Mitsubishi Electric M Z-C NA Series User manual

No. OBH802
REVISED EDITION-B
INDOOR UNIT
SERVICE MANUAL
Outdoor unit service manual
MXZ-C NA, MXZ-C NAHZ Series
(OBH702, OCH573)
PARTS CATALOG (OBB802)
CONTENTS
1. TECHNICAL CHANGES ··································· 2
2. PART NAMES AND FUNCTIONS····················· 3
3. SPECIFICATION················································ 4
4. OUTLINES AND DIMENSIONS ························ 6
5. WIRING DIAGRAM············································ 7
6. REFRIGERANT SYSTEM DIAGRAM··············· 9
7. SERVICE FUNCTIONS ··································· 10
8. MICROPROCESSOR CONTROL ··················· 13
9. TROUBLESHOOTING····································· 22
10. DISASSEMBLY INSTRUCTIONS···················· 37
OBH802 REVISED EDITION-A is void.
Revision B:
• MLZ-KP09/12/18NA2- U1 have been added.
Models
MLZ-KP09NA -U1 MLZ-KP09NA2 -U1
MLZ-KP12NA -U1 MLZ-KP12NA2 -U1
MLZ-KP18NA -U1 MLZ-KP18NA2 -U1

2
1TECHNICAL CHANGES
MLZ-KP09NA- U1
MLZ-KP12NA- U1
MLZ-KP18NA- U1
1. New model
MLZ-KP09NA- U1 MLZ-KP09NA2- U1
MLZ-KP12NA- U1 MLZ-KP12NA2- U1
MLZ-KP18NA- U1 MLZ-KP18NA2- U1
1. Indoor electronic control P.C. board has been changed.
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.
<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 pull 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.
Revision A:
• 5. WIRING DIAGRAM has been modified.
Revision B:
• MLZ-KP09/12/18NA2- U1 have been added.
WARNING
• When the refrigeration circuit has a leak, do not execute pump down with the compressor.
• When pumping down the refrigerant, stop the compressor before disconnecting the refrigerant pipes.
The compressor may burst if air etc. get into it.
• When opening or closing the valve below freezing temperatures, refrigerant may spurt out from the gap
between the valve stem and the valve body, resulting in injuries.
OBH802B

3
PART NAMES AND FUNCTIONS2
ACCESSORIES MODELS MLZ-KP09NA MLZ-KP12NA MLZ-KP18NA
MLZ-KP09NA2 MLZ-KP12NA2 MLZ-KP18NA2
Alkaline battery (AAA) for remote controller 2
Drain hose (with insulation) 1
Special washer (with cushion, 4pcs) 8
Installation template 1
Fixing screw for M5 х 30 mm 4
Band 1
Fixing screw for 4 х 16 mm 2
Remote controller 1
Remote controller holder 1
Fixing screw for 3.5 x 16 mm (Black) 2
INDOOR UNIT
MLZ-KP09NA MLZ-KP12NA MLZ-KP18NA
MLZ-KP09NA2 MLZ-KP12NA2 MLZ-KP18NA2
Display section
Horizontal vane
Vertical vane
Air outlet
Air filter
(Air purifying filter)
Air inlet
Air cleaning filter
(Anti-Allergy Enzyme
filter, option)
Intake grille
Safety strings Spec name plate
Open the display cover Remote control receiving section
Emergency operation switch
Operation indicator lamp
OBH802B

