SERVICE MANUAL MUZ-FH09NAH MUZ-FH12NAH MUZ-FH15NAH MUZ-FH09NA MUZ-FH12NA MUZ-FH15NA OUTDOOR UNIT. No. OBH684 REVISED EDITION-A.

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1 SPLIT-TYPE AIR CONDITIONERS Revision A: 3. SPECIFICATION has been modified. 10. TROUBLESHOOTING has been modified. Please void OBH684. OUTDOOR UNIT SERVICE MANUAL HFC utilized R410A. OBH684 REVISED EDITION-A Models MUZ-FH09NA MUZ-FH12NA MUZ-FH15NA MUZ-FH09NAH MUZ-FH12NAH MUZ-FH15NAH Indoor unit service manual MSZ-FH NA Series (OBH683) MUZ-FH09NA MUZ-FH12NA MUZ-FH09NAH MUZ-FH12NAH 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 DATA ACTUATOR CONTROL SERVICE FUNCTIONS TROUBLESHOOTING DISASSEMBLY INSTRUCTIONS 44 PARTS CATALOG (OBB684) NOTE: RoHS compliant products have <G> mark on the spec name plate.

2 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. Revision A: 3. SPECIFICATION has been modified. (The values of COP have been modified.) 10. TROUBLESHOOTING has been modified. 1 TECHNICAL CHANGES MUZ-FH09NA MUZ-FH12NA MUZ-FH15NA 1. New model MUZ-FH09NAH MUZ-FH12NAH MUZ-FH15NAH 2

3 2 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 Air inlet (back and side) Piping Drain hose Air outlet Drain outlet 3

4 3 SPECIFICATION Outdoor unit model Capacity Rated (Minimum~Maximum) Capacity Rated (Maximum) Power consumption Rated (Minimum~Maximum) MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH Cooling 1 Btu/h 9,000 (1,700 ~ 12,000) 12,000 (2,500 ~ 13,600) 15,000 (6,450 ~ 19,000) Heating 47 1 Btu/h 10,900 (1,600 ~ 18,000) 13,600 (3,700 ~ 21,000) 18,000 (5,150 ~ 24,000) Heating 17 2 Btu/h 6,700 (12,200) 8,000(13,600) 11,000 (18,000) Cooling 1 W 560 (100 ~ 1,000) 870 (170 ~ 1,150) 1,200 (410 ~ 2,200) Heating 47 1 W 710 (110 ~ 1,470) 950 (280 ~ 2,300) 1,300 (430 ~ 3,360) Power consumption Rated (Maximum) Heating 17 2 W 600 (1,440) 720 (1,900) 1,020 (2,480) EER 1 [SEER] 3 Cooling 16.1 [30.5] 13.8 [26.1] 12.5 [22.0] HSPF IV 4 Heating NA: 13.5 NA: 12.5 NA: 12.0 NAH: 12.5 NAH: 11.5 NAH: 11.0 COP Heating Power supply V, phase, Hz 208/230, 1, 60 Max. fuse size (time delay) A Min. circuit ampacity A Fan motor F.L.A Model SNB092FQAMT SNB140FQUMT SNB172FQKMT Compressor R.L.A L.R.A Refrigeration oil L (Model) 0.35 (FV50S) 0.35 (FV50S) 0.40 (FV50S) Refrigerant control Linear expansion valve Sound level 1 Cooling db(a) Heating db(a) Defrost method Reverse cycle W in. 31-1/2 33-1/16 Dimensions D in. 11-1/4 13 H in. 21-5/8 34-5/8 Weight Ib External fi nish Munsell 3Y 7.8/1.1 Remote controller Wireless type Control voltage (by built-in transformer) VDC Refrigerant piping t supplied Refrigerant pipe size (Min. wall thickness) Connection method Between the indoor & outdoor units Liquid in. 1/4 (0.0315) Gas in. 3/8 (0.0315) 1/2 (0.0315) Indoor Flared Outdoor Flared Height difference ft Piping length ft Refrigerant charge (R410A) 2 lb. 9 oz. 3 lb. 7 oz. NOTE: Test conditions are based on AHRI 210/240. 1: Rating conditions (Cooling) Indoor: 80 FDB, 67 FWB, Outdoor: 95 FDB, (75 FWB) (Heating) Indoor: 70 FDB, 60 FWB, Outdoor: 47 FDB, 43 FWB 2: (Heating) Indoor: 70 FDB, 60 FWB, Outdoor: 17 FDB, 15 FWB 4

5 Test condition 3, 4 ARI Mode Test SEER (Cooling) HSPF (Heating) "A-2" Cooling Steady State at rated compressor Speed "B-2" Cooling Steady State at rated compressor Speed "B-1" Cooling Steady State at minimum compressor Speed "F-1" Cooling Steady State at minimum compressor Speed "E-V" Cooling Steady State at Intermediate compressor Speed 5 "H1-2" Heating Steady State at rated compressor Speed "H3-2" Heating at rated compressor Speed "H0-1" Heating Steady State at minimum compressor Speed "H1-1" Heating Steady State at minimum compressor Speed "H2-V" Heating at Intermediate compressor Speed 5 Indoor air condition ( F) Outdoor air condition ( F) Dry bulb Wet bulb Dry bulb Wet bulb (75) (65) (65) (53.5) (69) : At Intermediate compressor Speed = ("Cooling rated compressor speed" - "minimum compressor speed") / 3 + "minimum compressor speed". OPERATING RANGE (1) POWER SUPPLY Rated voltage Guaranteed voltage (V) Outdoor unit 208/230 V 1 phase 60 Hz Min Max. 253 (2) OPERATION Intake air temperature ( F) Mode Condition Indoor Outdoor DB WB DB WB Standard temperature Cooling Maximum temperature Minimum temperature Maximum humidity 78 % Standard temperature Heating Maximum temperature Minimum temperature

6 4 OUTLINES AND DIMENSIONS MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH REQUIRED SPACE *1 4 in. (100 mm) or more when front and sides of the unit are clear 4 in. (100 mm) or more clear *1 4 in. (100 mm) or more Unit: inch 8 in. (200 mm) or more *2 14 in. (350 mm) or more *2 When any 2 sides of left, right and rear of the unit are clear holes Liquid refrigerant pipe joint Refrigerant pipe (flared) Ø 1/4 Gas refrigerant pipe joint Refrigerant pipe (flared) Ø 3/8 6

7 MUZ-FH15NA MUZ-FH15NAH Unit: inch REQUIRED SPACE *1 20 in. (500 mm) or more when front and sides of the unit are clear Clear *1 16-7/16 Air in Drain hole 1-9/16 1-5/8 4 in. (100 mm) or more 4 in. (100 mm) or more /16 Air out 6-7/ / /16 4-5/16 2-holes 13/32 13/16 3-3/16 20 in. (500 mm) or more *2 14in. (350 mm) or more *2 When any 2 sides of left, right and rear of the unit are clear Service panel Liquid refrigerant pipe joint Refrigerant pipe (flared) Ø 1/ / / /2 3-29/ /16 Gas refrigerant pipe joint Refrigerant pipe (flared) Ø 1/2 7

8 5 WIRING DIAGRAM MUZ-FH09NA MUZ-FH12NA MUZ-FH09NAH MUZ-FH12NAH 8

9 MUZ-FH15NA 9

10 MUZ-FH15NAH 10

11 6 REFRIGERANT SYSTEM DIAGRAM MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH Refrigerant pipe ø3/8 (with heat insulator) Flared connection Stop valve Muffler Service port 4-way valve Discharge temperature thermistor RT62 Muffler Service port Compressor Defrost thermistor RT61 Outdoor heat exchanger Outdoor heat exchanger temperature thermistor RT68 Ambient temperature thermistor RT65 Unit: inch Flared connection Refrigerant pipe ø1/4 (with heat insulator) Capillary tube O.D I.D /16 (ø4.0 ø ) Stop valve (with strainar) LEV Capillary tube O.D I.D /32 (ø3.0 ø ) Strainer #100 R.V. coil heating ON cooling OFF Refrigerant flow in cooling Refrigerant flow in heating MUZ-FH15NA MUZ-FH15NAH Refrigerant pipe ø1/2 (with heat insulator) 4-way valve Muffler #100 Service port Flared connection Stop valve Service port Discharge temperature thermistor RT62 Defrost thermistor RT61 Outdoor heat exchanger Ambient temperature thermistor RT65 Flared connection Refrigerant pipe ø1/4 (with heat insulator) Stop valve Strainer #100 Muffler Compressor LEV Capillary tube O.D I.D /16 (ø4.0 ø ) Strainer #100 Outdoor heat exchanger temperature thermistor RT68 R.V. coil heating ON cooling OFF Refrigerant flow in cooling Refrigerant flow in heating 11

