OUTDOOR UNIT No. OBH895 SERVICE MANUAL utilized Models MUFZ-KW25VGHZ MUFZ-KW35VGHZ MUFZ-KW50VGHZ MUFZ-KW60VGHZ Indoor unit service manual MFZ-KW•VG Series (OBH894) CONTENTS 1. TECHNICAL CHANGES ······························2 2. SERVICING PRECAUTIONS FOR UNITS USING REFRIGERANT R32 ·························3 3. PART NAMES AND FUNCTIONS ··················5 4. SPECIFICATION ········································6 5.
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.
SERVICING PRECAUTIONS FOR UNITS USING REFRIGERANT R32 Servicing precautions for units using refrigerant R32 WARNING This unit uses a flammable refrigerant. If refrigerant leaks and comes in contact with fire or heating part, it will create harmful gas and there is risk of fire. Do not use means to accelerate the defrosting process or to clean, other than those recommended by the manufacturer.
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5. Detection of Flammable Refrigerants Under no circumstances shall potential sources of ignition be used in the searching for or detection of refrigerant leaks. A halide torch (or any other detector using a naked flame) shall not be used. 6. Leak Detection Methods Electronic leak detectors may be used to detect refrigerant leaks but, in the case of flammable refrigerants, the sensitivity may not be adequate, or may need re-calibration.
PART NAMES AND FUNCTIONS MUFZ-KW25VGHZ MUFZ-KW35VGHZ Air inlet (Back and side) Piping Air outlet Drain hose Drain outlet MUFZ-KW50VGHZ MUFZ-KW60VGHZ Air inlet (Back and side) Piping Drain hose Air outlet Drain outlet OBH895...
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Specifications and rated conditions of main electric parts Model MUFZ-KW25VGHZ MUFZ-KW35VGHZ Item Smoothing capacitor (C61, C62, C63) 600 µF/ 620 µF 420 V (DB61) 15 A 600 V Diode module (DB65) 25A 600V (F701, F801, F901) T3.15AL250V Fuse (F61) 25 A 250 V (F62) 15 A 250 V Defrost heater...
OUTLINES AND DIMENSIONS MUFZ-KW25VGHZ MUFZ-KW35VGHZ Unit: mm OBH895...
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MUFZ-KW50VGHZ MUFZ-KW60VGHZ Unit: mm REQUIRED SPACE *1. 500 mm or more when front and sides of the unit are clear 417.5 Air in Air in Air out 2-holes 10 21 *2. When any 2 sides of left, right and rear of the unit are clear Service panel Liquid refrigerant pipe joint Refrigerant pipe (flared)
PERFORMANCE CURVES MUFZ-KW25VGHZ MUFZ-KW35VGHZ MUFZ-KW50VGHZ MUFZ-KW60VGHZ The standard specifications apply only to the operation of the air conditioner under normal conditions. Since operating condi- tions vary according to the areas where these units are installed, the following information has been provided to clarify the operating characteristics of the air conditioner under the conditions indicated by the performance curve.
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9-1. CAPACITY AND INPUT CURVES Cooling capacity (at Rated frequency) 12.9 14.6 12.1 Indoor intake air Wet-bulb 11.8 13.4 11.1 temperature( ) 10.8 12.2 10.1 11.0 Outdoor intake air Dry-bulb temperature(°C) Total input (Cooling : at Rated frequency Indoor intake air Wet-bulb temperature( ) Outdoor intake air Dry-bulb temperature (°C) Heating capacity...
