Mitsubishi Electric MFZ-KJ25VE User manual

CONTENTS
1. TECHNICAL CHANGES ··································· 2
2. PART NAMES AND FUNCTIONS····················· 3
3. SPECIFICATION················································ 4
4. NOISE CRITERIA CURVES······························ 5
5. OUTLINES AND DIMENSIONS ························ 6
6. WIRING DIAGRAM············································ 7
7. REFRIGERANT SYSTEM DIAGRAM··············· 8
8. SERVICE FUNCTIONS ····································· 9
9. MICROPROCESSOR CONTROL ····················11
10. TROUBLESHOOTING····································· 18
11. DISASSEMBLY INSTRUCTIONS···················· 31
SPLIT-TYPE AIR CONDITIONERS
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.
SERVICE MANUAL
Models
No. OBH666
REVISED EDITION-A
INDOOR UNIT
MFZ-KJ25VE -E1
MFZ-KJ35VE -E1
MFZ-KJ50VE -E1
Outdoor unit service manual
MUFZ-KJ•VE Series (OBH667)
MUFZ-KJ•VEHZ Series (OBH668)
Please void OBH666.
Revision A:
• MFZ-KJ50VE- E1 has been added.

2
1TECHNICAL CHANGES
MFZ-KJ25VE- E1
MFZ-KJ35VE- E1
MFZ-KJ50VE- E1
1. New model
With the horizontal vanes and the multi-flow vane, air blows to the expanded vertical area using only one fan.
These 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.
<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 specified 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.
OBH666A

3
2PART NAMES AND FUNCTIONS
MFZ-KJ25VE
MFZ-KJ35VE
MFZ-KJ50VE
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)
Air filter
(Nano platinum filter)
Panel
Front panel
Horizontal vane
Vertical vane
Multi-flow vane
ACCESSORIES
Remote controller holder
Fixing screw for 3.5 x 16 mm (Black)
Pipe cover
Band
Battery (AAA) for remote controller
Indoor unit mounting bracket
Fixing screw for 4 x 25 mm
Wood screw for the indoor unit fixation
Washer of
Felt tape (Used for left or left-rear piping)
Wireless remote controller
Air cleaning filter
MFZ-KJ25VE
MFZ-KJ35VE
MFZ-KJ50VE
1
2
1
2
2
1
5
4
4
1
1
2
OBH666A

4
3SPECIFICATION
Indoor model MFZ-KJ25VE MFZ-KJ35VE MFZ-KJ50VE
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 1 Cooling 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
Airflow
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
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
Fuse (F11) T3.15AL250V
Horizontal vane motor (Front) (MV1) 12 VDC 250 Ω
Horizontal vane motor (Back) (MV2) 12 VDC 250 Ω
Multi-flow vane motor (MV3) 12 VDC 350 Ω
Terminal block (TB) 3P
Varistor (NR11) S10K300E2K1
OBH666A

5
4NOISE CRITERIA CURVES
NC-60
NC-50
NC-40
NC-30
NC-20
NC-70
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
Test conditions
Cooling : Dry-bulb temperature 27 °C Wet-bulb temperature 19 °C
COOLING
FUNCTION
39
41
SPL(dB(A)) LINE
Super High
FAN SPEED
HEATING
Heating : Dry-bulb temperature 20 °C
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-10
MFZ-KJ25VE
INDOOR UNIT
WALL
1m
1m
MICROPHONE
MFZ-KJ35VE
MFZ-KJ50VE
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
OBH666A

6
OUTLINES AND DIMENSIONS
5
Unit: mm
MFZ-KJ25VE
MFZ-KJ35VE
MFZ-KJ50VE
OBH666A

7
6WIRING DIAGRAM
MFZ-KJ25VE
MFZ-KJ35VE
MFZ-KJ50VE
OBH666A

8
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-KJ35VE
MFZ-KJ50VE
OBH666A

9
SERVICE FUNCTIONS
8
8-1. TIMER SHORT MODE
For service, the following set time can be shortened by short circuiting 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-KJ35VE
MFZ-KJ50VE
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) 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.
OBH666A

1010
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.)
OBH666A