Mitsubishi Electric Mr. Slim MSZ-FE09NA User manual

SERVICE MANUAL
CONTENTS
1. TECHNICAL CHANGES······································· 2
2. PART NAMES AND FUNCTIONS····················· 3
3. SPECIFICATION················································ 5
4. OUTLINES AND DIMENSIONS ························ 6
5. WIRING DIAGRAM············································ 7
6. REFRIGERANT SYSTEM DIAGRAM ··············· 8
7. SERVICE FUNCTIONS ····································· 9
8. MICROPROCESSOR CONTROL ··················· 11
9. TROUBLESHOOTING····································· 21
10. DISASSEMBLY INSTRUCTIONS···················· 35
MSZ-FE09NA
MSZ-FE12NA
MSZ-FE18NA
SPLIT-TYPE AIR CONDITIONERS
INDOOR UNIT
Outdoor unit service manual
MUZ-FE•NA Series (OBH543)
MXZ-A·NA Series (OB444)
MXZ-B·NA Series (OB560)
NOTE:
RoHS compliant products have <G> mark on the spec name plate.
PARTS CATALOG (OBB542)
Models
No. OBH542
REVISED EDITION-A
Revision A:
• MSZ-FE18NA has been added.
Please void OBH542.
MSZ-FE09NA
MSZ-FE12NA

2
1TECHNICAL CHANGES
MSZ-FE09NA
MSZ-FE12NA
MSZ-FE18NA
1. New model
Revision A:
• MSZ-FE18NA has been added.

3
PART NAMES AND FUNCTIONS
2
MSZ-FE09NA MSZ-FE12NA
Front panel
Air filter
Air inlet
Operation indicator
lamp
Platinum deodorizing filter
Anti-allergy Enzyme Filter
Air outlet
Horizontal vane
i-see Sensor
Heat exchanger
Emergency operation switch (E.O. SW)
Remote control
receiving section
AREA lamp POWER lamp
Fan
Remote controller
Display section
AREA lamp indicates AREA setting
In AREA setting, the horizontal air
flow direction changes automatically
according to the detection of i-see
Sensor which detects the floor/wall
temperature to air-condition the room
evenly.
i-see control operation
i-see Sensor constantly measure
floor/wall temperature to automatically
adjust to the set temperature by
estimating the temperature actually
perceived by a person inside the room
(“sensible temperature”).

4
Remote controller
Display section
Front panel
Air filter
(Nano platinum filter)
Air inlet
Air cleaning filter
(Electrostatic anti-alergy
enzyme filter)
Air outlet
Horizontal vane
Heat exchanger
MSZ-FE18NA
ACCESSORIES
Models MSZ-FE09/12NA MSZ-FE18NA
Installation plate 1 1
Installation plate fixing screw 4 × 25 mm 5 7
Remote controller holder 1 1
Fixing screw for 3.5 × 1.6 mm (Black) 2 2
Battery (AAA) for remote controller 2 2
Wireless remote controller 1 1
Felt tape (Used for left or left-rear piping) 1 1
Air cleaning filter
- 2

