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27

10-4. TROUBLESHOOTING CRITERION OF MAIN PARTS

MUZ-GS30NA  MUZ-GS30NAH  MUZ-GS36NA  MUZ-GS36NAH  MUY-GS30NA  MUY-GS36NA

Part name 

Check method and criterion 

Figure

Defrost thermistor (RT61) 

Fin temperature 
thermistor (RT64)

Ambient temperature 
thermistor (RT65)

Outdoor heat exchanger 
temperature thermistor 
(RT68) 

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. 

Discharge temperature 
thermistor (RT62) 

Measure the resistance with a tester. Before measurement, hold the 
thermistor with your hands to warm it up.

Refer to 10-6. “Test point diagram and voltage”, 1. “Inverter P.C. 
board”, for the chart of thermistor. 

Compressor 

Measure the resistance between terminals using a tester.
[Temperature: 14 - 104°F (-10 - 40°C)]

Normal (Ω)

MUZ-GS30/36  MUY-GS30/36

U-V

U-W

V-W

1.38 - 1.87

Outdoor fan motor 

Measure the resistance between lead wires using a tester.
[Temperature: 14 - 104°F (-10 - 40°C)]

 Color of lead wire 

Normal (Ω)

MUZ-GS30/36  MUY-GS30/36

RED – BLK

BLK – WHT

WHT – RED

8 - 10

R. V. coil (21S4) 

Measure the resistance using a tester.
[Temperature: 14 - 104°F (-10 - 40°C)]

Normal (kΩ)

0.97 - 1.38

Expansion valve coil 
(LEV)

Measure the resistance using a tester. 
[Temperature: 14 - 104°F (-10 - 40°C)]

 Color of lead wire 

Normal (Ω)

RED – ORN

37 - 54

RED – WHT

RED – BLU

RED – YLW

   

RED

(+12V)

YLW

BLU

WHT

ORN

LEV

Defrost heater

Measure the resistance using a tester. 
[Temperature: 14 - 104°F (-10 - 40°C)]

Normal (Ω)

MUZ-GS30/36NAH

376 - 461

W

U

V

WHT

RED BLK

W

U

V

WHT

RED BLK

OBH875A

Содержание MUY-GS30NA

Страница 1: ...INES AND DIMENSIONS 6 5 WIRING DIAGRAM 7 6 REFRIGERANT SYSTEM DIAGRAM 9 7 DATA 11 8 ACTUATOR CONTROL 18 9 SERVICE FUNCTIONS 19 10 TROUBLESHOOTING 20 11 DISASSEMBLY INSTRUCTIONS 40 HFC utilized R410A OUTDOOR UNIT SERVICE MANUAL No OBH875 REVISED EDITION A Indoor unit service manual MSZ GS NA MSY GS NA Series OBH874 OBH875 is void Revision A A warning when opening or closing the valve has been added...

Страница 2: ...ion of the air conditioner turn off the power supply breaker and pull the power plug Discharge the capacitor before the work involving the electric parts Precautions during the repair service Do not perform the work involving the electric parts with wet hands Do not pour water into the electric parts Do not touch the refrigerant Do not touch the hot or cold areas in the refrigeration cycle When th...

Страница 3: ...3 MUZ GS30NA MUZ GS30NAH MUZ GS36NA MUZ GS36NAH MUY GS30NA MUY GS36NA PART NAMES AND FUNCTIONS 2 Air outlet Drain outlet Piping Drain hose Air inlet back and side OBH875A ...

Страница 4: ...ty A 19 Fan motor F L A A 0 93 Compressor Model SNB220FQAM1T R L A A 13 8 L R A A 17 3 Refrigeration oil fl oz L Model 15 6 0 46 FV50S Refrigerant control Linear expansion valve Sound level 1 Cooling dB A 55 56 Heating 3 dB A 57 Defrost method Reverse cycle Dimensions W in 33 1 16 D in 13 H in 34 5 8 Weight Ib NA 121 NAH 122 External finish Munsell 3Y 7 8 1 1 Remote controller Wireless type Contro...

