Mitsubishi Electric MSZ-FB25VA Service manual

Revision C:
• Some descriptions have been modified.
Please void OBH503 REVISED EDITION-B.
SPLIT-TYPE AIR CONDITIONERS
INDOOR UNIT
SERVICE MANUAL
No. OBH503
REVISED EDITION-C
Models
MSZ-FB25VA - ,
MSZ-FB35VA - ,
MSZ-FB50VA - ,
A1
A2
A1
A2
A1
A2
Outdoor unit service manual
MUZ-FB·VA Series(OBH504)
MXZ-A·VA Series (OB447)
MXZ-8A140A (OC316)
CONTENTS
1. TECHNICAL CHANGES ··································· 3
2. PART NAMES AND FUNCTIONS ····················· 4
3. SPECIFICATION ················································ 5
4. NOISE CRITERIA CURVES ······························ 6
5. OUTLINES AND DIMENSIONS ························ 7
6. WIRING DIAGRAM············································ 7
7. REFRIGERANT SYSTEM DIAGRAM ··············· 8
8. SERVICE FUNCTIONS ····································· 9
9. MICROPROCESSOR CONTROL ····················11
10. TROUBLESHOOTING ······································20
11. DISASSEMBLY INSTRUCTIONS ·····················36
PARTS CATALOG (OBB503)
NOTE:
RoHS compliant products have <G> mark on the spec name plate.
Revision A:
• MSZ-FB50VA -
Revision B:
• MSZ-FB•VA-
A2
A1
has been added.
has been added.
Revision C:
• Some descriptions have been modified.
(The description of the indirect airflow function has been deleted.)
OBH503C
2
1
TECHNICAL CHANGES
MSZ-FB25VA - A1
MSZ-FB35VA - A1
MSZ-FB50VA - A1
1. New model
MSZ-FB25VA - A1 → MSZ-FB25VA - A2
MSZ-FB35VA - A1 → MSZ-FB35VA - A2
MSZ-FB50VA - A1 → MSZ-FB50VA - A2
1. Remote controller has been changed. (KM08A → KM09D)
OBH503C
3
2
PART NAMES AND FUNCTIONS
MSZ-FB25VA MSZ-FB35VA MSZ-FB50VA
AREA lamp
POWER lamp
CLEAN lamp
PLASMA lamp
Remote control
receiving section
Operation Indicator
lamp
Front panel
Air filter
Air inlet
Remote controller
Plasma deodorizing filter
Plasma electrode unit
Plasma anti-allergy
enzyme filter
Emergency operation switch
i-see Sensor
Air outlet
Fan guard
Fan
Heat exchanger
Horizontal vane
Vertical vane
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”).
ACCESSORIES
Installation plate
Installation plate fixing screw 4 × 25 mm
Remote controller holder
Fixing screw for 3.5 × 1.6 mm (Black)
Battery (AAA) for remote controller
Wireless remote controller
Felt tape (Used for left or left-rear piping)
OBH503C
4
1
5
1
2
2
1
1
3
SPECIFICATION
Indoor model
MSZ-FB25VA
MSZ-FB35VA
Single phase
230 V, 50 Hz
28
33
0.27
0.32
RC0J40-GF
0.27
0.32
798 × 295 × 257
12
4
Electrical
data
Power supply
Power input
Cooling
Heating
Cooling
Heating
1
Running current
1
W
A
26
31
0.25
0.30
Model
Fan motor
Current
1
Cooling
Heating
Dimensions W × H × D
Weight
Air direction
Cooling
Airflow
Special remarks
Heating
Cooling
Sound level
Heating
Cooling
Fan speed
Heating
A
0.25
0.30
mm
kg
Super High
High
Med.
Low
3
m /h
Super High
High
Med.
Low
Super High
High
Med.
Low
dB(A)
Super High
High
Med.
Low
Super High
High
Med.
Low
rpm
Super High
High
Med.
Low
672
516
378
276
726
270
42
282
43
36
29
20
43
44
36
29
20
21
1,190
950
740
580
1,270
1,300
1,010
780
570
Fan speed regulator
Remote controller model
NOTE: Test conditions are based on AS/NZS 3823.1.1..
Cooling: Indoor
Dry-bulb temperature 27°C
Outdoor Dry-bulb temperature 35°C
Heating: Indoor
Dry-bulb temperature 20°C
Outdoor Dry-bulb temperature 7°C
1 Measured under rated operating frequency.
750
552
402
Wet-bulb
Wet-bulb
Wet-bulb
Wet-bulb
590
4
A1 : KM08A / A2 : KM09D
temperature 19°C
temperature 24°C
temperature 15.5°C
temperature
6°C
Specifications and rating conditions of main electric parts
Fuse
i-see Sensor motor
Horizontal vane motor
Vertical vane motor
Varistor
i-see Sensor
Terminal block
OBH503C
(F11)
(MT)
(MV1)
(MV2)
(NR11)
(RR)
(TB)
250 V 3.15 A
MP20Z 12 VDC 300 Ω (at 25°C)
MSFBC20C29 12 VDC 350 Ω (at 25°C)
MSBPC20M11 12 VDC 300 Ω (at 25°C)
S10K320E3K1
A2TPMI 23A FOV50 OBA060 P8L1 J4S
3P
5
MSZ-FB50VA
60
0.53
0.53
888
672
534
378
888
672
534
330
52
45
39
29
50
43
37
27
1,500
1,200
1,000
760
1,500
1,200
1,000
680
4
NOISE CRITERIA CURVES
MSZ-FB25VA
MSZ-FB35VA
FAN SPEED FUNCTION
Super High
SPL(dB(A))
COOLING
42
HEATING
43
LINE
FAN SPEED FUNCTION
Super High
80
70
NC-70
60
NC-60
50
NC-50
40
NC-40
30
NC-30
20
63
125
250
500
1000
70
NC-70
60
NC-60
50
NC-50
40
NC-40
30
NC-30
20
NC-20
NC-10
2000
4000
10
8000
63
125
250
1000
Test conditions
Cooling : Dry-bulb temperature 27
Heating : Dry-bulb temperature 20
FAN SPEED FUNCTION
Super High
SPL(dB(A))
COOLING
52
HEATING
50
0.8 m
MICROPHONE
70
NC-70
60
NC-60
50
NC-50
40
NC-40
30
NC-30
20
NC-20
NC-10
500
1000
2000
4000
8000
BAND CENTER FREQUENCIES, Hz
OBH503C
8000
Wet-bulb temperature 19
Wet-bulb temperature 15.5
WALL
80
250
4000
INDOOR UNIT
90
125
2000
LINE
1m
63
500
BAND CENTER FREQUENCIES, Hz
MSZ-FB50VA
OCTAVE BAND SOUND PRESSURE LEVEL, 0 dB = 20μPa
44
LINE
80
BAND CENTER FREQUENCIES, Hz
10
HEATING
NC-20
NC-10
10
43
90
OCTAVE BAND SOUND PRESSURE LEVEL, 0 dB = 20μPa
OCTAVE BAND SOUND PRESSURE LEVEL, 0 dB = 20μPa
90
SPL(dB(A))
COOLING
6
5
OUTLINES AND DIMENSIONS
MSZ-FB25VA MSZ-FB35VA MSZ-FB50VA
Unit: mm
64
21.5
225
155
345
54
330
42
155
Indoor unit
3
41
47
212.5
6.5
254
798
785
225
64
Installation plate
231.5
253
11 X 26 Oblong hole
211.5
11 X 20 Oblong hole
69
Wall hole ø65
Air in
Installation plate
5
56
Piping
55
43
688
100
7
69
295
257
55
43
97
19
Air out
Piping
159
58
Insulation
Liquid line
Gas line
Drain hose
6
Drain hose
85
WIRING DIAGRAM
MSZ-FB25VA MSZ-FB35VA MSZ-FB50VA
OBH503C
7
ø35 O.D
ø7 - 0.5m (Flared connection ø6.35)
25/35: ø9.52 - 0.43m (Flared connection ø9.52)
50: ø9.52 - 0.43m (Flared connection ø12.7)
Insulation ø28 O.D Connected part ø16 O.D
7
REFRIGERANT SYSTEM DIAGRAM
MSZ-FB25VA MSZ-FB35VA
Unit: mm
Refrigerant pipe 9.52
(with heat insulator)
Indoor
heat
exchanger
Indoor coil
thermistor
RT12 (main)
Flared connection
Indoor coil
thermistor
RT13 (sub)
Room temperature
thermistor
RT11
Flared connection
Refrigerant pipe 6.35
(with heat insulator)
Refrigerant flow in cooling
Refrigerant flow in heating
MSZ-FB50VA
Refrigerant pipe ø12.7
(with heat insulator)
Indoor
heat
exchanger
(Main)
Indoor coil
thermistor
RT12 (main)
Flared connection
Indoor coil
thermistor
RT13 (sub)
Indoor heat
exchanger
(Sub)
Room
temperature
thermistor
RT11
Flared connection
Refrigerant pipe ø6.35
(with heat insulator)
Refrigerant flow in cooling
Refrigerant flow in heating
OBH503C
8
8
SERVICE FUNCTIONS
MSZ-FB25VA MSZ-FB35VA MSZ-FB50VA
8-1. TIMER SHORT MODE
For service, set time can be shortened by short circuit of JPG and JPS on the electronic control P.C. board.