5
3SPECIFICATION
Indoor model MSZ-FE09NA MSZ-FE12NA MSZ-FE18NA
Power supply V, phase, Hz 208/230 , 1 , 60
Max. fuse size (time delay)/ Disconnect switch A15 20
Min. circuit ampacity A 1.0
Fan motor F.L.A 0.76
Airflow
Powerful - High - Med. - Low
COOL Dry
(Wet)
CFM 381 - 339 - 226 - 162
(343 - 307 - 202 - 144)
410 - 381 - 226 - 162
(367 - 350 - 202 - 144)
738 - 628 - 469 - 388
(661 - 562 - 420 - 347)
HEAT Dry CFM 381 - 367 - 240 - 166 420 - 399 - 240 - 166 738 - 628 - 469 - 388
Moisture removal pt./h 2.1 2.9 2.7
Sound level
Powerful - High - Med. - Low
Cooling dB(A) 42 - 39 - 31 - 22 45 - 43 - 33 - 22 53 - 49 - 41 - 34
Heating dB(A) 42 - 40 - 31 - 22 44 - 43 - 33 - 22 52 - 49 - 41 - 32
Cond. drain connection O.D. in. 5/8
Dimensions
W
in.
31-3/8 43-5/16
D 10-1/8 9-3/8
H 11-5/8 12-13/16
Weight Ib. 27 37
External finish Munsell 1.0Y 9.2/0.2
Remote controller Wireless type
Control voltage (by built-in transformer) 12 - 24 VDC
NOTE: Test conditions are based on AHRI 210/240.
3-2. OUTLET AIR SPEED AND COVERAGE
 The air coverage is the figure up to the
position where the air speed is 1 ft./s,
when air is blown out horizontally from
the unit properly at the High speed
position.
The coverage should be used only
as a general guideline since it varies
according to the size of the room and
furniture arranged inside the room.
(2) OPERATION
Mode Condition
Intake air temperature (°F)
Indoor Outdoor
DB WB DB WB
Cooling
Standard temperature 80 67 95 —
Maximum temperature 90 73 115 —
Minimum temperature 67 57 14 —
Maximum humidity 78% —
Heating
Standard temperature 70 60 47 43
Maximum temperature 80 67 75 65
Minimum temperature 70 60 -13 -15
3-1. OPERATING RANGE
(1) POWER SUPPLY
Rated voltage Guaranteed voltage (V)
Indoor unit
208/230 V
1 phase
60 Hz
Min. 187 208 230 Max. 253
Model Mode Function Airflow
(CFM)
Air speed
(ft./s)
Coverage (ft.)
MSZ-FE09NA
HEAT Dry 381 19.2 27.7
COOL Dry 339 17.1 24.7
Wet 307 15.5 22.4
MSZ-FE12NA
HEAT Dry 420 21.2 30.4
COOL Dry 381 19.2 27.7
Wet 350 17.6 25.4
MSZ-FE18NA
HEAT Dry 738 18.0 36.9
COOL Dry 738 18.0 36.9
Wet 661 16.1 33.2

6
4OUTLINES AND DIMENSIONS
Unit: inch
MSZ-FE09NA MSZ-FE12NA
30-7/8
31-3/8
1/2
1-7/8
2-3/16
11-5/8
27-1/16
3/4
2-5/16
6-1/4
1-11/16
2-11/16
2-3/16
3-15/16
1/2
10-1/8 1/4 Installation plate
Piping
2-3/16
Drain hose
1-11/16
3-3/8
3-13/16
Air out
Indoor unit 2-1/8
1-5/8
2-1/2
Installation plate
7/16 X 1 Oblong hole
8-7/8 8-7/8
8-3/8
10
13-9/16 13
6-1/8 6-1/8
Wall hole ø2-9/16
2-11/16
1/8
1-5/8
8-5/16
9-1/8
9-15/16
7/8
2-1/2
7/16 X 13/16 Oblong hole
ø1-3/8 O.D
ø1/4 19-11/16 (Flared connection ø1/4)
ø3/8 16-15/16 (Flared connection ø3/8)
Insulation ø1-1/8 O.D Connected part ø5/8 O.D
Air in
Piping
Insulation
Liquid line
Gas line
Drain hose
MSZ-FE18NA
42-7/8 3/16
43-5/16
1-3/4 9-3/8
10-3/16
1/8
11
8-7/8 8-7/8
5-1/16
9-7/16
11-1/16
1-3/4
1-15/16 19-3/4 17-5/16
7-27/327-27/32
4-3/8
2-9/16
2-1/2
333-1/8 7-1/8
2-9/16
2-9/16
1-3/16
2-1/2
2-9/16
2-5/8
2-1/2
12-13/16
1/8
3-15/16
4-7/8
6-5/16
4-5/16
( 70° )
9-3/8
3/16
8-1/4
27/32
7-1/4
1/2
Piping
Insulation Ø2 O.D
Liquid line Ø3/8 19-11/16 (Flared connection Ø3/8)
Gas line Ø1/2 16-15/16 (Flared connection Ø5/8)
Drain hose
Insulation Ø1-1/8 Connected part Ø5/8 O.D
Air out
Piping
Drain hose
7/16×1 Oblong hole 7/16×3/4 Oblong hole
Installation plate
Indoor unit
Wall hole Ø 3
Air in Installation plate
3/4
6-1/4
2-5/16

