• MFZ-KJ25VE2- , MFZ-KJ35VE2- and MFZ-KJ50VE2- have been added. Please void OBH666 REVISED EDITION-B. INDOOR UNIT No. OBH666 REVISED EDITION-C SERVICE MANUAL Models MFZ-KJ25VE MFZ-KJ25VE MFZ-KJ25VE2 MFZ-KJ35VE MFZ-KJ35VE MFZ-KJ35VE2 Outdoor unit service manual MFZ-KJ50VE MUFZ-KJ•VE Series (OBH667) MUFZ-KJ•VEHZ Series (OBH668) MFZ-KJ50VE2 CONTENTS 1.
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When the repair or the inspection of the circuit needs to be done without turning off the power, exercise great caution not to touch the live parts. Revision A: • MFZ-KJ50VE- has been added. Revision B: • MFZ-KJ25VE- , MFZ-KJ35VE- and MFZ-KJ50VE- have been added. Revision C: • MFZ-KJ25VE2-...
1. Indoor electronic control P.C. board has been changed. MFZ-KJ25VE2- MFZ-KJ35VE2- MFZ-KJ50VE2- MFZ-KJ25VE2- MFZ-KJ35VE2- MFZ-KJ50VE2- 1. New model Notes: MFZ-KJ25VE- MFZ-KJ35VE- • The model MFZ-KJ25VE- or MFZ-KJ35VE- is connected to the MUFZ-KJ·VE(HZ) outdoor unit only. MFZ-KJ25VE- MFZ-KJ35VE- MFZ-KJ50VE- • MFZ-KJ25VE2- MFZ-KJ35VE2- MFZ-KJ50VE2- The model MFZ-KJ25VE- , MFZ-KJ35VE-...
SPECIFICATION MFZ-KJ25VE MFZ-KJ35VE MFZ-KJ50VE Indoor model MFZ-KJ25VE2 MFZ-KJ35VE2 MFZ-KJ50VE2 Power supply Single phase 230 V, 50 Hz Cooling Power input Heating Running current Cooling 0.14 0.20 Heating 0.17 0.34 Model RC0J30-KX RC0J40-PA Cooling 0.14 0.20 Current Heating 0.17 0.34 Dimensions W × H × D 750 ×...
NOISE CRITERIA CURVES MFZ-KJ25VE MFZ-KJ35VE MFZ-KJ25VE2 MFZ-KJ35VE2 FAN SPEED FUNCTION SPL(dB(A)) LINE FAN SPEED FUNCTION SPL(dB(A)) LINE COOLING COOLING Super High Super High HEATING HEATING NC-70 NC-70 NC-60 NC-60 NC-50 NC-50 NC-40 NC-40 NC-30 NC-30 NC-20 NC-20 NC-10 NC-10 1000...
SERVICE FUNCTIONS MFZ-KJ25VE MFZ-KJ25VE2 MFZ-KJ35VE MFZ-KJ35VE2 MFZ-KJ50VE MFZ-KJ50VE2 8-1. TIMER SHORT MODE • For service, the following set time can be shortened by bridging the timer short mode point on the electronic control P.C. board. (Refer to 10-7.) • The set time for the ON/OFF timer can be reduced to 1 second for each minute.
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8-3. AUTO RESTART FUNCTION When the indoor unit is controlled with the remote controller, the operation mode, the set temperature, and the fan speed are memorized by the indoor electronic control P.C. board. “AUTO RESTART FUNCTION” automatically starts operation in the same mode just before the shutoff of the main power. Operation If the main power has been cut, the operation settings remain.
MICROPROCESSOR CONTROL MFZ-KJ25VE MFZ-KJ25VE2 MFZ-KJ35VE MFZ-KJ35VE2 MFZ-KJ50VE MFZ-KJ50VE2 WIRELESS REMOTE CONTROLLER MFZ-KJ25VE MFZ-KJ35VE MFZ-KJ50VE Signal transmitting section Distance of signal : About 6 m Beep(s) is (are) heard from the indoor unit when the signal is received. FAN SPEED CONTROL button...
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INDOOR UNIT DISPLAY SECTION Operation Indicator lamp The operation indicator at the right side of the indoor unit indicates the operation state. •The following indication applies regardless of shape of the indication. Indication Operation state Room temperature About 2°C or more The unit is operating to away from set tempera- reach the set temperature...