The time will be shortened as follows. (Refer to 10-7.)
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.)
8-2. 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:
J1
NOTE: For modification, take out
the batteries and press
the OPERATE/STOP (ON/
OFF) button twice or 3
times at first.
After modification, put back
the batteries then press the
RESET button.
J2
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 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 is turned OFF, or the power supply is shut down.
Please conduct the above setting once again after the power has restored.
OBH503C
9
8-3. 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.)
CN1T1 CN112
IC156
CN212
CN130
Turn OFF the main power for the unit.
Solder the Jumper wire JR07 on the indoor electronic control P.C. board.
(Refer to 10-7.)
CN1R1 CN211
How to release “AUTO RESTART FUNCTION”
CN151
CN1U1
JR07
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.
8-4. REMOTE CONTROLLER
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.
Slide switch
Area
Position of
the slide
switch
Display on
the remote
controller
Left
Center
Right
Where is the indoor unit installed in your room?
Installed at right, if the
distance is not more
than 50 cm.
Installed at left, if the
distance is not more
than 50 cm.
(Left)
(Center)
(Right)
Is the indoor unit
installed at right,
left or center?
NOTE:If the indoor unit is installed more than 50 cm away from the side walls, cabinets or other nearby objects, set the slide
switch to the “center” position.
OBH503C
10
9
MICROPROCESSOR CONTROL
MSZ-FB25VA MSZ-FB35VA MSZ-FB50VA
WIRELESS REMOTE CONTROLLER
Signal transmitting section
Operation display section
OPERATE/STOP
(ON/OFF) button
FAN SPEED CONTROL button
OPERATION SELECT button
ECONO COOL button
PLASMA button
Temperature buttons
CLEAN button
i-see button
AREA button
RESET button
VANE CONTROL button
OFF TIMER button
ON TIMER button
TIME SET buttons
FORWARD button
BACKWARD button
WIDE VANE button
(Vertical vane button)
CLOCK SET button
Indication of
remote controller
model is on back
NOTE: Last setting will be stored after the unit is turned OFF with the remote controller. Indoor unit receives the signal of the
remote controller with beeps.
INDOOR UNIT LAMP
The lamps at the center of the indoor unit indicates the operation state.
Lamp
AREA
POWER
CLEAN
PLASMA
OBH503C
Operation state
Refer to 9-7.
Lamp lights during operation.
Lamp blinks in abnormal condition.
Lamp lights during clean operation.
Refer to 9-9.
Lamp lights during PLASMA operation.
Refer to 9-8.
11
9-1. COOL ( ) OPERATION
(1) Press OPERATE/STOP (ON/OFF) button.
POWER lamp of the indoor unit turns on with a beep tone.
(2) Select COOL mode with OPERATION SELECT button.
(3) Press TEMPERATURE buttons (TOO WARM or TOO COOL button) to select the desired temperature.
The setting range is 16 ~ 31°C.
1. Coil frost prevention
The compressor operational frequency is controlled by the temperature of the indoor heat exchanger to prevent the coil
from frosting.
When the temperature of indoor heat exchanger becomes too low, the coil frost prevention mode works.
The indoor fan operates at the set speed and the compressor stops. This mode continues until the temperature of indoor
heat exchanger rises.
2. Low outside temperature operation
When the outside temperature is lower, low outside temperature operation starts, and the outdoor fan slows or stops.
9-2. DRY ( ) OPERATION
(1) Press OPERATE/STOP (ON/OFF) button.
POWER lamp of the indoor unit turns on with a beep tone.
(2) Select DRY mode with OPERATION SELECT button.
(3) The set temperature is determined from the initial room temperature.
1. Coil frost prevention
Coil frost prevention is as same as COOL mode. (9-1.1.)
2. Low outside temperature operation
Low outside temperature operation is as same as COOL mode. (9-1.2.)
9-3. HEAT ( ) OPERATION
(1) Press OPERATE/STOP (ON/OFF) button.
POWER lamp of the indoor unit turns on with a beep tone.
(2) Select HEAT mode with OPERATION SELECT button.
(3) Press TEMPERATURE buttons (TOO WARM or TOO COOL button) to select the desired temperature.
The setting range is 16 ~ 31°C.
1. Cold air prevention control
When the compressor is not operating or is starting, and the temperature of indoor heat exchanger and/or the room temperature is low or when defrosting is being done, the indoor fan will stop or rotate in Very Low speed.
2. High pressure protection
The compressor operational frequency is controlled by the temperature of the indoor heat exchanger to prevent the condensing pressure from increasing excessively.
When the temperature of indoor heat exchanger becomes too high, the high pressure protection works.
The indoor fan operates following the cold air prevention control. This mode continues until the temperature of indoor heat
exchanger falls.
3. Defrosting
Defrosting starts when the temperature of outdoor heat exchanger becomes too low.
The compressor stops once, the indoor/outdoor fans stop, the 4-way valve reverses, and the compressor re-starts.
This mode continues until the temperature of outdoor heat exchanger rises or the fixed time passes.
9-4. AUTO CHANGE OVER ··· AUTO MODE OPERATION
Once desired temperature is set, unit operation is switched automatically between COOL and HEAT operation.
Mode selection
(1) Initial mode
When unit starts the operation with AUTO operation from OFF:
• If the room temperature is higher than the set temperature, operation starts in COOL mode.
• If the room temperature is equal to or lower than the set temperature, operation starts in HEAT mode.
(2) Mode change
COOL mode changes to HEAT mode when about 15 minutes have passed with the room temperature 1°C below the set
temperature.
HEAT mode changes to COOL mode when about 15 minutes have passed with the room temperature 1°C above the set
temperature.
NOTE 1
If two or more indoor units are operating in multi system, there might be a case that the indoor unit, which is operating in
(AUTO), cannot change over to the other operating mode (COOL
HEAT) and becomes a state of standby.
Refer to NOTE 2 “FOR MULTI SYSTEM AIR CONDITIONER”.
OBH503C
12
NOTE 2
FOR MULTI SYSTEM AIR CONDITIONER
OUTDOOR UNIT: MXZ series
Multi system air conditioner can connect two or more indoor units with one outdoor unit.
•When you try to operate two or more indoor units with one outdoor unit simultaneously, one for the cooling and
the others for heating, the operation mode of the indoor unit that operates first is selected. Other indoor units
cannot operate, and operation indicator lamp flashes as shown in the figure below. In this case, please set all the
indoor units to the same operation mode.
L AREA R
POWER
CLEAN PLASMA
Lighted
Blinking
Not lighted
•When indoor unit starts the operation while the defrosting of outdoor unit is being done, it takes a few minutes (max.
10 minutes) to blow out the warm air.
•In the heating operation, though indoor unit that does not operate may get warm or the sound of refrigerant flowing may be heard, they are not malfunction. The reason is that the refrigerant continuously flows into it.
9-5. AUTO VANE OPERATION
1. Horizontal vane
(1) Vane motor drive
These models are equipped with a stepping motor for the horizontal vane. The rotating direction, speed, and angle of
the motor are controlled by pulse signals (approx. 12 V) transmitted from indoor microprocessor.
(2) The horizontal vane angle and mode change as follows by pressing VANE CONTROL button.
(3) Positioning
To confirm the standard position, the vane moves until it touches the vane stopper. Then the vane is set to the selected
angle.
Confirming of standard position is performed in the following cases:
(a) The operation starts or finishes (including timer operation).
(b) The test run operation starts.
(c) Standby mode (only during multi system operation) starts or finishes.
(4) VANE AUTO ( ) mode
The microprocessor automatically determines the vane angle to make the optimum room temperature distribution.
HEAT operation
COOL and DRY operation
Vane angle is fixed to Angle 4.
Vane angle is fixed to Angle 1.
1
(5) STOP (operation OFF) and ON TIMER standby
In the following cases, the horizontal vane returns to the closed position.
(a) When OPERATE/STOP (ON/OFF) button is pressed (POWER OFF).
(b) When the operation is stopped by the emergency operation.