4
3 SPECIFICATION
Indoor model MLZ-KP09NA
MLZ-KP09NA2 MLZ-KP12NA MLZ-KP12NA2 MLZ-KP18NA MLZ-KP18NA2
Power supply V, phase, Hz 208/230, 1, 60
Max. fuse size (time delay)/ Disconnect switch A 15
Airow
High - Med. - Low - SLow
COOL Dry
(Wet)
CFM 311 - 283 - 254 - 212 332 - 297 - 258 - 212 403 - 346 - 293 - 212
HEAT Dry CFM 325 - 290 - 247 - 212 350 - 311 - 272 - 212 417 - 364 - 311 - 212
Sound level
High - Med. - Low - SLow Cooling dB (A) 38 - 34 - 31 - 27 40 - 36 - 32 - 27 47 - 41 - 36 - 29
Heating dB (A) 37 - 34 - 29 - 26 40 - 36 - 32 - 26 48 - 42 - 37 - 26
Cond. drain connection O.D. in. Ø1 (26 mm)
Dimensions Win. 43-3/8 D14-3/16
H7-5/16
Weight Ib. 34
External nish White
Control voltage (by built-in transformer) 12 - 24 V DC
NOTE: Test conditions are based on ARI 210/240.
1. Multi connection
Specifications and rated conditions of main electric parts
Model
Item MLZ-KP09NA MLZ-KP12NA MLZ-KP18NA MLZ-KP09NA2 MLZ-KP12NA2 MLZ-KP18NA2
Fuse (F11) T3.15AL250V
Horizontal vane motor (MV1) 12 V DC
Vertical vane motor (MV2) 12 V DC
Varistor (NR11) 470 V
DRAIN PUMP (DP) 230 V 6.4 W
FLOAT SENSOR (FS) 5 V DC
OBH802B

5
● 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
Multi connection
Model Mode Function Airow
(CFM) Air speed (ft./s.)
Coverage (ft.)
MLZ-KP09NA
MLZ-KP09NA2
HEAT Dry 311 13.0 20.7
COOL Dry 325 13.6 21.7
Wet ———
MLZ-KP12NA
MLZ-KP12NA2
HEAT Dry 332 13.9 22.1
COOL Dry 350 14.6 23.3
Wet ———
MLZ-KP18NA
MLZ-KP18NA2
HEAT Dry 403 16.9 26.7
COOL Dry 417 17.5 27.6
Wet ———
(2) OPERATION
*The operating range of the outdoor unit depends on the connected outdoor unit.
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
OBH802B

6
4OUTLINES AND DIMENSIONS
Unit: inch
INDOOR UNIT
MLZ-KP09NA MLZ-KP12NA MLZ-KP18NA
MLZ-KP09NA2 MLZ-KP12NA2 MLZ-KP18NA2
OBH802B

7
WIRING DIAGRAM5
INDOOR UNIT
MLZ-KP09NA- U1
MLZ-KP12NA- U1
M M
M
1~
FROM OUTDOOR UNIT
CONNECTING WIRES
(POWER SUPPLY)
208/230V AC 60Hz
TO OUTDOOR UNIT
CONNECTING WIRES
S3
S2
S1
CN125
1
5
DISP
P.C.BOARD CN302
CN106
6
NR11
3
1
CN202
3 5 5
6
1
MF MS
3~
5
1
1
21
910
MV1 MV2
CN301
DP
CN145
CN201
LD103
6
CN112
1
CN111
1
3
1
3
F11
U
CN211
CN151
RT13
RT12
RT11
TB
2
1CN1N1
1 3
X11
BK BU
BU
RD
INDOOR ELECTRONIC
CONTROL P.C. BOARD
BK
REC
P.C.BOARD
R111
1
1
3
3
2
2
7
1CN1M1
222
CN24
CN105
~
-
~
+
TO OUTDOOR UNIT
CONNECTING WIRES
12-24V
RESISTOR
COIL TEMP.
THERMISTOR(MAIN)
COIL TEMP.
THERMISTOR(SUB)
VARISTOR
RT13
RT12
NR11
FUSE
(T3.15AL250V)
DRAIN PUMP
FLOAT SENSOR
FS
DP
HORIZONTAL
VANE MOTOR
VERTICAL
VANE MOTOR
TERMINAL
BLOCK
MV1
MV2
F11
TB
RELAYX11
ROOM TEMP.
THERMISTOR
SYMBOL SYMBOL
MF FAN MOTOR RT11
R111
NAME
NAME
t
t
t
FS
A disconnect should be
required by local code.
Se procurer un
sectionneur conforme aux
réglementations locales.
NOTES :
1.About the outdoor side electric wiring
refer to the outdoor unit electric wiring
diagram for servicing.
2.Use copper conductors only.
(For field wiring)
3.Symbols below indicate.
: Terminal
block : Connector
: Borne : Connecteur
REMARQUES :
1.Pour le câblage électronique côté
extérieur, se reporter au schéma
d'entretien du câblage électronique
de l'appareil extérieur.
2.Utiliser des fils d'alimentation en cuivre.
3.Les symboles ont les significations
suivantes
MLZ-KP09NA2- U1
MLZ-KP12NA2- U1
OBH802B

