Revision D: • Capacity corrections have been corrected [7-1. 2), 3)]. OBH747 REVISED EDITION-C is void. OUTDOOR UNIT HFC utilized SERVICE MANUAL No. OBH747 REVISED EDITION-D R410A Models MUZ-HM09NA , MUZ-HM18NA MUZ-HM09NA2 , MUZ-HM18NA2 MUZ-HM12NA , MUZ-HM24NA MUZ-HM12NA2 , MUZ-HM24NA2 MUZ-HM15NA Indoor unit service manual MUZ-HM15NA2 MSZ-HM•NA Series (OBH746) - U1 - - - U1 U1 - - U8 - U8 - U8 U1 U1 U1 - U8 U1 U1 U1 - U1 CONTENTS MUZ-HM24NA 1.
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: • MUZ-HM09/12NAbeen added.
1 TECHNICAL CHANGES MUZ-HM24NA - U1 1. New model MUZ-HM09NA MUZ-HM09NA2 MUZ-HM12NA MUZ-HM12NA2 MUZ-HM15NA MUZ-HM15NA2 MUZ-HM18NA MUZ-HM18NA2 MUZ-HM24NA2 U8 - U8 U8 - U8 U1 - U1 U1 - U1 - U1 1. New model MUZ-HM09NA MUZ-HM09NA2 MUZ-HM12NA MUZ-HM12NA2 U1 - U1 U1 - U1 1.
2 PART NAMES AND FUNCTIONS MUZ-HM09NA MUZ-HM09NA2 MUZ-HM12NA MUZ-HM12NA2 MUZ-HM15NA MUZ-HM15NA2 MUZ-HM18NA MUZ-HM18NA2 Air inlet (back and side) Piping Air outlet Drain hose Drain outlet MUZ-HM24NA MUZ-HM24NA2 Air inlet (back and side) Piping Drain hose Air outlet Drain outlet OBH747D 4
3 SPECIFICATION MUZ-HM09NA - U1 MUZ-HM09NA2 - U1 Outdoor unit model MUZ-HM09NA - U8 MUZ-HM09NA2 - U8 Capacity Cooling 1 Rated (Minimum~Maximum) Heating 47 1 Btu/h Btu/h 9,000 ( 3,800 ~ 10,000 ) 10,900 ( 4,500 ~ 11,800 ) Capacity Heating 17 2 Btu/h 6,700 (7,200) Rated (Maximum) Power consumption Cooling 1 Rated (Minimum~Maximum) Heating 47 1 W W Power consumption Heating 17 2 W Rated (Maximum) 750 (240 - 850) 900 (240 - 1,000) 750 (205 - 850) 900 (255 - 1,000) 700 (780) EER 1 [SEER]
MUZ-HM12NA - U1 MUZ-HM12NA2 - U1 Outdoor unit model MUZ-HM12NA - U8 MUZ-HM12NA2 - U8 Capacity Cooling 1 Rated (Minimum~Maximum) Heating 47 1 Btu/h Btu/h 12,000 ( 3,800 ~ 12,200 ) 12,200 ( 4,500 ~ 14,500 ) 12,200 ( 5,500 ~ 14,500 ) Capacity Heating 17 2 Btu/h 7,600 (9,000) Rated (Maximum) Power consumption Cooling 1 Rated (Minimum~Maximum) Heating 47 1 W W Power consumption Heating 17 2 W Rated (Maximum) 1,210 (240 - 1,300) 990 (240 - 1,220) 1,210 (205 - 1,300) 990 (340 - 1,660) 800 (
Capacity Cooling 1 Rated (Minimum~Maximum) Heating 47 1 Btu/h Btu/h MUZ-HM15NA MUZ-HM15NA2 14,000 (3,100 - 16,000) 18,000 (4,800 - 18,500) Capacity Heating 17 2 Btu/h 11,500 (14,000) 11,500 (15,000) Outdoor unit model Rated (Maximum) MUZ-HM18NA MUZ-HM18NA2 17,200 (5,800 - 18,000) 18,000 (5,400 - 20,900) Power consumption Cooling 1 Rated (Minimum~Maximum) Heating 47 1 W W 1,127 (187 - 1,957) 1,570 (190 - 1,980) 1,598 (308 - 2,028) 1,548 (288 - 2,208) Power consumption Heating 17 2 W 1
Cooling 1 Heating 47 1 Btu/h Btu/h MUZ-HM24NA MUZ-HM24NA2 22,500 (5,800 ~ 22,500) 26,000 (5,400 ~ 26,000) Heating 17 2 Btu/h 18,500 (18,500) Cooling 1 Heating 47 1 W W 2,575 (275 ~ 2,575) 2,445 (265 ~ 2,445) Heating 17 2 W 2,245 (2,245) Outdoor unit model Capacity Rated (Minimum~Maximum) Capacity Rated (Maximum) Power consumption Rated (Minimum~Maximum) Power consumption Rated (Maximum) EER 1 [SEER] 3 HSPF IV 4 COP Cooling Heating Heating 1 Cooling (208/230) % Power factor Heating (208/230)
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 MUZ-HM09NA MUZ-HM09NA2 MUZ-HM12NA MUZ-HM12NA2 MUZ-HM15NA MUZ-HM15NA2 MUZ-HM18NA MUZ-HM18NA2 *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 ) mm 00 re 1 ( o n. 4 i or m 14 in.