(c) When ON TIMER is ON standby.
(6) Dew prevention
During COOL or DRY operation with the vane angle at Angle 3 ~ 5 when the compressor cumulative operation time
exceeds 1 hour or 30 minutes, the vane angle automatically changes to Angle 2 for dew prevention.
OBH503C
13
(7) SWING ( ) mode
By selecting SWING mode with VANE CONTROL button, the horizontal vane swings vertically.
(8) Cold air prevention in HEAT operation
The horizontal vane position is set to Upward.
NOTE: When 2 or more indoor units are operated with multi outdoor unit, even if any indoor unit turns thermostat off,
this control does not work in the indoor unit.
(9) ECONO COOL ( ) operation (ECONOmical operation)
When ECONO COOL button is pressed in COOL mode, set temperature is automatically set 2°C higher.
Also the horizontal vane swings in various cycle.
SWING operation makes you feel cooler than set temperature. So, even though the set temperature is higher, the air
conditioner can keep comfort. As a result, energy can be saved.
ECONO COOL operation is cancelled when ECONO COOL button is pressed once again or VANE CONTROL button is
pressed or changed to other operation mode.
2. Vertical vane
(1) Vane motor drive
These models are equipped with a stepping motor for the vertical vane. The rotating direction, speed, and angle of the
motor are controlled by pulse signals (approx. 12 V) transmitted from microprocessor.
(2) The vertical vane angle and mode change as follows by pressing WIDE VANE button.
(3) Positioning
1
2
4
3
5
(SWING)
To confirm the standard position, the vane moves until it touches the vane stopper. Then the vane is set to the selected
angle.
Confirming of standard position is performed in the following cases:
(a) OPERATE/STOP (ON/OFF) button is pressed (POWER ON).
(b) SWING is started.
(4) SWING ( ) MODE
By selecting SWING mode with WIDE VANE button, the vertical vane swings horizontally. The remote controller displays
“ ”. Swing mode is cancelled when WIDE MODE button is pressed once again.
OBH503C
14
9-6. i-see CONTROL OPERATION
The sensors constantly measure the room and floor/wall temperatures to automatically adjust to the set temperature by estimating the temperature actually perceived by a person inside the room (“sensible temperature”).
Advantages
· The air inside the room is conditioned quickly to a comfortable condition.
· The room will not become too cold or hot even when the air conditioner is kept on for a long period.
· The air conditioner will not overcool or overheat, which means you can save on electricity.
i-see control operation is activated when i-see button is pressed with a thin stick in manual COOL or manual HEAT mode.
NOTE: i-see control operation is activated when the remote controller is first used following replacement of the batteries
or resetting of the remote controller.
i-see control operation is cancelled when i-see button is pressed with a thin stick once again.
NOTE: If the conditioner is turned OFF without cancelling i-see control operation, i-see control operation is activated
the next time the air conditioner is turned ON.
i-see Sensor
i-see Sensor, which is installed on the upper of the air outlet of the indoor unit, is moved with the stepping motor and it
detects the floor/wall temperature.
Enlarged view of i-see Sensor
i-see Sensor is installed here.
i-see Sensor
• When AREA setting is not activated, the sensing range of i-see Sensor differs depending on the installation location of
the air conditioner.
Installation
position
Installed at left
Installed at center
Installed at right
Right
Center
Left
Image of sensing
range
Direction of sensor
Refer to "Remote controller in SERVICE FUNCTIONS".
• Install the front panel correctly after being removed for maintenance or service so that the floor/wall temperatures can
be measured correctly.
9-7. AREA (
) SETTING
(1) Press OPERATE/STOP (ON/OFF) button to start the air conditioner.
(2) Press i-see button. (NOTE 1)
(3) Press AREA button.
Each time the button is pressed, the area is changed in sequence:
(AUTO)
(LEFT)
(RIGHT)
Cancel
i-see Sensor moves intermittently, measuring the floor and wall temperature.
(4) AREA setting is cancelled when the "cancel" is selected by pressing AREA button, or when WIDE VANE button is pressed.
NOTE 1: AREA setting is only available during i-see control operation.
NOTE 2: If AREA setting is cancelled, the vertical vane returns to the previously set position before AREA setting.
NOTE 3: The horizontal air flow direction (WIDE VANE button), including horizontal SWING, cannot be set during AREA
setting
OBH503C
15
Indoor unit installation location and air-conditioning area
Installed at left
LEFT
Installed at center
RIGHT
LEFT
Installed at right
RIGHT
LEFT
RIGHT
• 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.
(Refer to "Remote controller in SERVICE FUNCTIONS".)
To air-condition mainly
the left area of the room
Remote controller button
Press AREA button
to select LEFT.
To air-condition the entire room
To air-condition mainly
The horizontal air flow direction and in- the right area of the room
door unit display are switched according to the room temperature (floor/wall).
Press AREA button to select AUTO.
Press AREA button
to select RIGHT.
Remote controller display
i-see Sensor operation
Control range
of horizontal air
flow direction.
The vertical air
flow direction
conforms to the
setting on the
remote controller.
(The horizontal
air flow direction
is controlled in
this range.)
Indoor unit
display
Installed
at center
Installed
at left
Installed
at right
L
AREA
L
R
R
L
or
R
or
L
R
L
R
Lighted
Not lighted
NOTE
Indoor unit
Moving of horizontal air flow direction
display
When AREA is set to AUTO
• The vertical vane is controlled to maintain uniform temperature in the whole room.
• The i-see Sensor moves in a range of 150 degrees detecting floor/wall temperature of 3 areas
(left, right, center). Therefore, the detected temperatures may be different from the temperatures
measured on commercial thermometers depending on the condition or temperature
distribution on the floor and/or wall.
Approx. 150 degrees
Ex.) In COOL mode
Daytime
Nighttime
Warm area
Cold area
The indoor unit delivers cold air detecting the warm area in the room.
Indication of AREA setting
L AREA R
L AREA R
Lighted
Not lighted
• The horizontal air flow direction changes if i-see Sensor detects approx. 3 °C temperature difference.
• In AUTO of AREA setting, both right and left lamps are lighted when the room is evenly air-conditioned.
OBH503C
L AREA R
16
Operation and operating range
i-see sensor moves 30 degrees from the center in both right and left side.
i-see Sensor turning to the left
i-see Sensor turning to the center
i-see Sensor turning to the right
i-see Sensor operates as follows in accordance with AREA setting made with the remote controller.
“AUTO” in AREA setting: first turning to the LEFT for adjusting the position then.....
CENTER
RIGHT
CENTER
LEFT
CENTER......
(The sensor turns to the right, left and center.)
“RIGHT” in AREA setting: first turning to the LEFT for adjusting the position then....
CENTER
RIGHT
CENTER
RIGHT
CENTER......
(The sensor turns to the right and center.)
“LEFT” in AREA setting: first turning to the LEFT for adjusting the position then....
CENTER
LEFT
CENTER
LEFT
CENTER......
(The sensor turns to the left and center.)
The sensor finishes turning to one area to another for 3 seconds and it operates one area for 5 seconds.
9-8. PLASMA (
) OPERATION
(1) Press OPERATE/STOP (ON/OFF) button to start the air conditioner.
(2) Press PLASMA button to set PLASMA operation.
PLASMA lamp turns ON and plasma electrode unit is energized.
(3) Press PLASMA button again to cancel PLASMA operation.
Description of PLASMA operation:
Plasma operation consists of deodorizing and air purifying features.
Particles of odor-releasing substances are absorbed and decomposed by the plasma deodorizing filter.
Particles of allergens such as pollen and house dust are collected by the plasma anti-allergy filter.
These filters work with negative ions generated by the plasma electrode unit.
OBH503C
17
9-9. CLEAN (
) OPERATION
• When CLEAN operation is set, it performs for 40 minutes when unit is stopped after COOL/DRY operation. CLEAN
operation performs when: COOL is operated more than 3 minutes / DRY is operated more than 6 minutes.
• The horizontal vane is slightly opened and the fan is stopped for the first 15 minutes. Then, the horizontal vane is set to
higher than angle 1 and the fan is operated for 25 minutes.
9-10. TIMER OPERATION
1. How to set the time
(1) Check that the current time is set correctly.
NOTE: Timer operation will not work without setting the current time. Initially “0:00” blinks at the current time display of
TIME MONITOR, so set the current time correctly with CLOCK SET button.
How to set the current time
(a) Press the CLOCK set button.
(b) Press the TIME SET buttons (
and
) to set the current time.
) is pressed, the set time increases by 1 minute, and each time
• Each time FORWARD button (
BACKWARD button (
) is pressed, the set time decreases by 1 minute.
