✕1-31/32
Refrigerant pipe [3/8
(with heat insulator)
Refrigerant flow in cooling
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MICROPROCESSOR CONTROL
MS24WN MU24WN
WIRELESS REMOTE CONTROLLER
Once the operation mode is set, the same operation mode
can be repeated by simply turning the
OPERATE/STOP(ON/OFF) button ON.
Indoor unit receives the signal with a beep tone.
When the system turns off, 3-minute time delay will operate to
protect system from overload and compressor will not restart
for 3 minutes.
Signal transmitting section
Operation display section
PM
AM
OPERATE/ STOP
(ON/ OFF)button
TOO
ON/OFF WARM
TOO
COOL
TEMPERATURE buttons
8-1. “I FEEL CONTROL” (
Initial room temperature
CLOCK
77-F or more
PM
AM
TOO
ON/OFF WARM
more than 55-F,
less than 77-F
TOO
COOL
FAN SPEED CONTROL button
VANE button
(Horizontal vane button)
FAN
STOP
VANE
START
FAN
DRY
ON-TIMER button
MODE WIDE VANE
HR.
OPERATION SELECT button
LONG
MIN.
HR. button
MIN. button
(TIME SET button)
RESET CLOCK
CLOCK SET button
WIDE VANE button
(Vertical vane button)
LONG button
RESET button
INDOOR UNIT DISPLAY SECTION
Operation Indicator lamp
The operation indicator at the right side of the indoor
unit indicates the operation state.
• The following indication applies regardless of shape
of the indicator.
Operation Indicator
mode
COOL mode of
“I FEEL CONTROL“
DRY mode of
“I FEEL CONTROL”
● Once the mode is fixed, the mode does not change
by room temperature afterwards.
OFF-TIMER button
I FEEL COOL
) OPERATION
(1) Press OPERATE/STOP(ON/OFF) button on the remote
controller. OPERATION INDICATOR lamp of the indoor
unit turns on with a beep tone.
(2) Select “I FEEL CONTROL”(
) mode with the OPERATION SELECT button.
(3) The operation mode is determined by the room temperature at start-up of the operation.
● Under the ON-TIMER (
) operation, the mode
is determined according to the room temperature at
the set time the operation starts.
● When the system is stopped on the remote controller,
and restarted within 2 hours in “I FEEL CONTROL”
(
) mode, the system operates in previous mode
automatically regardless of the room temperature.
Operation timer chart
Example
Previous operation
COOL mode of
“I FEEL CONTROL” or
COOL mode
lighted
Restart
COOL mode of
“I FEEL CONTROL”
not lighted
Indication
Operation state
Difference
between set
temperature
and room
temperature
This shows that the
air conditioner is
operating to reach
the target temperature.
Please wait until the
target temperature is
obtained.
Approx. 4-F
or more
This shows that the
room temperature is
approaching the
target temperature.
Approx. 4-F
or less
When the system is restarted after 2 hours and more,
the operation mode is determined by the room temperature at start-up of the operation.
Operation timer chart
Example
Previous operation
COOL mode of
“I FEEL CONTROL”
or COOL mode
16
Restart
COOL or DRY mode of
“I FEEL CONTROL” that
determined by room
temperature at start-up
of the operation.
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Page 17
(4) The initial set temperature is decided by the initial room temperature.
Mode
COOL mode of
"I FEEL CONTROL"
DRY mode of
"I FEEL CONTROL"
Initial room temperature
Initial set temperature
79-F or more
75-F
77-F to 79-F
Initial room temperature
minus 4-F
❈1
more than 55-F, less than 77-F
Initial room temperature
minus 4-F
w 1 When the system is restarted with the remote controller, the system operates with the previous set temperature regardless of the room temperature at restart.
The set temperature is calculated by the previous set temperature.
(5) TEMPERATURE buttons
In “I FEEL CONTROL” (
) mode, set temperature is decided by the microprocessor based on the room temperature.
In addition, set temperature can be controlled by TOO WARM or TOO COOL buttons when you feel too cool or too warm.
Each time the TOO WARM or TOO COOL button is pressed the indoor unit receives the signal and emits a beep tone.
● Fuzzy control
When the TOO COOL or TOO WARM button is pressed the microprocessor changes the set temperature, considering
the room temperature, the frequency of pressing TOO COOL or TOO WARM button and the user’s preference to heat or
cool. So this is called “Fuzzy control”, and works only in “I FEEL CONTROL” mode.
In DRY mode of “I FEEL CONTROL”, the set temperature doesn’t change.
TOO
COOL
… To raise the set temperature 2~4 degrees(°F)
TOO
WARM
… To lower the set temperature 2~4 degrees(°F)
8-1-1. COOL mode of “I FEEL CONTROL”
1. Indoor fan speed control
Indoor fan operates at the set speed by FAN SPEED CONTROL button.
Difference between room
In AUTO the fan speed is as follows.
temperature and set temFan speed perature during operation
Initial temperature difference
Room temperature minus set temperature : 3 degrees or more········································High
Room temperature minus set temperature : Between 2 and 3 degrees····························Med.
4 deg.
Room temperature minus set temperature : less than 2 degree······································· Low
2 deg. 3 deg.
2. Coil frost prevention
1 Temperature control
When the indoor coil thermistor RT12 or RT13 reads 30°F or below, the coil frost prevention mode starts immediately.
However the coil frost prevention doesn’t work for 5 minutes since the compressor has started.
The indoor fan operates at the set speed and the compressor stops for 5 minutes.
After that, if RT12 or RT13 still reads below 30°F this mode prolonged until the RT12 and RT13 reads over 30°F.
2 Time control
When the three conditions as follows have been satisfied for 1 hour and 45 minutes, compressor stops for 3 minutes.
a. Compressor has been continuously operating.
b. Indoor fan speed is Low or Med.
c. Room temperature is below 79°F.
When compressor stops, the accumulated time is cancelled and when compressor restarts, time counting starts
from the beginning.
Time counting also stops temporarily when the indoor fan speed becomes High or the room temperature exceeds
79°F. However, when two of the above conditions (b.and c.) are satisfied again. Time accumulation is resumed.
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Operation chart
Example
Compressor
Outdoor fan
Indoor fan
Page 18
ON
ON
OFF
OFF
ON
(continuously at set speed)
3. Discharge temperature protection
The compressor is controlled by the temperature of discharge temperature thermistor RT62 for excess rise protection of
compressor discharge pressure.
• Compressor
When the temperature of discharge temperature thermistor RT62 goes to 248°F or more, the compressor is turned OFF.
After 3 minutes since the compressor has been turned OFF, if the temperature of discharge temperature thermistor RT62
becomes 212°F or less, the compressor is turned ON.
8-1-2. DRY mode of “I FEEL CONTROL”
The system for dry operation uses the same refrigerant circuit as the cooling circuit.
The compressor and the indoor fan are controlled by the room temperature.
By such controls, indoor flow amounts will be reduced in order to lower humidity without much room temperature
decrease.
1. Indoor fan speed control
Indoor fan operates at the set speed by FAN SPEED CONTROL button.
However, in AUTO fan operation, fan speed becomes Low.
2. The operation of the compressor and indoor / outdoor fan
Compressor operates by room temperature control and time control.
Set temperature is controlled to fall 4°F from initial room temperature.
Indoor fan and outdoor fan operate in the same cycle as the compressor.
• When the room temperature is 73°F or over:
When the thermostat is ON, the compressor repeats 8 minutes ON and 3 minutes OFF.
When the thermostat is OFF, the compressor repeats 4 minutes OFF and 1 minute ON.
• When the room temperature is under 73°F.
When the thermostat is ON, the compressor repeats 2 minutes ON and 3 minutes OFF.
When the thermostat is OFF, the compressor repeats 4 minutes OFF and 1 minute ON.
Operation time chart
Example
ON
Thermostat
ON
OFF
OFF
Indoor fan
OFF
OFF
ON
Outdoor fan
Compressor
OFF
OFF
ON
OFF
8 min.
ON
ON
ON
ON
OFF
3 min. 4 min.
1 min.
3. Coil frost prevention
The operation is as same as coil frost prevention during COOL mode of “I FEEL CONTROL”.
Indoor fan operates at the set speed and the compressor stops for 5minutes, because protection (Coil frost prevention) has
the priority. However when coil frost prevention works while the compressor is not operating, it’s speed becomes Low.
