Mitsubishi Electric M Series Service Manual
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Mitsubishi Electric M Series Service Manual

Mitsubishi Electric M Series Service Manual

Split type indoor unit
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INDOOR UNIT
INDOOR UNIT
SERVICE MANUAL
Models
MFZ-KX09NL
MFZ-KX12NL
MFZ-KX15NL
MFZ-KX18NL
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U1
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U1
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U1
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U1
Outdoor unit service manual
MXZ-D•NL Series (OBH949)
MXZ-SM•NL Series
MXZ-SM•NLHZ Series
SUZ-AA•NL Series
CONTENTS
1. TECHNICAL CHANGES ······························ 2
2. SAFETY PRECAUTION ······························· 3
3. PART NAMES AND FUNCTIONS ·················· 8
4. SPECIFICATION ········································ 9
5. OUTLINES AND DIMENSIONS ···················· 11
6. WIRING DIAGRAM ····································12
7. REFRIGERANT SYSTEM DIAGRAM ············13
8. SERVICE FUNCTIONS ·······························14
9. MICROPROCESSOR CONTROL ··················18
10. TROUBLESHOOTING ································28
11. DISASSEMBLY INSTRUCTIONS ··················46
PARTS CATALOG (OBB944)
No. OBH944

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Summary of Contents for Mitsubishi Electric M Series

  • Page 1: Table Of Contents

    INDOOR UNIT INDOOR UNIT No. OBH944 SERVICE MANUAL Models MFZ-KX09NL MFZ-KX12NL MFZ-KX15NL MFZ-KX18NL Outdoor unit service manual MXZ-D•NL Series (OBH949) MXZ-SM•NL Series MXZ-SM•NLHZ Series SUZ-AA•NL Series CONTENTS 1. TECHNICAL CHANGES ······························ 2 2. SAFETY PRECAUTION ······························· 3 3. PART NAMES AND FUNCTIONS ·················· 8 4.

  • Page 2: Technical Changes

    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.

  • Page 3: Safety Precaution

    SAFETY PRECAUTION MEANINGS OF SYMBOLS DISPLAYED ON THE UNIT Refrigerant This unit uses a flammable refrigerant. WARNING Safety Group If the refrigerant leaks and comes in contact with fire or a heating part, it will create a harmful gas and there (Risk of fire) is a risk of fire.
  • Page 4 [1] Warning for service (1) Do not alter the unit. (2) For installation and relocation work, follow the instructions in the Installation Manual and use tools and pipe components specifically made for use with refrigerant specified in the outdoor unit installation manual. (3) Ask a dealer or an authorized technician to install, relocate and repair the unit.
  • Page 5 [4] Cautions for unit using R454B refrigerant Basic work procedures are the same as those for conventional units using refrigerant R410A. However, pay careful attention to the following points. (1) Information on servicing (1-1) Checks to the area Prior to beginning work on systems containing FLAMMABLE REFRIGERANTS, safety checks are necessary to ensure that the risk of ignition is minimized.
  • Page 6 (3) Repair to intrinsically safe components Intrinsically safe components must be replaced. (4) Cabling Check that cabling will not be subject to wear, corrosion, excessive pressure, vibration, sharp edges or any other adverse environmental effects. The check shall also take into account the effects of aging or continual vibration from sources such as compressors or fans.
  • Page 7 (8) Decommissioning Before carrying out this procedure, it is essential that the technician is completely familiar with the equipment and all its detail. It is recommended good practice that all refrigerants are recovered safely. Prior to the task being carried out, an oil and refrigerant sample shall be taken in case analysis is required prior to re-use of recovered refrigerant.

  • Page 8: Part Names And Functions

    PART NAMES AND FUNCTIONS MFZ-KX09NL MFZ-KX12NL MFZ-KX15NL MFZ-KX18NL Horizontal vane Air outlet Vertical vane Multi-fl ow vane Fan guard Air cleaning filter (Anti-Allergy Enzyme Filter, option) (Microparticle catching filter, option) Panel Front panel Spec name plate *1 *1 The manufacturing year and month is indicated on the spec name plate.