• Pressing those buttons longer, the set time increases/decreases by 10 minutes.
(c) Press the CLOCK set button.
(2) Press OPERATE/STOP (ON/OFF) button to start the air conditioner.
(3) Set the time of timer.
ON timer setting
START
(a) Press ON TIMER button (
) during operation.
(b) Set the time of the timer using TIME SET buttons (
and
).
OFF timer setting
(a) Press OFF TIMER button ( STOP ) during operation.
(b) Set the time of the timer using TIME SET buttons (
and
).
Each time FORWARD button (
) is pressed, the set time increases by 10 minutes; each time BACKWARD button (
) is pressed, the set time decreases by 10 minutes.
2. To release the timer
To release ON timer, press ON TIMER button ( START).
To release OFF timer, press OFF TIMER button ( STOP ).
TIMER is cancelled and the display of set time disappears.
PROGRAM TIMER
• OFF timer and ON timer can be used in combination. The timer of the set time that is reached first will operate first.
• “ ” and “ ” display shows the order of OFF timer and ON timer operation.
(Example 1) The current time is 8:00 PM.
(Example 2) The current time is 11:00 AM.
The unit turns off at 11:00 PM, and on at 6:00 AM.
The unit turns on at 5:00 PM, and off at 9:00 PM.
NOTE: If the main power is turned OFF or a power failure occurs while ON/OFF timer is active, the timer setting is cancelled. As these models are equipped with an auto restart function, the air conditioner starts operating with timer
cancelled when power is restored.
OBH503C
18
9-11. EMERGENCY/TEST OPERATION
In case of test run operation or emergency operation, use EMERGENCY OPERATION switch on the right side of the
indoor unit. Emergency operation is available when the remote controller is missing, has failed or the batteries of the
remote controller run down. The unit will start and AREA lamp will light.
The first 30 minutes of operation is the test run operation. This operation is for servicing. The indoor fan runs at High
speed and thermostat is ON, but temperature control does not work.
After 30 minutes of test run operation, the system shifts to EMERGENCY COOL/HEAT MODE with a set temperature of
24°C. The fan speed shifts to Med.
All protective operations such as 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 EMERGENCY OPERATION switch is pressed once or twice or the unit receives any
signal from the remote controller. In case of latter, normal operation will start.
NOTE: Do not press EMERGENCY OPERATION switch during normal operation.
EMERGENCY OPERATION switch (E.O.SW)
Operation mode
COOL
HEAT
Set temperature
24°C
24°C
Fan speed
Med.
Med.
Horizontal vane
Auto
Auto
Vertical vane
Straight
Straight
The operation mode is indicated by the AREA lamp as following
AREA lamp
L
AREA
EMERGENCY
COOL
↓
EMERGENCY
HEAT
R
Lighted
Not lighted
↓
STOP
NOTE:
This is the indication of EMERGENCY OPERATION mode.
AREA setting is not available during EMERGENCY OPERATION.
9-12. 3-MINUTE TIME DELAY OPERATION
When the system turns OFF, compressor will not restart for 3 minutes as 3-minute time delay function operates to protect
compressor from overload.
OBH503C
19
10
TROUBLESHOOTING
MSZ-FB25VA MSZ-FB35VA MSZ-FB50VA
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 miswiring.
2. Take care of the following during servicing
1) Before servicing the air conditioner, be sure to turn OFF the main unit first with the remote controller, 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 P.C. board.
3) When removing the 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) When the P.C. board seems to be defective, check the copper foil pattern for disconnection and the components for
bursting and discoloration.
4) When troubleshooting, refer to 10-2., 10-3. and 10-4.
4. How to replace batteries
Weak batteries may cause the remote controller malfunction.
In this case, replace the batteries to operate the remote controller normally.
Remove the front lid and insert batteries.
Then reattach the front lid.
Press RESET button with a thin instrument, and
then use the remote controller.
Insert the negative pole of the
batteries first. Check if the polarity
of the batteries is correct.
RESET button
NOTE: 1. If RESET button is not pressed, the remote controller may not operate correctly.
2. This remote controller has a circuit to automatically reset the microcomputer when batteries are replaced.
This function is equipped to prevent the microcomputer from malfunctioning due to the voltage drop caused by the
battery replacement.
5. How to install the horizontal vane
If horizontal vane is not installed correctly, all of the operation indicator lamps will blink.
In this case, install the horizontal vane correctly by following the procedures to .
NOTE: Before installation of the horizontal vane, turn OFF the power supply.
In procedure lock the
stoppers until they click
into place.
2
Lock
1
OBH503C
20
10-2. FAILURE MODE RECALL FUNCTION
Outline of the function
This air conditioner can memorize the abnormal condition which has occurred once.
Even though LED indication listed on the troubleshooting check table (10-4.) disappears, the memorized failure details
can be recalled.
1. Flow chart of failure mode recall function for the indoor/outdoor unit
Operational procedure
The cause of abnormality cannot be found because the abnormality does not recur.
Setting up the failure mode recall function
Turn ON the power supply.
<Preparation of the remote controller>
While pressing both OPERATION SELECT button and TOO COOL button on the
remote controller at the same time, press RESET button.
First, release RESET button.
And release the other two buttons after all LCD in operation display section of the
remote controller is displayed after 3 seconds.
Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature is
displayed) with the remote controller headed towards the indoor unit. 1
1. Regardless of normal or abnormal condition, a short
beep is emitted once the signal is received.
Does the POWER lamp on the indoor unit blink at
the interval of 0.5 seconds?
Blinks: Either indoor or outdoor unit is abnormal.
Beep is emitted at the same timing as the
blinking of POWER lamp. 2
Judgment of indoor/outdoor abnormality
Indoor unit is normal.
But the outdoor unit might be abnormal because there are some abnormalities that can not be recalled with this way.
Confirm if outdoor unit is abnormal according to the detailed outdoor unit
failure mode recall function.
No
(OFF)
Yes
(Blinks)
Before blinking, does POWER lamp stay ON
for 3 seconds?
Stays ON for 3 seconds (without beep):
The outdoor unit is abnormal.
Yes
No
The indoor unit is abnormal.
Check the blinking pattern, and confirm the abnormal point with the indoor unit
failure mode table. (Refer to 10-2.4)
2
Make sure to check at least two consecutive blinking cycles.
The outdoor unit is abnormal.
Check the blinking pattern, and confirm the abnormal point with the
outdoor unit failure mode table. (Refer to outdoor unit service manual.)
Make sure to check at least two consecutive blinking cycles.
3
Releasing the failure mode recall function
Release the failure mode recall function by the following procedures.
Turn OFF the power supply and turn it ON again.
Press RESET button of the remote controller.
Repair the defective parts.
Deleting the memorized abnormal condition
After repairing the unit, recall the failure mode again according to "Setting up the failure mode recall
function" mentioned above.
Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature is displayed)
with the remote controller headed towards the indoor unit.
Press EMERGENCY OPERATION switch so that the memorized abnormal condition is deleted.
Release the failure mode recall function according to "Releasing the failure mode recall function"
mentioned above.
NOTE: 1. Make sure to release the failure mode recall function once it is set up, otherwise the unit cannot operate properly.
2. If the abnormal condition is not deleted from the memory, the last abnormal condition is kept memorized.
2. Blinking pattern when the indoor unit is abnormal:
Blinking at 0.52.5-second OFF second interval
Blinking at 0.52.5-second OFF second interval
ON
OFF
Beeps
Repeated cycle
Beeps
Repeated cycle
3.Blinking pattern when the outdoor unit is abnormal:
Blinking at 0.52.5-second OFF
3-second ON
second interval
Beeps
Repeated cycle
2.5-second OFF
3-second ON
Blinking at 0.5second interval
ON
OFF
No beep
Repeated cycle
OBH503C
Beeps
No beep
Repeated cycle
21
Beeps
Repeated cycle
2. Flow chart of PLASMA operation failure mode recall function
Operational procedure
The plasma electrode unit might be abnormal. Confirm if outdoor unit is
abnormal according to the following procedures.
Confirm that the remote controller is in the failure mode recall function.
1. Regardless of normal or abnormal condition, 2 short
beeps are emitted as the signal is received.
With the remote controller headed towards the indoor unit, press TOO
COOL or TOO WARM button to adjust the set temperature to 23°C. 1
Does POWER lamp on the indoor unit blink at the
interval of 0.5 seconds?
Blinks: The plasma electrode unit is abnormal. Beep
is emitted at the same timing as the blinking of
POWER lamp. 2
No
(OFF)
Yes
(Blinks)
The plasma electrode unit is abnormal.
Check the blinking pattern, and refer to confirm the abnormal point with
the PLASMA operation failure mode table. (10-2.5.)