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9-2. CAPACITY AND INPUT CORRECTION BY OPERATIONAL FREQUENCY OF COMPRESSOR MUFZ-KW25VGHZ Correction of Heating input Correction of Cooling capacity Correction of Cooling input Correction of Heating capacity The operational frequency The operational frequency The operational frequency The operational frequency of compressor (Hz) of compressor (Hz) of compressor (Hz) of compressor (Hz)
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9-4. OUTDOOR LOW PRESSURE AND OUTDOOR UNIT CURRENT COOL operation Dry-bulb temperature (°C) Relative humidity (%) Both indoor and outdoor unit are under the same temperature/ humidity condition. Operation: Test run operation (Refer to 9-3.) Outdoor low pressure MUFZ-KW25VGHZ MUFZ-KW35VGHZ (kgf/cm [Gauge])(MPa [Gauge]) (kgf/cm...
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HEAT operation Condition: Indoor Outdoor Dry bulb temperature (°C) 20.0 20.0 Wet bulb temperature (°C) 14.5 14.5 Operation: Test run operation (Refer to 9-3.) Outdoor unit current MUFZ-KW25VGHZ MUFZ-KW35VGHZ Ambient temperature (°C) Ambient temperature (°C) MUFZ-KW50VGHZ MUFZ-KW60VGHZ Ambient temperature (°C) Ambient temperature (°C) OBH895...
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t Rated frequency PERFORMANCE DATA COOL operation a MUFZ-KW25VGHZ CAPACITY: 2.5 kW SHF: 0.84 INPUT: 570 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT INPUT 2.94 1.94 0.66 2.81 1.86 0.66 2.70 1.78 0.66 2.60 1.72 0.66 3.06...
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t Rated frequency PERFORMANCE DATA COOL operation a MUFZ-KW25VGHZ CAPACITY: 2.5 kW SHF: 0.84 INPUT: 570 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT 2.45 1.62 0.66 2.25 1.49 0.66 2.08 1.37 0.66 2.58 1.39 0.54 2.40 1.30...
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t Rated frequency PERFORMANCE DATA COOL operation a MUFZ-KW35VGHZ CAPACITY: 3.5 kW SHF: 0.72 INPUT: 900 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT INPUT 4.11 2.22 0.54 3.94 2.13 0.54 3.78 2.04 0.54 3.64 1.97 0.54 4.29...
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t Rated frequency PERFORMANCE DATA COOL operation a MUFZ-KW35VGHZ CAPACITY: 3.5 kW SHF: 0.72 INPUT: 900 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT 3.43 1.85 0.54 3.15 1.70 0.54 2.91 1.57 0.54 3.61 1.51 0.42 3.36 1.41...
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t Rated frequency PERFORMANCE DATA COOL operation a MUFZ-KW50VGHZ CAPACITY: 5.0 kW SHF: 0.70 INPUT: 1360 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT INPUT 5.88 3.05 0.52 1088 5.63 2.92 0.52 1142 5.40 2.81 0.52 1197 5.20...
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t Rated frequency PERFORMANCE DATA COOL operation a MUFZ-KW50VGHZ CAPACITY: 5.0 kW SHF: 0.70 INPUT: 1360 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT 4.90 2.55 0.52 1333 4.50 2.34 0.52 1414 4.15 2.16 0.52 1469 5.15 2.06...
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t Rated frequency PERFORMANCE DATA COOL operation a MUFZ-KW60VGHZ CAPACITY: 6.1 kW SHF: 0.74 INPUT: 1730 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT INPUT 7.17 4.03 0.56 1384 6.86 3.86 0.56 1453 6.59 3.70 0.56 1522 6.34...
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t Rated frequency PERFORMANCE DATA COOL operation a MUFZ-KW60VGHZ CAPACITY: 6.1 kW SHF: 0.74 INPUT: 1730 W OUTDOOR DB (°C) INDOOR INDOOR DB (°C) WB (°C) INPUT INPUT INPUT 5.98 3.36 0.56 1695 5.49 3.09 0.56 1799 5.06 2.85 0.56 1868 6.28 2.78...
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PERFORMANCE DATA HEAT operation at Rated frequency MUFZ-KW25VGHZ CAPACITY: 3.4 kW INPUT: 830 W OUTDOOR WB (°C) INDOOR DB (°C) Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT Q INPUT 0.85 1.29 1.70...
