Revision B: • Capacity corrections have been corrected [7-1. 2), 3)]. OBH753 REVISED EDITION-A is void. OUTDOOR UNIT No. OBH753 REVISED EDITION-B SERVICE MANUAL Models MUFZ-KJ09NAHZ MUFZ-KJ12NAHZ MUFZ-KJ15NAHZ MUFZ-KJ18NAHZ - U1 - U1 - U1 - U1 Indoor unit service manual MFZ-KJ•NA Series (OBH752) CONTENTS 1. TECHNICAL CHANGES ······························2 2. PART NAMES AND FUNCTIONS ··················3 3. SPECIFICATION ········································4 4.
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 and 7-2.
2 PART NAMES AND FUNCTIONS MUFZ-KJ09NAHZ MUFZ-KJ12NAHZ Air inlet (back and side) Piping Air outlet Drain hose Drain outlet MUFZ-KJ15NAHZ MUFZ-KJ18NAHZ Air inlet (back and side) Piping Drain hose Air outlet Drain outlet OBH753B 3
3 SPECIFICATION Outdoor unit model MUFZ-KJ09NAHZ MUFZ-KJ12NAHZ MUFZ-KJ15NAHZ MUFZ-KJ18NAHZ Cooling 1 Btu/h 9,000 (2,300 - 14,000) 12,000 (2,300 - 15,000) 15,000 (5,300 - 19,000) 17,000 (5,300 - 22,500) Heating 47 1 Btu/h 11,000 (2,900 - 19,000) 13,000 (2,900 - 22,800) 18,000 (5,700 - 25,000) 21,000 (5,700 - 29,000) Heating 17 2 Btu/h 7,500 (13,400) 8,800(14,800) 12,000 (20,500) 12,800 (23,000) Cooling 1 W 570 (180 - 1,250) 890 (180 - 1,380) 1,120 (420 - 1,850) 1,350 (420 - 2,32
Test condition 3, 4 ARI Mode Indoor air condition (°F) Dry bulb Wet bulb Test Outdoor air condition (°F) Dry bulb Wet bulb "A-2" Cooling Steady State at rated compressor Speed 80 67 95 (75) "B-2" Cooling Steady State at rated compressor Speed 80 67 82 (65) SEER "B-1" Cooling Steady State (Cooling) at minimum compressor Speed 80 67 82 (65) "F-1" Cooling Steady State at minimum compressor Speed 80 67 67 (53.
4 OUTLINES AND DIMENSIONS Unit: inch MUFZ-KJ09NAHZ MUFZ-KJ12NAHZ *1 4 in. (100 mm) or more when front and sides of the unit are clear clear *1 REQUIRED SPACE 4 in .( or 100 m mo re m) ) mm 00 . (2 ore *2 n i 8 rm o 14 in. ( or m350 m ore m) *2 When any 2 sides of left, right and rear of the unit are clear 2 x hole 3/8 x 13/16 Liquid refrigerant pipe joint Refrigerant pipe (flared) Ø 1/4 Gas refrigerant pipe joint Refrigerant pipe (flared) Ø 3/8 OBH753B 6 ) mm 00 re 1 ( o n.
Unit: inch REQUIRED SPACE *1 20 in. (500 mm) or more when front and sides of the unit are clear Clear *1 MUFZ-KJ15NAHZ MUFZ-KJ18NAHZ 16-7/16 2 13 m) m 00 . (1 4 in more or 1-5/8 4i or mn. (10 ore 0 mm ) 14-3/16 Air in Drain hole 1-9/16 Air in ) mm 500 ( . 2 in 20 ore * or m Air out 2 x hole 13/32 x 13/16 6-7/8 19-11/16 14 or min.