MUZ-HM24NA MUZ-HM24NA2 Unit: inch Clear *1 REQUIRED SPACE *1 20 in. (500 mm) or more when front and sides of the unit are clear 16-7/16 2 13 Drain hole 1-9/16 ) mm 100 ( . 4 in more or 1-5/8 4i or mn. (10 ore 0 mm ) 14-3/16 Air in Air in ) mm 500 ( . n 2 i 20 ore * or m Air out 2-holes 13/32 13/16 6-7/8 19-11/16 14 or min.
5 WIRING DIAGRAM MUZ-HM09NA - U1 MUZ-HM09NA2 - U1 MUZ-HM12NA - U1 MUZ-HM12NA2 - U1 MUZ-HM09NA - U8 MUZ-HM09NA2 - U8 MUZ-HM12NA - U8 MUZ-HM12NA2 - U8 OBH747D 12
MUZ-HM15NA - OBH747D U1 MUZ-HM15NA2 - U1 MUZ-HM18NA - 13 U1 MUZ-HM18NA2 - U1
MUZ-HM24NA - OBH747D U1 MUZ-HM24NA2 - U1 14
6 REFRIGERANT SYSTEM DIAGRAM MUZ-HM09NA - U1 MUZ-HM09NA2 - U1 MUZ-HM12NA - MUZ-HM12NA2 U1 - U1 Unit: Inch (mm) Refrigerant pipe ø3/8 (ø9.
MUZ-HM12NA - U8 - MUZ-HM12NA2 Unit: Inch (mm) U8 Refrigerant pipe ø3/8 (ø9.52) (with heat insulator) 4-way valve Muffler Stop valve (with service port) Flared connection Discharge temperature thermistor RT62 Outdoor heat exchanger Muffler Service port Ambient temperature thermistor RT65 Compressor Service port Defrost thermistor RT61 Capillary tube O.D. 0.118 × I.D. 0.079 LEV × 9-7/16 (ø3.0 × ø2.0 × 240) Flared connection Outdoor heat exchanger temperature thermistor RT68 Capillary tube O.
Unit: Inch (mm) MUZ-HM24NA MUZ-HM24NA2 Muffler with #100 mesh strainer 4-way valve Refrigerant pipe ø5/8 (ø15.88) (with heat insulator) Service port Stop valve (with service port) Flared connection Discharge temperature Service thermistor RT62 port Defrost thermistor RT61 Outdoor heat exchanger Compressor Capillary tube O.D. 0.118× I.D. 0.079× 7-7/8 (ø3.0×ø2.0×200(×4)) Muffler Flared connection LEV Strainer #100 Stop valve Refrigerant pipe ø3/8 (ø9.52) (with heat insulator) Capillary tube O.D.
MAX. REFRIGERANT PIPING LENGTH and MAX. HEIGHT DIFFERENCE Refrigerant piping: ft. Max. Length Max. Height difference A B Model MUZ-HM09NA MUZ-HM09NA2 MUZ-HM12NA MUZ-HM12NA2 MUZ-HM15NA MUZ-HM15NA2 MUZ-HM18NA MUZ-HM18NA2 65 MUZ-HM24NA MUZ-HM24NA2 100 Piping size O.D: in. Gas Liquid 3/8 40 1/4 1/2 50 5/8 3/8 Indoor unit Max. Height difference B Max. Length A Outdoor unit ADDITIONAL REFRIGERANT CHARGE (R410A: oz.) NOTE: Refrigerant piping exceeding 25 ft.