12 MAX. REFRIGERANT PIPING LENGTH and MAX. HEIGHT DIFFERENCE Model MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH Max. Length A Refrigerant piping: ft. Max. Height difference B Gas Piping size O.D: in. Liquid /8 1/ /2 1/4 Indoor unit Max. Height difference B Max. Length A Outdoor unit ADDITIONAL REFRIGERANT CHARGE (R410A: oz.) NOTE: Refrigerant piping exceeding 25 ft. requires additional refrigerant charge according to the calculation. Model MUZ-FH09NA MUZ-FH09NAH Outdoor unit precharged Refrigerant piping length (one way): ft lb. 9 oz Calculation: X oz. = 1.08/5 oz./ft. (Refrigerant piping length (ft.) - 25) NOTE: Refrigerant piping exceeding 25 ft. requires additional refrigerant charge according to the calculation. Model MUZ-FH12NA MUZ-FH12NAH Outdoor unit precharged Refrigerant piping length (one way): ft lb. 9 oz Calculation: X oz. = 1.62/5 oz./ft. (Refrigerant piping length (ft.) - 25) NOTE: Refrigerant piping exceeding 25 ft. requires additional refrigerant charge according to the calculation. Model MUZ-FH15NA MUZ-FH15NAH Outdoor unit precharged Refrigerant piping length (one way): ft lb. 7 oz Calculation: X oz. = 1.08/5 oz./ft. (Refrigerant piping length (ft.) - 25) 12

13 7 DATA MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH 7-1. PERFORMANCE DATA 1) COOLING CAPACITY Indoor air Model IWB ( F) MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH Outdoor intake air DB temperature ( F) TC SHC TPC TC SHC TPC TC SHC TPC TC SHC TPC TC SHC TPC NOTE: 1. IWB : Intake air wet-bulb temperature TC : Total Capacity (x10 3 Btu/h) SHC : Sensible Heat Capacity (x10 3 Btu/h) TPC : Total Power Consumption (kw) 2. SHC is based on 80 F of indoor Intake air DB temperature. 2) COOLING CAPACITY CORRECTIONS Refrigerant piping length (one way: ft.) 25 (std.) MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH

14 3) HEATING CAPACITY Indoor air Outdoor intake air WB temperature ( F) Model IDB ( F) TC TPC TC TPC TC TPC TC TPC TC TPC TC TPC TC TPC MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH NOTE: 1. IDB : Intake air dry-bulb temperature TC : Total Capacity (x10 3 Btu/h) TPC : Total Power Consumption (kw) 2. Above data is for heating operation without any frost. How to operate with fixed operational frequency of the compressor. 1. Press the EMERGENCY OPERATION switch on the front of the indoor unit, and select either EMERGENCY COOL mode or EMERGENCY HEAT mode before starting to operate the air conditioner. 2. The compressor starts with operational frequency. 3. The fan speed of the indoor unit is High. 4. This operation continues for 30 minutes. 5. In order to release this operation, press the EMERGENCY OPERATION switch twice or once, or press any button on the remote controller. 14

15 7-2. PERFORMANCE CURVE Cooling Indoor air Wet-bulb temperature difference ( F) MUZ-FH09NA MUZ-FH09NAH Total power consumption (kw) SHF at rating condition = 0.92 Airflow = 381 CFM Indoor intake air WB temperature ( F) Outdoor intake air DB temperature ( F) MUZ-FH15NA MUZ-FH15NAH Total power consumption (kw) Capacity correction factors Cooling capacity (at Rated frequency) Outdoor intake air DB temperature( F) SHF at rating condition = 0.7 Airflow = 411 CFM Indoor intake air WB temperature ( F) Outdoor intake air DB temperature ( F) Indoor intake air Wet-bulb temperature( F) MUZ-FH12NA MUZ-FH12NAH This value of frequency is not the same as the actual frequency in operating. Refer to 7-5 and 7-6 for the relationships between frequency and capacity. 75 Total power consumption (kw) SHF at rating condition = 0.83 Airflow = 398 CFM Indoor intake air WB temperature ( F) Outdoor intake air DB temperature ( F)

16 Heating Indoor air Dry-bulb temperature difference ( F) Capacity correction factor Heating capacity (at Rated frequency) Indoor intake air Dry-bulb temperature ( F) Outdoor intake air WB temperature ( F) MUZ-FH09NA Total power consumption (kw) Total power consumption (kw) Indoor intake air DB temperature ( F) Airflow = 437 CFM MUZ-FH12NA Outdoor intake air WB temperature ( F) Indoor intake air DB temperature ( F) Airflow = 454 CFM MUZ-FH15NA Total power consumption (kw) Outdoor intake air WB temperature ( F) Indoor intake air DB temperature ( F) Airflow = 454 CFM Outdoor intake air WB temperature ( F) MUZ-FH09NAH Total power consumption (kw) MUZ-FH12NAH Total power consumption (kw) Indoor intake air DB temperature ( F) Outdoor intake air WB temperature ( F) Airflow = 437 CFM MUZ-FH15NAH Total power consumption (kw) Indoor intake air DB temperature ( F) Outdoor intake air WB temperature ( F) Indoor intake air DB temperature ( F) Airflow = 454 CFM Outdoor intake air WB temperature ( F) Airflow = 497 CFM This value of frequency is not the same as the actual frequency in operating. Refer to 7-5 and 7-6 for the relationships between frequency and capacity. 16

17 7-3. CONDENSING PRESSURE Cooling Data are based on the condition of indoor humidity 50 %. Air flow should be set to High speed. MUZ-FH09NA MUZ-FH09NAH (PSIG) 500 Condensing pressure Indoor DB temperature ( F) (PSIG) 190 Suction pressure Indoor DB temperature ( F) ( F) Outdoor ambient temperature Outdoor ambient temperature ( F) MUZ-FH12NA MUZ-FH12NAH (PSIG) 500 Condensing pressure Indoor DB temperature ( F) (PSIG) 180 Suction pressure Indoor DB temperature ( F) ( F) Outdoor ambient temperature Outdoor ambient temperature ( F) MUZ-FH15NA MUZ-FH15NAH (PSIG) 500 Condensing pressure Indoor DB temperature ( F) (PSIG) 180 Suction pressure Indoor DB temperature ( F) ( F) Outdoor ambient temperature Outdoor ambient temperature 17 ( F)

18 Heating Data are based on the condition of outdoor humidity 75%. Air flow should be set to High speed. Data are for heating operation without any frost. MUZ-FH09NA MUZ-FH09NAH Condensing pressure (PSIG) Indoor DB temperature ( F) 58.5Hz (PSIG) 210 Suction pressure Indoor DB temperature ( F) 58.5Hz ( F) Outdoor ambient temperature ( F) Outdoor ambient temperature MUZ-FH12NA MUZ-FH12NAH (PSIG) (PSIG) Condensing pressure Indoor DB temperature ( F) Suction pressure Indoor DB temperature ( F) Hz 75 49Hz ( F) Outdoor ambient temperature ( F) Outdoor ambient temperature MUZ-FH15NA MUZ-FH15NAH (PSIG) (PSIG) Condensing pressure Indoor DB temperature ( F) Suction pressure Indoor DB temperature ( F) Hz 75 50Hz ( F) Outdoor ambient temperature ( F) Outdoor ambient temperature 18

19 7-4. STANDARD OPERATION DATA Total Electrical circuit Refrigerant circuit Indoor unit Outdoor unit Model MSZ-FH09NA MSZ-FH12NA MSZ-FH15NA Item Unit Cooling Heating Cooling Heating Cooling Heating Capacity Btu/h 9,000 10,900 12,000 13,600 15,000 18,000 SHF Input kw Rated frequency Hz Indoor unit MSZ-FH09NA MSZ-FH12NA MSZ-FH15NA Power supply V, phase, Hz 208/230, 1, 60 Input kw Fan motor current A 0.30/ / /0.28 Outdoor unit MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH Power supply V, phase, Hz 208/230, 1, 60 Input kw Comp. current A 2.32/ / / / / /4.40 Fan motor current A 0.36/ / / / / /1.12 Condensing pressure PSIG Suction pressure PSIG Discharge temperature F Condensing temperature F Suction temperature F Comp. shell bottom temperature F Ref. pipe length ft. 25 Refrigerant charge (R410A) 2 lb. 9 oz. 3 lb 7 oz. Intake air temperature DB F WB F Discharge air temperature DB F WB F Fan speed (High) rpm 1,150 1,280 1,190 1,320 1,220 1,420 Airfl ow (High) CFM 381 (Wet) (Wet) (Wet) 497 Intake air temperature DB F WB F Fan speed rpm Airfl ow CFM 1,074 1,202 1,074 1,202 1,692 1,634 19