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8-2. COOL (
Page 19
) OPERATION
(1) Press OPERATE/STOP(ON/OFF) button.
OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone.
(2) Select COOL mode with the OPERATION SELECT button.
(3) Press TEMPERATURE buttons.
(TOO WARM or TOO COOL button) to select the desired temperature.
The setting range is 59 ~ 89°F.
w Indoor fan continues to operate regardless of thermostat’s OFF-ON at set speed.
w Coil frost prevention is as same as COOL mode of “I FEEL CONTROL”.
) OPERATION
(1) Press OPERATE/STOP(ON/OFF) button.
OPERATION INDICATOR lamp of the indoor unit
turns on with a beep tone.
(2) Select DRY mode with the OPERATION SELECT
button.
(3) The microprocessor reads the room temperature
and determines the set temperature. Set temperature is as shown on the right chart.
Thermostat (SET TEMP.) does not work.
The other operations are same as DRY mode of “I
FEEL CONTROL”.
(4) DRY operation will not function when the room temperature is 55°F or below.
8-4. FAN( d )OPERATION
(1) Press OPERATE/STOP(ON/OFF) button.
OPERATION INDICATOR lamp of the indoor unit
turns ON with a beep tone.
(2) Select FAN mode with the OPERATION SELECT
button.
Only indoor fan operates. Outdoor unit does not
operate.
Set temperature and initial temperature in DRY mode
-F
95
86
Set temperature
8-3. DRY (
77
68
59
50
50
59
68
77
Initial room temperature
86
95 -F
8-5. FAN MOTOR CONTROL
(1) Rotational frequency feedback control
The indoor fan motor is equipped with a rotational frequency sensor, and outputs signal to the microprocessor to
feedback the rotational frequency. Comparing the current rotational frequency with the target rotational frequency
(High,Med.,Low), the microprocessor controls, SR141 and adjusts fan motor electric current to make the current
rotational frequency close to the target rotational frequency. With this control, when the fan speed is switched,
the rotational frequency changes smoothly.
High
High
Med.
Low
(2) Fan motor lock-up protection
When the rotational frequency feedback signal has not output for 12 seconds, (or when the microprocessor cannot
detect the signal for 12 seconds) the fan motor is regarded locked-up. Then the electric current to the fan motor is shut
off. 3 minutes later, the electric current is applied to the fan motor again. During the fan motor lock-up, the OPERATION
INDICATOR lamp flashes on and off to show the fan motor abnormality. (Refer to page 29.)
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8-6. AUTO VANE OPERATION
1. Horizontal vane
(1) Vane motor drive
This model is equipped with a stepping motor for the horizontal vane. The rotating direction, speed, and angle of the
motor are controlled by pulse signals (approx. 12V) transmitted from microprocessor.
(2) The horizontal vane angle and mode change as follows by pressing the VANE button.
AUTO
Horizontal
Middle
Downward
Swing
(3) Positioning
The vane is once pressed to the vane stopper below to confirm the standard position and then set to the desired angle.
Confirming of standard position is performed in case of follows.
(a) When the OPERATE/STOP(ON/OFF) button is pressed(POWER ON/OFF).
(b) When the vane control is changed from AUTO to MANUAL.
(c) When the SWING is finished.
(d) When the test run starts.
(e) When the power supply turns ON.
(4) VANE AUTO (
) mode
In VANE AUTO mode, the microprocessor automatically determines the horizontal vane angle and operation to make the
optimum room-temperature distribution.
1 In COOL and DRY operation
Vane angle is fixed to Angle 1.
2 In FAN operation
Vane angle is fixed to Angle 4.
(5) STOP (operation OFF) and ON-TIMER standby.
When the following cases occur, the horizontal vane returns to the closed position.
(a) When the OPERATE/STOP(ON/OFF) button is pressed (POWER OFF).
(b) When the operation is stopped by the emergency operation.
(c) When the ON-TIMER is on standby.
(6) Dew prevention
During COOL or DRY operation at Vane Angle 4 or 5 when the compressor cumulative operation time exceeds 1 hour,
the vane angle automatically changes to Angle 1 for dew prevention.
(7) SWING MODE ( )
By selecting SWING mode with the VANE button, the horizontal vane swings vertically. The remote controller displays
“
”.
(8) LONG MODE (
)
By pressing the LONG button indoor fan speed becomes faster than setting fan speed on the remote controller, and the
horizontal vane moves to the position for LONG mode. The remote controller displays “
when the LONG button is pressed once again or the VANE button is pressed.
20
”. LONG mode is cancelled
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• In the following example, the vertical vane is set to
(front.).
COOL / DRY
FAN
Fan speed : Faster
Solid arrow : When the LONG mode is used.
Dotted arrow : When the LONG mode is not used.
2. Vertical vane
(1) Vane motor drive
This model is equipped with a stepping motor for the vertical vane. The rotating direction, speed, and angle of the motor
are controlled by pulse signals (approx. 12V) transmitted from indoor microprocessor.
(2) The vertical vane angle and mode changes as follows by pressing the WIDE VANE button.
1
2
4
3
SWING
5
6
Air flow direction
Air flow blowing range
(3) Positioning
The vane is once pressed to the vane stopper to confirm the standard position and then set to the desired angle.
Confirming of standard position is performed under following conditions.
(a) When the OPERATE/STOP(ON/OFF) button is pressed (POWER ON/OFF).
(b) When the SWING is started or finished.
(c) When the power supply turns ON.
(4) SWING MODE ( )
By selecting SWING mode with the WIDE VANE button, the vertical vane swings horizontally. The remote controller
displays “
”. The vane moves right and left in the width of Angle 4 repeatedly.
(5) WIDE MODE (
)
By selecting WIDE mode with the WIDE VANE button, indoor fan speed becomes faster than setting fan speed on the
remote controller(W). The remote controller displays “
”.
Horizontal AIR FLOW blowing range
About 100-
W Indoor fan speed becomes faster than setting fan speed on the
remote controller even when
or
is selected.
8-7. TIMER OPERATION
1. How to set the timer
(1) Press OPERATE/STOP(ON/OFF) button to start the air conditioner.
(2) Check that the current time is set correctly.
NOTE : Timer operation will not work without setting the current time. Initially “AM0:00” blinks at the current time display of
TIMER MONITOR, so set the current time correctly with CLOCK SET button.
(3) Press ON/OFF TIMER buttons to select the operation.
“ON-TIMER” button... AUTO START operation (ON timer)
“OFF-TIMER” button... AUTO STOP operation (OFF timer)
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(4) Press HR. and MIN. button (TIME set button) to set the timer. Time setting is 10-minute units.
HR. and MIN. button will work when “
” or “
” mark is flashing.
These marks disappear in 1 minute.
After setting the ON timer, check that OPERATION INDICATOR lamp of the indoor unit lights.
NOTE1 :Be sure to place the remote controller at the position where its signal can reach the air conditioner even during
TIMER operation, or the set time may deviate within the range of about 10 minutes.
NOTE2 :Reset the timer in the following cases, or the set time may deviate and other malfunctions may occur.
● A power failure occurs.
● The circuit breaker functions.
2. Cancel
TIMER setting can be cancelled with the ON/OFF TIMER buttons.
To cancel the ON timer, press the “ON-TIMER” button.
To cancel the OFF timer, press the “OFF-TIMER” button.
TIMER is cancelled and the display of set time disappears.
PROGRAM TIMER
● The OFF timer and ON timer can be used in combination.
●“
”and “
” display shows the order of the OFF timer and ON timer operation.
(Example 2) The current time is 11:00 AM.
(Example 1) The current time is 8:00 PM.
The unit turns on at 5:00 PM, and off at 9:00 PM.
The unit turns off at 11:00 PM, and on at 6:00 AM.
PM
PM
AM
PM
NOTE : TIMER setting will be cancelled by power failure or breaker functioning.
8-8. EMERGENCY-TEST OPERATION
In case of test run operation or emergency operation, use the EMERGENCY OPERATION switch on the front of the
indoor unit. Emergency operation is available when the remote controller is missing, has failed or the batteries of remote
controller run down. The unit will start and the OPERATION INDICATOR lamp will light.
The first 30 minutes of operation is the test run operation. This operation is for servicing. The indoor fan speed runs at
High speed and the system is in continuous operation. (The thermostat is ON.)
After 30 minutes of test run operation the system shifts to EMERGENCY COOL MODE with a set temperature of 75°F.
