Revision B: • 3-1. OPERATING RANGE has been modified. Please void OBH746 REVISED EDITION-A. INDOOR UNIT No. OBH746 REVISED EDITION-B SERVICE MANUAL Models MSZ-HM09NA MSZ-HM12NA MSZ-HM15NA MSZ-HM18NA MSZ-HM24NA - U1 - U1 - U1 - U1 - U1 Outdoor unit service manual MUZ-HM•NA Series (OBH747) CONTENTS MSZ-HM24NA 1. TECHNICAL CHANGES······································· 2 2. PART NAMES AND FUNCTIONS ····················· 3 3. SPECIFICATION ················································ 5 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: • MSZ-HM09/12/15/18NA- U1 have been added.
2 PART NAMES AND FUNCTIONS MSZ-HM09NA MSZ-HM12NA MSZ-HM15NA Air ¿lter Front panel Air cleaning ¿lter (Anti-Allergy Enzyme Filter, option) Air inlet Heat exchanger Air outlet Horizontal vane Remote controller Display section Remote control receiving section Operation indicator lamp Emergency operation switch ACCESSORIES Installation plate Attachment screws for the installation plate 4 × 25 mm Battery (AAA) for remote controller Wireless remote controller Felt tape (For left or left-rear piping) OBH74
MSZ-HM18NA MSZ-HM24NA Air inlet Front panel Air ¿lter Air cleaning ¿lter (Anti-Allergy Enzyme Filter, option) Heat exchanger Air outlet Horizontal vane Remote controller Display section Remote control receiving section Operation indicator lamp Emergency operation switch ACCESSORIES Installation plate Attachment screws for the installation plate 4 × 25 mm Wireless remote controller 1 Felt tape (For left or left-rear piping) 1 Battery (AAA) for remote controller 2 OBH746B 1 5 4
3 SPECIFICATION Indoor model MSZ-HM09NA Power supply MSZ-HM12NA V, phase, Hz 208/230, 1, 60 Max. fuse size (time delay)/ Disconnect switch A 15 Min. circuit ampacity A 1.0 Fan motor F.L.A COOL Dry Airflow CFM (Wet) Super High - High - Med. Low HEAT Dry CFM Moisture removal pt./h Sound level Cooling dB(A) Super High - High - Med. Heating dB(A) Low MSZ-HM15NA 0.76 399 - 321 - 237 - 170 (364 - 286 - 201 - 134) 533 - 420 - 335 - 272 (498 - 385 - 300 - 237) 1.5 406 - 321 - 237 - 170 2.
3-1. OPERATING RANGE (1) POWER SUPPLY Rated voltage 208/230 V 1 phase 60 Hz Indoor unit Guaranteed voltage (V) Min. 187 208 230 Max. 253 (2) OPERATION Intake air temperature (°F) Mode Condition Indoor DB 80 90 67 Standard temperature Maximum temperature Cooling Minimum temperature Maximum humidity Standard temperature Heating Maximum temperature Minimum temperature Outdoor WB 67 73 57 DB 95 115 14 60 67 60 47 75 -4(NA), 5(NA2) 78% 70 80 70 WB — — — — 43 65 -5 (NA), 4 (NA2) 3-2.
4 OUTLINES AND DIMENSIONS MSZ-HM09NA MSZ-HM12NA MSZ-HM15NA Unit: inch 11/16 Piping 5-1/2 2-1/4 Insulation Liquid line Gas line ø1 - 3/8 O.D ø1/4 19 - 11/16 (Flared connection ø1/4) ø3/8 16 - 15/16 (Flared connection: ø3/8 (HM09/12NA), ø1/2 (HM15NA)) Insulation ø1-1/8 O.D Connected part ø5/8 O.
