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28

No. Symptom 

Indication 

Abnormal point / Condition 

Condition 

Remedy

LED1
(Red) 

LED2

(Yellow) 

20

Outdoor 
unit oper-
ates. 

Once Lighting 

Primary current protection 

The input current exceeds 15 A. 

• These symptoms do not mean any abnormality of 

the product, but check the following points.

• Check if indoor 

fi

 lters are clogged.

• Check if refrigerant is short.
• Check if indoor/outdoor unit air circulation is short 

cycled. 

Secondary current protection  The current of the compressor exceeds 15 A. 

21

Twice Lighting 

High-pressure protection 
(MUZ) 

The indoor gas pipe temperature exceeds 113°F (45°C) dur-
ing heating. 

Defrosting in cooling 

The indoor gas pipe temperature falls 37°F (3°C) or below 
during cooling. 

22

3 times 

Lighting 

Discharge temperature protec-
tion 

The discharge temperature exceeds 212°F (100°C) during 
operation. 

• Check refrigerant circuit and refrigerant amount.
• Refer to 10-5.  "Check of LEV".
• Refer to 10-5.  "Check of outdoor thermistors". 

23

4 times 

Lighting 

Low discharge temperature 
protection 

The frequency of the compressor is kept 80 Hz or more and 
the discharge temperature is kept under 102°F (39°C) for 
more than 20 minutes. 

• Refer to 10-5.  "Check of LEV".
• Check refrigerant circuit and refrigerant amount. 

24

5 times 

Lighting 

Cooling high-pressure protec-
tion 

The outdoor heat exchanger temperature exceeds 136°F (58
°C) during operation. 

• This symptom does not mean any abnormality of 

the product, but check the following points.

• Check if indoor 

fi

 lters are clogged.

• Check if refrigerant is short.
• Check if indoor/outdoor unit air circulation is short 

cycled. 

25

Outdoor 
unit oper-
ates 

9 times 

Lighting  Inverter check mode 

The unit is operated with emergency operation switch. 

26

Lighting Lighting Normal 

OBH502E

Summary of Contents for MSY-D-NA Series

Page 1: ...G 22 11 DISASSEMBLY INSTRUCTIONS 41 Models MUZ D30NA 1 U1 U2 MUZ D36NA 1 U1 U2 MUY D30NA 1 MUY D36NA 1 Indoor unit service manual MSZ D NA Series OBH501 MSY D NA Series OBH501 NOTE RoHS compliant products have G mark on the spec name plate TM PARTS CATALOG OBB502 SERVICE MANUAL No OBH502 REVISED EDITION E OBH502 REVISED EDITION D is void HFC utilized R410A Revision E Capacity corrections have been...

Page 2: ... 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 D Check of outdoor thermistor has been corrected 10 5 B Re...

Page 3: ...0NA U2 MUZ D36NA MUZ D36NA 1 MUZ D36NA U1 MUZ D36NA U2 MUY D30NA MUY D30NA 1 MUY D36NA MUY D36NA 1 1 Wiring diagram has been changed 2 Fan motor has been changed PART NAMES AND FUNCTIONS 2 MUZ D30NA MUZ D36NA MUY D30NA MUY D36NA Piping Air outlet Drain hose Drain outlet Air inlet back and side 1 TECHNICAL CHANGES OBH502E ...

Page 4: ...ircuit ampacity A 21 Fan motor F L A 0 93 Compressor Model TNB220FMCHT R L A 16 L R A 20 Refrigeration oil cc 870 NEO22 Refrigerant control Linear expansion valve Sound level 1 Cooling dB A 55 55 56 56 Heating 57 57 Defrost method Reverse cycle Reverse cycle Dimensions W in 33 1 16 D 13 H 33 7 16 Weight Ib 141 126 141 126 External finish Munsell 3Y 7 8 1 1 Remote controller Wireless type Control v...

Page 5: ...Max temperature Heating at minimum compressor Speed 70 60 62 56 5 High temperature Heating at minimum compressor Speed 70 60 47 43 Frost Accumulation at rated compressor Speed 70 60 35 33 Frost Accumulation at Intermediate compressor Speed 5 70 60 35 33 5 At Intermediate compressor Speed Cooling rated compressor speed minimum compressor speed 3 minimum compressor speed 3 4 OPERATING RANGE 1 POWER ...