The fan speed shifts to Med. speed.
The coil frost prevention works even in emergency operation.
In the test run or emergency operation, the horizontal vane operates in VANE AUTO (
) mode.
Emergency operation continues until the EMERGENCY OPERATION switch is pressed again or the unit receives any signal from the remote controller. In case of latter normal operation will start.
NOTE : Do not press the EMERGENCY OPERATION switch during normal operation.
• The following indication applies regardless
of shape of the indicator.
OPERATION INDICATOR lamp
EMERGENCY OPERATION
switch
22
Press once
<Cool>
Press once again
<Stop>
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8-9. LEV control
General operation
Basic specification
LEV (Expansion valve) is controlled by “Thermostat ON” commands given from the unit.
Controlled range
Minimum : 54 pulse, Maximum : 500 pulse
Drive speed
30 ~ 90 pulse / second
Opening set
The setting is always in opening direction.
(To close the LEV, it is closed to the pulse smaller than the one which is
set finally. Then the LEV is opened to the final setting pulse.)
Stop of indoor unit
Opening in stop : 150 pulse ➔ LEV opening is set to becomes 500 pulse
after 3 minutes passed.
Remote controller ON
LEV positioning (LEV is closed completely at once)
Power ON (Breaker ON)
LEV is positioned. However, afterwards, LEV is not positioned at the first
remote controller ON.
Approximate for 2 minutes since
compressor has started.
Opening is set by the initial opening.
(Initial opening is set according to each operation modes and
outer temperature conditions.)
From approximate 2 minutes to
approximate 13 minutes
(for 11 minutes) since compressor
has started.
Opening is set by standard opening.
(Standard opening is set according to each operation modes and
outer temperature conditions.)
After 13 minutes passed since
compressor has started.
LEV opening is corrected to be once every 2 minutes so that discharge
temperature becomes the target discharge temperature.
(When the discharge temperature is lower than target one : LEV is corrected in
closed direction, when the discharge temperature is higher than target one :
LEV is corrected in opening direction.)
At thermostat OFF
Opening in stop : 150 pulse ➔ LEV is set to the initial opening after about
3 minutes passed.
At thermostat ON
Same as the starting of compressor operation
At remote controller OFF
Opening in stop : 150 pulse ➔ LEV is set so that the opening is opened
completely at the speed of 4 pulse every 5 seconds in opening after about
3 minutes passed.
(1) LEV opening correction by discharge temperature
The LEV opening is corrected according to the temperature difference between target discharge temperature (Tb) and
actual discharge temperature (Ta).
1 The LEV correction is used properly for two kinds according to the LEV opening status at operation off.
Opening immediately before having stopped last time
Rank
100 pulse or less
(Pulse)
100 pulse or more
(Pulse)
Ta (F-)
Cooling
Cooling
more than Tb+18
5
20
Tb+9 to Tb+18
2
10
Tb+4 to Tb+9
1
2
Tb-4 to Tb+4
0
0
Tb-9 to Tb-4
-1
-2
Tb-18 to Tb-9
-2
-5
less than Tb-18
-5
-10
NOTE : Discharge temperature : Ta, Target discharge temperature : Tb
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Page 24
2 When the temperature difference
RT between indoor coil thermistor (main) RT12 and indoor coil thermistor (sub)
RT13 in the indoor unit is 4deg. or more for a fixed time at cool or dry operation, the target discharge temperature is
changed. After the temperature is changed, when temperature difference
RT is 6deg. or more, the target
temperature is changed again. The LEV opening is controlled based on the changed target discharge temperature
and the temperature difference
RT.
RT
Ta (F-)
less than 4deg.
(Pulse)
4deg. or more and less than 6deg.
(Pulse)
6deg. or more
(Pulse)
more than Tb+18
20
60
60
Tb+9 to Tb+18
10
20
20
Tb+4 to Tb+9
2
10
10
Tb-4 to Tb+4
0
0
0
Tb-9 to Tb-4
-2
-2
-2
Tb-18 to Tb-9
-5
-5
-5
less than Tb-18
-10
-10
-10
NOTE : Discharge temperature : Ta, Target discharge temperature : Tb
The target discharge temperature (Tb) is set according to the operation mode or the unit status as follows.
Operation mode
Tb (-F)
COOL (Normal)
COOL (
RT is less than 4deg., or
COOL (
RT is 6deg or more.)
171
RT is 4deg. or more and less than 6deg..)
144
136
NOTE : Target discharge temperature : Tb
NOTE : When the discharge temperature (Ta) is 122°F or less on the cool operation LEV opening is set in 54 pulse.
When this state continues for 20 minutes, the compressor is stopped and restarts in 3 minutes.
When the compressor is stopped, the indoor unit indicates the abnormality of refrigerant system and stops.
(OPERATION INDICATOR lamp is 10-time flashing on and off.)
(2) LEV time chart
LEV opening
Open
Close
Opening
Power ON completely
Operation
Remote
➔ controller
ON
Standard opening
Initial opening
Positioning
Thermostat
OFF
Remote Opening ➔ Remote
controller completely controller
ON
Operation OFF
Standard opening
Thermostat
ON
Operation
Standard opening
Initial opening
Initial opening
Opening in stop
Opening in stop
Positioning
NOTE : Opening increases and decreases to be in the target discharge temperature during operation.
24
Time
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Page 25
SERVICE FUNCTIONS
MS24WN
9-1. TIMER SHORT MODE
For service, set time can be shortened by short circuit of JPG and JPS the electronic control P.C. board.
The time will be shortened as follows. (Refer to page 37.)
Set time : 1 minute ➔ 1-second
Set time : 3 minute ➔ 3-second (It takes 3 minutes for the compressor to start operation. However, the starting time is
shortened by short circuit of JPG and JPS.)
9-2. P.C. BOARD MODIFICATION FOR INDIVIDUAL OPERATION
A maximum of 4 indoor units with wireless remote controllers can be used in a room.
In this case, to operate each indoor unit individually by each remote controller, P.C. boards of remote controller must
be modified according to the indoor unit number.
How to modify the remote controller P.C. board
Remove batteries before modification.
The board has a print as shown below :
NOTE : For remodelling, take out the batteries
and press the
OPERATE/STOP(ON/OFF)button
twice or 3 times at first.
After finish remodelling, put back the
batteries then press the RESET
button.
The P.C. board has the print “J1” and “J2”. Solder “J1” and “J2” according to the number of indoor unit as shown in Table 1.
After modification, press the RESET button.
Table 1
1 unit operation
2 units operation
3 units operation
4 units operation
No. 1 unit
No modification
Same as at left
Same as at left
Same as at left
No. 2 unit
–
Solder J1
Same as at left
Same as at left
No. 3 unit
–
–
Solder J2
Same as at left
No. 4 unit
–
–
–
Solder both J1 and J2
How to set the remote controller exclusively for particular indoor unit
After you turn the breaker ON, the first remote controller that sends the signal to the indoor unit will be regarded as the
remote controller for the indoor unit.
The indoor unit will only accepts the signal from the remote controller that has been assigned to the indoor unit once
they are set.
The setting will be cancelled if the breaker has turned off, or the power supply has shut down.
Please conduct the above setting once again after the power has restored.
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9-3. AUTO RESTART FUNCTION
When the indoor unit is controlled with the remote controller, the operation mode, the set temperature, and the fan
speed are memorized by the indoor electronic control P.C. board.
When the main power is turned off and then turned back on, the unit restarts automatically in the memorized set
conditions approximately after 3 minutes.
How to release “AUTO RESTART FUNCTION”
1 Turn off the main power for the unit.
2 Pull out the indoor electronic control P.C. board and the display P.C.board. (Refer to page 40.)
3 Solder the Jumper wire or the Resistor 220Ω to the JR07 on the indoor electronic control P.C.board. (Refer to page 37.)
Operation
1 If the main power (115V AC) has been cut, the operation settings remain.
2 After the power is restored, the unit restarts automatically according to the memory. (However, it takes at least 3 minutes
for the compressor to start running.)
C11
CN
21
1
CN201
SW1
RA102
CN151
CN121
CN112
CN111
TAB12
IC101
IC152
JR07
NOTE:
•The operation settings are memorized when 10 seconds have passed after the indoor unit was operated with the remote
controller.
•If the main power is turned off or a power failure occurs while AUTO START/STOP timer is active, the timer setting is
cancelled.
