Mitsubishi Electric MFZ-KJ25VE User manual

INDOOR UNIT
Models
MFZ-KJ25VE - E1
MFZ-KJ25VE - E2 , ER2
MFZ-KJ25VE2 - E1 , ER1
MFZ-KJ35VE - E1
MFZ-KJ35VE - E2 , ER2
MFZ-KJ35VE2 - E1 , ER1
MFZ-KJ50VE - E1 , ER1
MFZ-KJ50VE2 - E1 , ER1
SERVICE MANUAL
PARTS CATALOG (OBB666)
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 ············································8
7. REFRIGERANT SYSTEM DIAGRAM ···············9
8. SERVICE FUNCTIONS ···································10
9. MICROPROCESSOR CONTROL ···················12
10. TROUBLESHOOTING ·····································20
11. DISASSEMBLY INSTRUCTIONS ····················35
NOTE:
• This service manual describes technical data of the indoor units.
• RoHS compliant products have <G> mark on the spec name plate.
For servicing of RoHS compliant products, refer to the RoHS Parts List.
No. OBH666
REVISED EDITION-C
Outdoor unit service manual
MUFZ-KJ•VE Series (OBH667)
MUFZ-KJ•VEHZ Series (OBH668)
Please void OBH666 REVISED EDITION-B.
Revision C:
• MFZ-KJ25VE2-
E1
,
ER1
, MFZ-KJ35VE2-
E1
,
ER1
and MFZ-KJ50VE2-
E1
,
ER1
have been
added.

2
<Preparation before the repair service>
Prepare the proper tools.
Prepare the proper protectors.
Provide adequate ventilation.
After stopping the operation of the air conditioner, turn off the power-supply breaker and remove the power plug.
Discharge the capacitor before the work involving the electric parts.
<Precautions during the repair service>
Do not perform the work involving the electric parts with wet hands.
Do not pour water into the electric parts.
Do not touch the refrigerant.
Do not touch the hot or cold areas in the refrigeration cycle.
When the repair or the inspection of the circuit needs to be done without turning off the power, exercise great caution not to
touch the live parts.
Use the specif ed refrigerant only
Never use any refrigerant other than that specified.
Doing so may cause a burst, an explosion, or fire when the unit is being used, serviced, or disposed of.
Correct refrigerant is specified in the manuals and on the spec labels provided with our products.
We will not be held responsible for mechanical failure, system malfunction, unit breakdown or accidents caused by
failure to follow the instructions.
Revision A:
• MFZ-KJ50VE- E1 has been added.
Revision B:
• MFZ-KJ25VE- E2 , ER2 , MFZ-KJ35VE- E2 , ER2 and MFZ-KJ50VE- ER1 have been added.
Revision C:
• MFZ-KJ25VE2- E1 , ER1 , MFZ-KJ35VE2- E1 , ER1 and MFZ-KJ50VE2- E1 , ER1 have been added.
OBH666C

3
1TECHNICAL CHANGES
MFZ-KJ25VE- E1
MFZ-KJ35VE- E1
MFZ-KJ50VE- E1
1. New model
MFZ-KJ50VE- ER1
1. New model
MFZ-KJ25VE- E1 MFZ-KJ25VE- E2 ,ER2
MFZ-KJ35VE- E1 MFZ-KJ35VE- E2 ,ER2
1. Indoor electronic control P.C. board has been changed.
MFZ-KJ25VE2- E1
MFZ-KJ35VE2- E1
MFZ-KJ50VE2- E1
MFZ-KJ25VE2- ER1
MFZ-KJ35VE2- ER1
MFZ-KJ50VE2- ER1
1. New model
• MFZ-KJ25VE- E1 MFZ-KJ35VE- E1
The model MFZ-KJ25VE- E1 or MFZ-KJ35VE- E1 is connected to the MUFZ-KJ·VE(HZ) outdoor unit only.