ACTUATOR CONTROL MUFZ-KW25VGHZ MUFZ-KW35VGHZ MUFZ-KW50VGHZ MUFZ-KW60VGHZ 10-1. 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. 5 seconds 15 seconds Compressor...
SERVICE FUNCTIONS MUFZ-KW25VGHZ MUFZ-KW35VGHZ MUFZ-KW50VGHZ MUFZ-KW60VGHZ 11-1. 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 12-6.1) Defrost finish temperature (°C) Jumper wire MUFZ-KW25VGHZ MUFZ-KW50VGHZ MUFZ-KW35VGHZ...
TROUBLESHOOTING MUFZ-KW25VGHZ MUFZ-KW35VGHZ MUFZ-KW50VGHZ MUFZ-KW60VGHZ 12-1. 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 confirming the horizontal vane is closed, turn OFF the breaker and/or disconnect the power plug.
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12-2. 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 (12-3.) disappears, the memorized failure details can be recalled. 1.
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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.
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3. Table of outdoor unit failure mode recall function NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (12-3.). Indoor/outdoor Outdoor unit POWER lamp Abnormal point LED indication unit failure Condition Remedy failure mode (Indoor unit) (Failure mode/protection) (Outdoor P.C.
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NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (12-3.). Indoor/outdoor Outdoor unit POWER lamp Abnormal point LED indication unit failure Condition Remedy failure mode (Indoor unit) (Failure mode/protection) (Outdoor P.C. board) mode recall recall function function 10-time blink Discharge temperature...
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12-3. TROUBLESHOOTING CHECK TABLE Abnormal point/ Con- Symptom LED indication Condition Remedy dition Outdoor unit 1-time blink 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.
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Abnormal point/ Con- Symptom LED indication Condition Remedy dition Outdoor unit 7-time blink Low discharge tem- Temperature of discharge temperature thermistor has been • Refer to 12-5. "Check of LEV". operates. 2.5 seconds OFF perature protection 50°C or less for 20 minutes. •...
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12-4. TROUBLESHOOTING CRITERION OF MAIN PARTS MUFZ-KW25VGHZ MUFZ-KW35VGHZ MUFZ-KW50VGHZ MUFZ-KW60VGHZ Part name Check method and criterion Figure Defrost thermistor (RT61) Measure the resistance with a tester. Refer to 12-6. “Test point diagram and voltage”, 1. “Inverter P.C. Fin temperature board”, for the chart of thermistor. thermistor (RT64) Ambient temperature thermistor (RT65)
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12-5. TROUBLESHOOTING FLOW A How to check inverter/compressor Disconnect the connector between the compressor and the power module (IC700). Check the voltage between terminals. See 12-5. “Check of open phase”. Replace the inverter P.C. board. Are the voltages balanced? Check the compressor. See 12-5.
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D Check of compressor winding ● Disconnect the connector between the compressor and the power module (IC700), 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>>...
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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 12-6.1.) board.
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H Check of R.V. coil MUFZ-KW25VGHZ MUFZ-KW35VGHZ * First of all, measure the resistance of R.V. coil to check if the coil is defective. Refer to 12-4. * 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.
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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 12-4.) Disconnect CN932 from the inverter P.C.
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J Check of power supply Disconnect the connector between the compressor and the power module (IC700). Turn ON power supply and Rectify indoor/outdoor press the emergency operation switch. connecting wire. Is there voltage 230 V AC Replace the indoor Does POWER lamp on the indoor electronic control P.C.
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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 2 buttons for another 3 seconds.
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L Check of inverter P.C. board Check the outdoor fan motor. (Refer to 12-5. .) 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.
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M How to check miswiring and serial signal error Turn the power supply OFF. Is there rated voltage of 230 V AC in the Check the power supply. power supply? Turn the power supply ON. Check for miswiring, broken wires, and loose wire connection between the power supply and Is there 230 V AC between outdoor terminal outdoor terminal block S1 and between the...