7 DATA MUZ-HM09NA MUZ-HM09NA2 MUZ-HM12NA MUZ-HM12NA2 MUZ-HM15NA MUZ-HM15NA2 MUZ-HM18NA MUZ-HM18NA2 MUZ-HM24NA MUZ-HM24NA2 7-1. PERFORMANCE DATA 1) COOLING CAPACITY Indoor air Model MUZ-HM09NA MUZ-HM09NA2 MUZ-HM12NA MUZ-HM12NA2 MUZ-HM15NA MUZ-HM15NA2 MUZ-HM18NA MUZ-HM18NA2 MUZ-HM24NA MUZ-HM24NA2 IWB (˚F) TC 75 SHC TPC TC Outdoor intake air DB temperature (˚F) 85 95 105 SHC TPC TC SHC TPC TC SHC TPC 115 SHC TPC 71 11.0 7.6 0.67 10.3 7.1 0.73 9.7 6.6 0.79 9.0 6.2 0.83 8.3 5.7 0.
3) HEATING CAPACITY CORRECTIONS Refrigerant piping length (one way: ft.) Model 25 (std.) 40 65 100 MUZ-HM09NA MUZ-HM09NA2 MUZ-HM12NA MUZ-HM12NA2 MUZ-HM15NA MUZ-HM15NA2 1.0 0.997 0.993 — MUZ-HM18NA MUZ-HM18NA2 MUZ-HM24NA MUZ-HM24NA2 1.0 0.997 0.993 0.987 4) HEATING CAPACITY Indoor air Model MUZ-HM09NA MUZ-HM09NA2 MUZ-HM12NA MUZ-HM12NA2 MUZ-HM15NA MUZ-HM15NA2 MUZ-HM18NA MUZ-HM18NA2 MUZ-HM24NA MUZ-HM24NA2 IDB (˚F) 75 70 65 75 70 65 75 70 65 75 70 65 75 70 65 5 TC 4.8 5.2 5.5 5.4 5.8 6.1 7.
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 79 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) MUZ-HM12NA MUZ-HM12NA2 1.0 0.9 Total power consumption (kW) SHF at rating condition = 0.82 Airflow = 399 CFM 71 67 63 0.8 0.7 rature 0.
Heating Heating capacity (at Rated frequency) 1.2 Capacity correction factor Indoor air Dry-bulb temperature difference (°F) 1.3 ure ( F) 59 68 79 rat 1.1 1.0 ulb e mp te y-b 0.9 0.8 r oo r ir D ea ak int Ind 0.7 0.6 0.5 0.4 -4 5 14 23 32 41 50 Outdoor intake air WB temperature (°F) MUZ-HM12NA MUZ-HM12NA2 Airflow = 406 CFM 1.1 75 70 65 0.9 0.7 0.5 0.
7-3. CONDENSING PRESSURE Cooling Data are based on the condition of indoor humidity 50 %. Air flow should be set to High speed.
MUZ-HM15NA MUZ-HM15NA2 (PSIG) 500 tu era mp oor 400 Ind te DB 160 350 300 250 200 65 (PSIG) 180 Suction pressure Condensing pressure 86 80 75 70 °F) re ( 450 86 80 75 70 140 120 100 rature (°F) 80 70 75 80 85 90 95 Indoor DB tempe 60 65 100 105 (°F) 70 Outdoor ambient temperature 75 80 85 90 95 Outdoor ambient temperature 100 105 (°F) MUZ-HM18NA MUZ-HM18NA2 (PSIG) 550 °F) re ( 500 tu era 86 80 75 70 oor 450 Ind D 180 400 350 300 250 65 (PSIG) 200 Suction pressur
MUZ-HM09NA MUZ-HM09NA2 MUZ-HM12NA (PSIG) 370 m B te 185 rD doo In 295 270 25 35 45 55 65 160 135 oor Ind 60 75(°F) 5 15 25 35 45 55 75(°F) 65 Outdoor ambient temperature U8 (PSIG) 460 (PSIG) 210 ) Suction pressure °F e( r atu r e mp 380 or DB te 58Hz o Ind 340 75 70 65 185 75 70 65 420 Condensing pressure te 85 MUZ-HM12NA2 - U8 DB 110 Outdoor ambient temperature MUZ-HM12NA - °F) re ( atu er mp 58Hz 58Hz 245 15 75 70 65 ) (°F Suction pressure