• MFZ-KJ25VE- E2 , ER2
MFZ-KJ35VE- E2 , ER2 MFZ-KJ50VE- E1 , ER1
MFZ-KJ25VE2- E1 , ER1
MFZ-KJ35VE2- E1 , ER1 MFZ-KJ50VE2- E1 , ER1
The model MFZ-KJ25VE- E2 ,ER2 ,MFZ-KJ35VE- E2 ,ER2 , MFZ-KJ50VE- E1 ,ER1 , MFZ-KJ25VE2- E1 ,ER1 ,
MFZ-KJ35VE2- E1 ,ER1 or MFZ-KJ50VE2- E1 ,ER1 is connectable with the MUFZ-KJ·VE(HZ) outdoor unit or the MXZ out-
door unit.
This model may be connected to the MUFZ-KJ·VE(HZ) series after once connected to the MXZ series and operated, for
example because of relocation. In that case, the MUFZ-KJ·VE(HZ) series outdoor units will not operate without taking a
step. Follow the procedure "Deleting the memorized abnormal condition" described in 10-2.1.
The following models are compatible with the outdoor units with low standby power control.
Connecting these models to the MUFZ-KJ·VE(HZ) series outdoor units enables the low standby power control. Low standby
power control can reduce standby power about 90%.
Refer to the technical guide (OBT17) about the low standby power control.
With the horizontal vanes and the multi-flow vane, air blows to the expanded vertical area using only one fan.
Notes:
OBH666C

4
2PART NAMES AND FUNCTIONS
MFZ-KJ25VE MFZ-KJ25VE2
MFZ-KJ35VE MFZ-KJ35VE2
MFZ-KJ50VE MFZ-KJ50VE2
E.O
SW
Display and operation section (When the front panel is opened)
Operation indicator lamp
Emergency operation
switch
Remote control receiving section
Fan guard
Air outlet
Air cleaning filter
[Anti-allergy enzyme filter
(MFZ-KJ25/35/50VE)
Silver-ionized air purifier filter
(MFZ-KJ25/35/50VE2)]
Air filter
[Nano platinum filter (MFZ-KJ25/35/50VE)
Air purifying filter (MFZ-KJ25/35/50VE2)]
Panel
Front panel
Horizontal vane
Vertical vane
Multi-flow vane
ACCESSORIES
MFZ-KJ25VE MFZ-KJ25VE2
MFZ-KJ35VE MFZ-KJ35VE2
MFZ-KJ50VE MFZ-KJ50VE2
Remote controller holder 1
Fixing screw for 3.5 x 16 mm (Black) 2
Pipe cover 1
Band 2
Battery (AAA) for remote controller 2
Indoor unit mounting bracket 1
Fixing screw for 4 x 25 mm 5
Wood screw for the indoor unit f xation 4
Washer of 4
Felt tape (Used for left or left-rear piping) 1
Wireless remote controller 1
Air cleaning f lter 2
OBH666C

5
3SPECIFICATION
Indoor model MFZ-KJ25VE
MFZ-KJ25VE2
MFZ-KJ35VE
MFZ-KJ35VE2
MFZ-KJ50VE
MFZ-KJ50VE2
Power supply Single phase 230 V, 50 Hz
Electrical data
Power input 1 Cooling W13 21
Heating 16 38
Running current
1
Cooling A0.14 0.20
Heating 0.17 0.34
Fan motor
Model RC0J30-KX RC0J40-PA
Current 1Cooling A0.14 0.20
Heating 0.17 0.34
Dimensions W × H × D mm 750 × 600 × 215
Weight kg 15
Special remarks
Air direction 1 FLOW: 4, 2 FLOW: 4
Airf ow
Cooling
Super High
m3/h
492 636
High 426 558
Med. 354 480
Low 294 402
Silent 234 336
Heating
Super High
m3/h
582 840
High 462 696
Med. 372 564
Low 306 444
Silent 234 360
Sound level
Cooling
Super High
dB(A)
39 44
High 35 39
Med. 30 35
Low 25 31
Silent 20 27
Heating
Super High
dB(A)
41 50
High 35 45
Med. 30 40
Low 25 35
Silent 19 29
Fan speed
Cooling
Super High
rpm
790 980
High 700 880
Med. 600 770
Low 520 670
Silent 440 580
Heating
Super High
rpm
910 1,250
High 750 1,060
Med. 630 890
Low 540 750
Silent 440 610
Fan speed regulator 5
Remote controller model SG132 (MFZ-KJ·VE)/SG161(MFZ-KJ·VE2)
NOTE: Test conditions are based on ISO 5151.