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N Check of the outdoor refrigerant circuit The operation has stopped to prevent the diesel explosion caused by air trapped in the refrigerant circuit. Close the stop Has the operation stopped during pump down? valve, and disconnect the power plug or turn the breaker OFF. CAUTION: Do not start the operation again to prevent hazards.
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O Electromagnetic noise enters into TV sets or radios Is the unit earthed? Earth the unit. Is the distance between the antennas Extend the distance between the antennas and and the indoor unit within 3 m, or is the the indoor unit, and/or the antennas and the distance between the antennas and the outdoor unit.
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12-6. TEST POINT DIAGRAM AND VOLTAGE 1. Inverter P.C. board MUFZ-KW25VGHZ MUFZ-KW35VGHZ R.V.coil Smoothing Smoothing Smoothing Back side of unit (CN721) DB61 capacitor (C61) capacitor capacitor 230 V AC 260 - 370 V DC (C63) (C62) 230 V AC Fuse (F901) Fuse (F801) Fuse (F701) T3.15AL250V...
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MUFZ-KW50VGHZ MUFZ-KW60VGHZ Jumper wire for pre-heat control setting (JK) LEV (CN724) Jumper wire for changing defrost setting (JS) Ambient temperature thermistor/RT65 (CN672) Heater (CN601) 230 V AC Outdoor heat exchanger temperature thermistor R.V. coil (CN602) /RT68 (CN671) 230 V AC Discharge temperature thermistor/RT62 (CN671)
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.
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PHOTOS/FIGURES OPERATING PROCEDURE 2. Removing the inverter assembly and inverter P.C. Photo 4 Screw of the P.B. support board and the separator Ambient temperature (1) Remove the cabinet and panels. (Refer to section 1.) Screws of thermistor (2) Disconnect the lead wire to the reactor and the following con- the terminal block nectors: support and...
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PHOTOS/FIGURES OPERATING PROCEDURE 3. Removing R.V. coil Photo 7 (1) Remove the cabinet and panels. (Refer to section 1.) (2) Disconnect the following connectors: Outdoor heat <Inverter P.C. board> exchanger tempera- CN721 (R.V. coil) ture thermistor (3) Remove the R.V. coil. Defrost thermistor 4.
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PHOTOS/FIGURES OPERATING PROCEDURE 6. Removing the compressor and 4-way valve Photo 9 (1) Remove the cabinet and panels. (Refer to section 1.) Discharge pipe Suction pipe (2) Remove the inverter assembly. (Refer to section 2.) brazed part brazed part (3) Recover gas from the refrigerant circuit. NOTE: Recover gas from the pipes until the pressure gauge shows 0 kg/cm...
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13-2. MUFZ-KW50VGHZ MUFZ-KW60VGHZ NOTE: Turn OFF the power supply before disassembly. PHOTOS/FIGURES OPERATING PROCEDURE 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. (3) Remove the screw of the valve cover.
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PHOTOS/FIGURES OPERATING PROCEDURE 2. Removing the inverter assembly and inverter P.C. Photo 3 Screws of the relay panel Inverter P.C board board (1) Remove the cabinet and the service panel. (Refer to section (2) Disconnect the lead wire to the reactor and the following connectors: <Inverter P.C.
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OPERATING PROCEDURE PHOTOS 3. Removing R.V. coil Photo 5 Screw of (1) Remove the cabinet and panels. (Refer to section 1.) the R.V. coil (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 4.
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PHOTOS/FIGURES OPERATING PROCEDURE 5. Removing outdoor fan motor Photo 7 (1) Remove the top panel, cabinet and service panel. (Refer to Propeller fan section 1.) (2) Disconnect the following connectors: <Inverter P.C. board> Propeller fan CN931, CN932 (Fan motor) (3) Remove the propeller fan nut. (4) Remove the propeller fan.
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