Page 6: ...pen 4 inch or more 8 inch or more if there are obstacles to both sides Open as a rule 20 inch or more if the back both sides and top are open 14 in or more 4 in or more REQUIRED SPACE Unit inch MUZ D30NA MUZ D36NA MUY D30NA MUY D36NA 4 OUTLINES AND DIMENSIONS OBH502E ...

Page 7: ...7 MUZ D30NA MUZ D30NA U1 MUZ D36NA MUZ D36NA U1 5 WIRING DIAGRAM OBH502E ...

Page 8: ...8 MUZ D30NA 1 MUZ D30NA U2 MUZ D36NA 1 MUZ D36NA U2 OBH502E ...

Page 9: ...9 MUY D30NA MUY D36NA OBH502E ...

Page 10: ...10 MUY D30NA 1 MUY D36NA 1 OBH502E ...

Page 11: ...sulator O D 0 142 I D 0 094 1 31 32 3 6 2 4 50 Oil separator Strainer 100 High pressure Switch Capillary tube O D 0 071 x I D 0 024 x 39 3 8 1 8 x 0 6 x 1 000 O D 0 142 x I D 0 094 x 1 31 32 3 6 x 2 4 x 50 Capillary tube High pressure Switch Flared connection Discharge temperature thermistor RT62 Flared connection Stop valve Stop valve with service port Capillary tube Refrigerant flow in cooling R...

Page 12: ...o the calculation Model Outdoor unit precharged Refrigerant piping length one way ft 25 30 40 50 60 70 80 90 100 MUZ D30NA MUZ D36NA 4 lb 10 oz 0 2 96 8 88 14 80 20 72 26 64 32 56 38 48 44 40 Calculation X oz 2 96 5 oz ft Refrigerant piping length ft 25 Model Outdoor unit precharged Refrigerant piping length one way ft 25 30 40 50 60 70 80 90 100 MUY D30NA MUY D36NA 4 lb 0 1 08 3 24 5 40 7 56 9 72...

Page 13: ...3 77 39 6 19 3 4 13 37 2 18 1 4 45 34 6 16 8 4 69 31 8 15 5 4 88 67 40 1 24 9 3 56 37 4 23 2 3 92 34 6 21 5 4 24 32 2 20 0 4 49 29 6 18 3 4 71 63 37 7 28 4 3 39 34 9 26 3 3 75 32 5 24 5 4 05 29 6 22 3 4 32 27 0 20 3 4 49 NOTE 1 IWB Intake air wet bulb temperature TC Total Capacity x103 Btu h SHC Sensible Heat Capacity x103 Btu h TPC Total Power Consumption kW 2 SHC is based on 80 F of indoor Intak...

Page 14: ...F at rating condition 0 62 763 CFM Airflow 65 75 85 95 105 115 Outdoor intake air DB temperature F Total power consumption kW Total capacity 10 3 Btu h MUZ D30NA MUZ D36NA Heating MUZ D30NA MUZ D36NA MUY D36NA MUY D30NA 71 67 63 71 67 63 24 26 28 30 32 34 36 38 40 Indoor intake air WB temperature F Indoor intake air WB temperature F 4 0 3 8 3 6 3 4 3 2 3 0 2 8 2 6 SHF at rating condition 0 64 763 ...

Page 15: ...re F MUZ D30NA PSIG Condensing pressure 86 80 75 70 68 70 75 80 85 90 95 100 105 F 90 100 110 120 130 140 150 Suction pressure Outdoor ambient temperature PSIG 86 80 75 70 68 70 75 80 85 90 95 100 105 F 260 300 340 380 420 460 500 540 580 Indoor DB temperature F Outdoor ambient temperature Indoor DB temperature F MUY D30NA PSIG Condensing pressure 86 80 75 70 68 70 75 80 85 90 95 100 105 F 90 100 ...