Cooling: Indoor Dry-bulb temperature 27°C Wet-bulb temperature 19°C
Outdoor Dry-bulb temperature 35°C
Heating: Indoor Dry-bulb temperature 20°C
Outdoor Dry-bulb temperature 7°C Wet-bulb temperature 6°C
1 Measured under rated operating frequency.
Specifications and rating conditions of main electric parts
Model
Item
MFZ-KJ25VE MFZ-KJ35VE MFZ-KJ50VE
MFZ-KJ25VE2 MFZ-KJ35VE2 MFZ-KJ50VE2
Fuse (F11) T3.15AL250V
Horizontal vane motor (Front) (MV1) 12 VDC 250 Ω
Horizontal vane motor (Back) (MV2) 12 VDC 250 Ω
Multi-f ow vane motor (MV3) 12 VDC 350 Ω
Terminal block (TB) 3P
Varistor (NR11) S10K300E2K1
OBH666C

6
4NOISE CRITERIA CURVES
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
80
70
60
50
40
30
20
10
063 125 250 500 1000 2000 4000 8000
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
COOLING
FUNCTION
39
41
SPL(dB(A)) LINE
Super High
FAN SPEED
HEATING
NC-10
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
80
70
60
50
40
30
20
10
063 125 250 500 1000 2000 4000 8000
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
COOLING
FUNCTION
39
41
SPL(dB(A)) LINE
Super High
FAN SPEED
HEATING
NC-10
MFZ-KJ25VE
MFZ-KJ25VE2
INDOOR UNIT
WALL
1m
1m
MICROPHONE
Test conditions
Cooling : Dry-bulb temperature 27 °C Wet-bulb temperature 19 °C
Heating : Dry-bulb temperature 20 °C
MFZ-KJ35VE
MFZ-KJ35VE2
MFZ-KJ50VE
MFZ-KJ50VE2
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
80
70
60
50
40
30
20
10
063 125 250 500 1000 2000 4000 8000
OCTAVE BAND SOUND PRESSURE LEVEL, dB re 0.0002 MICRO BAR
BAND CENTER FREQUENCIES, Hz
COOLING
FUNCTION
44
50
SPL(dB(A)) LINE
Super High
FAN SPEED
HEATING
NC-10
OBH666C

7
OUTLINES AND DIMENSIONS
5
Unit: mm
MFZ-KJ25VE MFZ-KJ25VE2
MFZ-KJ35VE MFZ-KJ35VE2
MFZ-KJ50VE MFZ-KJ50VE2
OBH666C

8
6WIRING DIAGRAM
MFZ-KJ25VE
MFZ-KJ35VE
MFZ-KJ50VE
MFZ-KJ25VE2
MFZ-KJ35VE2
MFZ-KJ50VE2
OBH666C

9
REFRIGERANT SYSTEM DIAGRAM
7
Indoor
heat
exchanger
Flared connection
Room temperature
thermistor
RT11
Indoor coil
thermistor
RT14, RT15
(main)
RT13 (sub)
Flared connection
Refrigerant flow in cooling
Refrigerant flow in heating
Refrigerant pipe 9.52 (MFZ-KJ25/35)
12.7 (MFZ-KJ50)
(with heat insulator)
Refrigerant pipe 6.35
(with heat insulator)
Indoor coil
thermistor
RT12 (main)
Distributor
Unit: mm
MFZ-KJ25VE MFZ-KJ25VE2
MFZ-KJ35VE MFZ-KJ35VE2
MFZ-KJ50VE MFZ-KJ50VE2
OBH666C

10
SERVICE FUNCTIONS
8
8-1. TIMER SHORT MODE
• For service, the following set time can be shortened by bridging the timer short mode point on the electronic control P.C.
board. (Refer to 10-7.)