5 WIRING DIAGRAM MUFZ-KJ09NAHZ MUFZ-KJ12NAHZ OBH753B 8
MUFZ-KJ15NAHZ MUFZ-KJ18NAHZ OBH753B 9
6 REFRIGERANT SYSTEM DIAGRAM MUFZ-KJ09NAHZ MUFZ-KJ12NAHZ Unit: inch (mm) Refrigerant pipe ø3/8 (ø9.52) (with heat insulator) 4-way valve Muffler Stop valve (with service port) Discharge temperature Service thermistor port RT62 Flared connection Outdoor heat exchanger Muffler Service port Outdoor heat exchanger temperature thermistor RT68 Ambient temperature thermistor RT65 Compressor Defrost thermistor RT61 Capillary tube O.D. 0.118 × I.D. 0.079 × 8-9/32 (ø3.0 × ø2.0 × 210) Capillary tube O.
MAX. REFRIGERANT PIPING LENGTH and MAX. HEIGHT DIFFERENCE Model Refrigerant piping: ft. Max. Length Max. Height difference A B Piping size O.D: in. Gas Liquid MUFZ-KJ09NAHZ MUFZ-KJ12NAHZ 65 40 3/8 1/4 MUFZ-KJ15NAHZ MUFZ-KJ18NAHZ 100 50 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.
7 DATA MUFZ-KJ09NAHZ MUFZ-KJ12NAHZ MUFZ-KJ15NAHZ MUFZ-KJ18NAHZ 7-1. PERFORMANCE DATA 1) COOLING CAPACITY Indoor air Model IWB (˚F) 71 67 63 71 67 63 71 67 63 71 67 63 MUFZ-KJ09NAHZ MUFZ-KJ12NAHZ MUFZ-KJ15NAHZ MUFZ-KJ18NAHZ TC 11.0 10.4 9.8 14.7 13.9 13.1 18.4 17.4 16.4 20.8 19.7 18.5 75 SHC 7.2 8.2 9.1 8.3 9.7 10.9 9.7 11.5 13.0 10.8 12.8 14.5 TPC 0.51 0.48 0.46 0.79 0.75 0.71 1.00 0.94 0.90 1.20 1.13 1.08 TC 10.3 9.7 9.1 13.7 13.0 12.1 17.2 16.2 15.2 19.5 18.4 17.
4) HEATING CAPACITY Indoor air Model MUFZ-KJ09NAHZ MUFZ-KJ12NAHZ MUFZ-KJ15NAHZ MUFZ-KJ18NAHZ IDB (˚F) 75 70 65 75 70 65 75 70 65 75 70 65 5 TC 4.8 5.2 5.5 5.7 6.2 6.5 7.9 8.6 9.0 9.2 10.0 10.5 15 TPC 0.57 0.55 0.54 0.66 0.64 0.62 0.95 0.92 0.88 1.14 1.10 1.05 TC 6.4 6.8 6.9 7.5 8.0 8.2 10.4 11.1 11.3 12.2 12.9 13.2 TPC 0.69 0.67 0.65 0.80 0.78 0.75 1.17 1.14 1.09 1.41 1.37 1.31 Outdoor intake air WB temperature (˚F) 25 35 43 TC TPC TC TPC TC TPC 8.0 0.79 9.5 0.73 10.7 0.77 8.3 0.77 9.7 0.71 11.
7-2. PERFORMANCE CURVE Cooling Capacity correction factors Indoor air Wet-bulb temperature difference (°F) Cooling capacity (at Rated frequency) 1.5 Indoor intake air Wet-bulb temperature( F) 1.4 1.3 1.2 76 1.1 75 1.0 0.9 14 23 32 41 50 59 68 77 86 95 104 72 68 64 113 Outdoor intake air DB temperature(°F) SHF at rating condition = 0.79 Airflow = 417 CFM 0.8 ) re (°F 0.7 ea r intak 0.6 ir WB Indoo ratu tempe 71 67 63 0.5 0.