Страница 5: ...ted compressor speed 70 60 17 15 H0 Low Heating Steady State at minimum compressor speed 70 60 62 56 5 H1 Low Heating Steady State at minimum compressor speed 70 60 47 43 H2 Int Heating at intermediate compressor speed 6 70 60 35 33 6 At intermediate compressor speed Rated compressor speed minimum compressor speed 3 minimum compressor speed 4 5 2 OPERATION Mode Condition Intake air temperature F I...

Страница 6: ...ø1 21 32 13 34 5 8 17 25 32 5 16 6 7 8 19 11 16 33 1 16 3 3 16 HANDLE 3 29 32 6 1 2 4 3 3 5 7 11 16 19 32 GAS REFRIGERANT PIPE JOINT LIQUID REFRIGERANT PIPE JOINT SERVICE PANEL VALVE COVER SERVICE PORT 4 in OR MORE BASICALLY OPEN 20 in OR MORE WITHOUT ANY OBSTRUCTION IN FRONT AND BOTH SIDES OF THE UNIT 14 in OR MORE 20 in OR MORE OPEN TWO SIDES OF RIGHT OR REAR SIDE 4 in OR MORE FLARED ø15 88 5 8 ...

Страница 7: ...7 5 WIRING DIAGRAM MUZ GS30NA MUZ GS36NA MUZ GS30NAH MUZ GS36NAH OBH875A ...

Страница 8: ...8 MUY GS30NA MUY GS36NA OBH875A ...

Страница 9: ...6 ø4 0 ø2 4 100 Refrigerant flow in cooling Compressor 4 way valve Refrigerant flow in heating Only MUZ Refrigerant pipe ø5 8 with heat insulator Refrigerant pipe ø1 4 with heat insulator LEV Only MUZ R V coil heating ON cooling OFF Muffler Strainer 100 Outdoor heat exchanger temperature thermistor RT68 Ambient temperature thermistor RT65 Strainer 100 Service port low pressure ACC Service port hig...

Страница 10: ...GS30NA MUY GS36NA 100 50 5 8 1 4 ADDITIONAL REFRIGERANT CHARGE R410A oz NOTE Refrigerant piping exceeding 25 ft requires additional refrigerant charge according to the calculation Model Outdoor unit precharged Refrigerant piping length one way ft 25 30 40 50 60 70 80 90 100 MUZ GS30NA MUZ GS30NAH MUZ GS36NA MUZ GS36NAH MUY GS30NA MUY GS36NA 4 lb 0 oz 0 1 08 3 24 5 40 7 56 9 72 11 88 14 04 16 20 Ca...

Страница 11: ...emperature F IWB F 105 115 TC SHC SHF TPC TC SHC SHF TPC MUZ GS30NA MUZ GS30NAH MUY GS30NA 71 30 7 18 0 0 59 3 67 28 2 16 6 0 59 3 82 67 28 6 20 6 0 72 3 52 26 2 18 9 0 72 3 69 63 26 2 22 4 0 85 3 39 23 9 20 4 0 85 3 52 MUZ GS36NA MUZ GS36NAH MUY GS36NA 208V 71 32 0 17 8 0 56 4 01 29 4 16 4 0 56 4 17 67 29 8 20 5 0 69 3 85 27 4 18 9 0 69 4 03 63 27 4 22 5 0 82 3 70 25 0 20 6 0 82 3 85 MUZ GS36NA M...

Страница 12: ...4 3 3 83 35 4 3 89 40 1 4 04 70 16 7 2 23 21 6 2 81 26 4 3 32 31 2 3 55 35 2 3 74 36 3 3 81 41 0 3 96 65 17 6 2 14 22 2 2 70 27 6 3 21 32 2 3 46 36 3 3 65 37 3 3 70 41 9 3 89 NOTE 1 IDB Intake air dry bulb temperature TC Total Capacity x103 Btu h TPC Total Power Consumption kW 2 Above data is for heating operation without any frost 7 2 PERFORMANCE CURVE Cooling MUZ GS30NA MUZ GS30NAH MUY GS30NA Co...