•If the unit has been off with the remote controller before power failure, the auto restart function does not work as the
power button of the remote controller is off.
•To prevent breaker off due to the rush of starting current, systematize other home appliances not to turn on at the same
time.
•When some air conditioners are connected to the same power supply system, if they are operated before power failure,
the starting current of all the compressors may flow simultaneously at restart.
Therefore, special counter-measures are required to prevent the main voltage-drop or the rush of the starting current
by adding to the system that allows the units to start one by one. (time delay)
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Page 27
TROUBLESHOOTING
MS24WN MU24WN
10-1. Cautions on troubleshooting
1. Before troubleshooting, check the following:
1) Check the power supply voltage.
2) Check the indoor/outdoor connecting wire for mis-wiring.
2. Take care the following during servicing.
1) Before servicing the air conditioner, first be sure to turn off the remote controller to stop the unit, and then after confirming the horizontal vane is closed, turn off the breaker and / or disconnect the power plug.
2) Be sure to turn OFF the power supply before removing the front panel, the cabinet, the top panel, and the electronic
control P.C. board.
3) When removing the electronic control P.C. board, hold the edge of the board with care NOT to apply stress on the
components.
4) When connecting or disconnecting the connectors, hold the housing of the connector. DO NOT pull the lead wires.
Lead wiring
Housing point
3. Troubleshooting procedure
1) First, check if the OPERATION INDICATOR lamp on the indoor unit is flashing on and off to indicate an abnormality.
To make sure, check how many times the abnormality indication is flashing on and off before starting service work.
2) Before servicing check that the connector and terminal are connected properly.
3) If the electronic control P.C. board is supposed to be defective, check the copper foil pattern for disconnection and the
components for bursting and discoloration.
4) When troubleshooting, refer to the flow chart on page 28 and the check table on page 29.
4. How to replace batteries
Weak batteries may cause the remote controller malfunction.
In this case, the remote controller can be repaired only by the battery replacement. To operate the remote controller normally, replace the batteries in the following order.
This remote controller has the RESET button. After refilling new batteries, press the RESET button with tip end of ball
point pen or the like, and then use the remote controller.
1 Remove the front lid and insert batteries.
Then reattach the front lid.
2 Press the RESET button.
Insert the negative pole
of the batteries first.
Check if the polarity of
the batteries are correct.
RESET button
NOTE : If the RESET button is not pressed, the remote controller may not operate correctly.
27
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Page 28
10-2. Instruction of troubleshooting
Start
Indoor unit
operates.
Outdoor unit
doesn't
operate.
w1.
Indoor unit
operates.
Outdoor unit
doesn't operate
normally.
Indoor unit
doesn't receive
the signal from
remote controller.
OPERATION INDICATOR
lamp on the indoor unit is
flashing on and off.
Outdoor unit
operates in
only Test Run
operation.
Outdoor unit
doesn't
operate
even in
Test Run
operation.
Outdoor unit
doesn't
stop even
if indoor unit
stops.
Indoor unit
operates, when
the
EMERGENCY
OPERATION
switch is pressed.
Indoor unit
doesn't operate,
when the
EMERGENCY
OPERATION
switch is pressed.
Check room
temperature
thermistor.
Refer to
"Test point
diagram and
voltage" on
page 37.
Refer to D
"Check of
outdoor unit"
on page 33.
Refer to E
"Check of
outdoor unit"
on page 34.
Refer to B
"Check of
remote controller
and receiver
P.C. board"
on page 31.
1. Check indoor /
outdoor
connecting wire.
2. Refer to C
"Check of indoor
electronic control
P.C. board"
on page 32.
Flash on and
off at 0.5second
intervals
Cause:
Indoor/
Outdoor unit
• Mis-wiring
2-time flash
Cause:
Indoor unit
• Trouble of
room temperature/
indoor coil
thermistor
3-time flash
Cause:
Indoor unit
• Trouble of
indoor fan
motor
4-time flash
Cause:
Indoor unit
• Trouble of
indoor unit
control
system
6-time flash
Cause:
Outdoor unit
• Trouble of
thermistor
in outdoor
unit
7-time flash
Cause:
Outdoor unit
• Trouble of
outdoor
control
system
10-time flash
Cause:
Outdoor unit
• Trouble of
low discharge
temperature
protection
Refer to F
"How to check
mis-wiring
(When
outdoor unit
doesn't oper
ate)"
on page 35.
Check room
temperature
thermistor
and indoor
coil thermistor.
Refer to
"Test point
diagram and
voltage"
on page 37.
Refer to A
"Check of
indoor fan
motor"
on page 31.
Replace the
indoor
electronic
control
P.C. board.
Refer to H
"Check of
outdoor
thermistor"
on page 36.
Replace the
deicer
P.C. board.
Refer to G
"Check of
LEV"
on page 36.
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1. Troubleshooting check table
• The following indication applies regardless of shape of the indicator.
flashing
Operation Indicator
· Flashing of the OPERATION INDICATOR lamp (on the left-hand side)
indicates possible abnormalities.
· The OPERATION INDICATOR lamp (on the left-hand side) is lighted during
normal operation.
Before taking measures, make sure that the symptom reappears for accurate troubleshooting.
Self check table
No.
Abnormal
point
Operation indicator lamp
Symptom
0.5-second ON
Outdoor unit
does not
operate.
1 Mis-Wiring
Detection method
Checkpoint
3 minutes after power supply turns ON, when
serial signal is not received.
• Refer to F "How to check
mis-wiring" on page 35.
Detect Indoor coil/room temperature
thermistor short or open circuit every 8
seconds during operation.
• Refer to the characteristics of
main indoor coil thermistor,
sub indoor coil thermistor,
and room temperature
thermistor on page 37.
When rotational frequency feedback signal is
not emitting during 12-second indoor fan
operation.
• Refer to A "Check of
indoor fan motor" on page 31.
When it cannot properly read data in the
nonvolatile memory of the indoor electronic
control P.C. board.
• Replace the indoor electronic
control P.C. board.
<Thermistor short>
Thermistors are abnormal when they short
after compressor start-up.
<Thermistor open>
Thermistors are abnormal when they open
after compressor start-up.
However, discharge temperature thermistor is
abnormal when open circuit is detected more
than 10 minutes after compressor start-up.
• Replace the deicer P.C.
board.
Refer to H "Check of outdoor
thermistor" on page 36.
• Reconnect the connector.
When it cannot properly read data in the
nonvolatile memory of the deicer P.C. board,
outdoor unit stops.
• Replace the deicer P.C.
board.
When discharge temperature has been 122°F
or less on cool operation, or is 120°F or less
on heat operation for 20 minutes.
• Refer to G "Check of LEV" on
page 36.
• Check refrigerant circuit and
refrigerant amount.
0.5-second OFF
Indoor coil
thermistor
2
Room
temperature
thermistor
2-time flash
Outdoor unit
does not
operate.
2.5-second OFF
Indoor fan
repeats 12
seconds ON
and 3
minutes
OFF.
When the
indoor fan
breaks, the
fan keeps
stopping.
3-time flash
3
Indoor fan
motor
2.5-second OFF
4-time flash
4
Indoor
control
system
Outdoor unit
does not
operate.
2.5-second OFF
6-time flash
5
Outdoor unit
does not
operate.
Outdoor
thermistors
2.5-second OFF
7-time flash
6
Outdoor unit
does not
operate.
Outdoor
control
system
2.5-second OFF
10-time flash
Low
discharge
7 temperature
protection
Outdoor unit
does not
operate.
2.5-second OFF
NOTE : When the indoor unit has started operation and the above detection method has detected an abnormality (the first
detection after the power ON), the indoor electronic control P.C. board turns OFF the indoor fan motor with the
OPERATION INDICATOR lamp flashing on and off.
29
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04.1.13 9:53 AM
Page 30
2. Trouble criterion of main parts
MS24WN MU24WN
Check method and criterion
Measure the resistance with a tester.
(Part temperature 50˚F ~ 86˚F)
Normal
8 k" ~ 20 k"
Indoor coil thermistor
(RT12(main), RT13(sub))
Ambient temperature
thermistor(RT63)
Abnormal
Open or short-circuit
Measure the resistance with a tester.
Before measurement, hold the thermistor with your hands to warm it up.
(Part temperature 32˚F ~ 104˚F)
Normal
120 k" ~ 800k"
Abnormal
Open or short-circuit
Measure the resistance with a tester.
