Mitsubishi Electric MUFZ-KJ-NAHZ Series User manual

INDOOR UNIT
SERVICE MANUAL
Models
MFZ-KJ09NA-U1
MFZ-KJ12NA-U1
MFZ-KJ15NA-U1
MFZ-KJ18NA-U1
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. OBH752
REVISED EDITION-B
PARTS CATALOG (OBB752)
Outdoor unit service manual
MUFZ-KJ•NAHZ Series (OBH753)
MXZ-C•NA, MXZ-C•NAHZ Series
(OBH702, OCH573)
CONTENTS
1. TECHNICAL CHANGES ··································· 3
2. PART NAMES AND FUNCTIONS····················· 4
3. SPECIFICATION················································ 5
4. OUTLINES AND DIMENSIONS ························ 7
5. WIRING DIAGRAM············································ 8
6. REFRIGERANT SYSTEM DIAGRAM··············· 9
7. SERVICE FUNCTIONS ··································· 10
8. MICROPROCESSOR CONTROL ··················· 12
9. TROUBLESHOOTING····································· 21
10. DISASSEMBLY INSTRUCTIONS···················· 36
OBH752 REVISED EDITION-A is void.
Revision B:
• 4. OUTLINES AND DIMENSIONS has been
modified.
INDOOR UNIT

2
Use the speci¿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:
• 3. SPECIFICATION and 4. OUTLINES AND DIMENSIONS have been modified.
Revision B:
• 4. OUTLINES AND DIMENSIONS has been modified.
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1TECHNICAL CHANGES
MFZ-KJ09NA- U1
MFZ-KJ12NA- U1
MFZ-KJ15NA- U1
MFZ-KJ18NA- U1
1. New model
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2PART NAMES AND FUNCTIONS
MFZ-KJ09NA MFZ-KJ12NA MFZ-KJ15NA MFZ-KJ18NA
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
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(Anti-allergy enzyme filter, option)
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Panel
Front panel
Horizontal vane
Vertical vane
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ACCESSORIES
MFZ-KJ09NA MFZ-KJ12NA
MFZ-KJ15NA MFZ-KJ18NA
Drain hose 1
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 ¿xation 4
Washer of 4
Felt tape (Used for left or left-rear piping) 1
Wireless remote controller 1
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3SPECIFICATION
Indoor model MFZ-KJ09NA MFZ-KJ12NA MFZ-KJ15NA MFZ-KJ18NA
Power supply V, phase, Hz 208/230, 1, 60
Max. fuse size (time delay)/ Disconnect switch A15 20
AirÀow
Super High - High - Med. -
Low - Quiet
COOL Dry
(Wet)
CFM 417 - 360 - 272 - 198 - 138
(354 - 306 - 231 - 168 - 117)
431 - 392 - 311 - 254 - 198
(366 - 333 - 264 - 216 - 168)
491 - 420 - 328 - 254 - 198
(417 - 357 - 279 - 216 - 168)
HEAT Dry CFM 417 - 328 - 254 - 191 - 138 470 - 399 - 328 - 268 - 212
Sound level
Super High - High - Med. -
Low - Quiet
Cooling dB (A) 46 - 41 - 34 - 27 - 21
47 - 43 - 38 - 33 - 28 50 - 45 - 39 - 33 - 28
Heating dB (A) 46 - 40 - 34 - 27 - 21 49 - 45 - 40 - 35 - 29 49 - 45 - 40 - 35 - 29
Cond. drain connection O.D. in. 5/8
Dimensions
W
in.
29-17/32
D8-15/32
H23-5/8
Weight Ib. 33
External ¿nish White
Control voltage (by built-in transformer) 12 - 24 VDC
NOTE: Test conditions are based on ARI 210/240.
Indoor model MFZ-KJ09NA MFZ-KJ12NA MFZ-KJ15NA MFZ-KJ18NA
Power supply V, phase, Hz 208/230, 1, 60
Max. fuse size (time delay)/ Disconnect switch A15 20
AirÀow
Super High - High - Med. -
Low - Quiet
COOL Dry
(Wet)
CFM 275 - 251 - 208 173 - 138
(234 - 213 - 177 - 147 - 117)
374 - 328 - 282 - 237 - 198
(318 - 279 - 240 - 201 - 168)
HEAT Dry CFM 343 - 219 - 180 - 159 - 138 470 - 325 - 290 - 254 - 212
Sound level
Super High - High - Med. -
Low - Quiet
Cooling dB (A) 38 - 34 - 30 - 25 - 21 43 - 40 - 36 - 31 - 28
Heating dB (A) 41 - 32 - 27 - 24 - 21 49 - 39 - 36 - 34 - 29
Cond. drain connection O.D. in. 5/8
Dimensions
W
in.