MUFZ-KJ12NAHZ 120% 120% 100% 100% 80% 80% % Heating Capacity % Heating Capacity Heating MUFZ-KJ09NAHZ 60% 40% 20% 0% -13 -5 5 15 25 35 45 55 65 0% -13 75 -13.0 66% -4.0 83% 5.0 100% 14.0 100% 23.0 100% 32.0 100% 5 41.0 100% 50.0 100% 69.8 100% HEATING CAPACITY Outdoor Temperature Degrees (°F) % Heating Capacity 75.0 100% 15 100% 100% 80% 80% % Heating Capacity 120% 60% 40% 35 45 55 65 75 -13.0 65% -4.0 83% 5.0 100% 14.0 100% 23.0 100% 32.0 100% 41.
7-3. CONDENSING PRESSURE Cooling Data are based on the condition of indoor humidity 50 %. Air flow should be set to High speed.
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.
7-4. STANDARD OPERATION DATA Model Item Unit Total Capacity Electrical circuit MFZ-KJ18NA Cooling Heating 11,000 12,000 13,000 15,000 18,000 17,000 21,000 SHF — 0.79 — 0.70 — 0.66 — 0.65 — Input kW 0.570 0.750 0.890 0.900 1.120 1.140 1.350 1.730 Rated frequency Hz 33 45 46 53 48 57 56 62 MFZ-KJ09NA MFZ-KJ12NA V, phase, Hz Input Fan motor current MFZ-KJ18NA 208/230, 1, 60 0.025 0.025 0.027 0.047 A 0.26/0.23 0.26/0.23 0.28/0.35 0.48/0.
7-5. CAPACITY AND INPUT CORRECTION BY INVERTER OUTPUT FREQUENCY MUFZ-KJ09NAHZ Correction of Cooling total input 2.5 1.0 0.5 0 25 50 75 100 (Hz) Capacity correction factors Input correction factors Capacity correction factors 1.5 2.0 2.0 1.5 1.0 0.5 0 25 50 75 100 (Hz) Correction of Heating capacity 1.5 1.0 0.5 0 3.5 Input correction factors Correction of Cooling capacity 2.
8 ACTUATOR CONTROL MUFZ-KJ09NAHZ MUFZ-KJ12NAHZ MUFZ-KJ15NAHZ MUFZ-KJ18NAHZ 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. 5 seconds 15 seconds ON Compressor OFF ON Outdoor fan motor OFF 8-2. R.V. COIL CONTROL Heating . . . . . . . . . . . . . . . . . ON Cooling . . . . . . . . . . . . . . . . . OFF Dry . .
9 SERVICE FUNCTIONS MUFZ-KJ09NAHZ MUFZ-KJ12NAHZ MUFZ-KJ15NAHZ MUFZ-KJ18NAHZ 9-1. CHANGE IN DEFROST SETTING Changing defrost finish temperature To change the defrost finish temperature, cut/solder the JS wire of the outdoor inverter P.C. board (Refer to 10-6.1.). Jumper JS Defrost finish temperature MUFZ-KJ09/12NAHZ MUFZ-KJ15/18NAHZ Soldered (Initial setting) 41°F (5°C) 50°F (10°C) None (Cut) 50°F (10°C) 64°F (18°C) 9-2.
10 TROUBLESHOOTING MUFZ-KJ09NAHZ MUFZ-KJ12NAHZ MUFZ-KJ15NAHZ MUFZ-KJ18NAHZ 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.
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.
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). 1 Does the left lamp of the OPERATION INDICATOR lamp on the indoor unit blink at the interval of 0.
3. Outdoor unit failure mode table The left lamp of the OPERATION INDICATOR lamp (Indoor unit) OFF 1-time flash 2.5 seconds OFF Abnormal point (Failure mode/protection) None (Normal) Indoor/outdoor communication, receiving error Indoor/outdoor communication, receiving error LED indication (Outdoor P.C. board) — — — 2-time flash 2.5 seconds OFF Outdoor power system 3-time flash 2.5 seconds OFF Discharge temperature thermistor Defrost thermistor 1-time flash every 2.
The left lamp of the Abnormal point OPERATION (Failure mode/protection) INDICATOR lamp (Indoor unit) 10-time flash Discharge temperature 2.5 seconds OFF 11-time flash 2.5 seconds OFF 14-time flash or more 2.5 seconds OFF DC voltage Each phase current of compressor Stop valve (Closed valve) LED indication (Outdoor P.C. board) — 8-time flash 2.5 seconds OFF 9-time flash 2.5 seconds OFF 14-time flash 2.