20 7-5. CAPACITY AND INPUT CORRECTION BY INVERTER OUTPUT FREQUENCY MUZ-FH09NA MUZ-FH09NAH Correction of Cooling capacity Correction of Cooling total input Correction of Heating capacity Correction of Heating total input 2.5 Capacity correction factors Input correction factors Capacity correction factors Input correction factors (Hz) (Hz) (Hz) (Hz) The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor MUZ-FH12NA MUZ-FH12NAH 2.0 Correction of Cooling capacity Correction of Cooling total input Correction of Heating capacity Correction of Heating total input 2.5 Capacity correction factors Input correction factors Capacity correction factors Input correction factors (Hz) (Hz) (Hz) (Hz) The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor MUZ-FH15NA MUZ-FH15NAH 2.0 Correction of Cooling capacity Correction of Cooling total input Correction of Heating capacity Correction of Heating total input 3.0 Capacity correction factors Input correction factors Capacity correction factors Input correction factors (Hz) (Hz) (Hz) (Hz) The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor 7-6. HOW TO OPERATE FIXED-FREQUENCY OPERATION (Test run operation) 1. Press EMERGENCY OPERATION switch to start COOL or HEAT mode (COOL: Press once, HEAT: Press twice). 2. Test run operation starts and continues to operate for 30 minutes. 3. Compressor operates at rated frequency in COOL mode or 58 Hz in HEAT mode. 4. Indoor fan operates at High speed. 5. After 30 minutes, test run operation finishes and EMERGENCY OPERATION starts (operation frequency of compressor varies). 6. To cancel test run operation (EMERGENCY OPERATION), press EMERGENCY OPERATION switch or any button on remote controller. 20

21 8 ACTUATOR CONTROL MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH 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. Compressor ON OFF 5 seconds 15 seconds Outdoor fan motor ON OFF 8-2. R.V. COIL CONTROL Heating ON Cooling OFF Dry OFF NOTE: The 4-way valve reverses for 5 seconds right before start-up of the compressor. <COOL> <HEAT> 5 seconds 5 seconds ON Compressor OFF R.V.coil ON OFF Outdoor fan ON motor OFF 8-3. RELATION BETWEEN MAIN SENSOR AND ACTUATOR Sensor Purpose Compressor LEV Actuator Outdoor fan motor R.V.coil Indoor fan motor Discharge temperature Protection thermistor Cooling: Coil frost prevention Indoor coil temperature thermistor Heating: High pressure protection Defrost thermistor Heating: Defrosting Fin temperature thermistor Protection Cooling: Low ambient temperature operation Ambient temperature thermistor Outdoor heat exchanger temperature thermistor *. MUZ-FH NAH only. Heating: Defrosting (Heater) Cooling: Low ambient temperature operation Cooling: High pressure protection Defrost heater * 21

22 9 SERVICE FUNCTIONS MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH 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 ). Defrost finish temperature Jumper MUZ-FH09/12NA MUZ-FH09/12NAH MUZ-FH15NA MUZ-FH15NAH JS Soldered (Initial setting) ne (Cut) 41 F (5 C) 50 F (10 C) 50 F (10 C) 64 F (18 C) 9-2. PRE-HEAT CONTROL SETTING MUZ-FH09/12 When moisture gets into the refrigerant cycle, it may interfere the start-up of the compressor at low outside temperature. The pre-heat control prevents this interference. The pre-heat control turns ON when the discharge temperature thermistor is 68 F (20 C) or below. When the pre-heat control turns ON, the compressor is energized. (About 50 W) MUZ-FH15 Prolonged low load operation, in which the thermostat is OFF for a long time, at low outside temperature [32 F (0 C) or less] may cause the following troubles. To prevent those troubles, activate the pre-heat control. 1) If moisture gets into the refrigerant cycle and freezes, it may interfer the start-up of the compressor. 2) If liquid refrigerant collects in the compressor, a failure in the compressor may occur. The pre-heat control turns ON when the compressor temperature is 68 F (20 C) or below. When the pre-heat control turns ON, the compressor is energized. (About 70 W) Pre-heat control setting <JK> ON: To activate the pre-heat control, cut JK wire of the inverter P.C. board. OFF: To deactivate the pre-heat control, solder JK wire of the inverter P.C. board. (Refer to ) NOTE: When the inverter P.C. board is replaced, check the jumper wires, and cut/solder them if necessary. 22

23 10 TROUBLESHOOTING MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH 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 confirming the horizontal vane is closed, turn off the breaker and/or disconnect the power plug. 2) Be sure to turn OFF the power supply before removing the front panel, the cabinet, the top panel, and the electronic control P.C. board. 3) When removing the electrical parts, be careful of the residual voltage of smoothing capacitor. 4) When removing the electronic control P.C. board, hold the edge of the board with care NOT to apply stress on the components. 5) When connecting or disconnecting the connectors, hold the housing of the connector. DO NOT pull the lead wires. <Incorrect> <Correct> Lead wiring Housing point 3. Troubleshooting procedure 1) Check if the OPERATION INDICATOR lamp on the indoor unit is flashing on and off to indicate an abnormality. To make sure, check how many times the OPERATION INDICATOR lamp is flashing on and off before starting service work. 2) Before servicing, check that the connector and terminal are connected properly. 3) When the electronic control P.C. board seems to be defective, check the copper foil pattern for disconnection and the components for bursting and discoloration. 4) Refer to 10-2 and

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. Flow chart of failure mode recall function for the indoor/outdoor unit Operational procedure The cause of abnormality cannot be found because the abnormality does not recur. Setting up the failure mode recall function Turn ON the power supply. <Preparation of the remote controller> While pressing 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 seconds. Make sure that the indicators on the LCD screen shown in the right fi gure are all displayed. Then release the buttons. Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature is displayed) with the remote controller headed towards the indoor unit Regardless of normal or abnormal condition, a short beep is emitted once the signal is received. Does the left lamp of the OPERATION INDICATOR lamp on the indoor unit blink at the interval of 0.5 seconds? Blinks: Either indoor or outdoor unit is abnormal. Beep is emitted at the same timing as the blinking of the left lamp of the OPERATION INDICATOR lamp. 2 Judgment of indoor/outdoor abnormality (Blinks) Before blinking, does the left lamp of the OPERATION INDI- CATOR lamp stay ON for 3 seconds? Stays ON for 3 seconds (without beep): The outdoor unit is abnormal. (OFF) Indoor unit is normal. But the outdoor unit might be abnormal because there are some abnormalities that can not be recalled with this way. Check if outdoor unit is abnormal according to the detailed outdoor unit failure mode recall function. (Refer to ) The indoor unit is abnormal. Check the blinking pattern, and identify the abnormal point by referring to the indoor unit failure mode table. (Refer to indoor unit service manual.) Make sure to check at least two consecutive blinking cycles. 2 The outdoor unit is abnormal. Check the blinking pattern, and identify the abnormal point by referring to the outdoor unit failure mode table. (Refer to ) Make sure to check at least two consecutive blinking cycles. 3 Releasing the failure mode recall function Release the failure mode recall function by the following procedures. Turn OFF the power supply and turn it ON again. Press RESET button of the remote controller. Repair the failure parts. Deleting the memorized abnormal condition After repairing the unit, recall the failure mode again according to "Setting up the failure mode recall function" mentioned above. Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature is displayed) with the remote controller headed towards the indoor unit. Press EMERGENCY OPERATION switch so that the memorized abnormal condition is deleted. Release the failure mode recall function according to "Releasing the failure mode recall function" mentioned above. NOTE: 1. Make sure to release the failure mode recall function after it is set up, otherwise the unit cannot operate properly. 2. If the abnormal condition is not deleted from the memory, the last abnormal condition is kept memorized. 2. Blinking pattern when the indoor unit is abnormal: 2.5-second OFF Blinking at 0.5- second interval 2.5-second OFF Blinking at 0.5- second interval ON OFF Beeps Repeated cycle Beeps Repeated cycle Beeps Repeated cycle 3.Blinking pattern when the outdoor unit is abnormal: Blinking at second OFF 3-second ON second interval 2.5-second OFF 3-second ON Blinking at 0.5- second interval ON OFF beep Repeated cycle Beeps 24 beep Repeated cycle Beeps Repeated cycle