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9-4. HEAT ( ) OPERATION (1) Press OPERATE/STOP (ON/OFF)(MFZ-KJ25/35/50VE)/ STOP/OPERATE (OFF/ON)(MFZ-KJ25/35/50VE2) button. OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone. (2) Select HEAT mode with OPERATION SELECT button. (3) Press TEMPERATURE buttons TEMP button to select the desired temperature. The setting range is 16 - 31°C. 1.
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(3) Positioning The vane presses the vane stopper once to confirm the standard position and then moves to the set angle. Confirming of standard position is performed in case of follows. (a) The power supply turns on. (b) The operation starts or finishes (including timer operation). (c) The test run starts.
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(8) SWING ( ) mode By selecting SWING mode with VANE CONTROL button, the horizontal vanes swing vertically. The remote controller displays " ". SWING mode is cancelled when VANE CONTROL button is pressed once again. (9) Cold air prevention in HEAT operation The horizontal vane position is set to Upward.
9-8. WEEKLY TIMER OPERATION • A maximum of 4 ON or OFF timers can be set for individual days of the week. • A maximum of 28 ON or OFF timers can be set for a week. NOTE: The simple ON/OFF timer setting is available while the weekly timer is on. In this case, the ON/OFF timer has priority over the •...
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(4) Press button to complete and transmit the weekly timer setting. which was blink- ing goes out, and the current time will be displayed. NOTE: • Press button to transmit the setting information of weekly timer to the indoor unit. Point the remote controller toward the indoor unit for 3 seconds.
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9-10. EMERGENCY/TEST OPERATION In the case of test run operation or emergency operation, use Operation mode COOL/HEAT EMERGENCY OPERATION switch on the right side of the indoor unit. Set temperature 24°C Emergency operation is available when the remote controller is miss- Fan speed Medium ing or has failed, or when the batteries in the remote controller are...
TROUBLESHOOTING MFZ-KJ25VE MFZ-KJ35VE MFZ-KJ50VE MFZ-KJ25VE2 MFZ-KJ35VE2 MFZ-KJ50VE2 10-1. CAUTIONS ON TROUBLESHOOTING 1. Before troubleshooting, check the following 1) Check the power supply voltage. 2) Check the indoor/outdoor connecting wire for miswiring. 2. Take care of the following during servicing 1) Before servicing the air conditioner, be sure to turn OFF the main unit first with the remote controller, and then after confirming the horizontal vane is closed, turn OFF the breaker.
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This mode is very useful when the unit needs to be repaired for the abnormality which does not recur. 1. Flow chart of failure mode recall function for the indoor/outdoor unit MFZ-KJ25VE MFZ-KJ25VE2 MFZ-KJ35VE...
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2. Indoor unit failure mode table NOTE: Blinking patterns of this mode differs from the ones of Troubleshooting check table (10-4.). Left lamp of Right lamp of Abnormal point Condition Remedy OPERATION OPERATION (Failure mode) INDICATOR lamp INDICATOR lamp Not lighted Not lighted Normal –...
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10-3. INSTRUCTION OF TROUBLESHOOTING Start Indoor unit Indoor unit does Indoor unit operates. OPERATION INDICATOR operates. not receive Outdoor unit does lamp on the indoor unit is Outdoor unit the signal from not operate normally. flashing ON and OFF. does not remote controller.
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10-4. TROUBLESHOOTING CHECK TABLE Before taking measures, make sure that the symptom reappears for accurate troubleshooting. When the indoor unit has started operation and detected an abnormality of the following condition (the first detection after the power ON), the indoor fan motor turns OFF and OPERATION INDICATOR lamp flashes. OPERATION INDICATOR Lighted Blinking...
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2.5-second OFF does not setting service manual. first has the priority. operate. 10-5. TROUBLE JUDGEMENT CRITERIA OF MAIN PARTS MFZ-KJ25VE MFZ-KJ25VE2 MFZ-KJ35VE MFZ-KJ35VE2 MFZ-KJ50VE MFZ-KJ50VE2 Part name Check method and criteria Figure Room temperature thermistor (RT11) Measure the resistance with a tester.
10-6. TROUBLESHOOTING FLOW A Check of indoor fan motor The indoor fan motor error has occurred, and the indoor fan does not operate. Turn OFF the power supply. Pay enough attention to the high voltage on the fan motor connector. Turn ON the power supply, wait 5 seconds or more, and then press EMERGENCY OPERATION switch.
