Mitsubishi Electric MUZ-FH18NA Service Manual
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Mitsubishi Electric MUZ-FH18NA Service Manual

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SPLIT-TYPE AIR CONDITIONERS
OUTDOOR UNIT
SERVICE MANUAL
Models
MUZ-FH09NA
MUZ-FH12NA
MUZ-FH15NA
MUZ-FH18NA
MUZ-FH09NA
MUZ-FH12NA
NOTE:
RoHS compliant products have <G> mark on the spec name plate.
MUZ-FH09NAH
MUZ-FH12NAH
MUZ-FH15NAH
MUZ-FH18NAH
MUZ-FH09NAH
MUZ-FH12NAH
Revision B:
• MUZ-FH18NA and MUZ-FH18NAH have been
added.
Please void OBH684 REVISED EDITION-A.
HFC
utilized
R410A
Indoor unit service manual
MSZ-FH•NA Series (OBH683)
CONTENTS
1. TECHNICAL CHANGES ··································· 2
2. PART NAMES AND FUNCTIONS ····················· 3
3. SPECIFICATION ················································ 4
4. OUTLINES AND DIMENSIONS ························ 6
5. WIRING DIAGRAM ············································ 8
6. REFRIGERANT SYSTEM DIAGRAM ··············11
7. DATA ································································ 13
8. ACTUATOR CONTROL ··································· 21
9. SERVICE FUNCTIONS ··································· 22
10. TROUBLESHOOTING ····································· 23
11. DISASSEMBLY INSTRUCTIONS ···················· 44
PARTS CATALOG (OBB684)
No. OBH684
REVISED EDITION-B

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Summary of Contents for Mitsubishi Electric MUZ-FH18NA

  • Page 1: Table Of Contents

    Revision B: • MUZ-FH18NA and MUZ-FH18NAH have been added. Please void OBH684 REVISED EDITION-A. SPLIT-TYPE AIR CONDITIONERS OUTDOOR UNIT No. OBH684 SERVICE MANUAL REVISED EDITION-B utilized R410A Models MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH MUZ-FH18NA MUZ-FH18NAH Indoor unit service manual MSZ-FH•NA Series (OBH683)

  • Page 2: Technical Changes

    Revision A: • 3. SPECIFICATION has been modified. (The values of COP have been modified.) • 10. TROUBLESHOOTING has been modified. Revision B: • MUZ-FH18NA and MUZ-FH18NAH have been added. TECHNICAL CHANGES MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH...

  • Page 3: Part Names And Functions

    PART NAMES AND FUNCTIONS MUZ-FH09NA MUZ-FH12NA MUZ-FH09NAH MUZ-FH12NAH Air inlet (back and side) Piping Air outlet Drain hose Drain outlet MUZ-FH15NA MUZ-FH15NAH MUZ-FH18NA MUZ-FH18NAH Air inlet (back and side) Piping Drain hose Air outlet Drain outlet OBH684B...

  • Page 4: Specification

    SPECIFICATION MUZ-FH09NA MUZ-FH12NA MUZ-FH15NA MUZ-FH18NA Outdoor unit model MUZ-FH09NAH MUZ-FH12NAH MUZ-FH15NAH MUZ-FH18NAH Btu/h 9,000 (1,700 ~ 12,000) 12,000 (2,500 ~ 13,600) 15,000 (6,450 ~ 19,000) 17,200 (6,450 ~ 21,000) Cooling 1 Capacity Rated (Minimum~Maximum) Btu/h 10,900 (1,600 ~ 18,000) 13,600 (3,700 ~ 21,000) 18,000 (5,150 ~ 24,000) 20,300 (5,150 ~ 30,000)
  • Page 5 Test condition 3, 4 Indoor air condition (°F) Outdoor air condition (°F) Mode Test Dry bulb Wet bulb Dry bulb Wet bulb "A-2" Cooling Steady State (75) at rated compressor Speed "B-2" Cooling Steady State (65) at rated compressor Speed SEER "B-1"...