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. With the remote controller headed towards the indoor unit, press TEMP button to adjust the set temperature to 77 F (25 C) Regardless of normal or abnormal condition, 2 short beeps are emitted as the signal is received. Does the left lamp of the OPERATION INDICATOR lamp on the indoor unit blink at the interval of 0.5 seconds? Blinks: The outdoor unit is abnormal. Beep is emitted at the same timing as the blinking of the left lamp of the OPERATION INDICATOR lamp. 2 (Blinks) (OFF) The outdoor unit is abnormal. Check the blinking pattern, and identify the abnormal point by referring to the outdoor unit failure mode table ( ). Make sure to check at least two consecutive blinking cycles. 2 The outdoor unit is normal. Releasing the failure mode recall function Release the failure mode recall function by the following procedures. Turn OFF the power supply and turn it ON again. Press RESET button of the remote controller. Release the failure mode recall function according to the left mentioned procedure. Repair the failure parts. Deleting the memorized abnormal condition After repairing the unit, recall the failure mode again according to "Setting up the failure mode recall function" ( ). Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature is displayed) with the remote controller headed towards the indoor unit. Press EMERGENCY OPERATION switch so that the memorized abnormal condition is deleted. Release the failure mode recall function according to "Releasing the failure mode recall function" mentioned above. NOTE: 1. Make sure to release the failure mode recall function after it is set up, otherwise the unit cannot operate properly. 2. If the abnormal condition is not deleted from the memory, the last abnormal condition is kept memorized. 2.Blinking pattern when outdoor unit is abnormal: 2.5-second OFF 3-second ON Blinking at 0.5- second interval 2.5-second OFF 3-second ON Blinking at 0.5- second interval ON OFF beep Repeated cycle Beeps beep Repeated cycle Beeps Repeated cycle 25

26 3. Outdoor unit failure mode table The left lamp of the OPERATION INDICATOR lamp (Indoor unit) Abnormal point (Failure mode/protection) LED indication (Outdoor P.C. board) Condition Remedy Indoor/outdoor unit failure mode recall function Outdoor unit failure mode recall function OFF ne (rmal) 1-time fl ash Indoor/outdoor Any signals from the inverter P.C. Refer to How 2.5 seconds OFF communication, receiving error board cannot be received normally for 3 minutes. to check miswiring and serial signal error. 2-time fl ash 2.5 seconds OFF 3-time fl ash 2.5 seconds OFF 4-time fl ash 2.5 seconds OFF 5-time fl ash 2.5 seconds OFF 6-time fl ash 2.5 seconds OFF 7-time fl ash 2.5 seconds OFF 8-time fl ash 2.5 seconds OFF 9-time fl ash 2.5 seconds OFF Indoor/outdoor communication, receiving error Outdoor power system Discharge temperature thermistor Defrost thermistor Fin temperature thermistor P.C. board temperature thermistor Ambient temperature thermistor Outdoor heat exchanger temperature thermistor Overcurrent Compressor synchronous abnormality (Compressor start-up failure protection) Discharge temperature High pressure Fin temperature/ P.C. board temperature Outdoor fan motor nvolatile memory data Power module (IC700) (FH09/12) IGBT module (IC700) (FH15) 1-time fl ash every 2.5 seconds 3-time fl ash 4-time fl ash 2-time fl ash 11-time fl ash 12-time fl ash 7-time fl ash 5-time fl ash 6-time fl ash Although the inverter P.C. board sends signal "0", signal "1" has been received 30 consecutive times. Overcurrent protection cut-out operates 3 consecutive times within 1 minute after the compressor gets started. Thermistor shorts or opens during compressor running. Large current fl ows into the power module (IC700) (FH09/12)/ IGBT module (IC700) (FH15). Waveform of compressor current is distorted. Temperature of discharge temperature thermistor exceeds 241 F (116 C), compressor stops. Compressor can restart if discharge temperature thermistor reads 212 F (100 C) or less 3 minutes later. Temperature indoor coil thermistor exceeds 158 F (70 C) in HEAT mode. Temperature defrost thermistor exceeds 158 F (70 C) in COOL mode. Temperature of the fin temperature thermistor on the inverter P.C. board exceeds 167 ~ 187 F (75 ~ 86 C) (FH09/12)/167 ~ 176 F (75 ~ 80 C) (FH15), or temperature of P.C. board temperature thermistor on the inverter P.C. board exceeds 162 ~ 185 F (72 ~ 85 C) (FH09/12)/158 ~ 167 F (70 ~ 75 C) (FH15). Outdoor fan has stopped 3 times in a row within 30 seconds after outdoor fan start-up. nvolatile memory data cannot be read properly. The interface short circuit occurs in the output of the power module (IC700) (FH09/12)/IGBT module (IC700) (FH15). The compressor winding shorts circuit. Refer to How to check miswiring and serial signal error. Reconnect connectors. Refer to "How to check inverter/ compressor". Check stop valve. Refer to "Check of outdoor thermistors". Defective outdoor thermistors can be identifi ed by checking the blinking pattern of LED. Reconnect compressor connector. Refer to "How to check inverter/ compressor". Check stop valve. Reconnect compressor connector. Refer to "How to check inverter/ compressor". Check refrigerant circuit and refrigerant amount. Refer to "Check of LEV". Check refrigerant circuit and refrigerant amount. Check stop valve. Check around outdoor unit. Check outdoor unit air passage. Refer to "Check of outdoor fan motor". Refer to "Check of outdoor fan motor". Refer to "Check of inverter P.C. board". Replace the inverter P.C. board. Refer to "How to check inverter/ compressor". NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (10-3.). 26

27 The left lamp of the OPERATION INDICATOR lamp (Indoor unit) 10-time fl ash 2.5 seconds OFF 11-time fl ash 2.5 seconds OFF 14-time fl ash or more 2.5 seconds OFF Abnormal point (Failure mode/protection) Discharge temperature DC voltage Each phase current of compressor Stop valve (Closed valve) 4-way valve/ Pipe temperature Outdoor refrigerant system abnormality LED indication (Outdoor P.C. board) 8-time fl ash 9-time fl ash 14-time fl ash 16-time fl ash 17-time fl ash Condition Temperature of discharge temperature thermistor has been 122 F (50 C) or less for 20 minutes. DC voltage of inverter cannot be detected normally. Each phase current of compressor cannot be detected normally. Closed valve is detected by compressor current. The 4-way valve does not work properly. The indoor coil thermistor detects an abnormal temperature. Remedy Indoor/outdoor unit failure mode recall function Outdoor unit failure mode recall function Refer to "Check of LEV". Check refrigerant circuit and refrigerant amount. Refer to "How to check inverter/ compressor". Check stop valve. Check the 4-way valve. Replace the inverter P.C. board. A closed valve and air trapped in the Check for a gas leak refrigerant circuit are detected based in a connecting piping on the temperature sensed by the etc. indoor and outdoor thermistors and the Check the stop valve. current of the compressor. Refer to Check of outdoor refrigerant circuit. NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (10-3.). 27