5 WIRING DIAGRAM MSZ-HM09NA MSZ-HM12NA MSZ-HM15NA MSZ-HM18NA MSZ-HM24NA OBH746B 8
6 REFRIGERANT SYSTEM DIAGRAM MSZ-HM09NA MSZ-HM12NA MSZ-HM15NA Unit: inch (mm) Refrigerant pipe ø3/8 (ø9.52) (MSZ-HM09/12NA) ø1/2 (ø12.7) (MSZ-HM15NA) (with heat insulator) Indoor coil thermistor RT12 (main) Indoor heat exchanger Flared connection Indoor coil thermistor RT13 (sub) Room temperature thermistor RT11 Flared connection Refrigerant pipe ø1/4 (ø6.35) (with heat insulator) Refrigerant flow in cooling Refrigerant flow in heating MSZ-HM18NA MSZ-HM24NA Refrigerant pipe ø1/2 (ø12.
7 SERVICE FUNCTIONS MSZ-HM09NA MSZ-HM12NA MSZ-HM15NA MSZ-HM18NA MSZ-HM24NA 7-1. TIMER SHORT MODE For service, the set time can be shortened by bridging of the timer short point on the indoor electronic control P.C. board. The time will be shortened as follows. (Refer to 9-7.) • The set time for the ON/OFF timer can be reduced to 1 second for each minute. • After the breaker is turned on, the time for starting the compressor, which normally takes 3 minutes, can be reduced to 3 seconds.
7-3. 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 shut-off of the main power. Operation If the main power has been cut, the operation settings remain. After the power is restored, the unit restarts automatically according to the memory.
8 MICROPROCESSOR CONTROL MSZ-HM09NA MSZ-HM12NA MSZ-HM15NA MSZ-HM18NA MSZ-HM24NA WIRELESS REMOTE CONTROLLER Signal transmitting section Operation display section OFF/ON (stop/operate) button Temperature buttons Fan speed control button ECONO COOL button Vane control button Operation select button Timer mode select button Time set buttons RESET button NOTE: Last setting will be stored after the unit is turned OFF with the remote controller.
8-2. DRY ( ) OPERATION (1) Press STOP/OPERATE (OFF/ON) button. OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone. (2) Select DRY mode with OPERATION SELECT button. (3) The set temperature is determined from the initial room temperature. 1. Coil frost prevention Coil frost prevention works the same way as that in COOL mode. (8-1.1.) 8-3. HEAT ( ) OPERATION (1) Press STOP/OPERATE (OFF/ON) button. OPERATION INDICATOR lamp of the indoor unit turns on with a beep tone.
(4) VANE AUTO ( ) mode In VANE AUTO mode, the microprocessor automatically determines the vane angle to make the optimum room temperature distribution. MSZ-HM09/12/15NA In COOL and DRY operation Vane angle is fixed to Horizontal position. In HEAT operation Vane angle is fixed to Angle 5. Horizontal position 5 MSZ-HM18/24NA In HEAT operation Vane angle is fixed to Angle 4. In COOL and DRY operation Vane angle is fixed to Horizontal position.
8-6. EMERGENCY/TEST OPERATION In the case of test run operation or emergency operation, use EMERGENCY OPERATION switch on the right side of the indoor unit. Emergency operation is available when the remote controller is missing or has failed, or when the batteries in the remote controller are running down. The unit will start and OPERATION INDICATOR lamp will light up. The first 30 minutes of operation is the test run operation. This operation is for servicing.
9 TROUBLESHOOTING MSZ-HM09NA MSZ-HM12NA MSZ-HM15NA MSZ-HM18NA MSZ-HM24NA 9-1. 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 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.
9-2. 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 (9-4.) 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. Indoor unit failure mode table Upper lamp of OPAbnormal point ERATION INDICA(Failure mode) TOR lamp Not lighted Normal Condition Remedy — The room temperature thermistor short or 1-time flash every Room temperature open circuit is detected every 8 seconds dur0.5-second thermistor ing operation. Indoor coil 2-time flash The indoor coil thermistor short or open circuit 2.5-second OFF is detected every 8 seconds during operation.
9-3. INSTRUCTION OF TROUBLESHOOTING Start Indoor unit operates. Outdoor unit does not operate. Outdoor unit operates only in Test Run operation. Outdoor unit does not operate even in Test Run operation. Indoor unit operates. Outdoor unit does not operate normally. Unit does not operate normal operation in COOL or HEAT mode. Indoor unit does not receive the signal from remote controller. Indoor unit operates, when EMERGENCY OPERATION switch is pressed.