(Part temperature 14˚F ~ 104˚F)
Normal
5 k" ~ 60 k"
Abnormal
Open or short-circuit
Measure the resistance between the terminals with a tester.
(Part temperature 14˚F ~ 104˚F)
INNER
PROTECTOR
320i 9-F OPEN
198i20-F CLOSE
Terminal
C–R
C–S
INNER
PROTECTOR
275i 9-F OPEN
187i27-F CLOSE
Outdoor fan motor(MF)
INNER
PROTECTOR
293i14-F OPEN
190i27-F CLOSE
Horizontal vane
motor(MV1)
Vertical vane
motor(MV2)
Normal
0.74 " ~ 0.91 "
1.84 " ~ 2.26 "
WHT C
P
AUX. MAIN
Abnormal
Open or
short-circuit
R
S
BLK
RED
Measure the resistance between the terminals with a tester.
(Part temperature 50˚F ~ 86˚F)
Color of lead wire
WHT – BLK
BLK – RED
Normal
35 " ~ 39 "
65 " ~ 71 "
Abnormal
Open or
short-circuit
WHT
MAIN
RED
AUX. BLK
P
Color of lead wire
BRN – YLW
YLW – GRY
Normal
4.5 ~ 5.5V
(When fan revolved one time)
0V➔5V➔0V
(Approx.)
GRY
BRN
Remain 0V or 5V
Measure the resistance between the terminals with a tester.
(Part temperature 14˚F ~ 104˚F)
Abnormal
Color of lead wire
Normal
WHT – BLK
51 " ~ 62 "
Open or
short-circuit
BLK – RED
50 " ~ 61 "
Measure the resistance between the terminal with a tester.
(Part temperature 50°F ~ 86°F)
Abnormal
Open or short-circuit
Normal
282" ~ 306 "
YLW
Abnormal
BLK
AUX.
RED
ORN
MAIN
WHT
RED
ROTOR
YLW
BRN
GRN
WHT6
Abnormal
Open or
short-circuit
RED1
LEV
ORN4
YLW5
Measure the resistance with a tester.
(Part temperature : 14˚F ~ 104˚F)
Normal
Color of lead wire
WHT – RED
RED – ORN
30.3 " ~ 37.0 "
YLW – BRN
BRN – BLU
1
2
3
P
ORN
LEV(Expansion valve)
1
2
3
Measure the voltage power ON.
Sensor part
Indoor fan motor(MF)
Motor part
Compressor(MC)
BLU3
Discharge temperature
thermistor(RT62)
Figure
BRN2
Part name
Room temperature
thermistor(RT11)
P :INNER PROTECTOR
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Page 31
When OPERATION INDICATOR lamp flashes 3-time.
Indoor fan motor doesn’t operate.
Turn OFF the power supply.
Check connector CN211 visually.
A Check of indoor fan motor
No
Are lead wires connected?
Yes
Is soldering point of the connector
correctly soldered?
No
Resolder it.
Yes
Reconnect the lead wires.
Disconnect lead wires from connector CN211 on the indoor electronic control P.C. board.
Measure resistance between lead wires : No.1 and No.4 and then No.3 and No.4.
Is resistance 0 (short circuit) or ∞ (open circuit)?
Yes ( 0 or ∞ )
No
(others)
Repair or replace the indoor fan motor.
Turn ON the power supply. Stop it if the unit operate.
Insert screwdriver into air outlet to rotate indoor fan
motor slowly for 1 revolution or over, and measure
voltage between No.2(+) and No.3(-) on CN121.
No
Does voltage repeat 0V DC and 5V DC?
Yes
Replace the indoor electronic control P.C. board.
Indoor unit operates by pressing the EMERGENCY OPERATION switch, but doesn’t operate with the remote controller.
B Check of remote controller and receiver P.C. board
wCheck if the remote controller is exclusive for this air conditioner.
Switch on the remote controller.
Is LCD display on the remote
controller displayed?
No
Replace the batteries.(Refer to page 27.)
(not clear)
Yes
Remove the batteries, then set them back
and press the RESET button. Check if the
unit operates with the remote controller.
Does the unit operate with the
remote controller?
No
Turn on a radio to AM and press switch on
the remote controller.
Yes
No
OK
Replace the remote controller.
Is noise heard from radio?
Yes
Are there any fluorescent lights of
inverter or rapid-start type within
the range of 1m?
Yes
● Reinstall the unit away from lights.
● Attach a filter on receiving part.
No
Measure the voltage between receiver P.C. board connector CN301 No.1(+) and No.3(-) when remote
controller button is pressed.
Yes
Is the voltage approx. 4V DC?
No(5V or 0V DC)
Replace the receiver P.C. board.
31
Replace the indoor electronic control P.C.
board.
OB311--2.qxp
04.1.13 10:01 AM
Page 32
The unit doesn’t operate with the remote controller.
Also, the OPERATION INDICATOR lamp doesn’t light up by pressing the EMERGENCY OPERATION switch.
C Check of indoor electronic control P.C. board
Check the both “parts side”and “pattern side” of
indoor electronic control P.C. board visually.
Varistor (NR11)
Turn OFF the power supply.
Remove indoor fan motor connector CN211 and vane
motor connector CN151 from the indoor electronic
control P.C. board and turn ON the power supply.
Fuse (F11)
Does the unit operate with the remote controller?
Does the OPERATION INDICATORE lamp light up
by pressing the EMERGENCY OPERATION switch?
Indoor electronic
control P.C. board
No
Yes
Turn OFF the
power supply.
Replace the vane
motor.
Turn OFF the
power supply.
Yes
Is winding
resistance of
vane motor 0 "?
Yes
No
Be sure to check both resistance.
Is winding
resistance of
fan motor 0 "?
Replace the fuse.
No
Is fuse(F11) blown?
Replace the
indoor electronic
control P.C. board.
Be sure to check both fuse
and varistor in any case.
Is varistor(NR11) burnt?
Yes
Yes
Replace the fan
motor.
No
Replace the varistor.
32
No
OB311--2.qxp
04.1.13 10:01 AM
Page 33
Compressor and / or outdoor fan doesn’t operate.
D Check of outdoor unit
Turn ON the power supply.
Is there 208/230V AC
between L1 - L2 on the
outdoor terminal block?
No
Check the outdoor power supply
and connection of wiring.
Yes
Compressor
does not operate.
Is there 5V DC between
J101 + - J401 on the
outdoor electronic control
P.C. board? w1
Yes
No
No
Make the connection
of wiring correct.
Yes
Operate the unit in
COOL mode by pressing
the EMERGENCY
OPERATION switch.
3minutes after the power
supply turns ON, is there
208/230V AC between
A1-A2 on the compressor
contactor(52C)?
Yes
Is there 208/230V AC
between 2/T1 on the
compressor contactor(52C)
and L2 on the outdoor
terminal block?
Yes
Is there 208/230V AC
between CN730 1-3 on the
outdoor electronic control
P.C. board? w1
Replace the outdoor
electronic control
P.C. board.
No
No
Check the compressor.
Replace the outdoor
electronic control
P.C. board.
Is there 208/230V AC
between 1/L1 on the
compressor contactor(52C)
and L2 on the outdoor
terminal block?
Yes
No
Make the connection
of wiring correct.
Replace the compressor
contactor.
Outdoor fan motor
does not operate.
Is there 5V DC between
J101 + - J401 on the
outdoor electronic control
P.C. board? w1
No
Yes
No
Make the connection
of wiring correct.
Yes
Operate the unit in
COOL mode by pressing
the EMERGENCY
OPERATION switch.
Is there 208/230V AC
between CN711 2-3 on
the outdoor electronic
control P.C. board? w1
Is there 208/230V AC
between CN730 1-3 on the
outdoor electronic control
P.C. board? w1
Replace the outdoor
electronic control
P.C. board.
No
Replace the outdoor
electronic control
P.C. board.
Yes
Check the outdoor fan
motor. Refer to page 30.
w1 Refer to page 38.
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Page 34
Compressor and / or outdoor fan motor doesn’t stop.
E Check of outdoor unit
1 Turn OFF the power supply.
2 After 30 seconds, turn ON the power supply again.
3 Operate the unit in COOL mode by pressing the
EMERGENCY OPERATION switch.
4 Operate the unit for 1 minute or more and stop it by
pressing the EMERGENCY OPERATION switch again.