28 10-3. TROUBLESHOOTING CHECK TABLE. Symptom LED indication Outdoor unit does not operate. 'Outdoor unit stops and restarts 3 minutes later' is repeated. 1-time fl ash every 2.5 seconds 6-time fl ash Abnormal point/ Condition Outdoor power system Condition Overcurrent protection cut-out operates 3 consecutive times within 1 minute after the compressor gets started. Outdoor thermistors Discharge temperature thermistor, fi n temperature thermistor, defrost thermistor, P.C. board temperature thermistor, outdoor heat exchanger temperature thermistor or ambient temperature thermistor shorts or opens during compressor running. Outdoor control system nvolatile memory data cannot be read properly. (The left lamp of the OPERATION INDICATOR lamp on the indoor unit lights up or fl ashes 7-time.) Serial signal The communication fails between the indoor and outdoor unit for 3 minutes. 11-time fl ash Stop valve/ Closed valve Closed valve is detected by compressor current. 14-time fl ash Outdoor unit Outdoor unit is defective. (Other abnormality) 16-time fl ash 17-time fl ash 2-time fl ash 3-time fl ash 4-time fl ash 5-time fl ash 8-time fl ash 10-time fl ash 4-way valve/ Pipe temperature Outdoor refrigerant system abnormality Overcurrent protection Discharge temperature overheat protection Fin temperature /P.C. board temperature thermistor overheat protection High pressure protection The 4-way valve does not work properly. The indoor coil thermistor detects an abnormal temperature. A closed valve and air trapped in the refrigerant circuit are detected based on the temperature sensed by the indoor and outdoor thermistors and the current of the compressor. Large current fl ows into the power module (IC700) (FH09/12)/ IGBT module (IC700) (FH15). Remedy Reconnect connector of compressor. Refer to "How to check inverter/compressor". Check stop valve. Refer to "Check of outdoor thermistors". Replace inverter P.C. board. Check connection between the inverter P.C. board and the relay P.C. board. (FH15) Refer to "How to check miswiring and serial signal error. Check stop valve. Refer to "Flow chart of the detailed outdoor unit failure mode recall function". Refer to "Check of R.V. coil". Replace the inverter P.C. board. Check for a gas leak in a connecting piping etc. Check the stop valve. Refer to Check of outdoor refrigerant circuit. Reconnect connector of compressor. Refer to "How to check inverter/compressor". Check stop valve. Temperature of discharge temperature thermistor exceeds Check refrigerant circuit and refrigerant amount. 241 F (116 C), compressor stops. Compressor can restart if discharge temperature thermistor reads 212 F (100 C) or less Refer to "Check of LEV". 3 minutes later. Temperature of the fin temperature thermistor on the heat sink exceeds 167 ~ 187 F (75 ~ 86 C) (FH09/12)/167 ~ 176 F (75 ~ 80 C) (FH15) or temperature of P.C. board temperature thermistor on the inverter P.C.board exceeds 162 ~ 185 F (72 ~ 85 C) (FH09/12)/158 ~ 167 F (70 ~ 75 C) (FH15). Indoor coil thermistor exceeds 158 F (70 C) in HEAT mode. Defrost thermistor exceeds 158 F (70 C) in COOL mode. Compressor synchronous abnormal- The waveform of compressor current is distorted. ity Outdoor fan motor Outdoor fan has stopped 3 times in a row within 30 seconds after outdoor fan start-up. Check around outdoor unit. Check outdoor unit air passage. Refer to "Check of outdoor fan motor". Check refrigerant circuit and refrigerant amount. Check stop valve. Reconnect connector of compressor. Refer to "How to check inverter/compressor". Refer to "Check of outdoor fan motor. Refer to "Check of inverter P.C. board. 12-time fl ash Each phase current Each phase current of compressor cannot be detected normally. inverter/compressor". Refer to "How to check of compressor 13-time fl ash DC voltage DC voltage of inverter cannot be detected normally. It occurs with following case. Instantaneous power voltage drop. (Short time power failure) (FH15) Refer to "Check of power supply". (FH15) Refer to "How to check inverter/compressor". NOTE: 1. The location of LED is illustrated at the right fi gure. Refer to LED is lighted during normal operation. The fl ashing frequency shows the number of times the LED blinks after every 2.5-second OFF. (Example) When the fl ashing frequency is second ON 0.5-second ON Inverter P.C. board MUZ-FH09/12NA(H) Flashing LED ON 2.5-second OFF OFF 2.5-second OFF 28 MUZ-FH15NA(H) Flashing LED

29 . Symptom LED indication Outdoor unit operates. Outdoor unit operates. 1-time fl ash 3-time fl ash 4-time fl ash MUZ-FH09/12 5-time fl ash 7-time fl ash 8-time fl ash 9-time fl ash Abnormal point/ Condition Frequency drop by current protection Frequency drop by high pressure protection Frequency drop by defrosting in COOL mode Frequency drop by discharge temperature protection Outside temperature thermistor protection Low discharge temperature protection MUZ-FH09/12 PAM protection PAM: Pulse Amplitude Modulation MUZ-FH15 Zero cross detecting circuit Inverter check mode FH09/12 Condition When the input current exceeds approximately 10A (FH09)/10.5A (FH12), compressor frequency lowers. FH15 Current from power outlet is nearing breaker capacity. Temperature of indoor coil thermistor exceeds 131 F (55 C) in HEAT mode, compressor frequency lowers. Indoor coil thermistor reads 46 F (8 C) or less in COOL mode, compressor frequency lowers. Temperature of discharge temperature thermistor exceeds 232 F (111 C), compressor frequency lowers. When the outside temperature thermistor shorts or opens, protective operation without that thermistor is performed. Temperature of discharge temperature thermistor has been 122 F (50 C) or less for 20 minutes. The overcurrent flows into PFC (Power factor correction :IC820) or the DC voltage reaches 394 V or more, PAM stops and restarts. Zero cross signal cannot be detected. The connector of compressor is disconnected, inverter check mode starts. Remedy The unit is normal, but check the following. Check if indoor fi lters are clogged. Check if refrigerant is short. Check if indoor/outdoor unit air circulation is short cycled. Check refrigerant circuit and refrigerant amount. Refer to "Check of LEV". Refer to "Check of outdoor thermistors". Refer to Check of outdoor thermistors. Refer to "Check of LEV". Check refrigerant circuit and refrigerant amount. This is not malfunction. PAM protection will be activated in the following cases: 1 Instantaneous power voltage drop. (Short time power failure) 2 When the power supply voltage is high. It occurs with following cases. 1 Instantaneous power voltage drop. (Short time power failure) 2 Distortion of primary voltage Refer to "Check of power supply". Check if the connector of the compressor is correctly connected. Refer to "How to check inverter/compressor". NOTE: 1. The location of LED is illustrated at the right fi gure. Refer to LED is lighted during normal operation. The fl ashing frequency shows the number of times the LED blinks after every 2.5-second OFF. (Example) When the fl ashing frequency is second ON 0.5-second ON Inverter P.C. board MUZ-FH09/12NA(H) Flashing LED ON OFF 2.5-second OFF 2.5-second OFF MUZ-FH15NA(H) Flashing LED 29

30 10-4. TROUBLE CRITERION OF MAIN PARTS MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH MUZ-FH15NA MUZ-FH15NAH Part name Check method and criterion Figure Defrost thermistor (RT61) Fin temperature thermistor (RT64) Ambient temperature thermistor (RT65) Measure the resistance with a tester. Refer to Test point diagram and voltage, 1. Inverter P.C. board, for the chart of thermistor. Outdoor heat exchanger temperature thermistor (RT68) Discharge temperature thermistor (RT62) Measure the resistance with a tester. Before measurement, hold the thermistor with your hands to warm it up. Refer to Test point diagram and voltage, 1. Inverter P.C. board, for the chart of thermistor. Measure the resistance between terminals using a tester. [Temperature: 14 ~ 104 F (-10 ~ 40 C)] WHT RED BLK Compressor U-V U-W V-W rmal (Ω) MUZ-FH09 MUZ-FH12 MUZ-FH ~ ~ ~ 1.18 V W U Outdoor fan motor Measure the resistance between lead wires using a tester. [Temperature: 14 ~ 104 F (-10 ~ 40 C)] Color of lead wire rmal (Ω) MUZ-FH09/12 MUZ-FH15 RED BLK BLK WHT WHT RED 29 ~ ~ 16 WHT V RED BLK W U R. V. coil (21S4) Measure the resistance using a tester. [Temperature: 14 ~ 104 F (-10 ~ 40 C)] rmal (kω) 0.97 ~ 1.38 Expansion valve coil (LEV) Measure the resistance using a tester. [Temperature: 14 ~ 104 F (-10 ~ 40 C)] Color of lead wire rmal (Ω) RED ORN RED WHT 37 ~ 54 RED BLU RED YLW WHT ORN RED (+12V) YLW LEV BLU Measure the resistance using a tester. [Temperature: 14 ~ 104 F (-10 ~ 40 C)] Defrost heater rmal (Ω) MUZ-FH09/12NAH MUZ-FH15NAH 349 ~ ~

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). Check the voltage between terminals. See Check of open phase. Are the voltages balanced? Replace the inverter P.C. board. Check the compressor. See Check of compressor. B Check of open phase With the connector between the compressor and the power module (IC700) (MUZ-FH09/12)/IGBT module (IC700) (MUZ-FH15) disconnected, activate the inverter and check if the inverter is normal by measuring the voltage balance between the terminals. Output voltage is V. (The voltage may differ according to the tester.) << Operation method>> Start cooling or heating operation by pressing EMERGENCY OPERATION switch on the indoor unit. (TEST RUN OPERA- TION: Refer to 7-6.) <<Measurement point>> Measure AC voltage between the lead wires at 3 points. At 3 points BLK (U)-WHT (V) BLK (U)-RED (W) WHT(V)-RED (W) NOTE: 1. Output voltage varies according to power supply voltage. 2. Measure the voltage by analog type tester. 3. During this check, LED of the inverter P.C. board fl ashes 9 times. (Refer to ) C Check of compressor Refer to Check of compressor winding. Is the compressor normal? Refer to Check of compressor operation time. Does the compressor operate continuously? OK. Replace the compressor. Refer to Check of compressor start failure. 31