• The set time for the ON/OFF timer can be reduced to 1 second for each minute.
• After the breaker is turned on, the time for starting the compressor, which normally takes 3 minutes, can be reduced to 1
minute. Restarting the compressor, which takes 3 minutes, cannot be reduced.
MFZ-KJ25VE MFZ-KJ25VE2
MFZ-KJ35VE MFZ-KJ35VE2
MFZ-KJ50VE MFZ-KJ50VE2
1. How to modify the electronic control P.C. board
Turn OFF the power supply before modification. To assign a number to each indoor unit , cut off “JR05” and “JR06” on the
electronic control P.C. board as shown in Table 1. (Refer to 10-7.)
Unit No. 1
Unit No. 2
Unit No. 3
Unit No. 4
JR05
No modification
Cut off JR05
No modification
Cut off JR05
JR06
No modification
No modification
Cut off JR06
Cut off JR06
Table 1
CN211
Fuse (F11)
VARISTOR (NR11)
Indoor electronic
control P.C. Board
CN151
JR05
JR06
R111
8-2. HOW TO SET REMOTE CONTROLLER EXCLUSIVELY FOR A PARTICULAR INDOOR UNIT
A maximum of 4 indoor units with wireless remote controllers can be used in a room.
To operate the indoor units individually with each remote controller, assign a number to each remote controller according
to the number of the indoor unit.
This setting can be set only when all the following conditions are met:
• The remote controller is powered OFF.
• Weekly timer is not set.
• Weekly timer is not being edited.
2. How to set the remote controller
(1) Hold down button on the remote controller for 2 seconds to enter the pairing mode.
(2) Press button again and assign a number to each remote controller.
Each press of button advances the number in the following order: 1 → 2 → 3 → 4.
(3) Press button to complete the pairing setting.
After the setting, turn ON the power supply and with the remote controller headed towards the indoor unit, press the
OPERATE/STOP (ON/OFF)(MFZ-KJ25/35/50VE)/ STOP/OPERATE (OFF/ON)(MFZ-KJ25/35/50VE2) button. If 1 or 2
beeps is heard from the indoor unit, the setting is completed correctly.
The remote controller that first sends a signal to an indoor unit will be regarded as the remote controller for the indoor
unit.
Once they are set, the indoor unit will only receive the signal from the assigned remote controller afterwards.
OBH666C

1111
CN123
CN105
CN104
CN111
CN211
T111
C111
L101
CN201 F11
JR77
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 can-
celled.
• 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 cur-
rent by adding to the system that allows the units to start one by one.
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.)
How to disable “AUTO RESTART FUNCTION”
Turn off the main power for the unit.
Cut the Jumper wire to JR77 on the indoor electronic control P.C. board. (Refer to 10-7.)
OBH666C

12
WIRELESS REMOTE CONTROLLER
MFZ-KJ25VE MFZ-KJ25VE2
MFZ-KJ35VE MFZ-KJ35VE2
MFZ-KJ50VE MFZ-KJ50VE2
MICROPROCESSOR CONTROL
9
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.
Signal transmitting section
Operation display section
TEMPERATURE buttons
OPERATE/STOP
(ON/OFF) button
Indication of
remote controller
model is on back
Distance of signal :
About 6 m
Beep(s) is (are) heard from
the indoor unit when the
signal is received.
FAN SPEED CONTROL button
OPERATION SELECT button
ECONO COOL button
CLOCK button
Lid
Slide the lid down
to open the remote
controller. Slide it down
further to get to the
weekly timer buttons.
WEEKLY TIMER
set buttons
TIME, TIMER set buttons
FORWARD button
BACKWARD button
RESET button
i-save button
VANE CONTROL button
AMPM AMPM
Signal transmitting section
Operation display section
TEMPERATURE buttons
STOP/OPERATE
(OFF/ON) button
Indication of
remote controller
model is on back
Distance of signal :
About 6 m
Beep(s) is (are) heard from
the indoor unit when the
signal is received.