Page 16: ... frost MUZ D36NA MUZ D30NA 75 70 65 75 70 65 PSIG PSIG Condensing pressure Outdoor ambient temperature 14 20 25 30 35 40 45 50 55 60 65 70 F 200 500 480 460 440 420 400 380 360 340 320 300 280 260 240 220 Indoor DB temperature F Suction pressure Outdoor ambient temperature 14 20 25 30 35 40 45 50 55 58Hz 58Hz 60 65 70 F 140 150 130 120 110 100 90 80 70 60 50 Indoor DB tem perature F MUY D36NA PSIG...

Page 17: ...8 65 17 86 17 25 15 56 15 05 13 56 18 95 17 26 Fan motor current A 0 80 0 72 Refrigerant circuit Condensing pressure PSIG 468 404 480 420 453 475 Suction pressure PSIG 126 96 122 94 125 119 Discharge temperature F 186 8 169 7 198 7 168 8 191 3 197 1 Condensing temperature F 126 5 114 3 128 5 117 0 123 8 127 4 Suction temperature F 45 5 29 8 48 0 29 1 54 7 48 6 Comp shell bottom temperature F 175 6...

Page 18: ...ncy of compressor 0 50 100 150 0 5 1 0 1 5 Hz 0 50 100 150 0 5 1 0 1 5 Hz 0 50 100 150 0 5 1 0 1 5 Hz 0 50 100 150 0 5 1 0 1 5 Hz Capacity correction factors Input correction factors Input correction factors Capacity correction factors Correction of Cooling capacity The operational frequency of compressor Correction of Cooling total input The operational frequency of compressor Correction of Heati...

Page 19: ...ntinues to operate for 30 minutes 3 Compressor operates at rated frequency in COOL mode or 58 Hz in HEAT mode 4 Indoor fan operates at High speed 5 After 30 minutes test run operation finishes and EMERGENCY OPERATION starts Operation frequency of compressor varies 6 To cancel test run operation EMERGENCY OPERATION press EMERGENCY OPERATION switch or any button on remote controller OBH502E ...

Page 20: ...mbient temperature thermistor Cooling Low ambient temperature operation 8 2 R V COIL CONTROL MUZ Heating ON Cooling OFF Dry OFF NOTE The 4 way valve reverses for 5 seconds right before start up of the compressor ON OFF ON OFF Outdoor fan motor Compressor 5 seconds 15 seconds Outdoor fan motor ON OFF COOL 5 seconds HEAT 5 seconds R V coil ON OFF ON or OFF ON or OFF 8 1 OUTDOOR FAN MOTOR CONTROL The...

Page 21: ...How to activate pre heat control 1 Turn OFF the power supply for the air conditioner before making the setting 2 Set the 2nd Dip Switch of SW1 on the outdoor electronic control P C board to ON to activate pre heat control function 1 2 3 4 ON 9 2 CHANGE IN DEFROST SETTING Changing defrost finish temperature 1 Turn OFF the power supply for the air conditioner before making the setting 2 Set the 4th ...

Page 22: ...hen removing the electronic control P C board hold the edge of the board with care NOT to apply stress on the components 5 When connecting or disconnecting the connectors hold the connector housing DO NOT pull the lead wires 3 Troubleshooting procedure 1 First check if the OPERATION INDICATOR lamp on the indoor unit is flashing on and off to indicate an abnormality To make sure check how many time...

Page 23: ...onds Make sure that the indicators on the LCD screen shown in the right figure are all displayed Then release the buttons Press OPERATE STOP ON OFF button of the remote controller the set temperature is displayed with the remote controller headed towards the indoor unit 1 Judgment of indoor outdoor abnormality Before blinking does the left lamp of OPERATION INDICA TOR lamp stay ON for 3 seconds Wh...

Page 24: ...ON again Press RESET button of the remote controller Repair the failure parts The outdoor unit is normal Release the failure mode recall function accord ing to the left mentioned procedure Deleting the memorized abnormal condition After repairing the unit recall the failure mode again according to Setting up the failure mode recall function 10 2 1 Press OPERATE STOP ON OFF button of the remote con...