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), and measure the resistance between the compressor terminals. <<Measurement point>> At 3 points BLK-WHT BLK-RED Measure the resistance between the lead wires at 3 points. WHT-RED <<Judgement>> Refer to [Ω] Abnormal [short] Infinite [Ω] Abnormal [open] NOTE: Be sure to zero the ohmmeter before measurement. E Check of compressor operation time Connect the compressor and activate the inverter. Then measure the time until the inverter stops due to over current. <<Operation method>> Start heating or cooling operation by pressing EMERGENCY OPERATION switch on the indoor unit. (TEST RUN OPERATION: Refer to 7-6.) <<Measurement>> Measure the time from the start of compressor to the stop of compressor due to overcurrent. F Check of compressor start failure <<Judgement>> 0 second 1 second 2 seconds 10 seconds 10 minutes Compressor starts Abnormal (IC700 failure) (Compressor winding short) Abnormal (Compressor lock out) (Starting defect) Abnormal (Poor contact) (Inverter P.C. board defect) (Disconnected connector) Abnormal (Refrigerant circuit defect) (Closed valve) rmal Confi rm that ~ is normal. Electrical circuit check. Contact of the compressor connector. Output voltage of inverter P.C. board and balance of them (See ). Direct current voltage between DB61(+) and (-) (MUZ-FH09/12)/JP715(+) and JP30(-) (MUZ-FH15) on the inverter P.C. board. Voltage between outdoor terminal block S1-S2 Does the compressor run for 10 seconds or more after it starts? Check the refrigerant circuit. Check the stop valve. After the compressor is heated with a drier, does the compressor start? 1 Compressor start failure. Activate pre-heat control. (Refer to 9-2. "PRE-HEAT CONTROL SETTING") Replace the compressor. 1 Heat the compressor with a drier for about 20 minutes. Do not recover refrigerant gas while heating. 32 Heating part

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. Is the resistance of thermistor normal? (Refer to ) Reconnect the connector of thermistor. Turn ON the power supply and press EMERGENCY OPERATION switch. Replace the thermistor except RT64. When RT64 is abnormal, replace the inverter P.C. board. Does the unit operate for 10 minutes or more without showing thermistor abnormality? OK. (Cause is poor contact.) Replace the inverter P.C. board. MUZ-FH09/12 Thermistor Symbol Connector, Pin. Board Defrost RT61 Between CN641 pin1 and pin2 Discharge temperature RT62 Between CN641 pin3 and pin4 Fin temperature RT64 Between CN642 pin1 and pin2 Inverter P.C. board Ambient temperature RT65 Between CN643 pin1 and pin2 Outdoor heat exchanger temperature RT68 Between CN644 pin1 and pin3 MUZ-FH15 Thermistor Symbol Connector, Pin. Board Defrost RT61 Between CN671 pin1 and pin2 Discharge temperature RT62 Between CN671 pin3 and pin4 Fin temperature RT64 Between CN673 pin1 and pin2 Inverter P.C. board Ambient temperature RT65 Between CN672 pin1 and pin2 Outdoor heat exchanger temperature RT68 Between CN671 pin5 and pin6 33

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 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. coil. Check if CN721 is connected. Unit operates COOL mode even if it is set to HEAT mode. Disconnect connector between the compressor and the power module (IC700). Turn ON the power supply and press EMERGENCY OPERATION switch twice (HEAT mode). Is there 208/230 VAC between CN721 and on the inverter P.C. board 3 minutes after the power supply is turned ON? Replace the 4-way valve. Replace the inverter P.C. board. Unit operates HEAT mode even if it is set to COOL mode. Disconnect connector between the compressor and the power module (IC700). Turn ON the power supply and press EMERGENCY OPERATION switch once (COOL mode). Is there 208/230 VAC between CN721 and on the inverter P.C. board 3 minutes after the power supply is turned ON? Replace the 4-way valve. Replace the inverter P.C. board. MUZ-FH15 First of all, measure the resistance of R.V. coil to check if the coil is defective. Refer to In case CN602 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. coil. Check if CN602 is connected. Unit operates COOL mode even if it is set to HEAT mode. Disconnect connector between the compressor and the IGBT module (IC700). Turn ON the power supply and press EMERGENCY OPERATION switch twice (HEAT mode). Is there 208/230 VAC between CN602 and on the inverter P.C. board 3 minutes after the power supply is turned ON? Replace the 4-way valve. Replace the inverter P.C. board. Unit operates HEAT mode even if it is set to COOL mode. Disconnect connector between the compressor and the IGBT module (IC700). Turn ON the power supply and press EMERGENCY OPERATION switch once (COOL mode). Is there 208/230 VAC between CN602 and on the inverter P.C. board 3 minutes after the power supply is turned ON? Replace the 4-way valve. Replace the inverter P.C. board. 34

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 terminal of outdoor fan motor normal? (Refer to 10-4.) Disconnect CN932 from the inverter P.C. board, and turn on the power supply. Rotate the outdoor fan motor manually and measure the voltage of CN931. Between 1(+) and 5(-) Between 2(+) and 5(-) Between 3(+) and 5(-) Replace the outdoor fan motor. (Fixed to either 5 or 0 VDC) Does the voltage between each terminal become 5 and 0 VDC repeatedly? Does the outdoor fan motor rotate smoothly? Replace the inverter P.C. board. 35

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). Turn ON power supply and press EMERGENCY OPERATION switch. Rectify indoor/outdoor connecting wire. Does the left lamp of the OPERATION INDICATOR lamp on the indoor unit light up? Is there voltage 208/230 VAC between the indoor terminal block S1 and S2? Replace the indoor electronic control P.C. board. Is there DC voltage VDC between DB61 (+) and DB61 ( ) (MUZ-FH09/12)/ VDC between JP715 (+) and JP30 ( ) (MUZ-FH15) on the inverter P.C. board? (Refer to ) Check the electric parts in main circuit. Does LED on the inverter P.C. board light up or fl ash? (Refer to ) If light up, OK. If fl ash, refer to DB61 Replace the inverter P.C. board VDC Inverter P.C. board (Solder side) MUZ-FH09/12 JP30 JP VDC MUZ-FH15 36

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 seconds. Make sure that the indicators on the LCD screen shown in the right fi gure are all displayed. Then release the buttons. Press OPERATE/STOP (ON/OFF) button of the remote controller (the set temperature is displayed) with the remote controller headed towards the indoor unit. 1 Expansion valve operates in full-opening direction. Do you hear the expansion valve "click, click "? Do you feel the expansion valve vibrate on touching it? OK 1. Regardless of normal or abnormal condition, a short beep is emitted once the signal is received. Is LEV coil properly fi xed to the expansion valve? Does the resistance of LEV coil have the characteristics? (Refer to 10-4.) Replace the LEV coil. Properly fi x the LEV coil to the expansion valve. Measure each voltage between connector pins of CN724 on the inverter P.C. board. 1. Pin (-) Pin (+) 2. Pin (-) Pin (+) 3. Pin (-) Pin (+) 4. Pin (-) Pin (+) Is there about 3-5 VAC between each? NOTE: Measure the voltage by an analog tester. Replace the inverter P.C. board. Replace the expansion valve. NOTE: After check of LEV, do the undermentioned operations. 1. Turn OFF the power supply and turn it ON again. 2. Press RESET button on the remote controller. 37

38 L Check of inverter P.C. board Check the outdoor fan motor. (Refer to ) Is the fuse (F901) blown on the inverter 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. Check the LED indication on the inverter P.C. board. Does the LED flash 10 times? (10-time fl ash) Check the corresponding parts following LED indication. (Refer to 10-3.) Replace the inverter P.C. board. 38