8
MLZ-KP18NA- U1
M M
t
t
t
t
t
M
1~
~
-
~
+
S3
S2
S1
CN125
1
5
DISP
P.C.BOARD CN302
6
NR11
3
1
CN202
3 5 5
6
1
MF MS
3~
5
1
1
21
910
MV1 MV2
CN301
DP
CN145
CN201
LD103
6
CN112
1
CN111
1
3
1
3
F11
U
CN211
CN151
RT13
RT14
RT12
RT11
TB
2
1CN1N1
1 3
X11
BU
BU
RD
INDOOR ELECTRONIC
CONTROL P.C. BOARD
BK
REC
P.C.BOARD
R111
1
1
3
3
2
2
7
1CN1M1
222
CN24
CN105
RT15 1
CN113
4
BK
CN106
RESISTOR
COIL TEMP.
THERMISTOR(MAIN1)
COIL TEMP.
THERMISTOR(MAIN2)
COIL TEMP.
THERMISTOR(MAIN3)
COIL TEMP.
THERMISTOR(SUB)
VARISTOR
RT13
RT12
RT15
RT14
NR11
FUSE
(T3.15AL250V)
DRAIN PUMP
FLOAT SENSOR
FS
DP
HORIZONTAL
VANE MOTOR
VERTICAL
VANE MOTOR
TERMINAL
BLOCK
MV1
MV2
F11
TB
RELAYX11
ROOM TEMP.
THERMISTOR
SYMBOL SYMBOL
MF FAN MOTOR RT11
R111
NAME
NAME
A disconnect should be
required by local code.
Se procurer un
sectionneur conforme aux
réglementations locales.
REMARQUES :
1.Pour le câblage électronique côté
extérieur, se reporter au schéma
d'entretien du câblage électronique
de l'appareil extérieur.
2.Utiliser des fils d'alimentation en cuivre.
3.Les symboles ont les significations
suivantes
NOTES :
1.About the outdoor side electric wiring
refer to the outdoor unit electric wiring
diagram for servicing.
2.Use copper conductors only.
(For field wiring)
3.Symbols below indicate.
FROM OUTDOOR UNIT
CONNECTING WIRES
(POWER SUPPLY)
208/230V AC 60Hz
TO OUTDOOR UNIT
CONNECTING WIRES
TO OUTDOOR UNIT
CONNECTING WIRES
12-24V
: Terminal
block : Connector
: Borne : Connecteur
FS
MLZ-KP18NA2- U1
OBH802B

9
REFRIGERANT SYSTEM DIAGRAM6
Indoor
heat
exchanger
Flared connection
Room temperature
thermistor
RT11
Indoor coil
thermistor
RT13 (sub)
Flared connection
Refrigerant pipe Ø3/8(Ø9.52)
(with heat insulator)
Refrigerant pipe Ø1/4(Ø6.35)
(with heat insulator)
Indoor coil
thermistor
RT12 (main)
Indoor
heat
exchanger
Flared connection
Room temperature
thermistor
RT11
Indoor coil
thermistor
RT13 (sub)
Flared connection
Refrigerant flow in cooling
Refrigerant flow in heating
Refrigerant pipe Ø1/2(Ø12.7)
(with heat insulator)
Refrigerant pipe Ø1/4(Ø6.35)
(with heat insulator)
Indoor coil
thermistor
RT12,RT14,
RT15 (main)
INDOOR UNIT
Unit: inch(mm)
MLZ-KP09NA
MLZ-KP12NA
MLZ-KP09NA2
MLZ-KP12NA2
MLZ-KP18NA
MLZ-KP18NA2
OBH802B

10
7SERVICE FUNCTIONS
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.
Table 1
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 → 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
STOP/OPERATE (OFF/ON) 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.
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
C111
IC101
JR05
JR06
MLZ-KP09NA MLZ-KP12NA MLZ-KP18NA
MLZ-KP09NA2 MLZ-KP12NA2 MLZ-KP18NA2
OBH802B