After 30 seconds,
does compressor stop?
No
Yes
Is there 208/230V AC
between A1-A2 on the
compressor contactor(52C)?
Yes
Ok
Replace the outdoor
electronic control
P.C. board.
After 30 seconds, does
outdoor fan motor stop?
No
Replace the outdoor
electronic control
P.C. board.
Yes
Ok
34
No
Is there 208/230V AC
between 2/T1 on the
compressor contactor(52C)
and L2 on the outdoor
terminal block?
Yes
Replace the compressor
contactor(52C).
No
Make the connection
of wiring correct.
OB311--2.qxp
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Page 35
When OPERATION INDICATOR lamp flashes ON and OFF in every 0.5-second.
Outdoor unit doesn’t operate.
F How to check mis-wiring
Start
Turn OFF the power supply.
Turn ON the power supply.
No
Rectify the wiring.
Is the power voltage to terminal blocks of
indoor/outdoor units normal?
Yes
Turn ON the EMERGENCY OPERATION switch.
(any mode possible)
After 3 minutes that power supply has
been turned on, does the compressor
start operating?
Yes
No
Correct the mis-wiring.
No
Is the terminal blocks 1 and 3 on the
indoor unit properly connected to their
counter parts on outdoor unit?
Yes
Turn OFF the power supply.
Check by using checking mode.
1Disconnect indoor/outdoor wiring (at indoor terminal blocks 1 and 3)
2Short circuit between indoor terminal blocks 1 and 3.
Turn ON the power supply.
3While pressing the OPERATION SELECT button and the TOO COOL
button on the remote controller, press the RESET button on the
remote controller.
4Release the RESET button on the remote controller.
(After 3 seconds, LCD on the remote controller displays all signs.)
Press the OPERATE/STOP(ON/OFF) button on
the remote controller to send signal.
Make sure the unit emits a beep tone.
No
Replace the indoor electronic
control P.C. board. ❈
Does the OPERATION INDICATOR
lamp on the indoor unit flash on?
Yes
Replace the outdoor electronic control P.C.board. ❈
Before the unit resumes normal operation.
•Release the checking mode by pressing the
RESET button on the remote controller, and then
send the unit signal to stop operation.
•Turn OFF the power supply to indoor/outdoor
units.
•Get indoor terminal blocks 1 and 3 opened, and
reconnect indoor/ outdoor wiring.
sure to turn OFF the power supply to
[ ❈ Be
]
indoor/outdoor units in replacing P.C. board.
35
OK
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04.1.13 10:01 AM
Page 36
When OPERATION INDICATOR lamp flashes 10-time.
Cooling doesn’t operate.
G Check of LEV (Expansion valve)
1 During pressing the OPERATION SELECT button
and the TOO COOL button on the remote controller,
press the RESET button.
2 First, release the RESET button.
(After 3 seconds, confirm all displays of the remote
controller.)
3 Then release the OPERATION SELECT button.
1 During pressing the OPERATION SELECT
button and the TOO COOL button on the
remote controller, press RESET button.
2 First, release the RESET button.
With remote controller set toward the indoor unit, press
the OPERATE/ STOP(ON/ OFF) button and confirm
one beep tone.
(After 3 seconds, confirm all displays of the
remote controller.)
3 Then release the OPERATION SELECT button.
˚F
CLOCK
AMPM
LEV operates in full-opening
direction.
Do you hear LEV "click,
click·······"?
Do you touch LEV and feel
it vibrate?
AMPM
Yes
Ok
No
Is LEV coil properly fixed to
the body?
No
Properly fix LEV coil to
the body.
Yes
Does the resistance of LEV coil
have the characteristics?
No
Yes
Characteristics of LEV coil
LEV (CN724)
Replace the
LEV coil.
Replace the outdoor
electronic control P.C. board.
Resistance
WHT–RED
RED–ORN
YLW–BRN
NOTE : After check of LEV, do the undermentioned operations.
1. Turn OFF the power supply of the unit and turn ON again.
30.3 " ~ 37.0 "
2. Press the RESET button on the remote controller.
BRN–BLU
When OPERATION INDICATOR lamp flashes 6-time.
Thermistors in the outdoor unit are abnormal.
H Check of outdoor thermistor
w Disconnect the connectors CN662 from the outdoor electronic control P.C. board.
(Check the characteristics of each thermistor.)
Discharge temperature
thermistor(RT62)
Measure
resistance
between CN 662
1 and 2.
Turn OFF the
power supply.
Ambient temperature
thermistor(RT63)
Replace the outdoor
electronic control P.C.
board.
Does the resistance
of thermistor have
the characteristics
on page 38?
No
Measure
resistance
between CN 662
3 and 4.
Yes
Connect CN662.
Turn ON the power
supply and press
the EMERGENCY
OPERATION
switch.
No
Does the unit operate
10 minutes or more?
Yes
Ok W1.
Replace the
thermistor.
W1. It is thought defective contact of the connector.
36
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Page 37
TEST POINT DIAGRAM AND VOLTAGE
MS24WN
Indoor electronic control P.C. board
Varistor(NR11)
}
Fan motor power
supply
}
Power supply input
115V AC
+
Fuse (F11)
250V AC 3.15A
} 5V DC
Room temperature
thermistor(RT11)
Indoor coil
thermistor(RT12(main))
Indoor coil
thermistor(RT13(sub))
R132
Emergency operation
switch
Timer short mode point
(JPS, JPG)
(Refer to page 25.)
+
}
Receiver P.C. board
12V DC
Room temperature thermistor (RT11)
Indoor coil thermistor[RT12(main), RT13(sub)]
Auto restart function
Solder the Jumper wire or the
Resistor 220Ω to the JR07.
(Refer to page 26.)
32 50 68 86 104 122 140
F
37
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04.1.13 10:01 AM
Page 38
MU24WN
Outdoor electronic control P.C. board
Ambient temperature thermistor (RT63)
100
Discharge temperature thermistor(RT62)
900
Resistance(k")
800
700
600
Resistance(k")
90
80
70
60
50
40
500
400
30
300
20
200
10
100
0
32 50 68 86 104 122 140 158 176 194 212 230 248
Temperature(-F)
CN662 1-2
Discharge
temperature
thermistor
(RT62)
(Refer to page 36.)
0
-4
14 32 50 68 86 104
Temperature(-F)
CN662 3-4
Ambient
temperature
thermistor
(RT63)
(Refer to page 36.)
LEV
connector
(CN724)
Fan motor
connector
(CN711)
+
} 12V DC
Fuse (F61)
3.15A / 250V
J101 +
5V
DC
J401
(Refer to
page 33.)
}
} CN7301-3
208/230V AC
(Refer to
page 33.)
38
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Page 39
RELAY OPERATION
MS24WN
COMPRESSOR CONTACTOR
• EACH MODE
MODE
COOL & COOL mode
of I FEEL CONTROL
THERMOSTAT
52C CONTACTOR
ON
ON
AUTO or set speed
OFF
OFF
OFF for 2 min.
after unit starts operation
DRY & DRY mode
of I FEEL CONTROL
FAN
INDOOR FAN SPEED
ON
Repeat of 8 min. ON/ 3min.
OFF operation or 2 min.
ON/3 min. OFF operation
OFF
Repeat of 4 min. OFF/
1 min. ON operation
OFF
OFF
AUTO or set speed
AUTO or set speed links with
52C CONTACTOR
AUTO or set speed
NOTE : Once the compressor is OFF, “3-minute time delay circuit” works at next start-up.
• COIL FROST PREVENTION
MODE
THERMOSTAT
52C CONTACTOR
ON
OFF for 5 min.
After that, OFF is
prolonged until
indoor coil thermistor
reads termination
temperature.
COOL & COOL mode
of I FEEL CONTROL
DRY & DRY mode
of I FEEL CONTROL
39
INDOOR FAN SPEED
AUTO or set speed
AUTO or set speed
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Page 40
DISASSEMBLY INSTRUCTIONS
<"Terminal with lock mechanism" Detaching points>
In case of terminal with lock mechanism, detach the terminal as shown below.
There are two types ( Refer to (1) and (2)) of the terminal with lock mechanism.
The terminal with no lock mechanism can be removed by pulling it out.
Check the shape of the terminal and work.
(1) Slide the sleeve and check if there is a locking lever or not.