Page 25: ...ng Lighting The outdoor heat exchanger temperature exceeds 158 F 70 C during cooling or the indoor gas pipe temperature exceeds 158 F 70 C during heating MUZ Check refrigerant circuit and refrigerant amount Check the stop valve 7 time flash Fin temperature 3 times Goes out The fin temperature exceeds 189 F 87 C during opera tion Check around outdoor unit Check outdoor unit air pas sage Refer to 10...

Page 26: ...tion Check the voltage of power supply Replace the power board Bus bar voltage 1 5 times Goes out The bus bar voltage exceeds 400 V or falls to 200 V or below during compressor operating Bus bar voltage 2 Even if this protection stop is performed continuously 3 times it does not mean the abnormality in outdoor power system 6 times Goes out The bus bar voltage exceeds 400 V or falls to 50 V or belo...

Page 27: ...e connecting wire among outdoor elec tronic control P C board noise filter P C board and power board 10 Outdoor unit stops and restarts 3 minutes later is repeated Twice Goes out IPM protection Overcurrent is detected after 30 seconds of compressor start up Reconnect compressor connector Refer to 10 5 How to check inverter compres sor Refer to 10 5 Check of compressor start failure Check the stop ...

Page 28: ...discharge temperature exceeds 212 F 100 C during operation Check refrigerant circuit and refrigerant amount Refer to 10 5 Check of LEV Refer to 10 5 Check of outdoor thermistors 23 4 times Lighting Low discharge temperature protection The frequency of the compressor is kept 80 Hz or more and the discharge temperature is kept under 102 F 39 C for more than 20 minutes Refer to 10 5 Check of LEV Chec...

Page 29: ...ur hands to warm it up Refer to 10 6 Test point diagram and voltage 1 Outdoor electron ic control P C board the chart of thermistor Compressor Measure the resistance between terminals using a tester Temperature 14 104 F 10 40 C Normal 1 24 1 53 Ω Outdoor fan motor Measure the resistance between lead wires using a tester Temperature 14 104 F 10 40 C Color of lead wire Normal RED BLK 13 16 Ω BLK WHT...

Page 30: ...sor winding resistance between the compressor terminals Is the resistance between each terminal normal Yes No Replace the compressor Reconnect the lead wire of compressor and turn on power supply to indoor and outdoor unit 3 minutes later starts EMERGENCY OPERATION Clarify the causes by counting time until the inverter stops 0 to 10 seconds compressor layer short 10 to 60 seconds compressor lock 6...

Page 31: ...oard Is the thermistor normal Refer to 10 6 1 Reconnect the connector of thermistor Turn ON the power supply and press EMERGENCY OPERATION switch No Replace the thermistor except RT64 When RT64 is abnormal replace the outdoor power board Does the unit operate for 10 minutes or more without showing thermistor abnormality OK Cause is poor contact Replace the outdoor electronic control P C board Yes ...

Page 32: ...Replace the 4 way valve Replace the noise filter P C board Yes Replace the electronic control P C board Cooling operation does not work Is there voltage of 208 230 VAC between pin1 and pin 2 at connector CN912 1 Disconnect the lead wire leading to the compressor 2 3 minutes after turning on the power supply start EMERGENCY OPERATION in COOL mode 1 Turn OFF power supply of indoor and outdoor unit a...

Page 33: ...an motor Replace the outdoor electronic control P C board Yes Yes No Fixed to either 5 or 0 VDC No No Yes Is there voltage of 208 230 VAC in the power supply terminal block Check the connecting of parts of main power supply circuit Check the power supply cable Turn ON power supply Is the output voltage from the noise filter P C board 208 230 VAC Replace the noise filter P C board No Yes No Yes Is ...

Page 34: ...tart 1 Replace the compressor Compressor start failure Activate pre heat control Refer to 9 1 PRE HEAT CONTROL No Yes Does the compressor run for 10 seconds or more after it starts Check the refrigerant circuit Check the stop valve Yes No Confirm that 1 4 is normal Electrical circuit check 1 Contact of lead wire leading to compressor 2 Output voltage of the outdoor electronic control P C board and...