FAN SPEED CONTROL button
OPERATION SELECT button
ECONO COOL button
CLOCK button
Lid
Slide the lid down
to open the remote
controller. Slide it down
further to get to the
weekly timer buttons.
WEEKLY TIMER
set buttons
TIME, TIMER set buttons
FORWARD button
BACKWARD button
RESET button
i-save button
VANE CONTROL button
AMPM AMPM
MFZ-KJ25VE2 MFZ-KJ35VE2 MFZ-KJ50VE2
MFZ-KJ25VE MFZ-KJ35VE MFZ-KJ50VE
OBH666C

13
INDOOR UNIT DISPLAY SECTION
9-1. COOL ( ) OPERATION
(1) Press OPERATE/STOP (ON/OFF)(MFZ-KJ25/35/50VE)/ STOP/OPERATE (OFF/ON)(MFZ-KJ25/35/50VE2) button.
OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone.
(2) Select COOL mode with OPERATION SELECT button.
(3) Press TEMPERATURE buttons TEMP or 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.
3. Indoor fan speed control
When the thermostat turns OFF, the indoor fan operates at the setting fan speed.
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 indication.
Indication Operation state Room temperature
The unit is operating to
reach the set temperature
About 2°C or more
away from set tempera-
ture
The room temperature is
approaching the set tem-
perature
About 1 to 2°C from
set temperature
Standby mode (only during
multi system operation) —
Lighted
Blinking
Not lighted
9-2. DRY ( ) OPERATION
(1) Press OPERATE/STOP (ON/OFF)(MFZ-KJ25/35/50VE)/ STOP/OPERATE (OFF/ON)(MFZ-KJ25/35/50VE2) button.
OPERATION INDICATOR 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 works the same way as that in COOL mode. (9-1.1.)
2. Low outside temperature operation
Low outside temperature operation works the same way as that in COOL mode. (9-1.2.)
3. Indoor fan speed control
Indoor fan speed control works the same way as that in COOL mode. (9-1.3.)
However in AUTO setting, the fan speed changes.
9-3. FAN ( ) OPERATION
(1) Press OPERATE/STOP (ON/OFF)(MFZ-KJ25/35/50VE)/ STOP/OPERATE (OFF/ON)(MFZ-KJ25/35/50VE2) button.
OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone.
(2) Select FAN mode with OPERATION SELECT button.
(3) Select the desired fan speed. When AUTO, it becomes Low.
Only indoor fan operates.
Outdoor unit does not operate.
NOTE: Temperature cannot be set during FAN mode.
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14
9-4. HEAT ( ) OPERATION
(1) Press OPERATE/STOP (ON/OFF)(MFZ-KJ25/35/50VE)/ STOP/OPERATE (OFF/ON)(MFZ-KJ25/35/50VE2) button.
OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone.
(2) Select HEAT mode with OPERATION SELECT button.
(3) Press TEMPERATURE buttons TEMP or 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 tem-
perature 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 con-
densing pressure from increasing excessively.
When the temperature of indoor heat exchanger becomes too high, the high pressure protection works.
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.
9-5. AUTO CHANGE OVER ··· AUTO MODE OPERATION
Once desired temperature is set, unit operation is switched automatically between COOL and HEAT operation.
1. Mode selection
(1) Initial mode
At first indoor unit operates only indoor fan with outdoor unit OFF for 3 minutes to detect present room temperature.
Following the conditions below, operation mode is selected.
If the room temperature thermistor RT11 reads more than set temperature, COOL mode is selected.
If the room temperature thermistor RT11 reads set temperature or less, HEAT mode is selected.
(2) Mode change
In case of the following conditions the operation mode is changed.
COOL mode changes to HEAT mode when 15 minuets have passed with the room temperature 2 degrees below the
set temperature.
HEAT mode changes to COOL mode when 15 minuets have passed with the room temperature 2 degrees below the
set temperature.
In the other cases than the above conditions, the present operation mode is continued.