(2) The terminal with this connector is a terminal
with lock mechanism.
Sleeve
Locking lever
1Slide the sleeve.
2Pull the terminal while
pushing the locking
lever.
1Hold the sleeve, and
pull out the terminal
slowly.
Connector
11-1. MS24WN
INDOOR UNIT
PHOTOS
OPERATING PROCEDURE
1. Removing the front panel
(1) Remove the screw caps of the front panel.
Remove the screws.
(2) Pull the panel down to your side slightly and unhook the
catches at the top.
Photo 1
Front panel
Screws
2. Removing the electronic control P.C. board, the receiver
P.C. board and the display P.C. board
NOTE : In case of removing only indoor electronic control
P.C. board work (2) and (3) are not necessary.
(1) Remove the front panel. (Refer to 1.)
(2) Remove the R.L holder from the bottom of electrical box.
(3) Open the R.L holder, remove the receiver P.C. board and
the display P.C. board.
(4) Remove the screw of the electrical cover and the electrical
cover.
(5) Pull out indoor electronic control P.C. board slightly.
(6) Disconnect all the connectors on the electronic control P.C.
board.
(7) Remove the electronic control P.C. board.
Photo 2
Indoor
electronic
control
P.C.board
Screw of
the electrical
cover
R.L
Screw of
holder the corner
box
40
Receiver
P.C.
board
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04.1.13 10:02 AM
Page 41
OPERATING PROCEDURE
PHOTOS
3. Removing the electrical box
(1) Remove the front panel. (Refer to 1.)
(2) Remove the electrical cover. (Refer to 2.)
(3) Disconnect the connector of the indoor coil
thermistor (CN112), the fan motor connector (CN211 and
CN121) and the vane motor connector (CN151) on the
electronic control P.C. board.
(4) Remove the screw of ground wire.
(5) Remove the fan motor lead wire, indoor coil thermistor and
ground wire from the electrical box.
(6) Remove the lead wire of vane motor from the bottom of
electrical box.
(7) Remove the screw of corner box and corner box. (Photo 2)
(8) Remove the screw of conduit cover and conduit cover.
(9) Remove the screws fixing the conduit plate.
(10) Pull out the conduit plate and the indoor/ outdoor unit connecting wire.
(11) Remove the lock nut from the connector of indoor/ outdoor
connecting wire.
(12) Remove the screw fixing the electrical box, remove the
electrical box.
4. Removing the vane motor
(1) Remove the front panel. (Refer to 1.)
(2) Remove the electrical cover. (Refer to 2.)
(3) Remove the lead wire of
Photo 5
vane motor. (Refer to 3.)
(4) Remove the R.L. holder.
(5) Pull out the drain hose
from the nozzle assembly, remove the nozzle
assembly.
(6) Remove the screws of the
vane motor, disconnect
the connector.
(7) Remove the vane motor.
Photo 3
Screws of the ground wire
Fan motor
connectors
Indoor coil
thermistor
connector
Vane motor
connector
Screw of the
electrical box
Screws of
the conduit
plate
Screw of the
conduit cover
Photo 4
Vane motors
Screws of the
vane motor
Vane motor
5. Removing the line flow fan and the indoor fan motor
(1) Remove the front panel. (Refer to 1.)
(2) Remove the electrical box. (Refer to 3.)
(3) Pull out the drain hose from the nozzle assembly, remove
the nozzle assembly.
(4) Remove the water cut.
(5) Slide the hole cover, remove the hole cover.
(6) Remove the hexagon socket set screw from the line flow
fan.
(7) Remove the screws fixing the fan motor, remove the fan
motor. (Be careful not to drop the fan motor because it is
heavy.)
Photo 8
(8) Remove the screws fixing the left
side of the heat exchanger.
(9) Lift the left side of the heat
exchanger.
(10) Remove the line flow fan.
Photo 6
Screws fixing the left
side of the
heat
exchanger
Photo 7
Indoor
coil
thermistor
Water cut
Screws
fixing
the fan
motor
Hole
cover
41
Screws
of the
vane
motor
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04.1.13 10:02 AM
Page 42
11-2. MU24WN
OUTDOOR UNIT
OPERATING PROCEDURE
PHOTOS
1. Removing the cabinet
(1) Remove the screws of the top panel and the top panel.
(2) Remove the screw of the service panel. To remove the
service panel, pull it down toward you and unhook the
catches on the both sides.
(3) Remove the screw of the cover panel. To remove the
cover panel.
(4) Remove the screws of the cabinet.
Open the cabinet to a 45-degree angle. Then lift it and
unhook the catches to remove.
Photo 1
Screws of the top panel
Photo 2
Discharge
pipe
Cover panel
Screw of the
service panel
Suction
pipe
Screws of the cabinet
2. Removing the outdoor electronic control P.C. board
(1) Remove the top panel, the service panel and the cover
panel.
(2) Disconnect all the connectors and the terminals on the
outdoor electronic control P.C. board.
(3) Remove the outdoor electronic control P.C. board.
Relay
panel
Fan motor
connector
Photo 3
Outdoor
electronic
control P.C.
board
Compressor
contactor
Terminal
blocks
3. Removing the propeller and the outdoor fan motor
(1) Remove the cabinet. (Refer to 1.)
(2) Remove the propeller nut and the propeller.
NOTE:Loose the propeller in the rotating direction for
removal.
When attaching the propeller, align the mark on the
propeller and the motor shaft cut section.
Set the propeller in position by using the cut on the
shaft and the mark on the propeller.
(3) Remove the lead clamps and disconnect the outdoor
fan motor connector. (Photo 3)
(4) Remove the screws of the outdoor fan motor and the
outdoor fan motor.
Photo 4
Screws Lead
of the
clamps
fan motor
Screw of
the side
panel
Screws of
the valve
bed
Propeller
Propeller
nut
Screw of
the side
panel
Screws of the
motor support
42
Screw of the
separator
support plate
Screw of the separator
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04.1.13 10:02 AM
Page 43
OPERATING PROCEDURE
PHOTOS
4. Removing the heat exchanger and compressor
(1) Remove the screws of the rear panel. Remove the
screws of the valve bed and the valve bed.
(The valve bed is fixed by the catches on the right and
left sides. Lift it to remove.)
Open the rear panel to the rear to remove.
NOTE :
All panels are fixed by catches, and must be removed
by up and down.
(2) Remove the screws of the side panel and the side
panel.
(Photo 4)
(3) Remove the screws of the rear guard and the rear
guard.
(4) Remove the screws of the separator support plate and
the separator support plate. (Photo 4)
(5) Remove the screws of the motor support and the motor
support. (Photo 4)
(6) Remove the relay panel. (Photo 3)
(7) Remove the fan motor lead wire from lead clamps.
(Photo 4)
(8) Remove the soundproof felt.
(9) Remove the screws of the separator and the separator.
(10) Recover gas from the refrigerant circuit.
(11) Remove the heat exchanger.
Detach the welded part of pipe.
(12) Remove the nuts of the compressor and the compressor.
Detach the welded part of the suction pipe and the
discharge pipe. (Photo 2)
Photo 5
Screws of the
rear guard
Screws of the
rear panel
Screws of the
rear guard
Photo 6
Heat exchanger
Accumulator
Photo 7
Screw of the
separator
Stop valve
Compressor
Soundproof
felt
43
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12
04.1.13 10:02 AM
Page 44
PARTS LIST
MS24WN (W)
12-1. INDOOR UNIT STRUCTURAL PARTS
12-2. INDOOR UNIT HEAT
EXCHANGER
1
2
10
3
8
4
Optional
parts
(See
back
cover.)
CATCH
5
SCREW
CAP
11
12
6
7
12-1. INDOOR UNIT STRUCTURAL PARTS
Part number that is circled is not shown in the illustration.
NO.
1
2
3
4
5
6
7
8
9
Part No.