  • Page 9: Specification

    SPECIFICATION 1. Single connection MFZ-KX09NL MFZ-KX12NL MFZ-KX15NL MFZ-KX18NL Indoor model Power supply V, phase, Hz 208/230, 1, 60 Disconnect switch COOL Dry 417 - 360 - 272 - 198 - 138 431 - 392 - 311 - 254 - 198 491 - 420 - 328 - 254 - 198 Airflow (Wet)

  • Page 10: Operation

    4-1. OPERATING RANGE (1) POWER SUPPLY Rated voltage Guaranteed voltage (V) 208/230 V Min. 187 Max. 253 Indoor unit 1 phase 60 Hz (2) OPERATION Intake air temperature (°F) Mode Condition Indoor Outdoor Standard temperature — Maximum temperature — Cooling Minimum temperature —...

  • Page 11: Outlines And Dimensions

    OUTLINES AND DIMENSIONS MFZ-KX09NL MFZ-KX12NL MFZ-KX15NL MFZ-KX18NL Unit: inch (mm) OBH944...

  • Page 12: Wiring Diagram

    WIRING DIAGRAM MFZ-KX09NL MFZ-KX12NL MFZ-KX15NL MFZ-KX18NL OBH944...

  • Page 13: Refrigerant System Diagram

    REFRIGERANT SYSTEM DIAGRAM MFZ-KX09NL MFZ-KX12NL MFZ-KX15NL MFZ-KX18NL Unit: inch (mm) Refrigerant pipe ø3/8 (ø9.52) (MFZ-KX09/12) ø1/2 (ø12.7) (MFZ-KX15/18) (with heat insulator) Indoor heat exchanger Flared connection Distributor Indoor coil thermistor RT12 (main), RT13 (sub) Room temperature thermistor RT11 Flared connection Refrigerant pipe ø1/4 (ø6.35) Refrigerant flow in cooling (with heat insulator)

  • Page 14: Service Functions

    SERVICE FUNCTIONS MFZ-KX09NL MFZ-KX12NL MFZ-KX15NL MFZ-KX18NL 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. •...

  • Page 15: Auto Restart Function

    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.

  • Page 16: Wireless Lan Control

    8-4. WIRELESS LAN CONTROL 1. Radio wave usage precautions 2. Wireless LAN module introduction This Wireless LAN module, communicates the status information and Contains FCC ID:NKR-MB43 Contains IC:4441A-MB43 controls the commands from the kumo cloud by connecting to an ® indoor unit.

  • Page 17: Specifications

    Wi-Fi service. in order to change the settings to a different network, the user can follow the • This Wireless LAN module should not be connected to any Mitsubishi Electric instructions below to place the system back into network configuration mode.

  • Page 18: Microprocessor Control

    MICROPROCESSOR CONTROL MFZ-KX09NL MFZ-KX12NL MFZ-KX15NL MFZ-KX18NL WIRELESS REMOTE CONTROLLER Signal transmitting section Distance of signal: About 20 ft. (6 m) Battery replacement indicator Beep(s) is (are) heard from the indoor unit when the signal is received. FAN speed control button Operation select button POWERFUL button ECONO COOL button...
  • Page 19 9-1. COOL ( ) OPERATION (1) Press OFF/ON (stop/operate) 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 button to select the desired temperature. The setting range is 61 - 88°F (16 - 31°C).
  • Page 20 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.
  • Page 21 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 DC) transmitted from indoor microprocessor. (2) The horizontal vane angle and mode change as follows by pressing VANE control ( ) button.
  • Page 22 (5) VANE AUTO ( ) mode In VANE AUTO mode, the microprocessor automatically determines the horizontal vane angle to make the optimum room temperature distribution. In COOL, DRY and FAN operation In HEAT operation 2 FLOW: Vane angle is fixed to position 2. 2 FLOW: Vane angle is fixed to position 2.

  • Page 23: Timer Operation

    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.

  • Page 24: Weekly Timer Operation

    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. E.g. : Runs at 75°F (24°C) from waking up to leaving home, and runs at 81°F (27°C) from getting home to going to bed on weekdays.

  • Page 25: Sleep Operation

    (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.

  • Page 26: Self Clean Operation

    Set temperature for SLEEP operation For about 30 minutes after SLEEP ( ) button is pressed, the set temperature remains as set for the operation running when the SLEEP button is pressed. It will change to the set temperature for SLEEP operation in about 30 minutes. Pressing SLEEP ( ) button again returns the operation to the previous settings.