Make sure to check at least two consecutive blinking cycles. 2
The plasma electrode unit is normal.
Releasing the failure mode recall function
Release the failure mode recall function by the following procedures.
Turn OFF the power supply and turn it ON again.
Press RESET button of the remote controller.
Release the failure mode recall function according to the left mentioned procedure.
Repair the defective parts.
Deleting the memorized abnormal condition
After repairing the unit, recall the failure mode again according to "Setting up the failure mode recall
function". (10-2.1.)
Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature is displayed) with
the remote controller headed towards the indoor unit.
Press EMERGENCY OPERATION switch so that the memorized abnormal condition is deleted.
Release the failure mode recall function according to "Releasing the failure mode recall function" mentioned above.
NOTE: 1. Make sure to release the failure mode recall function once it's set up, otherwise the unit cannot operate properly.
2. If the abnormal condition is not deleted from the memory, the last abnormal condition is kept memorized.
2.Blinking pattern when plasma unit is abnormal:
Blinking at 0.52.5-second OFF second interval
Blinking at 0.52.5-second OFF second interval
ON
OFF
Beeps
Repeated cycle
Beeps
Repeated cycle
Beeps
Repeated cycle
3. PLASMA operation check
PLASMA operation goes ON when PLASMA button on the remote controller is pressed with any set temperature displayed
during failure mode recall function.
PLASMA lamp
Correspondence
Continuously blinking Follow "Check of PLASMA operation" to identify the error. (Refer to 10-6. )
2-time flash
There is failure in PLASMA operation control circuit on the indoor electronic control P.C. board. (Refer
to 10-6. )
Not lighted
Normal
OBH503C
22
4. Indoor unit failure mode table
POWER lamp
Not lighted
Abnormal point
(Failure mode)
Normal
Condition
Correspondence
—
The room temperature thermistor short or
1-time flash every Room temperature
open circuit is detected every 8 seconds dur0.5-second
thermistor
ing operation.
Indoor coil
The indoor coil thermistor short or open circuit
2-time flash
2.5-second OFF
is detected every 8 seconds during operation.
thermistor
3-time flash
The serial signal from outdoor unit is not reSerial signal
2.5-second OFF
ceived for a maximum of 6 minutes.
The rotational frequency feedback signal is not
11-time flash
Indoor fan motor
emitted during the 12 seconds the indoor fan
2.5-second OFF
operation.
It cannot properly read data in the nonvolatile
12-time flash
Indoor control
memory of the indoor electronic control P.C.
2.5-second OFF
system
board.
—
Refer to the characteristics of the room temperature
thermistor (10-7.).
Refer to the characteristics of the main indoor coil thermistor, the sub indoor coil thermistor (10-7.).
Refer to 10-6. "How to check miswiring and serial
signal error".
Refer to 10-6.
"Check of indoor fan motor".
Replace the indoor electronic control P.C. board.
NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (10-4.).
5. PLASMA operation failure mode table
POWER lamp
Abnormal point
(Failure mode)
Condition
Correspondence
1-time flash
PLASMA power
supply control
PLASMA power supply cannot be turned OFF
even if the PLASMA operation is turned OFF Replace the indoor electronic control P.C. board.
with the remote controller.
2-time flash
Spark discharge
The voltage between CN1 (+) and (GND)
on the PLASMA POWER P.C. board falls below
1.6 V (spark discharge judgment voltage).
3-time flash
Abnormal electric
discharge error 1
The voltage between CN1 (+) and (GND)
on the PLASMA POWER P.C. board falls by
0.9 V below the normal voltage value (3 V).
4-time flash
Abnormal electric
discharge error 2
The voltage between CN1 (+) and (GND)
on the PLASMA POWER P.C. board falls
significantly. (0.4 V / 0.5 ms)
5-time flash
PLASMA
DEODORIZING
The voltage between CN1 (+) and (GND)
on the PLASMA POWER P.C board rises
above the normal voltage value (3 V).
Refer to 10-6. "Check of PLASMA operation".
NOTE1: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (10-4.).
NOTE2: As soon as an abnormality is detected, PLASMA operation goes OFF, therefore measuring instrument which records
the voltage wave is required in order to perform the above mentioned voltage measurement.
NOTE3: When POWER lamp flashes 1-time or 2-time, please perform PLASMA operation check (Refer to 10-2.3).
OBH503C
23
10-3. INSTRUCTION OF TROUBLESHOOTING
Start
Indoor unit operates.
Outdoor unit
does not operate.
Indoor unit operates.
Outdoor unit does
not operate normally.
"Test Run operation" means
the operation within 30 minutes
after EMERGENCY OPERATION switch is pressed.
Indoor unit does
not receive
the signal from
remote controller.
If blinking of OPERATION INDICATOR lamp cannot be checked,
it can be checked with failure
mode recall function.
OPERATION INDICATOR
lamp on the indoor unit is
flashing on and off.
Outdoor unit
operates only
in Test Run
operation.
Outdoor unit
does not
operate even
in Test Run
operation.
Unit does not
operate normal operation
in COOL or
HEAT mode.
Indoor unit
operates, when
EMERGENCY
OPERATION
switch is pressed.
Indoor unit does
not operate, when
EMERGENCY
OPERATION
switch is pressed.
Check room
temperature
thermistor.
Refer to 10-7.
"Test point
diagram and
voltage".
Refer to "How
to check
inverter/compressor".
Refer to
"Check of R.V.
coil".
Refer to 10-6.
"Check of remote
controller and
receiver P.C.
board".
1. Check indoor/outdoor connecting wire.
(Check if the power is
supplied to the indoor
unit.)
2. Refer to 10-6.
"Check of indoor
electronic control P.C.
board and indoor fan
motor".
PLASMA lamp 2-time
flash
Cause:
• Trouble of PLASMA
operation
Refer to 10-6. "Check of
PLASMA operation".
Refer to outdoor unit service manual.
All lamps
Flash on and
off at 0.5-second intervals
Cause:
Indoor unit
• The horizontal vane is
not installed
correctly.
POWER lamp
Flash on and
off at 0.5-second intervals
Cause:
Indoor/Outdoor
unit
• Miswiring or
trouble of
serial signal
POWER lamp
2-time flash
Cause:
Indoor unit
• Trouble
of room
temperature
/ indoor coil
thermistor
POWER
lamp
3-time flash
Cause:
Indoor unit
• Trouble of
indoor fan
motor
POWER lamp
4-time flash
Cause:
Indoor unit
• Trouble
of indoor
unit control
system
POWER
lamp
5-time flash
Cause:
Outdoor unit
• Outdoor
power system abnormality
POWER lamp
6-time flash
Cause:
Outdoor unit
• Trouble of
thermistor in
outdoor unit
POWER lamp
7-time flash
Cause:
Outdoor unit
• Trouble of
outdoor control system
POWER lamp
14-time flash
Cause:
Outdoor unit
• Other abnormality
Refer to
10-6.
"Check of installation of
the horizontal vane".
Refer to
10-6. "How
to check miswiring and
serial signal
error".
Check room
temperature
thermistor
and indoor
coil thermistor. Refer to
10-7. "Test
point diagram
and voltage".
Refer to
10-6.
"Check of
indoor fan
motor".
Replace the
indoor electronic control
P.C. board.
Refer to
"How to
check
inverter/compressor".
Refer to
"Check of
outdoor thermistors".
Replace the
inverter P.C.
board or
the outdoor
electronic
control P.C.
board.
Check "Flow
chart of the
detailed
outdoor unit
failure mode
recall function."
OBH503C
24
10-4. TROUBLESHOOTING CHECK TABLE
Before taking measures, make sure that the symptom reappears for accurate troubleshooting.
When the indoor unit has started operation and detected an abnormality of the following condition (the first detection after the
power ON), the indoor fan motor turns OFF and OPERATION INDICATOR lamp flashes.
L AREA R
POWER
CLEAN PLASMA
Lighted
Blinking
Not lighted
No.
1
Abnormal
point
Miswiring
or serial
signal
Indoor coil
thermistor
2
Room temperature
thermistor
Operation indicator lamp
Symptom
Condition
POWER lamp flashes.
0.5-second ON
The serial signal from the outdoor unit is not
received for 6 minutes.
0.5-second OFF
POWER lamp flashes.
2-time flash
Correspondence
• Refer to 10-6. "How to check
miswiring and serial signal error".
The indoor coil or the room temperature thermistor is short or open circuit.
• Refer to 10-7. the characteristics of indoor coil thermistor,
and the room temperature thermistor.
The rotational frequency feedback signal is
not emitted during the indoor fan operation.
• Refer to 10-6. "Check of
indoor fan motor".