MUZ-HM18NA MUZ-HM18NA2 (PSIG) 500 (PSIG) 200 75 70 65 ) atu per oor Ind 400 m B te D 350 300 5 15 25 35 45 55 Outdoor ambient temperature 65 ) 150 e r tu (°F ra pe m 125 or DB te o nd I 100 75 58Hz 250 75 70 65 175 Suction pressure Condensing pressure 450 °F re ( 75 (°F) 50 58Hz 5 15 25 35 45 55 Outdoor ambient temperature 65 75 (°F) MUZ-HM24NA MUZ-HM24NA2 (PSIG) 550 (PSIG) 200 175 450 75 70 65 °F) re ( atu per oor 400 Ind m B te D 350 300 250 Suct
7-4. STANDARD OPERATION DATA MSZ-HM09NA - Model Item Total Capacity Cooling Heating Cooling Heating Btu/h 9,000 10,900 9,000 10,900 SHF — 0.82 — 0.82 — Input kW 0.750 0.900 0.750 0.900 Rated frequency Hz 59.5 79.0 59.5 77.5 MSZ-HM09NA V, phase, Hz Electrical circuit Power supply Input Fan motor current 208/230, 1, 60 kW 0.022 0.023 0.022 0.023 A 0.24/0.22 0.25/0.23 0.24/0.22 0.25/0.23 Outdoor unit V, phase, Hz Power supply Comp.
7-4. STANDARD OPERATION DATA MSZ-HM12NA - Model Item Total Capacity Cooling Heating Cooling Heating Btu/h 12,000 12,200 12,000 14,400 SHF — 0.77 — 0.77 — Input kW 1.210 0.990 1.210 0.990 Rated frequency Hz 89.0 90.0 69.0 77.0 MSZ-HM12NA V, phase, Hz Electrical circuit Power supply Input Fan motor current 208/230, 1, 60 kW 0.022 0.023 0.022 0.023 A 0.24/0.22 0.25/0.23 0.24/0.22 0.25/0.23 Outdoor unit V, phase, Hz Power supply Comp.
7-4. STANDARD OPERATION DATA Model MSZ-HM15NA Item Total Capacity Cooling Heating Cooling Heating Cooling Heating Btu/h 14,000 18,000 17,200 18,000 22,500 26,000 SHF — 0.78 — 0.86 — 0.89 — Input kW 1.17 1.60 1.64 1.59 2.63 2.5 Rated frequency Hz 56.5 74 68 74 98 108 MSZ-HM15NA V, phase, Hz Electrical circuit Power supply Input Fan motor current Fan motor current Refrigerant circuit 0.043 0.030 0.042 0.042 0.055 A 0.43/0.39 0.34/0.31 0.44/0.40 0.44/0.
7-5. CAPACITY AND INPUT CORRECTION BY INVERTER OUTPUT FREQUENCY MUZ-HM09NA - U1 MUZ-HM09NA2 - U1 Correction of Cooling capacity Capacity correction factors 1.5 Correction of Cooling total input 1.5 Correction of Heating capacity 1.5 Correction of Heating total input 2.0 1.5 1.0 1.0 1.0 1.0 0.5 0.5 0.5 0.5 0.0 0 50 100 0.0 0 50 100 0.0 0 50 100 150 The operational frequency of compressor The operational frequency of compressor The operational frequency of compressor 0.
MUZ-HM15NA MUZ-HM15NA2 Correction of Cooling capacity Correction of Cooling total input 0.5 0 25 50 75 1.5 1.0 0.5 100 (Hz) The operational frequency of compressor 0 25 50 75 1.5 1.0 0.5 100 (Hz) The operational frequency of compressor 2.0 Input correction factors 1.0 2.0 Capacity correction factors 1.5 Correction of Heating total input Correction of Heating capacity 2.0 Input correction factors Capacity correction factors 2.
8 ACTUATOR CONTROL MUZ-HM09NA MUZ-HM09NA2 MUZ-HM12NA MUZ-HM12NA2 MUZ-HM15NA MUZ-HM15NA2 MUZ-HM18NA MUZ-HM18NA2 MUZ-HM24NA MUZ-HM24NA2 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 . . . . . . . . . . . . . . .