10-3. TROUBLESHOOTING CHECK TABLE No. 1 Symptom Outdoor unit does not operate. Abnormal point/ Condition 1-time flash every Outdoor power sys2.5 seconds tem Condition LED indication • Reconnect connector of compressor. • Refer to 10-5. "How to check inverter/compressor". • Check stop valve. Outdoor thermistors Discharge temperature thermistor, fin temperature thermistor, • Refer to 10-5. "Check of outdoor defrost thermistor, P.C. board temperature thermistor, outdoor thermistors".
No. Symptom Outdoor unit operates. LED indication 1-time flash 2.5 seconds OFF Abnormal point/ Condition Frequency drop by current protection 16 3-time flash 2.5 seconds OFF 17 20 Outdoor unit operates. When the input current exceeds approximately The unit is normal, but check the 10A (KJ09)/10.5A (FH12), compressor frequency following. lowers. • Check if indoor filters are clogged. KJ15/18 Current from power outlet is nearing breaker ca- • Check if refrigerant is short.
10-4. TROUBLE CRITERION OF MAIN PARTS MUFZ-KJ09NAHZ MUFZ-KJ12NAHZ MUFZ-KJ15NAHZ MUFZ-KJ18NAHZ Part name Defrost thermistor (RT61) Fin temperature thermistor (RT64) Ambient temperature thermistor (RT65) Check method and criterion Figure Measure the resistance with a tester. Refer to 10-6. “Test point diagram and voltage”, 1. “Inverter P.C. board”, for the chart of thermistor.
10-5. TROUBLESHOOTING FLOW A How to check inverter/compressor Disconnect the connector between the compressor and the power module (IC700) (MUFZ-KJ09/12)/ IGBT module (IC700) (MUFZ-KJ15/18). See 10-5. Check the voltage between terminals. Are the voltages balanced? Yes No Replace the inverter P.C. board. See 10-5. Check the compressor. “Check of open phase”. “Check of compressor”.
D Check of compressor winding ●Disconnect the connector between the compressor and the power module (IC700) (MUFZ-KJ09/12)/IGBT module (IC700) (MUFZ-KJ15/18), and measure the resistance between the compressor terminals. <> At 3 points BLK-WHT Measure the resistance between the lead wires at 3 points. BLK-RED WHT-RED <> Refer to 10-4. 0 [Ω] ················Abnormal [short] Infinite [Ω] ·······Abnormal [open] NOTE: Be sure to zero the ohmmeter before measurement.
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 10-6.1.) Yes No Replace the thermistor except RT64. When RT64 is abnormal, replace the inverter P.C. board. Reconnect the connector of thermistor. Turn ON the power supply and press EMERGENCY OPERATION switch.
H Check of R.V. coil MUFZ-KJ09/12 First of all, measure the resistance of R.V. coil to check if the coil is defective. Refer to 10-4. In case CN721 is disconnected or R.V. coil is open, voltage is generated between the terminal pins of the connector although no signal is being transmitted to R.V. 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).
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.) No Yes 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.
J Check of power supply Disconnect the connector between the compressor and the power module (IC700) (MUFZ-KJ09/12)/IGBT module (IC700) (MUFZ-KJ15/18). 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? Yes No Is there DC voltage 260 - 370 VDC between DB61 (+) and DB61 (–) (MUFZ-KJ09/12)/294 - 370 VDC between JP715 (+) and JP30 (–) (MUFZ-KJ15/18) on the inverter P.C.
K Check of LEV (Expansion valve) Turn ON the power supply. 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. Make sure that the indicators on the LCD screen shown in the right figure are all displayed. Then release the buttons.
L Check of inverter P.C. board Check the outdoor fan motor. (Refer to 10-5. .) Is the fuse (F901) blown on the inverter P.C. board? No Yes 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? Yes (10-time flash) No Check the corresponding parts following LED indication. (Refer to 10-3.