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.
2.5-second OFF
POWER lamp flashes.
3-time flash
3
Indoor fan
motor
2.5-second OFF
POWER lamp flashes.
4-time flash
4
Indoor control system
2.5-second OFF
5
Outdoor
power system
POWER lamp flashes.
5-time flash
Indoor unit and
outdoor unit do
not operate.
2.5-second OFF
• Refer to "How to check of inIt consecutively occurs 3 times that the comverter/compressor".
pressor stops for overcurrent protection or
Refer to outdoor unit service
start-up failure protection within 1 minute after
manual
start-up.
• Check the stop valve.
POWER lamp flashes.
6-time flash
6
Outdoor
thermistors
The outdoor thermistors short or open circuit
during the compressor operation.
• Refer to "Check of outdoor
thermistor".
Refer to outdoor unit service
manual.
It cannot properly read data in the nonvolatile
memory of the inverter P.C. board or the outdoor electronic control P.C. board.
• Replace the inverter P.C. board
or the outdoor electronic control P.C. board.
Refer to outdoor unit service
manual.
An abnormality other than above mentioned
is detected.
• Check the stop valve.
• Confirm the abnormality in
detail using the failure mode
recall function for outdoor unit.
It cannot properly read data in the nonvolatile
memory of the inverter P.C. board or the outdoor electronic control P.C. board.
• Check the blinking pattern of
the LED on the inverter P.C.
board or the outdoor electronic
control P.C. board.
2.5-second OFF
7
Outdoor
control system
POWER lamp flashes.
7-time flash
2.5-second OFF
POWER lamp flashes.
14-time flash
8
Other abnormality
2.5-second OFF
9
Outdoor
control sys- POWER lamp lights up
tem
OBH503C
Outdoor unit
does not operate
25
L AREA R
No.
Abnormal
point
POWER
CLEAN PLASMA
Operation indicator lamp
Symptom
Condition
Correspondence
All lamps flash at the same time.
1
L AREA R
No.
1
Abnormal
point
MXZ type
Operation
mode
setting
L AREA R
No.
Indoor unit and
outdoor unit do
not operate.
Attachment 0.5-second ON
of the horizontal vane 0.5-second OFF
Abnormal
point
POWER
• Refer to 10-6. "Check of installation of the horizontal vane".
CLEAN PLASMA
Operation indicator lamp
POWER lamp is lighted.
AREA lamps flash.
2.5-second OFF
POWER
The electricity is not conducted to the interlock switch (Fan) of the horizontal vane.
Symptom
Condition
Correspondence
The operation mode of the each indoor unit
Outdoor unit
is differently set to COOL (includes DRY) and • Unify the operation mode.
operates but
HEAT at the same time, the operation mode
Refer to outdoor unit service
indoor unit does
of the indoor unit that has operated at first has manual.
not operate.
the priority.
CLEAN PLASMA
Operation indicator lamp
Symptom
Condition
Correspondence
PLASMA lamp flashes.
2-time flash
1
PLASMA
control
2.5-second OFF
OBH503C
Indoor unit and
outdoor unit do
not operate.
PLASMA operation can not be turned OFF
even if the PLASMA operation is turned OFF
with remote controller.
26
• Refer to 10-6. ”Check of
PLASMA operation”.
10-5. TROUBLE CRITERION OF MAIN PARTS
MSZ-FB25VA MSZ-FB35VA MSZ-FB50VA
Part name
Room temperature thermistor (RT11)
Indoor coil thermistor
(RT12, RT13)
Indoor fan motor (MF)
Horizontal vane motor
(MV1)
Vertical vane motor
(MV2)
i-see Sensor motor
(MT)
Check method and criterion
Measure the resistance with a tester.
Figure
Refer to 10-7. "Test point diagram and voltage", "Indoor electronic control
P.C. board", for the chart of thermistor.
Check 10-6. .
Measure the resistance between the terminals with a tester.
(Part temperature 10 ~ 30°C)
ROTOR
Color of the lead wire
Horizontal vane motor (MV1)
Vertical vane motor (MV2)
i-see Sensor motor (MT)
BRN - other one
Normal
313 ~ 375 Ω
268 ~ 322 Ω
223 ~ 268 Ω
Cover the i-see Sensor with black vinyl tape. Then, turn ON the power
supply. (i-see Sensor is energized.) Measure the voltage between connector
terminals of i-see Sensor with a tester.
(Part temperature 10 ~ 40°C)
i-see Sensor
Cover the i-see
Sensor with
black vinyl tape.
4
3
2(GND)
1
i-see Sensor P.C. board
i-see Sensor (RR)
connector
Black vinyl tape
i-see Sensor connector terminals
(GND) - (+)
(+) - (GND)
NOTE: Pay attention to static electricity.
PLASMA electrode unit
OBH503C
RED
Check 10-6.
27
Normal range
1.874 ~ 3.387 VDC
1.010 ~ 1.420 VDC
YLW
BRN
ORN
GRN
10-6. TROUBLESHOOTING FLOW
A Check of indoor fan motor
The indoor fan motor error has occurred, and the indoor fan does not operate.
Turn OFF the power supply.
Pay enough attention to the high voltage on the fan motor connector CN211.
Is there any foreign matter that interferes
the rotation of the line flow fan?
Turn ON the power supply, wait 5 seconds or more, and then press
EMERGENCY OPERATION switch.
Measure the supply voltage as follows within 12 seconds after EMERGENCY OPERATION switch is pressed.
If more than 12 seconds passes, turn OFF the power supply and turn it
ON again, then measure the voltage.
1. Measure the voltage between CN211 (+) and (-).
2. Measure the voltage between CN211 (+) and (-).
No
Yes
If more than 12 seconds passes after EMERGENCY OPERATION switch
is pressed, the voltage measured at 2. above goes 0 VDC although the
indoor electronic control P.C. board is normal
Remove the foreign matter and
adjust the line flow fan.
Is there 325 VDC between CN211
(+) and (-), and does the voltage
between CN211 (+) and (-) rise
to the range of 3 to 6 VDC within 12
seconds after EMERGENCY OPERATION switch is pressed?
CN211
Yes
Replace the indoor fan motor.
Indoor electronic
control P.C. board
No
Replace the indoor electronic control P.C. board.
The indoor fan motor error has occurred, and the indoor fan repeats "12-second ON and 30-second OFF" 3 times, and then stops.
Measure the voltage between CN211
(+) and (-) while the fan motor is
rotating.
Is it unchanged holding
0 or 15 VDC?
Yes
(Unchanged)
Replace the indoor fan motor.
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No
(Changed)
Replace the indoor electronic control P.C. board.
B Check of remote controller and indoor electronic control P.C. board
Check if the remote controller is exclusive for this air conditioner.
Press OPERATE/STOP (ON/OFF) button
on the remote controller.
Is LCD display on the remote controller
visible?
Yes
No
(Not clear)
Replace the batteries. (Refer to 10-1.4.)
Remove the batteries, then set them back
and press RESET button. (Refer to 10-1.4.)
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 OPERATE/STOP (ON/OFF) button on the
remote controller.
Yes
OK
Is noise heard from radio?
No
Replace the remote controller.
Yes
Are there any fluorescent lights of
inverter or rapid-start type within the
range of 1 m.?
No
Replace the indoor electronic control
P.C. board. (Including the receiver)
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Yes
• Reinstall the unit away from lights.
• Attach a filter on receiving part.
C Check of indoor electronic control P.C. board and indoor fan motor
Turn OFF the power supply.
Remove indoor fan motor connector CN211,
vane motor connector CN151 and the i-see
Sensor motor connector CN110 from the
indoor electronic control P.C. board and turn
ON the power supply.
Does the unit operate with the remote
controller?
Does POWER lamp light up by pressing
EMERGENCY OPERATION switch?
No
Yes
Measure the resistance of the i-see
Sensor motor coil.
(Refer to 10-5.)
Short/open circuit:
Replace the i-see Sensor motor and the
indoor electronic control P.C. board.
Measure the resistance between
CN211 and of the indoor fan motor
connector.
Short/open circuit:
Replace the indoor fan motor.
Measure the resistance of the horizontal vane motor coil and the vertical vane
motor coil.
(Refer to 10-5.)
Short/open circuit:
Replace the horizontal vane motor, the
vertical vane motor and the indoor electronic
control P.C. board.
Replace the varistor (NR11)
and fuse (F11).
Yes
Is the varistor (NR11)
burnt and the fuse (F11)
blown?
Turn OFF the power supply.
Check both “parts side” and “pattern
side” of the indoor electronic control
P.C. board visually.
No
Be sure to check both the fuse
and the varistor in any case.