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? Turn ON the power supply. Check the power supply. Is there rated voltage between the outdoor terminal block S1 and S2? Press EMERGENCY OPERATION switch once. Check the wiring. Does the left lamp of OPERATION INDICATOR lamp light up? <Confi rmation of the power to the indoor unit> Is serial signal error indicated 6 minutes later? Is there any miswiring, poor contact, or wire disconnection of the indoor/outdoor connecting wire? Correct them. B A Turn OFF the power supply. Check once more if the indoor/outdoor connecting wire is not miswiring. Bridge the outdoor terminal block S2 and S Miswiring may damage indoor electronic control P.C. board during the operation. Be sure to confirm the wiring is correct before the operation starts. 3. Be sure to check this within 3 minutes after turning ON. After 3 minutes, LED blinks 6 times. Even when the inverter P.C. board is normal, LED blinks 6 times after 3 minutes. Turn ON the power supply. Is the bus-bar voltage of the inverter P.C. board normal? (Refer to "TEST POINT DIAGRAM AND VOLTAGE" in the outdoor service manual.) Check of power supply. (Refer to the outdoor service manual.) Does the LED on the inverter P.C. board repeat "3.6-second-OFF and 0.8-second-ON quick blinking"? 3 Turn OFF the power supply. Remove the bridge between the outdoor terminal block S2 and S3. Turn ON the power supply. (Lighted or not lighted) Replace the inverter P.C. board Be careful of the residual voltage of smoothing capacitor. Is there rated voltage between the indoor terminal block S1 and S2? <Confi rmation of power voltage> Check the wiring If there are any error of the indoor/outdoor connecting wire: such as the damage of the wire, intermediate connection, and/or poor contact to the terminal block, replace the indoor/ outdoor connecting wire. A Turn OFF inverter-controlled lighting equipment. Turn OFF the power supply and then turn ON again. Press EMERGENCY OPERATION switch. Is serial signal error indicated 6 minutes later? B Is there amplitude of 10 to 20 VDC between the indoor terminal block S2 and S3? <Confi rmation of serial signal> Reinstall either the unit or the light away from each other. Attach a fi lter on remote control receiving section of the indoor unit. Is there 2 VDC or less between CN202 (+) and JPG (GND)(-) on the indoor electronic control P.C. board? Is there 2 VDC or less between Is there 2 VDC or less between CN202A (+) and JPG (GND)(-) CN202 (+) and JPG (GND)(-) on on the indoor electronic control P.C. the indoor electronic control P.C. board? board? Replace the indoor power P.C. board. 39 Replace the indoor electronic control P.C. board.

40 N Check of defrost heater MUZ-FH09NAH MUZ-FH12NAH MUZ-FH15NAH Check the following points before checking electric continuity. 1. Does the resistance of ambient temperature thermistor have the characteristics? Refer to Is the resistance of defrost heater normal? Refer to Does the heater protector remain conducted (not open)? 4. Are both ambient temperature thermistor and circuit of defrost heater securely connected to connectors? In HEAT mode, for more than 5 minutes, let the ambient temperature thermistor continue to read 32 F (0 C) or below, and let the defrost thermistor continue to read 30 F (-1 C) or below. NOTE: In case both thermistors are more than the above temperature, cool them with cold water etc... Is there 208/230 VAC between CN722 and (MUZ-FH09/12)/CN601 and (MUZ-FH15) on the inverter P.C. board? Refer to t the problem of the inverter P.C. board. Replace the inverter P.C. board. O Check of outdoor refrigerant circuit Has the operation stopped during pump down? Was the operation started with the stop valve closed, and was it opened during operation? The unit occasionally stops when the stop valve is opened or closed during operation. Open the stop valve and start the cooling operation again. The operation has stopped to prevent the diesel explosion caused by air trapped in the refrigerant circuit. Close the stop valve, and disconnect the power plug or turn the breaker OFF. The refrigerant gas amount may be 60% or less than the normal amount. Identify where the gas is leaking from, and fi x the leak. CAUTION : Do not start the operation again to prevent hazards. 40

41 P Electromagnetic noise enters into TV sets or radios Is the unit grounded? Ground the unit. Is the distance between the antennas and the indoor unit within 9.91 ft. (3m), or is the distance between the antennas and the outdoor unit within 9.91 ft. (3m)? Extend the distance between the antennas and the indoor unit, and/or the antennas and the outdoor unit. Is the distance between the TV sets or radios and the indoor unit within 3.28 ft. (1m), or is the distance between the TV sets or radios and the outdoor unit within 9.91 ft. (3m)? Extend the distance between the TV sets and/or radios and the indoor unit, or the TV sets or radios and the outdoor unit. Are the antennas damaged? Is the coaxial cable damaged? Is there any poor contact in the antenna wiring? Replace or repair the antenna. Replace or repair the coaxial cable. Is the indoor/outdoor connecting wire of the air conditioner and the wiring of the antennas close? Extend the distance between the indoor/outdoor connecting wire of the air conditioner and the wiring of the antennas. Even if all of the above conditions are fulfi lled, the electromagnetic noise may enter, depending on the electric fi eld strength or the installation condition (combination of specifi c conditions such as antennas or wiring). Check the following before asking for service. 1. Devices affected by the electromagnetic noise TV sets, radios (FM/AM broadcast, shortwave) 2. Channel, frequency, broadcast station affected by the electromagnetic noise 3. Channel, frequency, broadcast station unaffected by the electromagnetic noise 4. Layout of: indoor/outdoor unit of the air conditioner, indoor/outdoor wiring, ground wire, antennas, wiring from antennas, receiver 5. Electric field intensity of the broadcast station affected by the electromagnetic noise 6. Presence or absence of amplifi er such as booster 7. Operation condition of air conditioner when the electromagnetic noise enters in 1) Turn OFF the power supply once, and then turn ON the power supply. In this situation, check for the electromagnetic noise. 2) Within 3 minutes after turning ON the power supply, press OPERATE/STOP (ON/OFF) button on the remote controller for power ON, and check for the electromagnetic noise. 3) After a short time (3 minutes later after turning ON), the outdoor unit starts running. During operation, check for the electromagnetic noise. 4) Press OPERATE/STOP (ON/OFF) button on the remote controller for power OFF, when the outdoor unit stops but the indoor/outdoor communication still runs on. In this situation, check for the electromagnetic noise. 41

42 10-6. TEST POINT DIAGRAM AND VOLTAGE 1. Inverter P.C. board MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH Back side of unit Smoothing capacitor (C62) DB VDC (-) (+) R.V.coil Heater connector (CN722) (CN721) 208/230 VAC (MUZ-FH09/12NAH) Smoothing capacitor (C61) Fuse (F701) T3.15AL250V Fuse (F801) T3.15AL250V 208/230 VAC Fuse (F901) T3.15AL250V Output to drive outdoor fan motor (CN932) 208/230 VAC Output to drive compressor (LDU, LDV, LDW) Jumper wire for changing defrost setting (JS) LEV connector (CN724) Outdoor heat exchanger temperature thermistor /RT68 (CN644) Discharge temperature thermistor/rt62 (CN641) Defrost thermistor /RT61(CN641) Ambient temperature thermistor/rt65 (CN643) Signal of outdoor fan motor (CN931) Front side of unit Fin temperature thermistor/rt64 (CN642) LED Defrost thermistor(rt61) Ambient temperature thermistor(rt65) Outdoor heat exchanger temperature thermistor(rt68) Temperature( F) Resistance(kΩ) Fin temperature thermistor(rt64) 160 Discharge temperature thermistor(rt62) 700 Resistance(kΩ) Resistance(kΩ) 80 Jumper wire for pre-heat control setting (JK) Temperature( F) Temperature( F)

43 MUZ-FH15NA MUZ-FH15NAH Fuse (F601) T3.15AL250V Heater connector (CN601) 208/230 VAC (MUZ-FH15NAH) R.V. coil (CN602) 208/230 VAC Signal of outdoor fan motor (CN931) LEV connector (CN724) Output to drive outdoor fan motor (CN932) Fuse (F901) T3.15AL250V Fuse (F880) T3.15AL250V JP715 (+) VDC JP30 (-) LED Defrost thermistor /RT61 (CN671) Discharge temperature thermistor/rt62 (CN671) Outdoor heat exchanger temperature thermistor /RT68 (CN671) Ambient temperature thermistor/rt65 (CN672) Fin temperature thermistor/rt64 (CN673) Jumper wire for changing defrost setting (JS) Jumper wire for pre-heat control setting (JK) Resistance(k ) Defrost thermistor(rt61) Ambient temperature thermistor(rt65) Outdoor heat exchanger temperature thermistor(rt68) Temperature( F) Resistance(k ) Discharge temperature thermistor(rt62) Temperature( F) 43 Resistance(k ) Fin temperature thermistor(rt64) Temperature( F)