NOTE 1: Mode selection is performed when multi standby (refer to NOTE 2) is released and the unit starts operation
with ON-timer. (MFZ-KJ25/35VE-E2 ,ER2 , MFZ-KJ25/35VE2-E1 ,ER1 , MFZ-KJ50VE/VE2)
NOTE 2: If 2 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 the other operating mode (COOL ↔ HEAT) and becomes a state
of standby. (MFZ-KJ25/35VE-E2 ,ER2 , MFZ-KJ25/35VE2-E1 ,ER1 , MFZ-KJ50VE/VE2)
NOTE 3: At the beginning of AUTO mode, the air flow direction and the fan speed are set to AUTO and the air outlet
selection is set to 2 FLOW.
9-6. AUTO VANE OPERATION
1. Horizontal vane (Horizontal vane/Multi-flow vane)
(1) Vane motor drive
These models are equipped with a stepping motors for the horizontal vanes. The rotating direction, speed, and angle
of the motor are controlled by pulse signals (approximately 12 V) transmitted from indoor microprocessor.
(2) The horizontal vane angle and mode change as follows by pressing VANE CONTROL ( ) button.
(AUTO) (2) (3) (4)(1) (SWING)
OBH666C

15
In COOL, DRY and FAN operation
2 FLOW: Vane angle is fixed to position 2.
In HEAT operation
2 FLOW: Vane angle is fixed to position 2.
(5) VANE AUTO ( ) mode
In VANE AUTO mode, the microprocessor automatically determines the vane angle to make the optimum room tem-
perature distribution.
(4) Air outlet selection
The air outlet(s) can be selected by pressing to VANE CONTROL ( ) button.
When 2 FLOW is selected, air blows from the top and the front of the unit. When 1 FLOW is selected, air blows only
from the top of the unit.
The multi-flow vane is automatically set to the appropriate position.
In HEAT, the multi-flow vane automatically changes its position according to the indoor fan speed.
Even if 2 FLOW is selected, air will blow only from the top of the unit in the following conditions:
• During COOL/DRY: The room temperature is close to set temperature.
The air conditioner has operated for 0.5 to 1 hour.
• During HEAT: The air flow temperature is low. (During defrosting operation, start of operation, etc.)
NOTE:
Movement at the start of the 2 FLOW operation
• COOL/DRY, HEAT: It takes 0.5 to 1 minute to start the 2 FLOW operation.
• HEAT: When cold air blows out from the air outlet, the multi-flow vane may stop moving for up to 10 minutes to
make and blow out warm air.
(2 FLOW) (1 FLOW)
1 FLOW: Vane angle is fixed to position 1. 1 FLOW: Vane angle is fixed to position 3.
(3) Positioning
The vane presses the vane stopper once to confirm the standard position and then moves to the set angle.
Confirming of standard position is performed in case of follows.
(a) The power supply turns on.
(b) The operation starts or finishes (including timer operation).
(c) The test run starts.
(d) The multi-standby starts or finishes.
(e) Every time the vane has swung more than the specified numbers of times.
(f) The horizontal vane automatically moves in certain intervals to determine its position, and then it returns to
set position.
(g) The vane operates for the dew prevention.
(6) 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)(MFZ-KJ25/35/50VE)/ STOP/OPERATE (OFF/ON)(MFZ-KJ25/35/50VE2)
button is pressed (POWER OFF).
(b) When the operation is stopped by the emergency operation.
(c) When ON TIMER is ON standby.
(7) Dew prevention
During COOL or DRY operation with the vane angle at Angle 3 or 4 when the compressor cumulative operation time
exceeds 1 hour, the vane angle automatically changes to Angle 1 for dew prevention.
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(8) SWING ( ) mode
By selecting SWING mode with VANE CONTROL button, the horizontal vanes swing vertically.
The remote controller displays " ". SWING mode is cancelled when VANE CONTROL button is pressed once again.
(9) Cold air prevention in HEAT operation
The horizontal vane position is set to Upward.