Страница 13: ...oor intake air DB temperature F 803 CFM Airflow Outdoor intake air WB temperature F Total power consumption kW MUZ GS36NA 65 70 75 5 5 15 25 35 45 55 65 0 2 1 2 2 2 3 2 4 2 5 2 Indoor intake air DB temperature F 803 CFM Airflow Outdoor intake air WB temperature F Total power consumption kW MUZ GS36NAH 65 70 75 5 5 15 25 35 45 55 65 0 3 1 3 2 3 3 3 4 3 Indoor intake air DB temperature F 803 CFM Air...

Страница 14: ... pressure Suction pressure Outdoor ambient temperature Indoor DB temperature F PSIG Indoor DB temperature F Outdoor ambient temperature 86 80 75 70 86 80 75 70 MUZ GS30NA MUZ GS30NAH MUY GS30NA 65 70 75 80 85 90 95 100 105 110 115 200 240 280 320 360 400 440 480 520 560 600 F F 65 70 75 80 85 90 95 100 105 110 115 80 100 120 140 160 PSIG Condensing pressure Suction pressure Outdoor ambient tempera...

Страница 15: ... temperature 5 15 25 35 45 55 65 75 200 240 280 320 360 400 440 480 520 560 600 Indoor DB temperature F 5 15 25 35 45 55 65 75 20 60 100 140 180 220 Indoor DB temperature F MUZ GS36NA MUZ GS36NAH 75 70 65 75 70 65 PSIG Condensing pressure Outdoor ambient temperature F F PSIG Suction pressure Outdoor ambient temperature 5 15 25 35 45 55 65 75 200 240 280 320 360 400 440 480 520 560 600 Indoor DB te...

Страница 16: ...5 3 552 3 692 3 685 Comp current A 12 61 11 41 13 25 11 98 14 42 15 18 15 68 14 18 Fan motor current A 0 84 0 76 0 83 0 75 0 98 0 89 0 83 0 75 Refrigerant circuit Condensing pressure PSIG 423 430 426 452 Suction pressure PSIG 125 97 114 95 Discharge temperature F 175 180 182 185 Condensing temperature F 121 122 121 126 Suction temperature F 49 30 44 29 Comp shell bottom temperature F 164 169 170 1...

Страница 17: ...0 0 0 0 5 1 0 1 5 2 0 0 25 50 75 100 0 0 0 5 1 0 1 5 2 0 0 25 50 75 100 0 0 0 5 1 0 1 5 2 0 0 25 50 75 100 0 0 0 5 1 0 1 5 2 0 MUZ GS36NA MUZ GS36NAH MUY GS36NA 208V 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 frequen...

Страница 18: ...Purpose Actuator Compressor LEV Outdoor fan motor R V coil Indoor fan motor Defrost heater Discharge temperature thermistor Protection Indoor coil temperature thermistor Cooling Coil frost prevention Heating High pressure protec tion Defrost thermistor Heating Defrosting Fin temperature thermistor Protection Ambient temperature thermistor Cooling Low ambient tempera ture operation Heating Defrosti...

Страница 19: ...t cycle and freezes it may interfer the start up of the compressor 2 If liquid refrigerant collects in the compressor a failure in the compressor may occur The pre heat control turns ON when the compressor temperature is 68 F 20 C or below When the pre heat control turns ON the compressor is energized About 70 W Pre heat control setting JK ON To activate the pre heat control cut JK wire of the inv...

Страница 20: ...capacitor 4 When 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 Check if the OPERATION INDICATOR lamp on the indoor unit is blinking on and off to indicate an abnormality To make sure check how ma...

Страница 21: ...e left lamp of the OPERATION INDI CATOR lamp stay ON for 3 seconds When it stays ON for 3 seconds without beep The outdoor unit is abnormal The indoor unit is abnormal Check the blinking pattern and identify the abnormal point by referring to the table of indoor unit failure mode recall function Refer to indoor unit service manual Make sure to check at least 2 consecutive blinking cycles 2 Releasi...

Страница 22: ...ttern and identify the abnormal point by referring to the table of outdoor unit failure mode recall function 10 2 3 Make sure to check at least 2 consecutive blinking cycles 2 Releasing the failure mode recall function Release the failure mode recall function by the following procedures Turn OFF the power supply and turn it ON again Press RESET button of the remote controller Repair the failure pa...