Is the fuse (F11) blown
only?
No
Yes
Measure the resistance between
(+) and (-) of the indoor fan motor
connector. 1, 2
Is the resistance 1 MΩ
or more?
Yes
No
1. The fan motor connector's
black.
lead wire is red, whereas
is
2. Connect "+" of the tester to fan motor connector's lead
wire, and "-" to lead wire, otherwise the resistance cannot be measured properly.
Replace the fuse (F11) and the
indoor fan motor.
Replace the fuse (F11).
Measure the resistance of cement
resistor (R111) on the indoor electronic control P.C. board.
Is the resistance approx.
4 Ω?
No
Replace the indoor electronic control P.C.
board and the indoor fan motor.
Yes
Replace the indoor electronic control P.C. board.
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D How to check miswiring and serial signal error
Turn OFF the power supply.
Is there rated voltage in the
power supply?
Check the power supply.
No
Yes
Turn ON the power supply.
Is there rated voltage between
outdoor terminal block S1 and
S2?
Yes
Check the wiring.
No
Press EMERGENCY OPERATION switch once.
Does AREA-L lamp light up? <Confirmation of
the power to the indoor unit>
No
Yes
Is serial signal error indicated 6 minutes later?
Is there any miswiring,
poor contact, or wire
disconnection of the
indoor/outdoor connecting wire?
No
No
Yes
Yes
Correct them.
A
Turn OFF the power supply.
Check once more if the indoor/outdoor
B connecting wire is not miswiring.
Short-circuit outdoor terminal block S2
and S3. 1
1. Miswiring may damage indoor electronic control P.C.
board during the operation.
Be sure to confirm the wiring is correct before the operation starts.
3. Be sure to check this within 3 minutes after turning ON.
After 3 minutes, LED blinks 6 times. Even when the
inverter P.C. board or the outdoor electronic control P.C.
board is normal, LED blinks 6 times after 3 minutes.
(Except for outdoor unit of multi system type)
Turn ON the power supply.
Does the LED on the inverter P.C. board or
the outdoor electronic control P.C. board
repeat "3.6-second-OFF and 0.8-secondON quick blinking"? 3
Yes
A
• Turn OFF inverter-controlled lighting
equipment.
• Turn OFF the power supply and then
turn ON again.
• Press EMERGENCY OPERATION
switch.
Is serial signal
error indicated 6
minutes later?
Yes
B
• Reinstall
either the unit
or the light
away from
each other.
• Attach a filter
No on remote
control receiving section
of the indoor
unit.
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Turn OFF the power supply.
Remove the short-circuit between outdoor terminal block S2 and S3.
Turn ON the power supply.
Is there amplitude of 10 to 20 VDC
between outdoor terminal block S2 and
S3? <Confirmation of serial signal>
Yes
Is there rated voltage between
indoor terminal block S1 and S2?
<Confirmation of power voltage>
Yes
No
(Lighted
or not
lighted)
Is there any error of the indoor/outdoor connecting wire,
such as the damage of the wire,
Yes
intermediate connection, poor
contact to the terminal block?
No
Replace the indoor electronic control P.C. board.
Be sure to release the failure-mode recall function
after checking.
31
2. Be careful of the residual voltage
of smoothing capacitor.
Is there any error of the indoor/outdoor connecting wire,
such as the damage of the
wire, intermediate connection, Yes
poor contact to the terminal
block?
No
No
No
Replace the inverter P.C. board or the
outdoor electronic control P.C. board.
2
Replace the indoor/outdoor connecting wire.
Replace the indoor/outdoor connecting wire.
E Check of installation of the horizontal vane
Turn OFF the power supply.
Is the stopper of the horizontal vane
locked to the indoor unit correctly?
Yes
No
Re-lock the stopper of the horizontal vane to the indoor unit.
(Refer to 10-1.5.)
Turn ON the
power supply.
Are all lamps flashing?
No
OK
Yes
To check the continuity of the interlock
switch (Fan), measure the resistance of
connector - connected to CN1R1 on
the indoor electronic control P.C. board.
Is there resistance 0 Ω?
Yes
Turn OFF the power supply.
Replace the interlock switch (Fan).
No(∞)
Replace the indoor electronic
control P.C. board.
F Check of PLASMA operation
High voltage (approx. -4.4 kV) is generated during PLASMA
operation.
Pay careful attention and never touch PLASMA ELECTRODE
UNIT and the high-voltage lead part (red wire).
Turn ON the power supply.
Does PLASMA lamp flash
2-time with unit stopping?
No
Replace the indoor electronic control P.C. board.
Yes
While pressing both OPERATION SELECT button and TOO
COOL button on the remote controller at the same time,
press RESET button.
First, release RESET button.
And release the other two buttons after all LCD except the
set temperature in operation display section of the remote
controller is displayed after 3 seconds.
Press OPERATE/STOP (ON/OFF) button (the set temperature is displayed)
And press PLASMA button once with the remote controller
headed towards the indoor unit. 1
PLASMA operation is selected.
The plasma operation check mode is set. (Refer to 10-2.5.)
Does PLASMA lamp stay OFF, or continuously blink?
Continuously blinking.
Replace the PLASMA POWER P.C. board.
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OFF
PLASMA
operation
1 Regardless of normal or abnormal condition, a short beep is emitted once the signal is received.
Normal
2 Turn PLASMA operation OFF and ON again.
(For turning OFF PLASMA operation, refer to 10-2.3.)
(If it goes normal without turning OFF and ON, PLASMA lamp does not go OFF.)
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G Electromagnetic noise enters into TV sets or radios
Is the unit earthed?
Yes
Is the distance between the antennas
and the indoor unit within 3 m, or is the
distance between the antennas and the
outdoor unit within 3 m?
No
Earth the unit.
No
Yes
Extend the distance between the antennas and
the indoor unit, and/or the antennas and the
outdoor unit.
Is the distance between the TV sets or
radios and the indoor unit within 1 m, or
is the distance between the TV sets or
radios and the outdoor unit within 3 m?
No
Yes
Extend the distance between the TV sets and/or
radios and the indoor unit, or the TV sets or
radios and the outdoor unit.
Are the antennas damaged?
Is the coaxial cable damaged?
Is there any poor contact in the antenna wiring?
No
Yes
Replace or repair the antenna.
Replace or repair the coaxial cable.
Yes
Extend the distance between the indoor/outdoor
connecting wire of the air conditioner and the
wiring of the antennas.
Is the indoor/outdoor connecting wire
of the air conditioner and the wiring of
the antennas close?
No
Even if all of the above conditions are fulfilled, the electromagnetic noise may enter, depending on the electric field strength
or the installation condition (combination of specific conditions such as antennas or wiring).
Check the following before asking for service.
1. Devices affected by the electromagnetic noise
TV sets, radios (FM/AM broadcast, shortwave)
2. Channel, frequency, broadcast station affected by the electromagnetic noise
3. Channel, frequency, broadcast station unaffected by the electromagnetic noise
4. Layout of ;
indoor/outdoor unit of the air conditioner, indoor/outdoor wiring, earth wire, antennas, wiring from antennas, receiver
5. Electric field intensity of the broadcast station affected by the electromagnetic noise
6. Presence or absence of amplifier such as booster
7. Operation condition of air conditioner when the electromagnetic noise enters in
1) Turn OFF the power supply once, and then turn ON the power supply. In this situation, check for the electromagnetic
noise.
2) Within 3 minutes after turning ON the power supply, press OPERATE/STOP (ON/OFF) button on the remote controller
for power ON, and check for the electromagnetic noise.
3) After a short time (3 minutes later after turning ON), the outdoor unit starts running. During operation, check for the
electromagnetic noise.
4) Press OPERATE/STOP (ON/OFF) button on the remote controller for power OFF, when the outdoor unit stops but the
indoor/outdoor communication still runs on. In this situation, check for the electromagnetic noise.
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10-7. TEST POINT DIAGRAM AND VOLTAGE
MSZ-FB25VA MSZ-FB35VA MSZ-FB50VA
1. Indoor electronic control P.C. board.
5 VDC
12 VDC
Cement resistor
(R111)
Indoor fan motor
(CN211)
325 VDC
Power supply input
230 VAC
(-) Fiducial terminal of
cathode side on measuring high-voltage DC
15 VDC
(+)3-6 VDC
(+)0 or 15 VDC
{
Interlock switch (Fan)
(CN1R1)
Room temperature
thermistor RT11
(CN111)
Varistor (NR11)
CN201
(Used for check of conducting of thermal fuse)
SW P.C. Board
Emergency
operation
switch (SW1)
Indoor coil thermistor
RT12, RT13 (CN112)
Plasma electrode unit
(CN1T1)
Horizontal vane (CN1U1)
Vertical vane (CN151)
i-see Sensor
(CN110)
Release of Auto restart
function
Solder the Jumper wire
JR07
(Refer to 8-3.)