(10) ECONO COOL ( ) operation (ECONOmical operation)
When ECONO COOL button is pressed in COOL mode, set temperature is automatically set 2°C higher by the
microprocessor. However, the temperature on the LCD screen on the remote controller is not changed. Also the hori-
zontal 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.
To cancel this operation, select a different mode or press one of the following buttons in ECONO COOL operation:
ECONO COOL, VANE CONTROL button.
9-7. 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 button.
How to set the current time
(a) Press the CLOCK button.
(b) Press the TIME SET buttons ( and ) to set the current time.
• Each time FORWARD button ( ) is pressed, the set time increases by 1 minute, and each time 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)(MFZ-KJ25/35/50VE)/ STOP/OPERATE (OFF/ON)(MFZ-KJ25/35/50VE2) button to
start the air conditioner.
(3) Set the time of timer.
ON timer setting
(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 ( ) 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 but-
ton ( ) is pressed, the set time decreases by 10 minutes.
2. To release the timer
To release ON timer, press ON TIMER button ( ).
To release OFF timer, press OFF TIMER button( ).
TIMER is cancelled and the display of set time disappears.
(Example 1) The current time is 8:00 PM.
The unit turns off at 11:00 PM, and on at 6:00 AM.
• OFF timer and ON timer can be used in combination. The set time that is reached first will operate first.
• “ ” and “ ” display shows the order of OFF timer and ON timer operation.
PROGRAM TIMER
(Example 2) The current time is 11:00 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 can-
celled. As these models are equipped with an auto restart function, the air conditioner starts operating with timer
cancelled when power is restored.
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9-8. WEEKLY TIMER OPERATION
• A maximum of 4 ON or OFF timers can be set for individual days of the week.
• A maximum of 28 ON or OFF timers can be set for a week.
* Make sure that the current time and day are set correctly.
(1) Press button to enter the weekly timer setting mode.
(2) Press and buttons to select setting day and number.
(3) Press , , and buttons to set ON/OFF, time, and temperature.
E.g. : [ON], [6:00]
and [24°C] are
selected.
Pressing
selects ON/OFF timer.
Pressing
deletes timer setting.
Pressing
adjusts the time.
Pressing
adjusts the tem-
perature.
* Hold down the button to change the time quickly.
* The temperature can be set between 16 °C and 31 °C at weekly timer.
* blinks.
Pressing selects the day of
the week to be set.
Pressing selects
the setting number.
E.g. : [Mon Tue ... Sun]
and [1] are selected.
* All days can be selected.
NOTE:
• The simple ON/OFF timer setting is available while the weekly timer is on. In this case, the ON/OFF timer has priority over the
weekly timer; the weekly timer operation will start again after the simple ON/OFF timer is complete.
• When the weekly timer is set, temperature cannot be set to 10°C.
• The weekly timer operation and i-save operation cannot be used together.
1. How to set the weekly timer
Press and buttons to continue setting the timer for other days and/or numbers.
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(5) Press button to turn the weekly timer ON. ( lights.)
•When the weekly timer is ON, the day of the week whose timer setting is complete, will light.
Press button again to turn the weekly timer OFF. ( goes out.)
NOTE:
The saved settings will not be cleared when the weekly timer is turned OFF.
2. Checking weekly timer setting
2. Checking weekly timer setting
(1) Press button to enter the weekly timer setting mode.
* blinks.
(2) Press or buttons to view the setting of the particular day or number.
(3) Press button to exit the weekly timer setting.
9-9. i-save ( ) OPERATION
1. How to set i-save operation
(1) Press OPERATE/STOP (ON/OFF)(MFZ-KJ25/35/50VE)/ STOP/OPERATE (OFF/ON)(MFZ-KJ25/35/50VE2) button.
(2) Select COOL or HEAT mode.
(3) Press i-save button.
(4) Set the temperature, fan speed, airf ow direction, and 2 FLOW/1 FLOW for i-save operation.
NOTE:
• i-save operation cannot be selected during DRY, FAN or AUTO mode operation.
• The setting range of HEAT mode i-save operation is 10°C and 16 - 31°C.