9 SERVICE FUNCTIONS MUZ-HM09NA MUZ-HM09NA2 MUZ-HM12NA MUZ-HM12NA2 MUZ-HM15NA MUZ-HM15NA2 MUZ-HM18NA MUZ-HM18NA2 MUZ-HM24NA MUZ-HM24NA2 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.).
10 TROUBLESHOOTING MUZ-HM09NA MUZ-HM09NA2 MUZ-HM12NA MUZ-HM12NA2 MUZ-HM15NA MUZ-HM15NA2 MUZ-HM18NA MUZ-HM18NA2 MUZ-HM24NA MUZ-HM24NA2 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 TOO COOL button to adjust the set temperature to 77°F (25°C).
NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (10-3.). 3. Table of outdoor unit failure mode recall function MUZ-HM09NA MUZ-HM09NA2 MUZ-HM12NA MUZ-HM12NA2 OPERATION Abnormal point INDICATOR (Failure mode / protection) upper lamp (Indoor unit) OFF None (Normal) 2-time flash Outdoor power system 2.5 seconds OFF 3-time flash 2.5 seconds OFF 4-time flash 2.5 seconds OFF LED indication (Outdoor P.C.
NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (10-3.). OPERATION Abnormal point INDICATOR (Failure mode / protection) upper lamp (Indoor unit) 11-time flash DC voltage 2.5 seconds OFF Each phase current of compressor 12-time flash Overcurrent Compressor open2.5 seconds phase OFF 14-time flash Stop valve (Closed valve) 2.5 seconds OFF 4-way valve/ Pipe temperature Outdoor refrigerant system abnormality (MUZHM09/12NA(2) - U1 ) OBH747D LED indication (Outdoor P.C.
MUZ-HM15NA MUZ-HM15NA2 MUZ-HM18NA MUZ-HM18NA2 MUZ-HM24NA MUZ-HM24NA2 NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (10-3.). The upper lamp of the OPERATION Abnormal point LED indication INDICATOR (Failure mode/protection) (Outdoor P.C. board) lamp (Indoor unit) OFF None (Normal) — Indoor/outdoor communication, 1-time flash 2.5 seconds receiving error — OFF Indoor/outdoor communication, receiving error — 2-time flash 2.
NOTE: Blinking patterns of this mode differ from the ones of TROUBLESHOOTING CHECK TABLE (10-3.). The upper lamp of the OPERATION Abnormal point INDICATOR (Failure mode/protection) 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 LED indication (Outdoor P.C. board) — Condition Remedy Temperature of discharge temperature • Refer to 10-5. "Check of LEV". thermistor has been 122°F (50°C) or less for 20 minutes.
10-3. TROUBLESHOOTING CHECK TABLE No. 1 Symptom Outdoor unit does not operate. 3 4 5 6 8 Condition Overcurrent protection cut-out operates 3 consecutive times within 1 minute after the compressor gets started. Outdoor thermistors Discharge temperature thermistor, fin temperature thermistor, defrost thermistor, P.C. board temperature thermistor, outdoor heat exchanger temperature thermistor or ambient temperature thermistor shorts or opens during compressor running.
No. 16 Symptom Outdoor unit operates. LED indication 1-time flash 2.5 seconds OFF 3-time flash 2.5 seconds OFF 16 4-time flash 2.5 seconds OFF 18 5-time flash 2.5 seconds OFF 19 20 Outdoor unit operates. 7-time flash 2.5 seconds OFF 8-time flash 2.
10-4. TROUBLE CRITERION OF MAIN PARTS MUZ-HM09NA MUZ-HM09NA2 MUZ-HM12NA MUZ-HM12NA2 MUZ-HM15NA MUZ-HM15NA2 MUZ-HM18NA MUZ-HM18NA2 MUZ-HM24NA MUZ-HM24NA2 Part name Defrost thermistor (RT61) Check method and criterion Figure Fin temperature thermistor (RT64) Measure the resistance with a tester. Ambient temperature thermistor (RT65) 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 (IPM) (MUZ-HM09/12NA(2) - U8 )/(IC700) (MUZ-HM09/12NA(2) - U1 , MUZ-HM15/18/24NA(2)) 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 (IPM) (MUZ-HM09/12NA(2) - U8 )/(IC700) (MUZHM09/12NA(2) - U1 , MUZ-HM15/18/24NA(2)), 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.
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.