Страница 23: ...pressor Check stop valve Compressor synchronous abnormality Compressor start up failure protection 12 time blink 2 5 seconds OFF Waveform of compressor current is distorted Reconnect compressor connector Refer to 10 5 How to check inverter compressor 5 time blink 2 5 seconds OFF Discharge temperature Temperature of discharge temperature thermistor exceeds 241 F 116 C compressor stops Compressor ca...

Страница 24: ...or thermistor is detected Check the 4 way valve Replace the inverter P C board Refer to TEST POINT DIAGRAM AND VOLTAGE on the service manual of indoor and outdoor unit for the characteristics of the thermistors Do not start the operation again without repair to prevent hazards 16 time blink 2 5 seconds OFF 1 Outdoor refrigerant system abnormality 1 time blink 2 5 seconds OFF A closed valve and air...

Страница 25: ...p valve 9 3 time blink 2 5 seconds OFF Discharge tem perature overheat protection Temperature of discharge temperature thermistor exceeds 241 F 116 C compressor stops Compressor can restart if discharge temperature thermistor reads 212 F 100 C or less 3 minutes later Check refrigerant circuit and refrig erant amount Refer to 10 5 Check of LEV 10 4 time blink 2 5 seconds OFF Fin temperature P C boa...

Страница 26: ...f outdoor thermistors 19 Outdoor unit operates 7 time blink 2 5 seconds OFF Low discharge tem perature protection Temperature of discharge temperature thermistor has been 122 F 50 C or less for 20 minutes Refer to 10 5 Check of LEV Check refrigerant circuit and refrig erant amount 20 8 time blink 2 5 seconds OFF Zero cross detecting circuit Zero cross signal cannot be detected It occurs with follo...

Страница 27: ...Inverter P C board for the chart of thermistor Compressor Measure the resistance between terminals using a tester Temperature 14 104 F 10 40 C Normal Ω MUZ GS30 36 MUY GS30 36 U V U W V W 1 38 1 87 Outdoor fan motor Measure the resistance between lead wires using a tester Temperature 14 104 F 10 40 C Color of lead wire Normal Ω MUZ GS30 36 MUY GS30 36 RED BLK BLK WHT WHT RED 8 10 R V coil 21S4 Mea...

Страница 28: ...ck of open phase C Check of compressor With the connector between the compressor and the power module IC700 disconnected activate the inverter and check if the inverter is normal by measuring the voltage balance between the terminals Output voltage is 50 130 V The voltage may differ according to the tester Operation method Start cooling or heating operation by pressing the emergency operation swit...

Страница 29: ...ier for about 20 minutes Do not recover refrigerant gas while heating Heating part Connect the compressor and activate the inverter Then measure the time until the inverter stops due to overcurrent Operation method Start heating or cooling operation by pressing the emergency operation switch on the indoor unit TEST RUN OPERATION Refer to 7 6 Measurement Measure the time from the start of compresso...

Страница 30: ...r more without showing thermistor abnormality OK Cause is poor contact Yes Yes Disconnect the connector of thermistor in the inverter P C board see below table and measure the resistance of thermistor MUZ GS30 36 MUY GS30 36 Thermistor Symbol Connector Pin No Board Defrost RT61 Between CN671 pin1 and pin2 Inverter P C board Discharge temperature RT62 Between CN671 pin3 and pin4 Fin temperature RT6...

Страница 31: ...er P C board Replace the 4 way valve Unit operates in COOL mode even if it is set to HEAT mode Is there 208 230 V AC between CN602 and on the inverter P C board 3 minutes after the power supply is turned ON Yes No Replace the inverter P C board Replace the 4 way valve Unit operates in HEAT mode even if it is set to COOL mode Disconnect connector between the compressor and the power module IC700 Tu...

Страница 32: ...asure the voltage of CN931 Between 1 and 5 Between 2 and 5 Between 3 and 5 Does the voltage between each terminal become 5 and 0 V DC repeatedly Does the outdoor fan motor rotate smoothly Replace the outdoor fan motor Replace the inverter P C board Yes Yes No Fixed to either 5 or 0 V DC No No Yes Disconnect the connectors CN931 and CN932 from the inverter P C board Check the connection between the...