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Check of remote controller, display receiver P.C. board and indoor control P.C. board Check if the remote controller is exclusive for this air conditioner. Press OPERATE/STOP (ON/OFF) (MFZ-KJ25/35/50VE)/ STOP/ 1 Look at the image of the signal transmitting section of OPERATE (OFF/ON)(MFZ- the remote controller through the monitor of a digital KJ25/35/50VE2) button on the...
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Check of indoor electronic control P.C. board and indoor fan motor Turn OFF the power supply. Remove indoor fan motor connector CN211 Measure the resistance of indoor fan and vane motor connector CN151 from the Short circuit: motor. indoor electronic control P.C. board and turn Replace the indoor fan motor.
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How to check miswiring and serial signal error MUFZ-KJ25/35 Turn OFF the power supply. Is there rated voltage in the Check the power supply. power supply? Turn ON the power supply. Is there rated voltage between Check the wiring. outdoor terminal block S1 and S2? Press EMERGENCY OPERATION switch once.
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MUFZ-KJ50 Turn the power supply OFF. NOTE: Refer to the indoor unit service manual. Is there rated voltage in the power supply? Check the power supply. Check for incorrect indoor-outdoor connecting wiring. Was the indoor unit ever connected to the Multi (MXZ) series and operated (turned on)? The connection information to the Multi series is stored in the indoor unit.
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MXZ Type 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 outdoor terminal block S1 and S2? Check the wiring. Press EMERGENCY OPERATION switch once. Does the left lamp of the OPERATION INDICATOR lamp light up? <Conf rmation of the power to the indoor unit>...
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Turn ON the power supply. LED indication for communication status Communication status is indicated by the LED. Is there rated voltage Check the power supply Unit status between outdoor Blinking: normal communication and correct the problem. terminal block S1 and S2 ? Lighted: abnormal communication or not connected Not lighted: The outdoor P.C.
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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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10-7. TEST POINT DIAGRAM AND VOLTAGE MFZ-KJ25VE MFZ-KJ35VE MFZ-KJ50VE MFZ-KJ25VE2 MFZ-KJ35VE2 MFZ-KJ50VE2 Indoor electronic control P.C. board FUSE (F11) T3.15AL250V Varistor (NR11) Serial signal input (CN202) JR05 Modification JR06 point for Power supply (CN201) individual input 230 VAC operation (Refer to 8-2.) To disable "Auto...
Slide the sleeve. pull out the terminal Pull the terminal while slowly. pushing the locking Locking lever lever. Connector 11-1. MFZ-KJ25VE MFZ-KJ35VE MFZ-KJ50VE MFZ-KJ25VE2 MFZ-KJ35VE2 MFZ-KJ50VE2 NOTE: Turn OFF the power supply before disassembly. OPERATING PROCEDURE PHOTOS 1. Removing the panel Photo 1 (1) Push down the tabs on the both sides of the unit.
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OPERATING PROCEDURE PHOTOS 3. Removing the electronic control P.C. board and Photo 4 the display receiver P.C. board (1) Remove the panel. (Refer to 1.) Earth wire connect to (2) Remove the electrical box. (Refer to 2.) the heat exchanger (3) Remove the earth wire connected to the electronic control P.C.
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How to remove the multi-flow Horizontal vane (back) vane and the horizontal vanes Horizontal vane (front) Unit body (1) Removing the horizontal vane (front/back) (1)-1. See the figure below and push to open the indicated Multi-flow vane places on the horizontal vanes (between front and back) with your fingers so that you can access 4 vane shafts positioned on the back of the horizontal vanes.
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OPERATING PROCEDURE PHOTOS Photo 9 5. Removing the horizontal vane motor (1) Remove the panel. (Refer to 1.) Screws of the nozzle (2) Remove the screws of the horizontal vane motor sup- port and pull out the horizontal vane motor support from the nozzle.
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OPERATING PROCEDURE PHOTOS 7. Removing the line flow fan and the indoor fan Photo 13 Screw of the line flow fan motor (1) Remove the panel. (Refer to 1.) (2) Remove the electrical box. (Refer to 2.) (3) Remove the nozzle. (Refer to 4.) (4) Disengage the water cover from the catches.
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HEAD OFFICE: TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN Copyright 2013 MITSUBISHI ELECTRIC CORPORATION Distributed in Jan. 2016. No. OBH666 REVISED EDITION-C Distributed in Jan. 2014. No. OBH666 REVISED EDITION-B Distributed in Oct. 2013. No. OBH666 REVISED EDITION-A Distributed in Jun. 2013. No. OBH666 New publication, effective Jan.
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