  • Page 6: Outlines And Dimensions

    OUTLINES AND DIMENSIONS Unit: inch MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH REQUIRED SPACE 4 in. (100 mm) or more when front and sides of the unit are clear When any 2 sides of left, right and rear of the unit are clear holes Liquid refrigerant pipe joint Refrigerant pipe (flared)
  • Page 7 Unit: inch MUZ-FH15NA MUZ-FH15NAH MUZ-FH18NA MUZ-FH18NAH REQUIRED SPACE *1 20 in. (500 mm) or more when front and sides of the unit are clear 16-7/16 Air in 1-9/16 Air out 2-holes 13/32 13/16 6-7/8 19-11/16 *2 When any 2 sides of left, right...

  • Page 8: Wiring Diagram

    WIRING DIAGRAM MUZ-FH09NA MUZ-FH12NA MUZ-FH09NAH MUZ-FH12NAH OBH684B...
  • Page 9 MUZ-FH15NA MUZ-FH18NA OBH684B...
  • Page 10 MUZ-FH15NAH MUZ-FH18NAH OBH684B...

  • Page 11: Refrigerant System Diagram

    ON cooling OFF Stop valve (with strainar) Refrigerant pipe ø1/4 Refrigerant flow in cooling (with heat insulator) Refrigerant flow in heating MUZ-FH15NA MUZ-FH15NAH MUZ-FH18NA MUZ-FH18NAH Muffler Refrigerant pipe ø 1/2 #100 4-way valve (with heat insulator) Service port Stop valve...
  • Page 12 Max. Length Max. Height difference Liquid MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH MUZ-FH18NA MUZ-FH18NAH Indoor unit Max. Height difference Max. Length Outdoor unit ADDITIONAL REFRIGERANT CHARGE (R410A: oz.) NOTE: Refrigerant piping exceeding 25 ft. requires additional refrigerant charge according to the calculation.

  • Page 13: Data

    DATA MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH MUZ-FH18NA MUZ-FH18NAH 7-1. PERFORMANCE DATA 1) COOLING CAPACITY Indoor air Outdoor intake air DB temperature (˚F) Model IWB (˚F) SHC TPC SHC TPC SHC TPC SHC TPC SHC TPC 11.0 0.50 10.3 0.55 0.59...
  • Page 14 1.20 18.5 1.27 19.1 1.29 21.4 1.35 1.01 11.8 1.28 14.7 1.51 17.6 1.68 19.8 1.76 20.4 1.79 23.1 1.86 MUZ-FH18NA 0.97 12.5 1.24 15.2 1.47 18.0 1.63 20.3 1.72 20.9 1.75 23.6 1.82 10.2 0.93 12.8 1.19 15.9 1.42 18.6...
  • Page 15 = 398 CFM Airflow Airflow Outdoor intake air DB temperature (°F) Outdoor intake air DB temperature (°F) MUZ-FH15NA MUZ-FH15NAH MUZ-FH18NA MUZ-FH18NAH SHF at rating condition = 0.7 SHF at rating condition = 0.67 = 411 CFM Airflow = 437 CFM Airflow Outdoor intake air DB temperature (°F)
  • Page 16 = 454 CFM = 497 CFM Airflow Airflow 1.50 1.25 1.00 0.75 0.50 Outdoor intake air WB temperature (°F) Outdoor intake air WB temperature (°F) MUZ-FH18NA MUZ-FH18NAH Airflow = 514 CFM Airflow = 514 CFM 2.00 2.00 1.75 1.75 1.50 1.50...
  • Page 17 (PSIG) 100 105 (°F) (°F) Outdoor ambient temperature Outdoor ambient temperature MUZ-FH15NA MUZ-FH15NAH (PSIG) (PSIG) 100 105 (°F) (°F) Outdoor ambient temperature Outdoor ambient temperature MUZ-FH18NA MUZ-FH18NAH (PSIG) (PSIG) 100 105 (°F) (°F) Outdoor ambient temperature Outdoor ambient temperature OBH684B...
  • Page 18 (PSIG) 49Hz 49Hz (°F) (°F) Outdoor ambient temperature Outdoor ambient temperature MUZ-FH15NA MUZ-FH15NAH (PSIG) (PSIG) 50Hz 50Hz (°F) (°F) Outdoor ambient temperature Outdoor ambient temperature MUZ-FH18NA MUZ-FH18NAH (PSIG) (PSIG) 61Hz 61Hz (°F) (°F) Outdoor ambient temperature Outdoor ambient temperature OBH684B...
  • Page 19 Power supply phase, 208/230, 1, 60 Input 0.029 0.029 0.031 0.033 Fan motor current 0.30/0.27 0.30/0.27 0.31/0.28 0.34/0.31 MUZ-FH09NA MUZ-FH12NA MUZ-FH15NA MUZ-FH18NA Outdoor unit MUZ-FH09NAH MUZ-FH12NAH MUZ-FH15NAH MUZ-FH18NAH Power supply phase, 208/230, 1, 60 Input 0.531 0.681 0.841 0.921 1.169 1.269 1.397...
  • Page 20 The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor MUZ-FH18NA MUZ-FH18NAH Correction of Cooling capacity Correction of Cooling total input Correction of Heating total input Correction of Heating capacity...