9-4. 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 Not lighted No.
9-5. TROUBLE CRITERION OF MAIN PARTS MSZ-HM09NA MSZ-HM12NA MSZ-HM15NA MSZ-HM18NA MSZ-HM24NA Part name Room temperature thermistor (RT11) Indoor coil thermistor (RT12, RT13) Indoor fan motor (MF) Check method and criterion Measure the resistance with a tester. Refer to 9-7. "Test point diagram and voltage", 1 or 2. "Indoor electronic control P.C. board", for the chart of thermistor. Check 9-6. Measure the resistance between the terminals with a tester.
9-6. TROUBLESHOOTING FLOW A Check of indoor fan motor The indoor fan motor error has occurred, and the indoor fan does not operate. Pay enough attention to the high voltage on the fan motor connector. Turn OFF the power supply. Is there any foreign matter that interferes the rotation of the line flow fan? No Yes Remove the foreign matter and adjust the line flow fan. Turn ON the power supply, wait 5 seconds or more, and then press EMERGENCY OPERATION switch.
B Check of remote controller and indoor electronic control P.C. board Check if the remote controller is exclusive for this air conditioner. Press STOP/OPERATE (OFF/ON) button on the remote controller. Is LCD display on the remote controller visible? Yes No (Not clear) 1 Look at the image of the signal transmitting section of the remote controller through the monitor of a digital camera or a camera phone.
C Check of indoor P.C. board and indoor fan motor Turn OFF the power supply. Remove indoor fan motor connector CN211 from indoor power P.C. board and vane motor connector CN151 from the indoor electronic control P.C. board and turn ON the power supply. Does the unit operate with the remote controller? Does OPERATION INDICATOR lamp light up by pressing EMERGENCY OPERATION switch? No Yes Measure the resistance of indoor fan motor. (Refer to 9-6 .) Short/ open circuit: Replace the indoor fan motor.
D How to check miswiring and serial signal error MSZ-HM09/12/15NA Turn OFF the power supply. Is there rated voltage in the power supply? Yes Check the power supply. No Turn ON the power supply. Yes Is there rated voltage between outdoor terminal block S1 and S2? No Check the wiring. Press EMERGENCY OPERATION switch once.
MSZ-HM18/24NA Turn OFF the power supply. Is there rated voltage in the power supply? Yes Check the power supply. No Turn ON the power supply. No Is there rated voltage between outdoor terminal block S1 and S2? Yes Check the wiring. Press EMERGENCY OPERATION switch once. Does the OPERATION INDICATOR lamp light up? Yes Is serial signal error indicated 6 minutes later? Yes A Turn OFF the power supply.
E 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.(3 m), or is the distance between the antennas and the outdoor unit within 9.91 ft.(3 m)? Ground the unit. No Yes Extend the distance between the antennas and the indoor unit, and/or the antennas and the outdoor unit. Yes Extend the distance between the TV sets and/ or radios and the indoor unit, or the TV sets or radios and the outdoor unit.
9-7. Test point diagram and voltage MSZ-HM09/12/15NA 1. Indoor power P.C. board, Indoor terminal P.C. board Indoor terminal P.C. board Fuse (F11)( ) Indoor power P.C. board Varistor (NR11) Resistor (R111) Indoor fan motor (CN211) (+)0-6 V (+)3-6 VDC 15 VDC (–) GND (highvoltage DC) 294/325 VDC Terminal block Connector to indoor electronic control P.C. board (CN20A) GND 5 VDC 12 VDC Please replace the fuse after removing the indoor terminal P.C. board from the electrical box. MSZ-HM09/12/15NA 2.