Page 35: ...ted or not lighted Replace the inverter P C board or the outdoor electronic control P C board 2 2 Be careful of the residual voltage of smoothing capacitor Turn OFF the power supply Remove the bridge between outdoor terminal block S2 and S3 Turn ON the power supply Is there amplitude of 10 to 20 VDC between outdoor terminal block S2 and S3 Confirmation of serial signal Yes No Is there any error of...

Page 36: ...age of power supply Confirm outdoor unit failure mode recall function Refer to 10 2 2 Blink 5 times Confirm LED1 indication lamp on the outdoor electronic control P C board Replace the power board Blink 9 times Replace the outdoor elec tronic control P C board Turn OFF power supply before removing P C board Confirm LED1 indication lamp on the outdoor electronic con trol P C board Turn ON power sup...

Page 37: ...trength or the installation condition combination of specific conditions such as antennas or wiring Check the followings before asking for service 1 Devices affected by the electromagnetic noise TV sets radios FM AM broadcast shortwave 2 Channel frequency broadcast station affected by the electromagnetic noise 3 Channel frequency broadcast station unaffected by the electromagnetic noise 4 Layout o...

Page 38: ...r Defrost thermistor RT61 MUZ CN661 Discharge temperature thermistor RT62 CN661 Outdoor heat exchanger temperature thermistor RT68 CN661 Rush current relay R V coil 12 VDC 15 V 15 V CN931 CN701 Signal transmission To power board 5 VDC pulse wave GND CN702 Signal reception From power board 5 VDC pulse wave GND power board CN781 CN795 12 VDC pulse wave LEV F801 FUSE T3 15AL250V Ambient temperature t...

Page 39: ... 2 Noise filter P C board MUZ CN912 R V coil 208 230 VAC 60 Hz Output 208 230 VAC 60 Hz Input 208 230 VAC 60 Hz Output F64 FUSE T2AL250V CN902 To power board CN903 To power board CN61 NR64 VARISTOR CN901 To electronic control P C board OBH502E ...

Page 40: ... ground CN5 Primary current detection Connect to the noise filter CN2 Connect to the controller board 1 5 Signal transmission To electronic control P C board 5 VDC pulse wave 2 5 Zero cross signal 3 4 Not used 6 5 15 V 7 5 15 V Signal reception From electronic control P C board 5 VDC pulse wave CN3 Fin temperature thermistor RT64 Red White 1 3 OBH502E ...

Page 41: ...king lever Slide the sleeve Pull the terminal while pushing the locking lever Hold the sleeve and pull out the terminal slowly Photo 2 Photo 1 Photo 3 Screws of the cabinet Screws of the cabinet Screw of the top panel Screws of the top panel Screws of the cabinet Screw of the service panel Screw of the valve cover Set screws of the back panel Screw of the motor support Screws of the back panel Con...

Page 42: ...res on the electronic control P C board 7 Remove the electronic control P C board from the inverter assembly 8 Remove the screws fixing the power board assembly 9 Disconnect all connectors and lead wires on the power board 10 Remove the power board from the inverter assembly 11 Disconnect all connectors and lead wires on the noise filter P C board 12 Remove the noise filter P C board from the inve...

Page 43: ...stor from its holder MUZ 4 Pull out the discharge temperature thermistor from its hold er Photo 4 5 Pull out the outdoor heat exchanger temperature thermistor from its holder 6 Pull out the ambient temperature thermistor from its holder 5 Removing outdoor fan motor 1 Remove the top panel cabinet service panel and the back panel Refer to 1 2 Disconnect the following connectors Electronic control P ...

Page 44: ...oving the reactor 1 Remove the top panel cabinet service panel and the back panel Refer to 1 2 Disconnect the reactor lead wire 3 Remove the screws of the reactor and remove the reactor Photo 9 Brazed parts of 4 way valve R V coil Photo 10 Brazed part of the discharge pipe Brazed part of the suction pipe HEAD OFFICE TOKYO BUILDING 2 7 3 MARUNOUCHI CHIYODA KU TOKYO 100 8310 JAPAN Copyright 2008 MIT...

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