  • Page 21: Actuator Control

    ACTUATOR CONTROL MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH MUZ-FH18NA MUZ-FH18NAH 8-1. OUTDOOR FAN MOTOR CONTROL The fan motor turns ON/OFF, interlocking with the compressor. [ON] The fan motor turns ON 5 seconds before the compressor starts up. [OFF] The fan motor turns OFF 15 seconds after the compressor has stopped running.

  • Page 22: Service Functions

    SERVICE FUNCTIONS MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH MUZ-FH18NA MUZ-FH18NAH 9-1. CHANGE IN DEFROST SETTING Changing defrost finish temperature <JS> To change the defrost finish temperature, cut/solder the JS wire of the outdoor inverter P.C. board (Refer to 10-6.1.). Defrost fi nish temperature...

  • Page 23: Troubleshooting

    TROUBLESHOOTING MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH MUZ-FH18NA MUZ-FH18NAH 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, then after con- firming the horizontal vane is closed, turn off the breaker and/or disconnect the power plug.
  • Page 24 10-2. FAILURE MODE RECALL FUNCTION Outline of the function This air conditioner can memorize the abnormal condition which has occurred once. Even though LED indication listed on the troubleshooting check table (10-3.) disappears, the memorized failure details can be recalled. 1.
  • Page 25 2. Flow chart of the detailed outdoor unit failure mode recall function Operational procedure The outdoor unit might be abnormal. Check if outdoor unit is abnormal according to the following procedures. Make sure that the remote controller is set to the failure mode recall function. 1.
  • Page 26 3. Outdoor unit failure mode table The left lamp of the Indoor/outdoor Outdoor unit OPERATION Abnormal point LED indication unit failure Condition Remedy failure mode INDICATOR (Failure mode/protection) (Outdoor P.C. board) mode recall recall function lamp function (Indoor unit) None (Normal) —...
  • Page 27 The left lamp of the Indoor/outdoor Outdoor unit OPERATION Abnormal point LED indication unit failure Condition Remedy failure mode INDICATOR (Failure mode/protection) (Outdoor P.C. board) mode recall recall function lamp function (Indoor unit) 10-time fl ash Discharge temperature Temperature of discharge temperature •...
  • Page 28 10-3. TROUBLESHOOTING CHECK TABLE Abnormal point/ Symptom LED indication Condition Remedy Condition Outdoor unit 1-time fl ash every Outdoor power sys- Overcurrent protection cut-out operates 3 consecutive times • Reconnect connector of compres- does not op- 2.5 seconds within 1 minute after the compressor gets started. sor.
  • Page 29 Abnormal point/ Symptom LED indication Condition Remedy Condition Outdoor unit 1-time fl ash Frequency drop by FH09/12 When the input current exceeds approximately The unit is normal, but check the operates. 2.5 seconds OFF current protection 10A (FH09)/10.5A (FH12), compressor frequency following.
  • Page 30 10-4. TROUBLE CRITERION OF MAIN PARTS MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH MUZ-FH18NA MUZ-FH18NAH Part name Check method and criterion Figure Defrost thermistor (RT61) Fin temperature thermistor (RT64) Measure the resistance with a tester. Ambient temperature Refer to 10-6. “Test point diagram and voltage”, 1. “Inverter P.C.
  • Page 31 10-5. TROUBLESHOOTING FLOW A How to check inverter/compressor Disconnect the connector between the compressor and the power module (IC700) (MUZ-FH09/12)/IGBT module (IC700) (MUZ-FH15/18). Check the voltage between terminals. See 10-5. “Check of open phase”. Replace the inverter P.C. board. Are the voltages balanced? Check the compressor.