44 11 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. (1) Slide the sleeve and check if there is a locking lever or not. (2) The terminal with this connector has the locking mechanism. Sleeve Locking lever MUZ-FH09NA MUZ-FH09NAH MUZ-FH12NA MUZ-FH12NAH Slide the sleeve. Pull the terminal while pushing the locking lever. OPERATING PROCEDURE 1. Removing the cabinet (1) Remove the screw fixing the service panel. (2) Pull down the service panel and remove it. (3) Remove the screws fixing the conduit cover. (4) Remove the conduit cover. (Photo 4) (5) Remove the screw fixing the conduit plate. (Photo 5) (6) Remove the conduit plate. (7) Disconnect the power supply wire and indoor/outdoor connecting wire. (8) Remove the screws fixing the top panel. (9) Remove the top panel. (10) Remove the screws fixing the cabinet. (11) Remove the cabinet. (12) Remove the screws fixing the back panel. (13) Remove the back panel. Photo 1 Connector Hold the sleeve, and pull out the terminal slowly. NOTE: Turn OFF power supply before disassembly. PHOTOS Screws of the top panel Back panel Screws of the back panel Photo 2 Screws of the top panel Photo 3 Screws of the cabinet Screw of the cabinet Service panel Screws of the terminal block support and the back panel Direction to remove Screws of the cabinet Screws of the cabinet Hooks 44

45 OPERATING PROCEDURE Photo 4 Photo 5 Screws of the conduit cover PHOTOS Screw of the conduit plate 2. Removing the inverter assembly, inverter P.C. board (1) Remove the cabinet and panels. (Refer to 1.) (2) Disconnect the lead wire to the reactor and the following connectors: <Inverter P.C. board> CN721 (R.V. coil) CN722 (Defrost heater and heater protector) (MUZ-FH09/ 12NAH) CN931, CN932 (Fan motor) CN641 (Defrost thermistor and discharge temperature thermistor) CN643 (Ambient temperature thermistor) CN644 (Outdoor heat exchanger temperature thermistor) CN724 (LEV) (3) Remove the compressor connector (CN61). (4) Remove the screws fixing the heat sink support and the separator. (5) Remove the fixing screws of the terminal block support and the back panel. (6) Remove the inverter assembly. (7) Remove the screw of the ground wire and screw of the terminal block support. (8) Remove the heat sink support from the P.C. board support. (9) Remove the screw of the inverter P.C. board and remove the inverter P.C. board from the P.C. board support. 3. Removing R.V. coil (1) Remove the cabinet and panels. (Refer to 1.) (2) Disconnect the following connectors: <Inverter P.C. board> CN721 (R.V. coil) (3) Remove the R.V. coil. Photo 6 Screws of the heat sink support and the separator Photo 7 Heat sink Heat sink support P.C. board support Screws of the terminal block support and the back panel Screw of the Terminal block support Terminal block support 45 Screw of the inverter P.C. board Screw of the ground wire

46 OPERATING PROCEDURE 4. Removing the discharge temperature thermistor, defrost thermistor, outdoor heat exchanger temperature 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. board> CN641 (Defrost thermistor and discharge temperature thermistor) CN643 (Ambient temperature thermistor) CN644 (Outdoor heat exchanger temperature thermistor) (3) Pull out the discharge temperature thermistor from its holder. (4) Pull out the defrost thermistor from its holder. (Photo 6) (5) Pull out the outdoor heat exchanger temperature thermistor from its holder. (Photo 6) (6) Pull out the ambient temperature thermistor from its holder. Photo 8 PHOTOS Discharge temperature thermistor Screw of the R.V. coil Photo 9 Outdoor heat exchanger temperature thermistor Defrost thermistor Photo 10 Ambient temperature thermistor 46

47 OPERATING PROCEDURE 5. Removing 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 nut. (4) Remove the propeller. (5) Remove the screws fixing the fan motor. (6) Remove the fan motor. Photo 11 PHOTOS Screws of the outdoor fan motor Propeller Propeller nut 6. Removing the compressor and 4-way valve (1) Remove the cabinet and panels. (Refer to 1.) (2) Remove the inverter assembly. (Refer to 2.) (3) Remove the screws fixing the reactor. (4) Remove the reactor. (5) Remove the soundproof felt. (6) Recover gas from the refrigerant circuit. NOTE: Recover gas from the pipes until the pressure gauge shows 0 PSIG. (7) Detach the brazed part of the suction and the discharge pipe connected with compressor. (8) Remove the nuts fixing the compressor. (9) Remove the compressor. (10) Detach the brazed part of pipes connected with 4-way valve. Photo 12 Screws of the reactor Photo 13 Soundproof felt Suction pipe brazed part Discharge pipe brazed part Brazed parts of 4-way valve 47

48 11-2. MUZ-FH15NA MUZ-FH15NAH OPERATING PROCEDURE 1. Removing the cabinet (1) Remove the screws of the service panel. (2) Remove the screws of the top panel. (3) Remove the screw of the valve cover. (4) Remove the service panel. (5) Remove the screws fixing the conduit cover. (6) Remove the conduit cover. (7) Remove the screw of fixing the conduit plate. (8) Remove the conduit plate. (9) Remove the top panel. (10) Remove the valve cover. (11) Disconnect the power supply and indoor/outdoor connecting wire. (12) Remove the screws of the cabinet. (13) Remove the cabinet. (14) Remove the screws of the back panel. (15) Remove the back panel. NOTE: Turn OFF power supply before disassembly. PHOTOS Photo 1 Screws of the top panel Photo 2 Screws of the top panel Screw of the back panel Screws of the cabinet Screws of the cabinet Screws of the cabinet Photo 3 Screws of the conduit cover Photo 4 Screws of the cabinet Screw of the conduit plate Screw of the valve cover Screws of the service panel Screws of the back panel 48

49 OPERATING PROCEDURE 2. Removing the inverter assembly, inverter P.C. board and relay P.C. board (1) Remove the cabinet and panels. (Refer to 1.) (2) Disconnect the lead wire to the reactor and the following connectors: <Inverter P.C. board> CN602 (R.V. coil) CN931, CN932 (Fan motor) CN671 (Defrost thermistor, discharge temperature thermistor and outdoor heat exchanger temperature thermistor) CN672 (Ambient temperature thermistor) CN724 (LEV) CN601 (Defrost heater and heater protector) (MUZ-FH15NAH) (3) Remove the compressor connector. (4) Remove the screws fixing the relay panel. (5) Remove the relay panel. (6) Remove the ground wires and the lead wires of the inverter P.C. board. (7) Remove the screws of the P.B. support. (8) Remove the inverter P.C. board from the P.B. support. Photo 5 Inverter P.C. board Screws of the P.B. support Screw of the relay panel PHOTOS Screw of the relay panel Ground wires Screw of the relay panel Screws of the P.B. support Photo 6 Screw of the R.V. coil 3. Removing R.V. coil (1) Remove the cabinet and panels. (Refer to 1.) (2) Disconnect the following connector: <Inverter P.C. board> CN602 (R.V. coil) (3) Remove the R.V. coil. Brazed parts of 4-way valve 49

50 OPERATING PROCEDURE 4. Removing the discharge temperature thermistor, defrost thermistor, outdoor heat exchanger temperature 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. board> CN671 (Defrost thermistor, discharge temperature thermistor and outdoor heart exchanger temperature thermistor) CN672 (Ambient temperature thermistor) (3) Pull out the discharge temperature thermistor from its holder. (4) Pull out the defrost thermistor from its holder. (5) Pull out the outdoor heat exchanger temperature thermistor from its holder. (6) Pull out the ambient temperature thermistor from its holder. PHOTOS Photo 7 Outdoor heat exchanger Ambient temperature temperature thermistor thermistor 5. Removing outdoor fan motor (1) Remove the top panel, cabinet and service panel. (Refer to 1.) (2) Disconnect the following connectors: <Inverter P.C. board> CN931 and CN932 (Fan motor) (3) Remove the propeller. (4) Remove the screws fixing the fan motor. (5) Remove the fan motor. Photo 8 Defrost thermistor 6. Removing the compressor and 4-way valve (1) Remove the top panel, cabinet and service panel. (Refer to 1.) (2) Remove the back panel. (Refer to 1.) (3) Remove the inverter assembly. (Refer to 2.) (4) Remove the soundproof felt. (5) Recover gas from the refrigerant circuit. NOTE: Recover gas from the pipes until the pressure gauge shows 0 PSIG. (6) Detach the brazed part of the suction and the discharge pipe connected with compressor. (7) Remove the nuts fixing the compressor. (8) Remove the compressor. (9) Detach the brazed parts of 4-way valve and pipe. (Photo 4) Photo 9 Brazed part of the suction pipe Screws of the outdoor fan motor Soundproof felt Brazed part of the discharge pipe Discharge temperature thermistor 50