7
5WIRING DIAGRAM
MSZ-FE09NA MSZ-FE12NA
MSZ-FE18NA

8
REFRIGERANT SYSTEM DIAGRAM
6
MSZ-FE09NA MSZ-FE12NA
Refrigerant flow in cooling
Refrigerant flow in heating
Unit: inch
Indoor
heat
exchanger
Flared connection
Room temperature
thermistor
RT11
Flared connection
Refrigerant pipe 3/8
(with heat insulator)
Refrigerant pipe 1/4
(with heat insulator)
Indoor coil
thermistor
RT12 (main)
Indoor coil
thermistor
RT13 (sub)
MSZ-FE18NA
Indoor
heat
exchanger
Flared connection
Room temperature
thermistor
RT11
Flared connection
Refrigerant pipe ø5/8
(with heat insulator)
Refrigerant pipe ø3/8
(with heat insulator)
Indoor coil
thermistor
RT12 (main)
Indoor coil
thermistor
RT13 (sub)
Refrigerant flow in cooling
Refrigerant flow in heating

9
7-1. TIMER SHORT MODE
For service, set time can be shortened by short circuit of JPG and JPS the indoor electronic control P.C. board.
The time will be shortened as follows. (Refer to 9-7.)
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.)
7-2. 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 number of the indoor unit.
How to modify the remote controller P.C. board
Remove batteries before modification.
The board has a print as shown below:
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.
NOTE: For modification, take out the batteries and
press the OPERATE/STOP (ON/OFF) but-
ton twice or 3 times at first.
After finish modification, put back the bat-
teries then press the RESET button.
J2
J1
MSZ-FE09NA MSZ-FE12NA MSZ-FE18NA
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 accept 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.
7SERVICE FUNCTIONS

10
NOTE:
• The operation settings are memorized when 10 seconds have passed after the indoor unit was operated with the
remote controller.
• If 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 appliance not to turn ON at the
same time.
• When some air conditioners are connected to the same supply system, if they are operated before power failure, the
starting current of all the compressors may flow simultaneously at restart.
Therefore, the 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.
7-3. 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. “AUTO RESTART FUNCTION” automatically starts operation in
the same mode just before the shutoff of the main power.
Operation
If the main power has been cut, the operation settings remain.
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.)
How to release “AUTO RESTART FUNCTION”
Turn off the main power of the unit.
Solder the Jumper wire JR07 on the indoor electronic control P.C. board. (Refer to 9-7.)
JR07
CN151 CN211CN112 CN1R1
CN212
CN1T1
CN1U1
CN130
IC156
Area Left Center Right
Where is the indoor unit installed in your room?
(Left) (Center) (Right)
Position of
the slide
switch
Display on
the remote
controller
Installed at left, if the
distance is not more
than 19-3/4 inch (50 cm).
Installed at right, if the
distance is not more
than 19-3/4 inch (50 cm).
NOTE:If the indoor unit is installed more than 19-3/4 inch (50 cm) away from the side walls, cabinets or other nearby
objects, set the slide switch to the “center” position.
Is the indoor unit
installed at right,
left or center?
Slide swich
7-4. REMOTE CONTROLLER (MSZ-FE09NA MSZ-FE12NA)
Be sure to set the slide switch inside the remote controller to an appropriate position in accordance with the installed
position of the indoor unit. If the switch is not set correctly, the air conditioner may not function properly.
MSZ-FE09NA MSZ-FE12NA MSZ-FE18NA
CN111
CN112
CN152
CN10A
Indoor electronic
control P.C. board
JR07
CN151