  • Page 32 D Check of compressor winding ●Disconnect the connector between the compressor and the power module (IC700) (MUZ-FH09/12)/IGBT module (IC700) (MUZ-FH15/18), and measure the resistance between the compressor terminals. <<Measurement point>> At 3 points BLK-WHT Measure the resistance between the lead wires at 3 points. BLK-RED WHT-RED <<Judgement>>...
  • Page 33 G Check of outdoor thermistors Disconnect the connector of thermistor in the inverter P.C. board (see below table), and measure the resistance of thermistor. Replace the thermistor except RT64. Is the resistance of thermistor normal? When RT64 is abnormal, replace the inverter P.C. (Refer to 10-6.1.) board.
  • Page 34 H Check of R.V. coil MUZ-FH09/12 First of all, measure the resistance of R.V. coil to check if the coil is defective. Refer to 10-4. In case CN721 is disconnected or R.V. coil is open, voltage is generated between the terminal pins of the connector although no signal is being transmitted to R.V.
  • Page 35 I Check of outdoor fan motor Disconnect the connectors CN931 and CN932 from the inverter P.C. board. Check the connection between the connector CN931 and CN932. Is the resistance between each ter- minal of outdoor fan motor normal? (Refer to 10-4.) Disconnect CN932 from the inverter P.C.
  • Page 36 J Check of power supply Disconnect the connector between the compressor and the power module (IC700) (MUZ-FH09/12)/IGBT module (IC700) (MUZ-FH15/18). Rectify indoor/outdoor Turn ON power supply and press connecting wire. EMERGENCY OPERATION switch. Does the left lamp of the Is there voltage 208/230 VAC Replace the indoor OPERATION INDICATOR lamp on between the indoor terminal...
  • Page 37 K Check of LEV (Expansion valve) Turn ON the power supply. <Preparation of the remote controller> While pressing both OPERATION SELECT button and TEMP button on the remote controller at the same time, press RESET button. First, release RESET button. Hold down the other two buttons for another 3 sec- onds.
  • Page 38 L Check of inverter P.C. board Check the outdoor fan motor. (Refer to 10-5. .) Is the fuse (F901) blown on the in- verter P.C. board? Check the connection of the connectors (CN931, CN932) of the outdoor fan motor. If the connection is poor, make it correct. Operate the outdoor unit by starting EMERGENCY OPERATION.
  • Page 39 M How to check miswiring and serial signal error NOTE: Refer to the indoor unit service manual. Turn OFF the power supply. Is there rated voltage in the power supply? Check the power supply. Turn ON the power supply. Is there rated voltage between the outdoor terminal block S1 and S2? Check the wiring.
  • Page 40 N Check of defrost heater MUZ-FH09NAH MUZ-FH12NAH MUZ-FH15NAH MUZ-FH18NAH Check the following points before checking electric continuity. 1. Does the resistance of ambient temperature thermistor have the characteristics? Refer to 10-6.1. 2. Is the resistance of defrost heater normal? Refer to 10-4. 3.
  • Page 41 P 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 or is the distance between the antennas outdoor unit.
  • Page 42 10-6. TEST POINT DIAGRAM AND VOLTAGE 1. Inverter P.C. board MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH Smoothing Smoothing R.V.coil Heater connector (CN722) capacitor capacitor (CN721) DB61 Back side of unit (MUZ-FH09/12NAH) (C62) (C61) 208/230 VAC 260 - 370 VDC Fuse (F701) Fuse (F801) 208/230 VAC T3.15AL250V T3.15AL250V...
  • Page 43 MUZ-FH15NA MUZ-FH15NAH MUZ-FH18NA MUZ-FH18NAH Fuse (F601) T3.15AL250V Heater connector R.V. coil (CN602) (CN601) 208/230 VAC 208/230 VAC (MUZ-FH15NAH MUZ-FH18NAH) Signal of out- door fan motor (CN931) LEV connector (CN724) Output to drive outdoor fan motor Defrost thermistor (CN932) /RT61 (CN671)