29-17/32
D8-15/32
H23-5/8
Weight Ib. 33
External ¿nish White
Control voltage (by built-in transformer) 12 - 24 VDC
NOTE: Test conditions are based on ARI 210/240.
1. Single connection
2. Multi connection
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 The air coverage is the figure up to the
position where the air speed is 1 ft./s.,
when air is blown out horizontally from
the unit properly at the High speed posi-
tion.
The coverage should be used only as a
general guideline since it varies accord-
ing to the size of the room and furniture
arranged inside the room.
3-2. OUTLET AIR SPEED AND COVERAGE
1. Single connection
Model Mode Function AirÀow
(CFM)
Air speed
(ft./s.)
Coverage (ft.)
MFZ-KJ09NA
MFZ-KJ12NA
HEAT Dry 417 20.3 29.6
COOL Dry 417 20.3 29.6
Wet 354 17.2 25.3
MFZ-KJ15NA
HEAT Dry 470 22.9 33.3
COOL Dry 431 21.0 30.6
Wet 366 17.8 26.2
MFZ-KJ18NA
HEAT Dry 470 22.9 33.3
COOL Dry 491 23.9 34.8
Wet 417 20.3 29.7
2. Multi connection
Model Mode Function AirÀow
(CFM)
Air speed
(ft./s.)
Coverage (ft.)
MFZ-KJ09NA
MFZ-KJ12NA
HEAT Dry 343 16.7 24.5
COOL Dry 275 13.4 19.8
Wet 234 11.4 16.9
MFZ-KJ15NA
MFZ-KJ18NA
HEAT Dry 470 22.9 33.3
COOL Dry 374 18.2 26.7
Wet 318 15.5 22.8
(2) OPERATION
Mode Condition
Intake air temperature (°F)
Indoor Outdoor
DB WB DB WB
Cooling
Standard temperature 80 67 95 —
Maximum temperature 90 73 115 —
Minimum temperature 67 57 14 —
Maximum humidity 78% —
Heating
Standard temperature 70 60 47 43
Maximum temperature 80 67 75 65
Minimum temperature 70 60 -13 -14
3-1. OPERATING RANGE
(1) POWER SUPPLY
Rated voltage Guaranteed voltage (V)
Indoor unit
208/230 V
1 phase
60 Hz
Min. 187 208 230 Max. 253
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4OUTLINES AND DIMENSIONS
MFZ-KJ09NA MFZ-KJ12NA MFZ-KJ15NA MFZ-KJ18NA Unit: inch
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MFZ-KJ09NA MFZ-KJ12NA MFZ-KJ15NA MFZ-KJ18NA
5WIRING DIAGRAM
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MFZ-KJ09NA MFZ-KJ12NA MFZ-KJ15NA MFZ-KJ18NA
Unit: inch (mm)
6REFRIGERANT SYSTEM DIAGRAM
Indoor
heat
exchanger
Flared connection
Room temperature
thermistor
RT11
Indoor coil
thermistor
RT12, RT14,
RT15
(main)
RT13 (sub)
Flared connection
Refrigerant flow in cooling
Refrigerant flow in heating
Refrigerant pipe 3/8 ( 9.52) (MFZ-KJ09/12)
1/2 ( 12.7) (MFZ-KJ15/18)
(with heat insulator)
Refrigerant pipe 1/4 ( 6.35)
(with heat insulator)
Distributor
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SERVICE FUNCTIONS
7
7-1. 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 9-7.)
• 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 3
seconds. Restarting the compressor, which takes 3 minutes, cannot be reduced.
MFZ-KJ09NA MFZ-KJ12NA MFZ-KJ15NA MFZ-KJ18NA
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 9-7.)
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
7-2. 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 ĺ2 ĺ3 ĺ4.
(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
STOP/OPERATE (OFF/ON) button. If 1 or 2 beeps are 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.
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