Mitsubishi Electric MXZ-C NA Series User manual

No. OBH802
Models
MLZ-KP09NA -U1
MLZ-KP12NA -U1
MLZ-KP18NA -U1
INDOOR UNIT
NOTE:
RoHS compliant products have <G> mark on the spec name plate.
MLZ-KP09NA
MLZ-KP12NA
MLZ-KP18NA
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·············8
7. SERVICE FUNCTIONS································9
8. MICROPROCESSOR CONTROL ················12
9. TROUBLESHOOTING·······························21
10. DISASSEMBLY INSTRUCTIONS ················35

2
1TECHNICAL CHANGES
MLZ-KP09NA- U1
MLZ-KP12NA- U1
MLZ-KP18NA- U1
1. New model
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 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.
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3
2PART NAMES AND FUNCTIONS
ACCESSORIES
MODELS MLZ-KP09NA MLZ-KP12NA MLZ-KP18NA
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 х30 mm 4
Band 1
Fixing screw for 4 х16 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
Display section
Horizontal vane
Vertical vane
Air outlet
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Air inlet
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Intake grille
Safety strings Spec name plate
Open the display cover Remote control receiving section
Emergency operation switch
Operation indicator lamp
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4
SPECIFICATION
3
Indoor model MLZ-KP09NA MLZ-KP12NA MLZ-KP18NA
Power supply V, phase, Hz 208/230, 1, 60
Max. fuse size (time delay)/ Disconnect switch A15
Airflow
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 D 14-3/16
H 7-5/16
Weight Ib. 34
External finish 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
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
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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
1. Multi connection
Model Mode Function Airflow
(CFM) Air speed (ft./s.)
Coverage (ft.)
MLZ-KP09NA HEAT Dry 311 13.0 20.7
COOL Dry 325 13.6 21.7
Wet — — —
MLZ-KP12NA HEAT Dry 332 13.9 22.1
COOL Dry 350 14.6 23.3
Wet — — —
MLZ-KP18NA 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
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6
OUTLINES AND DIMENSIONS
4
Unit: inch
INDOOR UNIT
MLZ-KP09NA MLZ-KP12NA MLZ-KP18NA
OBH802

7
5WIRING DIAGRAM
INDOOR UNIT
MLZ-KP09NA- U1
MLZ-KP12NA- U1
MLZ-KP18NA- U1
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8
REFRIGERANT SYSTEM DIAGRAM
6
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-KP18NA
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9
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 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 3
seconds. Restarting the compressor, which takes 3 minutes, cannot be reduced.
MLZ-KP09NA
MLZ-KP12NA
MLZ-KP18NA
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
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10
NOTE:
• The operation settings are memorized when 10 seconds has 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 tripping 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.
C111
JR77
IC101
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 9-7.)
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.)
7-3. 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.
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11
Change dip switch SW3 setting according to the height of ceiling.
Dip switch SW3
Ceiling height
Normal
8.0 ft. (2.4 m) or below
Increase airflow volume
above 8.0 ft. (2.4 m) and 9.0 ft. (2.7 m) or below
How to change Dip switch (SW3) setting (Factory setting is normal)
1. Make sure that the breaker for air conditioner is turned OFF.
2. Remove the electrical cover (1) and (2) of the indoor unit.
3. Slide out the electronic control P.C. board, and switch up the slide switch (SW).
4. Put the electronic control P.C. board back to the original position, and install the electrical cover (1) and (2).
NOTE:
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NOTE: When the ceiling is above 9.0 ft. (2.7 m), airflow volume may be insufficient even with the Dip switch (SW3) set to
"increase airflow".
Electrical cover (1)
Electrical cover (2)
Electronic
control P.C.
board
Slide switch SW3
Normal Up
(Increase airflow
volume)
7-4. P.C. BOARD MODIFICATION FOR CHANGING AIRFLOW VOLUME
How to change Dip switch (SWV1) setting (Factory setting is normal)
1. Make sure that the breaker for air conditioner is turned OFF.
2. Remove the electrical cover (1) and (2) of the indoor unit.
3. Slide out the electronic control P.C. board, and change the slide switch (SWV1) to up.
4. Put the electronic control P.C. board back to the original position, and install the electrical cover (1) and (2).
NOTE:
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Electrical cover (1)
Electrical cover (2)
Electronic
control P.C.
board
Slide switch SWV1
Normal Up
(Airflow direction
is heightened.)
(AUTO) (1) (2) (3) (4) (5) (SWING)
The setting when the higher airflow is preferred in the Airflow direction (1)
The angle of airflow direction (1) can be slightly heightened by changing SWV1 to up.
However, it may cause the dirt on the ceiling.
7-5. P.C. BOARD MODIFICATION FOR CHANGING AIRFLOW DIRECTION ADJUSTMENT
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12
MLZ-KP09NA MLZ-KP12NA MLZ-KP18NA
WIRELESS REMOTE CONTROLLER
MICROPROCESSOR CONTROL
8
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 DISPLAY SECTION
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 4°F(2°C) or more
away from set tempera-
ture
The room temperature is
approaching the set tem-
perature About 2 to 4°F(1 to 2°C)
from set temperature
Standby mode
(Refer to multi system
operation)
-
Lit
Blinking
Not lit
Signal transmitting section
Battery replacement indicator
Operation display section
Temperature buttons
STOP/OPERATE
(OFF/ON) button
Indication of
remote controller
model is on back
FAN SPEED CONTROL button
OPERATION SELECT button
ECONO COOL button
CLOCK SET button
WEEKLY TIMER
set button
TIME, TIMER set buttons
FORWARD button
BACKWARD button
RESET button
SMART SET button
SLEEP button
WIDE VANE control button
VANE CONTROL button
Distance of signal: About 20 ft. (6 m)
Beep(s) is (are) heard from
the indoor unit when the
signal is received.
90°
Operate the remote control-
ler in the area where signal is
received, and beep is heard.
OBH802