  • Page 27: Emergency/Test Operation

    9-12. EMERGENCY/TEST OPERATION Operation mode COOL/HEAT In the case of test run operation or emergency operation, use the emer- Set temperature 75°F (24°C) gency operation switch on the right side of the indoor unit. Emergency Fan speed Medium operation is available when the remote controller is missing or has failed, Horizontal vane Auto or when the batteries in the remote controller are running out.

  • Page 28: Troubleshooting

    TROUBLESHOOTING MFZ-KX09NL MFZ-KX12NL MFZ-KX15NL MFZ-KX18NL 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 con- firming the horizontal vane is closed, turn OFF the breaker.
  • Page 29 5. Description of multi system air conditioner 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 blinks as shown in the figure below when the total capacity of the indoor units exceed the capacity of the outdoor unit.
  • Page 30 10-2. FAILURE MODE RECALL FUNCTION AND ERROR CODE DISPLAY MODE Outline of the function This air conditioner can memorize the failure which has occurred last time. Even though LED indication listed on the troubleshooting check table (10-4.) disappears, the memorized failure can be recalled.
  • Page 31 A (From previous page) Press OFF/ON (stop/operate) button of the remote controller with the remote controller headed towards the indoor unit. *1. The indoor unit is normal, but the outdoor unit might be abnormal. Does the left OPERATION INDICATOR lamp on the There are some abnormalities that cannot be recalled with this way.
  • Page 32 2. Flow chart of error code display mode This explains how customers can check the error code on their own. This is included in OPERATING INSTRUCTIONS. Operational procedure The remote controller is powered OFF. Get close to the front of the indoor unit. Point the remote controller at the receiving section of the indoor unit, and and keep pressing CHECK with a fine-tipped object unil the beeps.
  • Page 33 3. Table of indoor unit failure mode recall function Left OPERATION Error Abnormal point Condition Remedy INDICATOR lamp code (Failure mode) Not blink Normal — — The room temperature thermistor short or 1-time blink every Room temperature Refer to the characteristics of the room open circuit is detected every 8 seconds 0.5-second thermistor...
  • Page 34 10-3. INSTRUCTION OF TROUBLESHOOTING 1. Check of the unit Start Indoor unit operates. Indoor unit operates. Indoor unit does not receive Operation indicator lamp on Outdoor unit does not Outdoor unit does not the signal from remote indoor unit is blinking ON operate.
  • Page 35 2. Check of Wireless LAN module Follow the procedure below if the air conditioner cannot be monitored or controlled with a device such as a smartphone. Did the right lamp of the operation indicator lamp There is a problem in a communication between the air blink 10 times after you selected the setting of the conditioner and the Wireless LAN module.
  • Page 36 Abnormal Operation indicator lamp Symptom Condition Remedy point Left lamp blinks. An abnormality other than above men- • Check the stop valve. 14-time blink or more tioned is detected. • Check the 4-way valve. Indoor unit and Other • Check the abnormality in detail using outdoor unit do abnormality the failure mode recall function.
  • Page 37 FL: Refrigerant leakage Abnormal points and detection methods Causes and checkpoints Refrigerant is leaking from the air conditioner. • Refrigerant leak from air conditioner The refrigerant sensor has detected refrigerant leak. • Refrigerant leak from piping Refrigerant is leaking in the room where the alarm is beeping. •...
  • Page 38 FH: Refrigerant sensor error Abnormal points and detection methods Causes and checkpoints A refrigerant sensor has failed. • A refrigerant sensor connected to an M-IC has failed. • A Sensor and Alarm Kit connected to a branch box has failed. Diagnosis of failure Check the display of the remote controller or the 7-segment LED on the outdoor controller board...
  • Page 39 10-5. TROUBLESHOOTING CRITERIA OF MAIN PARTS MFZ-KX09NL MFZ-KX12NL MFZ-KX15NL MFZ-KX18NL Part name Check method and criteria Figure Room temperature Measure the resistance with a multimeter. thermistor (RT11) Refer to 10-7. “Test point diagram and voltage”, “Indoor electronic control Indoor coil thermistor P.C.