• 2 groups of setting can be saved. (One for COOL, one for HEAT)
• i-save operation and the weekly timer operation cannot be used together.
2. How to cancel operation
• Press i-save button again.
• i-save operation can also be cancelled by pressing OPERATION SELECT button to change the operation mode.
The same setting is selected from the next time by simply pressing i-save button.
(4) Press button to complete and transmit the weekly timer setting.
* which was blink-
ing goes out, and the
current time will be
displayed.
NOTE:
• Press button to transmit the setting information of weekly timer to the indoor unit. Point the remote controller toward the
indoor unit for 3 seconds.
• When setting the timer for more than one day of the week or one number, button does not have to be pressed per each
setting. Press button once after all the settings are complete. All the weekly timer settings will be saved.
• Press button to enter the weekly timer setting mode, and press and hold button for 5 seconds to erase all weekly
timer settings. Point the remote controller toward the indoor unit.
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9-10. EMERGENCY/TEST OPERATION
In the 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 miss-
ing or has failed, or when the batteries in the remote controller are
running down. The unit will start and OPERATION INDICATOR lamp
will light up.
The first 30 minutes of operation is the test run operation. This opera-
tion is for servicing. The indoor fan runs at High speed and the tem-
perature control does not work. In COOL MODE, the air outlet selec-
tion is set to 2 FLOW during the test run operation.
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 Medium.
The coil frost prevention works even in the test run or the 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 the latter case, normal operation will start.
NOTE: Do not press EMERGENCY OPERATION switch during nor-
mal operation.
Operation mode COOL/HEAT
Set temperature 24°C
Fan speed Medium
Horizontal vane Auto
Air outlet 2 FLOW
The operation mode is indicated by the Operation
Indicator lamp as following
Operation Indicator lamp
EMERGENCY COOL
↓
EMERGENCY HEAT
↓
STOP
Lighted
Not lighted
9-11. 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.
Emergency
operation switch
(E.O. SW)
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TROUBLESHOOTING
10
MFZ-KJ25VE MFZ-KJ35VE MFZ-KJ50VE MFZ-KJ25VE2 MFZ-KJ35VE2 MFZ-KJ50VE2
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.
3. Do not use the leaking batteries.
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.
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 connector housing. DO NOT pull the lead wires.
3. Troubleshooting procedure
1) 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 OPERATION INDICATOR lamp is flashing ON and OFF before starting
service work.
2) Before servicing, check that the connector and terminal are connected properly.
3) When the electronic control 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.
Lead wiring Connector housing
<Incorrect> <Correct>
Press RESET button with a thin instrument, and
then use the remote controller.
Remove the front lid and insert batteries.
Then reattach the front lid.
Insert the negative pole of the
batteries first. Check if the polarity
of the batteries is correct.
RESET button
• When the indoor units start operation while the defrosting of the outdoor unit is being performed, it takes a few minutes (up
to 10 minutes) to blow out warm air.
• In the heating operation, even though the indoor unit is not running, the room may get warm or the sound of refrigerant
flowing may be heard. This is not a malfunction. They happen because the refrigerant is continuously flowing inside the
unit.
5. Description of multi system air conditioner
INDOOR UNIT: MFZ-KJ25/35VE-
E2
,
ER2
, MFZ-KJ25/35VE2-
E1
,
ER1
, MFZ-KJ50VE/VE2 OUTDOOR UNIT: MXZ series
The multi system outdoor unit can be connected to 2 or more indoor units.
•
The units do not operate and the operation indicator lamp flashes as shown in the figure below when the total capacity of
the indoor units exceeds the capacity of the outdoor unit. Do not connect the indoor units beyond the outdoor unit capacity.
• When operating the 2 or more indoor units connected to a multi system outdoor unit, set all the indoor units to the
same operation mode. If the COOL and the HEAT modes are selected for those indoor units, the indoor unit which has
started operation first has a priority. The other indoor units set to the different operation mode later do not start opera-
tion and the operation indicator lamp flashes as shown in the figure below.
OPERATION INDICATOR
Not lighted
Blinking
Lighted
(Green)
(Green)
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