M How to check miswiring and serial signal error Turn OFF the power supply. Is there rated voltage in the power supply? Yes Check the power supply. No Turn ON the power supply. Is there rated voltage between the outdoor terminal block S1 and S2? Yes No Check the wiring. Press EMERGENCY OPERATION switch once.
N Check of defrost heater MUFZ-KJ09NAHZ MUFZ-KJ12NAHZ MUFZ-KJ15NAHZ MUFZ-KJ18NAHZ Check the following points before checking electric continuity. 1. Does the resistance of ambient temperature thermistor have the characteristics? Refer to 10-6.1. 2. Is the resistance of defrost heater normal? Refer to 10-4. 3. Does the heater protector remain conducted (not open)? 4.
P Electromagnetic noise enters into TV sets or radios Is the unit grounded? Yes 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)? No 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)? Ground the unit.
10-6. TEST POINT DIAGRAM AND VOLTAGE 1. Inverter P.C. board MUFZ-KJ09NAHZ MUFZ-KJ12NAHZ Back side of unit Smoothing capacitor (C62) DB61 260 - 370 VDC (-) (+) R.V.coil (CN721) Smoothing capacitor (C61) 208/230 VAC Heater connector (CN722) 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) (Refer to 9-1.
MUFZ-KJ15NAHZ MUFZ-KJ18NAHZ Fuse (F601) T3.15AL250V R.V. coil (CN602) 208/230 VAC Heater connector (CN601) 208/230 VAC Signal of outdoor fan motor (CN931) LEV connector (CN724) Output to drive outdoor fan motor (CN932) 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) Fuse (F901) T3.15AL250V Fuse (F880) T3.
11 DISASSEMBLY INSTRUCTIONS <"Terminal with locking mechanism" Detaching points> The terminal which has the locking mechanism can be detached as shown below. There are 2 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.
OPERATING PROCEDURE Photo 4 PHOTOS Photo 5 Screws of the conduit cover 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: CN721 (R.V.
OPERATING PROCEDURE PHOTOS 4. Removing the discharge temperature thermistor, defrost thermistor, outdoor heat exchanger temperature thermistor and ambient temperature thermistor Screw of the R.V. coil Photo 8 (1) Remove the cabinet and panels. (Refer to 1.) (2) Disconnect the lead wire to the reactor and the following connectors:
PHOTOS OPERATING PROCEDURE 5. Removing outdoor fan motor Photo 11 Screws of the outdoor fan motor (1) Remove the cabinet and panels. (Refer to 1.) (2) Disconnect the following connectors: CN931, CN932 (Fan motor) (3) Remove the propeller fan nut. (4) Remove the propeller fan. (5) Remove the screws fixing the fan motor. (6) Remove the fan motor. NOTE: The propeller fan nut is a revers thread. Propeller fan 6.
11-2. MUFZ-KJ15NAHZ MUFZ-KJ18NAHZ NOTE: Turn OFF the power supply before disassembly. OPERATING PROCEDURE PHOTOS 1. Removing the cabinet Photo 1 (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.
OPERATING PROCEDURE PHOTOS 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: CN602 (R.V.
OPERATING PROCEDURE PHOTOS 4. Removing the discharge temperature thermistor, defrost thermistor, outdoor heat exchanger temperature thermistor and ambient temperature thermistor Photo 7 Outdoor heat exchanger temperature thermistor Ambient temperature thermistor (1) Remove the cabinet and panels. (Refer to 1.) (2) Disconnect the lead wire to the reactor and the following connectors:
HEAD OFFICE: TOKYO BLDG., 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN © Copyright 2016 MITSUBISHI ELECTRIC CORPORATION Issued: Jul. 2017. No. OBH753 REVISED EDITION-B Issued: Mar. 2016. No. OBH753 REVISED EDITION-A Published: Feb. 2016. No. OBH753 Made in Japan Specifications are subject to change without notice.