  • Page 40: Troubleshooting Flow

    10-6. TROUBLESHOOTING FLOW A Check of indoor fan motor The indoor fan motor error has occurred, and the indoor fan does not operate. Turn OFF the power supply. Pay enough attention to the high voltage on the fan motor connector. Turn ON the power supply, wait 5 seconds or more, and then press the emergency operation switch.
  • Page 41 B Check of remote controller, display receiver P.C. board and indoor control P.C. board * Check if the remote controller is exclusive for this air conditioner. Press OFF/ON (stop/operate) button on the remote controller. *1 Look at the image of the signal transmitting section of the remote controller through the monitor of a digital camera or a camera phone.
  • Page 42 C Check of indoor electronic control P.C. board and indoor fan motor Turn OFF the power supply. Remove indoor fan motor connector CN211 Measure the resistance between and vane motor connector CN151 from the Short circuit: CN211 of the indoor fan motor indoor electronic control P.C.
  • Page 43 When the left lamp of operation indicator lamp blinks ON and OFF in every 0.5-second, outdoor unit does not operate. D How to check miswiring and serial signal error Turn OFF the power supply. Is there rated voltage of 208/230 V AC in the power supply? Check the power supply.
  • Page 44 E Electromagnetic noise enters into TV sets or radios Is the unit grounded? Ground the unit. Is the distance between the antennas Extend the distance between the antennas and and the indoor unit within 9.91 ft. (3m), the indoor unit, and/or the antennas and the out- or is the distance between the antennas door unit.
  • Page 45 10-7. TEST POINT DIAGRAM AND VOLTAGE MFZ-KX09NL MFZ-KX12NL MFZ-KX15NL MFZ-KX18NL Indoor electronic control P.C. board FUSE (F11) T6.3AL250V Varistor (NR11) Serial signal input (CN202) JR06 Modification Power supply (CN201) JR05 point for input 208/230 V AC individual operation (Refer to 8-2.) Resistor (R111) 13 V DC...

  • Page 46: Disassembly Instructions

    DISASSEMBLY INSTRUCTIONS <Detaching method of the terminal with locking mechanism> The terminal which has the locking mechanism can be detached as shown below. There are 2 types of the terminal with locking mechanism. The terminal without locking mechanism can be detached by pulling it out. Check the shape of the terminal before detaching.
  • Page 47 OPERATING PROCEDURE PHOTOS/FIGURES 3. Removing the electronic control P.C. board and Photo 4 the display receiver P.C. board (1) Remove the panel. (Refer to section 1.) (2) Remove the electrical box. (Refer to section 2.) (3) Remove the ground wire connected to the electronic control P.C.
  • Page 48 How to remove the multi-flow Horizontal vane (back) vane and the horizontal vanes Horizontal vane (front) Unit body (1) Removing the horizontal vane (front/back) (1)-1. See the figure below and push to open the indicated Multi-flow vane places on the horizontal vanes (between front and back) with your fingers so that you can access 4 vane shafts positioned on the back of the horizontal vanes.
  • Page 49 OPERATING PROCEDURE PHOTOS/FIGURES 5. Removing the horizontal vane motor Photo 9 Screws of the nozzle (1) Remove the panel. (Refer to section 1.) (2) Remove the screws of the horizontal vane motor sup- port and pull out the horizontal vane motor support from the nozzle.
  • Page 50 OPERATING PROCEDURE PHOTOS/FIGURES 7. Removing the line flow fan and the indoor fan Photo 13 motor Screw of the line flow fan (1) Remove the panel. (Refer to section 1.) (2) Remove the electrical box. (Refer to section 2.) (3) Remove the nozzle. (Refer to section 4.) (4) Disengage the water cover from the catches.
  • Page 51 OPERATING PROCEDURE PHOTOS/FIGURES 8. Removing the refrigerant sensor Photo 18 (1) Remove the panel. (Refer to section 1.) (2) Loosen the screw of the refrigerant sensor plate, and take the refrigerant sensor plate. (3) Cut the band fixing the lead wire. (4) Disengage the refrigerant sensor cover from the refrig- erant sensor plate.
  • Page 52 Cable tie binding the cable of the wireless LAN module HEAD OFFICE: TOKYO BUILDING, 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN © Copyright 2024 MITSUBISHI ELECTRIC CORPORATION Published: Oct. 2024. No. OBH944 Made in Japan Specifications are subject to change without notice.

This manual is also suitable for:

Mfz-kx09nlMfz-kx12nlMfz-kx15nlMfz-kx18nlMfz-kx09nl-u1Mfz-kx12nl-u1 ... Show all

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