  • Page 44: Disassembly Instructions

    DISASSEMBLY INSTRUCTIONS <"Terminal with locking mechanism" Detaching points> The terminal which has the locking mechanism can be detached as shown below. There are two types (refer to (1) and (2)) 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 45 OPERATING PROCEDURE PHOTOS Photo 4 Photo 5 Screws of the Screw of the conduit cover conduit plate 2. Removing the inverter assembly, inverter P.C. board Photo 6 (1) Remove the cabinet and panels. (Refer to 1.) Screws of the heat sink (2) Disconnect the lead wire to the reactor and the following support and the separator connectors:...
  • Page 46 OPERATING PROCEDURE PHOTOS Screw of the 4. Removing the discharge temperature thermistor, Photo 8 R.V. coil defrost thermistor, outdoor heat exchanger tempera- ture thermistor and ambient temperature thermistor (1) Remove the cabinet and panels. (Refer to 1.) (2) Disconnect the lead wire to the reactor and the following con- nectors: <Inverter P.C.
  • Page 47 OPERATING PROCEDURE PHOTOS 5. Removing outdoor fan motor Photo 11 Screws of the outdoor fan motor (1) Remove the cabinet and panels. (Refer to 1.) (2) Disconnect the following connectors: <Inverter P.C. board> CN931, CN932 (Fan motor) (3) Remove the propeller fan nut. (4) Remove the propeller fan.
  • Page 48 11-2. MUZ-FH15NA MUZ-FH15NAH MUZ-FH18NA MUZ-FH18NAH NOTE: Turn OFF the power supply before disassembly. OPERATING PROCEDURE PHOTOS 1. Removing the cabinet Photo 1 Screws of the top panel (1) Remove the screws of the service panel. (2) Remove the screws of the top panel.
  • Page 49 OPERATING PROCEDURE PHOTOS Screw of the 2. Removing the inverter assembly, inverter P.C. board Photo 5 relay panel and relay P.C. board Screws of the (1) Remove the cabinet and panels. (Refer to 1.) P.B. support Inverter P.C. Ground wires (2) Disconnect the lead wire to the reactor and the following con- board nectors:...
  • Page 50 OPERATING PROCEDURE PHOTOS 4. Removing the discharge temperature thermistor, Photo 7 defrost thermistor, outdoor heat exchanger tempera- Outdoor heat exchanger Ambient temperature temperature thermistor thermistor ture thermistor and ambient temperature thermistor (1) Remove the cabinet and panels. (Refer to 1.) (2) Disconnect the lead wire to the reactor and the following connectors: <Inverter P.C.
  • Page 51 OBH684B...
  • Page 52 HEAD OFFICE: TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN © Copyright 2014 MITSUBISHI ELECTRIC CORPORATION Distributed in Dec. 2014. No. OBH684 REVISED EDITION-B Distributed in Apr. 2014. No. OBH684 REVISED EDITION-A New publication, effective Dec. 2014 Distributed in Feb. 2014. No. OBH684 Specifications are subject to change without notice.

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