MSZ-HM18NA MSZ-HM24NA 1. Indoor power P.C. board 12 VDC Connector to indoor electronic control P.C. board (CN20A) 5 VDC 12V 5V Connector to Terminal block (CN201) GND Fuse (F11) T3.15AL250V Varistor (NR11) Connector to Indoor fan motor (CN211) 294/325 VDC (-) GND (High voltage DC) 15 VDC GND Resistor (R111) (+)0 or 15 VDC (+)3-6 VDC 2. Indoor electronic control P.C. board Room temperature thermistor RT11 (CN111) To disable "Auto restart function",cut the Jumper wire to JR77. (Refer to 7-3.
10 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 PHOTOS 2. Removing the indoor electronic control P.C. board and the room temperature thermistor Photo 2 (1) Remove the panel (Refer to 1.) and the corner box. (2) Remove the screw of the V.A. clamp and the V.A. clamp. (3) Loosen the screw of the indoor/outdoor connecting wire and remove the indoor/outdoor connecting wire. (4) Remove the screw of the electrical cover and the electrical cover. (5) Open the indoor electronic control P.C.
OPERATING PROCEDURE PHOTOS 4. Removing the nozzle assembly Photo 5 (1) Remove the panel (Refer to 1.) and the corner box. (2) Remove the indoor/outdoor connecting wire (Refer to 2 (2)-(7).). (3) Remove the indoor electronic control P.C. board holder. (4) Pull out the drain hose from the nozzle assembly and remove the nozzle assembly. 5. Removing the horizontal vane motor (1) Remove the nozzle assembly. (Refer to 5.) (2) Remove the screws of the horizontal vane motor unit.
OPERATING PROCEDURE PHOTOS 6. Removing the indoor fan motor, the indoor coil thermistor, and the line flow fan Photo 6 (1) Remove the panel (Refer to 1.) and the corner box. (2) Remove the indoor electronic control P.C. board holder, the electrical box and the nozzle assembly. (3) Remove the screws fixing the motor bed. (4) Loosen the screw fixing the line flow fan. (5) Remove the motor bed together with fan motor and motor band. (6) Release the hooks of the motor band. Remove the motor band.
10-2. MSZ-HM18NA MSZ-HM24NA NOTE: Turn OFF the power supply before disassembly. OPERATING PROCEDURE PHOTOS Photo 1 1. Removing the panel (1) Remove the screw caps on the panel and remove the screws of the panel. (2) Pull the panel slightly toward you, and then remove the panel by pushing it upward.
OPERATING PROCEDURE PHOTOS 2. Removing the indoor power P.C. board and the electrical box Photo 2 (1) Remove the panel. (Refer to 1.) Remove the right corner box. (2) Disconnect the following connectors: CN151 (Vane motor) CN112 (Indoor coil thermistor) CN10A (To the indoor power P.C. board) Screws of the ground plate Water cover Screw of the electrical cover Screw of the V.A. clamp (3) Unhook the catch on the left side of the control P.C. board holder.
OPERATING PROCEDURE PHOTOS 3. Removing the indoor electronic control P.C. board Photo 5 Control P.C. board holder (Inside) (1) Remove the panel. (Refer to 1.) Remove the right corner box. (2) Disconnect the following connectors: CN151 (Vane motor) CN112 (Indoor coil thermistor) CN10A (To the indoor power P.C. board) Catch Indoor electronic control P.C. board (3) Unhook the catch on the left side of the control P.C. board holder. Pull the control P.C.
OPERATING PROCEDURE PHOTOS 5. Removing the indoor fan motor, the indoor coil thermistor and the line flow fan Photo 7 (1) Remove the panel. (Refer to 1.) Remove the right corner box. (2) Remove the control P.C. board holder, the water cover, the electrical box and the nozzle assembly. (Refer to 2.) (3) Remove the screws fixing the motor bed. (4) Loosen the screw fixing the line flow fan. (5) Remove the motor bed together with the indoor fan motor and the motor band.
Fixing the indoor coil thermistor There are 2 forms of parts for fixing the indoor coil thermistor. Clip shape When fixing the indoor coil thermistor to the clip-shape/holder-shape part, the lead wire should point down. Holder shape About the same length Position and procedure for mounting the clip-shape part 1. Set the indoor coil thermistor in the center of the clip-shape part. 2. Check the (marked) mounting position. 3. Mount the clip-shape part.