I Check of outdoor fan motor Check the connection between the connector CN931 and CN932. Disconnect the connectors CN931 and CN932 from the inverter P.C. board. 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 (IPM) (MUZ-HM09/12NA(2) - U8 )/(IC700) (MUZHM09/12NA(2) - U1 , MUZ-HM15/18/24NA(2)). Turn ON power supply and press EMERGENCY OPERATION switch. Does the upper lamp of the OPERATION INDICATOR lamp on the indoor unit light up? Yes Is there DC voltage 260 - 325 VDC (MUZ-HM09/12NA(2) - U8 )/260 370 VDC (MUZ-HM09/12NA(2) - U1 , MUZ-HM15/18/24NA(2)) between DB61 (+) and DB61 (–) on the inverter P.C.
K Check of LEV (Expansion valve) Turn ON the power supply. While pressing both OPERATION SELECT button and TOO COOL 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 MUZ-HM09/12NA(2) 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 No Is there rated voltage between outdoor terminal block S1 and S2? Check the wiring. Press EMERGENCY OPERATION switch once.
MUZ-HM15/18/24NA(2) Turn OFF the power supply. NOTE: Refer to the indoor unit service manual. 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.
N Check of defrost heater (Optional parts) 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 MUZ-HM09NA- U1 MUZ-HM09NA2- U1 MUZ-HM12NA- U1 MUZ-HM12NA2- U1 DB61 260 - 370 VDC (-) (+) Back side of unit Smoothing capacitor (C62) Smoothing capacitor (C61) Fuse (F701) T3.15AL250V Fuse (F801) T3.15AL250V 208/230 VAC R.V.coil (CN721) 208/230 VAC Fuse (F901) T3.
1. Inverter P.C. board MUZ-HM09NA- U8 MUZ-HM09NA2- U8 MUZ-HM12NA- U8 MUZ-HM12NA2- U8 Back side of unit 208/230 VAC Bus-bar voltage DB61 260-325 VDC (+) (-) Smoothing capacitor (C63) Smoothing capacitor (C62) Fuse (F701) T3.15AL250V Fuse (F801) T3.15AL250V R.V.coil (CN721) 208/230 VAC Fuse (F901) T3.
1. Inverter P.C. board MUZ-HM15NA MUZ-HM18NA MUZ-HM15NA2 MUZ-HM18NA2 Smoothing capacitor (C63) DB61 260 - 370 VDC (-) (+) Back side of unit Smoothing capacitor (C62) Smoothing capacitor (C61) Fuse (F801) T3.15AL250V 208/230 VAC R.V.coil Fuse (F701) (CN721) 208/230 VAC T3.15AL250V Fuse (F901) T3.
1. Inverter P.C. board MUZ-HM24NA MUZ-HM24NA2 Smoothing capacitor (C63) Smoothing DB61 capacitor (C62) 260 - 370 VDC Back side of unit (-) (+) R.V.coil (CN721) Smoothing capacitor (C61) 208/230 VAC Heater connector (CN722) (Optional parts) Fuse (F701) T3.15AL250V Fuse (F801) T3.15AL250V 208/230 VAC Fuse (F901) 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 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 10 (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. Screws of the outdoor fan motor Propeller fan 6.
11-2. MUZ-HM24NA MUZ-HM24NA2 NOTE: Turn OFF the power supply before disassembly. OPERATING PROCEDURE PHOTOS Screws of the top panel Photo 1 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.
OPERATING PROCEDURE PHOTOS 2. Removing the inverter assembly, inverter P.C. board Photo 5 Screws of the terminal (1) Remove the cabinet and panels. (Refer to 1.) Screw of the heat sink block support and the (2) Disconnect the lead wire to the reactor and the following con- support and the separator back panel nectors: CN721 (R.V.
OPERATING PROCEDURE PHOTOS 4. Removing the discharge temperature thermistor, defrost thermistor, outdoor heat exchanger temperature thermistor and ambient temperature thermistor Photo 8 Outdoor heat exchanger 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 BUILDING, 2-7-3, MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN © Copyright 2015 MITSUBISHI ELECTRIC CORPORATION Issued: Jul. 2017. No. OBH747 REVISED EDITION-D Issued: Feb. 2017. No. OBH747 REVISED EDITION-C Issued: Mar. 2016. No. OBH747 REVISED EDITION-B Issued: Feb. 2016. No. OBH747 REVISED EDITION-A Published: Dec. 2015. No. OBH747 Made in Japan Specifications are subject to change without notice.