Fuse
(F11)
Timer short mode
point JPG, JPS
(Refer to 8-1.)
Room temperature thermistor (RT11)
Indoor coil thermistor (RT12, RT13)
Resistance (k )
(LD101)
- : Connect to the monitor P.C.board
- : Connect to the power monitor receiver
P.C.board
}
Temperature ( )
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2. Power monitor receiver P.C. board
3. Monitor P.C. board
4. Plasma power P.C. board
CN1
DC 2.5 V during PLASMA DEODORIZING operation
GND
DC 12.5 V during PLASMA DEODORIZING operation
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11
DISASSEMBLY INSTRUCTIONS
<"Terminal with locking mechanism" Detaching points>
The terminal which has the locking mechanism can be detached as shown below.
There are two types (refer to (1) and (2)) of the terminal with locking mechanism.
The terminal without locking mechanism can be detached by pulling it out.
Check the shape of the terminal before detaching.
(1) Slide the sleeve and check if there is a locking lever or not.
Sleeve
Locking lever
(2) The terminal with this connector has the
locking mechanism.
Slide the sleeve.
Pull the terminal while
pushing the locking
lever.
Hold the sleeve, and
pull out the terminal
slowly.
Connector
MSZ-FB25VA MSZ-FB35VA MSZ-FB50VA
NOTE: Turn OFF power supply before disassembling.
OPERATING PROCEDURE
PHOTOS
1. Removing the panel
Photo 1
(1) Hold both sides of the front panel and lift the front
panel until it is level. Pull the hinges forward to
remove the front panel.
(2) Remove the horizontal vanes.
(3) Remove the screw caps of the panel. Remove the
screws.
(4) Unhook the lower part ( ) of the panel.
(5) Hold the lower part of both ends of the panel and pull
it slightly toward you, and then remove the panel by
pushing it upward.
Horizontal vane
Front panel
A
Screws of the panel
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OPERATING PROCEDURE
PHOTOS
2. Removing the electronic control P.C. board, the
power monitor receiver P.C. board, i-see Sensor,
SW P.C. board and the terminal block
Photo 2
(1) Remove the panel (refer to 1.) and the corner box.
(2) Remove the screw of the V.A. clamp. Remove the V.A.
clamp and the indoor/outdoor connecting wire. (Photo
2)
(3) Remove the sensor holder from the electrical cover.
(Photo 3)
(4) Remove the screw of the electrical cover, and then
the electrical cover. (Photo 3)
(5) Remove the earth wire connected to the indoor electronic control P.C. board from the electrical box. (Photo
3.)
(6) Remove the power monitor receiver P.C. board holder. (Photo 4.)
(7) Pull out the i-see Sensor from the power monitor
receiver P.C. board holder.
( ) Install the i-see Sensor in its former position when
assembling it. (Photo 5)
(8) Open the rear cover of the power monitor receiver P.C.
board holder and pull out the power monitor receiver
P.C. board.
(9) Open the sensor holder and pull out the SW P.C.
board.
(10) Pull the electronic control P.C. board slightly toward
you from the electrical box, and disconnect TAB3 and
all the connectors on the electronic control P.C. board.
(11) Pull out the electronic control P.C. board from the
electrical box.
(12) Remove the earth wire connected to the heat
exchanger from the electrical box. (Photo 3)
(13) Unhook the catches of the electrical box, and pull out
the electrical box.
(14) Remove the screw of the terminal block cover, and
then the terminal block cover and the terminal block
holder. (Photo 2)
(15) Remove the terminal block by sliding it.
Photo 4
Plasma power P.C. board holder
i-see Sensor
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Screw of the
terminal block
cover
Drain hose
Photo 3
Screw of the V.A. clamp
Earth wire to the heat exchanger
Sensor holder
Screw of the
electrical cover
Sensor holder (inside)
Catches of the
electrical box
SW P.C. board
Power monitor receiver
P.C. board holder
37
OPERATING PROCEDURE
PHOTOS
Photo 5
3. Removing the electrical box
(1) Remove the panel (refer to 1.) and the corner box.
(2) Remove the indoor/outdoor connecting wire, the sensor holder, the electrical cover and the earth wire.
(Refer to 2.)
(3) Disconnect the following connectors on the electronic
control P.C. board:
CN211 (Fan motor)
CN112 (Indoor coil thermistor)
CN1U1 (Horizontal vane motor)
CN151 (Vertical vane motor)
CN1R1 (Interlock switch)
CN1T1 (Plasma power P.C. board)
(4) Unhook the catches of the electrical box, and pull out
the electrical box. (Photo 4)
Be sure to assemble the i-see Sensor
in the correct position
Photo 6
4. Removing the nozzle assembly
(1) Remove the panel (refer to 1.) and the corner box.
(2) Remove the V.A. clamp, and then the indoor/outdoor
connecting wire. (Photo 2)
(3) Remove the sensor holder and the electrical cover.
(Photo 3.)
(4) Disconnect the following connectors on the electronic
control P.C. board:
CN1U1 (Horizontal vane motor)
CN151 (Vertical vane motor)
CN1R1 (Interlock switch)
(5) Remove the power monitor receiver P.C. board holder
and the plasma power P.C. board holder. (Photo 4)
(6) Pull out the drain hose from the nozzle assembly and
remove the nozzle assembly.
(7) Remove the interlock switch.
Interlock switch
Screws of the interlock switch
Photo 7
5. Removing the vertical vane motor unit
(1) Remove the nozzle assembly. (Refer to 4.)
(2) Remove the crank of the vertical vane motor unit from
the arm of the vertical vane.
(3) Remove the screw of the vertical vane motor unit, and
pull the vertical vane motor unit.
(4) Remove the screws of the vertical vane motor unit
cover.
(5) Remove the crank of the vertical vane motor unit from
the shaft of the vane motor.
( ) Only the crank of the left side vertical vane motor unit.
(Photo 7)
(6) Remove the vertical vane motor from the vertical vane
motor unit.
(7) Disconnect the connector of vertical vane motor from
the vertical vane motor.
Screws of the vertical vane motor unit cover
Crank of the vertical
vane motor unit
Photo 8
Screws of the vertical vane motor unit cover
Screw of the vertical
vane motor unit
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Screw of the vertical
vane motor unit
Crank of the vertical
vane motor unit
OPERATING PROCEDURE
PHOTOS
6. Removing the horizontal vane motor
Photo 9
Screws of the horizontal
vane motor unit cover
(1) Remove the nozzle assembly. (Refer to 4.)
(2) Remove the screws of the horizontal vane motor unit,
and pull out the horizontal vane motor unit.
(3) Remove the screws of the horizontal vane motor unit
cover.
(4) Remove the horizontal vane motor from the horizontal
vane motor unit.
(5) Disconnect the connector from the horizontal vane
motor.
Screws of the horizontal vane motor unit
7. Removing the indoor fan motor and the line flow
fan
Photo 10
(1) Remove the panel (refer to 1.) and the corner box.
(2) Remove the sensor holder, the power monitor receiver
P.C. board holder, the electrical box (Refer to 3.) and
the nozzle assembly (Refer to 4.).
(4) Remove the screws fixing the motor bed. (Photo 10)
(5) Loosen the screw fixing the line flow fan. (Photo 11)
(6) Remove the motor bed together with fan motor and
motor band.
(7) Release the hooks of the motor band. Remove the
motor band. Pull out the indoor fan motor.
(8) Remove the indoor coil thermistor from the heat
exchanger.
( ) Install the indoor coil thermistor (RT12) in its former
position when assembling it. (Refer to Photo 13)
(9) Remove the screws fixing the left side of the heat
exchanger. (Photo 12)
(10) Lift the heat exchanger, and pull out the line flow fan
to the lower-left.
Motor band
Screws of the
motor bed
Photo 11
Photo 13
MSZ-FB25/35
Screw of the
line flow fan
Indoor coil thermistor (RT12)
Photo 12
MSZ-FB50
Screws of the
left side of the
heat exchanger
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HEAD OFFICE: TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN
© Copyright 2008 MITSUBISHI ELECTRIC CORPORATION
Distributed in Mar. 2014. No. OBH503 REVISED EDITION-C
Distributed in Dec. 2008. No. OBH503 REVISED EDITION-B 5
Distributed in Jul. 2008. No. OBH503 REVISED EDITION-A 6
Distributed in Apr. 2008. No. OBH503 6
Made in Japan
New publication, effective Mar. 2014
Specifications are subject to change without notice.