E02
E02
E02
E02
E02
E02
E02
E02
E02
527
527
527
408
527
527
527
527
530
970
234
000
142
067
010
100
975
007
Part Name
Symbol
in Wiring
Diagram
Q'ty/unit
MS24WN
(W)
1
1
1
4
3
1
2
1
1
INSTALLATION PLATE
BOX (W)
FRONT PANEL ASSEMBLY (W)
CATCH
SCREW CAP (W)
GRILLE (W)
AIR FILTER
CORNER BOX RIGHT
LAMP PANEL
Remarks
Including No.4,5,6
4PCS/ SET
3PCS/ SET
12-2. INDOOR UNIT HEAT EXCHANGER
1
1
1
10 E02 527 620 INDOOR HEAT EXCHANGER
11 E02 527 666 UNION (GAS)
12 E02 527 667 UNION (LIQUID)
44
{5/8
{3/8
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04.1.13 10:02 AM
Page 45
MS24WN (W)
12-4. ACCESSORY AND
REMOTE CONTROLLER
12-3. INDOOR UNIT FUNCTIONAL PARTS AND
ELECTRICAL PARTS
20
1
19
23
24
2
3
SLEEVE
BEARING
4
12
18
11
ROOM
TEMPERATURE
THERMISTOR
5
6
13
14
10
7
FUSE
8
9
VARISTOR
15 16
17
12-3. INDOOR UNIT FUNCTIONAL PARTS AND ELECTRICAL PARTS
Part numbers that are circled are not shown in the illustration.
NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
Part No.
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
527
408
001
408
527
527
527
784
784
527
784
448
408
527
528
527
784
527
545
527
528
529
302
509
504
702
235
040
041
382
385
034
300
303
303
333
329
468
452
308
375
307
034
034
Part Name
Symbol
in Wiring
Diagram
LINE FLOW FAN
BEARING MOUNT
SLEEVE BEARING
DRAIN HOSE
NOZZLE ASSEMBLY
VANE UPPER (W)
VANE LOWER (W)
F11
FUSE
NR11
VARISTOR
VANE CRANK SET
MF
INDOOR FAN MOTOR ASSEMBLY
MV2
VANE MOTOR (VERTICAL)
MV1
VANE MOTOR (HORIZONTAL)
MOTOR BAND
DISPLAY P.C. BOARD
RECEIVER P.C. BOARD
ELECTRONIC CONTROL P.C. BOARD
RT11
ROOM TEMPERATURE THERMISTOR
TB
TERMINAL BLOCK
RT12, RT13
INDOOR COIL THERMISTOR
VANE MOTOR SUPPORT SET(RIGHT)
VANE MOTOR SUPPORT SET(LEFT)
Q'ty/unit
MS24WN
(W)
1
1
1
1
1
1
1
1
1
1
1
2
1
1
1
1
1
1
1
1
1
1
12-4. ACCESSORY AND REMOTE CONTROLLER
1
1
23 E02 784 426 REMOTE CONTROLLER
24 E02 527 083 REMOTE CONTROLLER HOLDER
45
Remarks
3.15A
RC4W33 Including RUBBER MOUNT
RIGHT & LEFT
UP & DOWN
AUTO RESTART
Including No.16
OB311--2.qxp
04.1.13 10:02 AM
Page 46
MU24WN
12-5. OUTDOOR UNIT STRUCTURAL PARTS, ELECTRICAL PARTS
AND FUNCTIONAL PARTS
30
31
9
29
1
28
2
3
4
5
6
27
26
7
25
8
19
11
A
B
18
12
2
13
9
15 16
17
24
14
10
20
46
21
22
23
OB311--2.qxp
04.1.13 10:02 AM
Page 47
MU24WN
12-5. OUTDOOR UNIT STRUCTURAL PARTS, ELECTRICAL PARTS
AND FUNCTIONAL PARTS
Part numbers that are circled are not shown in the illustration.
NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
Part No.
E02
E02
E02
E02
E02
E07
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E07
E07
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
E02
813
528
527
784
214
070
813
813
819
784
528
527
527
784
527
527
001
012
474
813
813
480
481
784
784
544
128
784
813
813
814
527
784
262
527
784
297
309
630
301
501
508
290
232
009
521
493
640
506
900
662
661
641
641
642
245
006
374
374
351
340
353
383
451
522
523
249
515
382
936
936
936
Part Name
Symbol
in Wiring
Diagram
TOP PANEL
RT62, RT63
THERMISTOR
OUTDOOR HEAT EXCHANGER
MF
OUTDOOR FAN MOTOR
PROPELLER
PROPELLER NUT
BASE
CABINET
HANDLE
FAN GUARD
LEV
EXPANSION VALVE COIL
EXPANSION VALVE
COMPRESSOR RUBBER SET
MC
COMPRESSOR
STOP VALVE (LIQUID)
STOP VALVE (GAS)
SERVICE PORT
SERVICE PORT
FUSIBLE PLUG
SERVICE PANEL
COVER PANEL
TB1
TERMINAL BLOCK
TB2
TERMINAL BLOCK
C2
OUTDOOR FAN CAPACITOR
COMPRESSOR CONTACTOR
52C
COMPRESSOR CAPACITOR
C1
SURGE ABSORBER
DSAR
OUTDOOR ELECTRONIC CONTROL P.C. BOARD
REAR PANEL
REAR GUARD
SIDE PANEL
MOTOR SUPPORT
F61
FUSE
CAPILLARY TUBE
CAPILLARY TUBE
CAPILLARY TUBE (TAPER PIPE)
47
Q'ty/unit
MU24WN
1
1
1
1
1
1
1
1
3
1
1
1
4
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Remarks
NEW WHITE(Brighter)
DISCHARGE, AMBIENT
RA6N66-
NEW WHITE(Brighter)
NEW WHITE(Brighter)
NEW WHITE(Brighter)
NEW WHITE(Brighter)
4RUBBERS/SET
PH33NPBT
{3/8
{5/8
NEW WHITE(Brighter)
NEW WHITE(Brighter)
4P (FIGURE A)
4P (FIGURE B)
5.0+/440VAC
35+/370VAC
NEW WHITE(Brighter)
NEW WHITE(Brighter)
NEW WHITE(Brighter)
250V/3.15A
{0.16✕{0.09✕7-7/8
{0.16✕{0.09✕3-15/16
{0.14✕{0.09✕1-31/32
OB311--2.qxp
13
04.1.13 10:02 AM
Page 48
OPTIONAL PARTS
13-1. REFRIGERANT PIPES
The air conditioner has flared connections its on indoor and outdoor sides.
Please use the optional extension pipe as follows.
Model
Part No.
Pipe length
MAC-860PI
MAC-861PI
MAC-862PI
MAC-863PI
MAC-864PI
MS24WN
MU24WN
13-2. AIR CLEANING FILTER
10ft.
16ft.
23ft.
33ft.
49ft.
,
Pipe size
A-Gas(in.)
B-Liquid(in.)
Crosssection
Outside Wall Outside Wall
diameter thickness diameter thickness
5/8
0.0315
3/8
0.0285
Additional
refrigerant
Insulation charge
(in.)
R22(oz.)
C 1-7/32
D 1-1/16
0
1.3
3.9
● AIR CLEANING FILTER removes fine dust of 0.01 micron from air by means of static electricity.
● Normal life of AIR CLEANING FILTER is 4 months. However, when it becomes dirty, replace it as soon as possible.
● Clogged AIR CLEANING FILTER may reduce the air conditioner capacity or cause frost on the air outlet.
● DO NOT reuse AIR CLEANING FILTER even if it is washed.
● DO NOT remove or attach AIR CLEANING FILTER during unit operation.
Model
Part No.
MS24WN
MAC-1700FT
Air cleanig filter (White bellow type)
13-3. DEODORIZING FILTER
● DEODORIZING FILTER removes ammonia and hydrogen sulphide emitted from tobacco, and odor of pets.
● Clean DEODORIZING FILTER every two weeks. If the filter is particularly dirty, clean the filter more often.
● For cleaning, soak the filter in warm water for a while, and then wash and rinse it. Dry the filter in the shade
thoroughly.
● When the filter color is still dark even after cleaning, replace the filter with a new one.
Replace the filter at least once a year.
Model
Part No.
MS24WN
MAC-2200DF
● DEODORIZING FILTER and AIR CLEANING FILTER
can be attached on either side.
Deodorizing filter (Gray sponge type)
.
CCopyright 2003 MITSUBISHI ELECTRIC ENGINEERING CO.,LTD.
Distributed in Jan. 2004. No. OB311 REVISED EDITION-A 6
Distributed in Mar. 2003. No. OB311 17
New publication, effective Jan. 2004
Specifications subject to change without notice.
3400 Lawrenceville Suwanee Road ● Suwanee, Georgia 30024
Toll Free: 800-433-4822 ● Toll Free Fax: 800-889-9904
www.mrslim.com
Specifications are subject to change without notice.