Страница 33: ...t up Does LED on the inverter P C board light up or blink Refer to 10 6 1 No Replace the inverter P C board Is there bus bar voltage 260 370 V DC between 294 370 V DC between IC700 P and N on the inverter P C board Refer to 10 6 1 No Check the electric parts in main circuit Yes Yes No Disconnect the connector between the compressor and the power module IC700 Turn ON power supply and press the emer...

Страница 34: ...y an analog tester Properly fix the LEV coil to the expansion valve Replace the inverter P C board Replace the LEV coil Replace the expansion valve Is LEV coil properly fixed to the expansion valve Does the resistance of LEV coil have the characteristics Refer to 10 4 Do you hear the expansion valve click click Do you feel the expansion valve vibrate when touching it Turn ON the power supply Prepa...

Страница 35: ...oor fan motor If the connection is poor make it correct Operate the outdoor unit by starting EMERGENCY OPERATION Check the LED indication on the in verter P C board Does the LED blink 10 times Replace the inverter P C board Check the corresponding parts following LED indication Refer to 10 3 Yes No Yes 10 time blink No L Check of inverter P C board OBH875A ...

Страница 36: ...nverter 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 short circuit between out door terminal block S2 and S3 Turn ON the power supply Is there amplitude of 10 to 20 V DC between outdoor terminal block S2 and S3 Confirmation of serial signal Yes No Is there any error of the indoor outdoor con...

Страница 37: ...mistor continue to read 30 F 1 C or below NOTE In case both thermistors are more than the above temperature cool them with cold water etc MUZ GS30NA MUZ GS30NAH MUZ GS36NA MUZ GS36NAH MUY GS30NA MUY GS36NA O Check of outdoor refrigerant circuit Has the operation stopped during pump down Was the operation started with the stop valve closed and was it opened during operation No Yes The operation has...

Страница 38: ...ondition combination of specific conditions such as antennas or wiring Check the following 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 of indoor outdoor unit of the a...

Страница 39: ...oothing Capacitor CB3 Smoothing Capacitor CB2 Smoothing Capacitor CB1 Defrost thermistor RT61 CN671 Ambient temperature thermistor RT65 CN672 Heater CN601 208 230 V AC MUZ GS30 36NAH R V coil 21S4 CN602 208 230 V AC Jumper wire for pre heat controlsetting JK Jumper wire for changing defrost setting JS 4 14 32 50 68 86 104 0 10 20 30 40 50 60 70 80 90 100 Temperature F 32 50 68 86 104 122 140 158 1...

Страница 40: ... back panel Photo 2 Photo 1 40 1 Slide the sleeve and check if there is a locking lever or not 2 The terminal with the connector shown below has the locking mechanism Slide the sleeve Pull the terminal while pushing the locking lever Hold the sleeve and pull out the terminal slowly Connector Sleeve Locking lever Detaching method of the terminal with locking mechanism The terminal which has the loc...

Страница 41: ...s of the terminal block support and the back panel 7 Remove the inverter assembly 8 Remove the screws of the ground wires 9 Remove the screw of the heat sink support and the heat sink support from the P C board support 10 Remove the screws of the terminal block support and the screws of the ground wires Photo 7 11 Remove the terminal block support 41 Photo 3 Screws of the conduit cover Photo 4 Scr...

Страница 42: ...ion valve coil to the connector on the inverter P C board Pull the lead wires of the expansion valve coil toward you and put them on the left hook on the P C board support as shown in Photo 9 Photo 7 Photo 8 Photo 9 42 Screws of the terminal block support Screws of the ground wires and the terminal block support Lead wires of the expansion valve coil Hook of the lead wires of the reactor Hook of t...

Страница 43: ...istor from its hold er Photo 12 4 Pull out the defrost thermistor from its holder 5 Pull out the outdoor heat exchanger temperature thermistor from its holder Photo 10 6 Pull out the ambient temperature thermistor from its holder Photo 10 4 Removing outdoor fan motor 1 Remove the top panel cabinet and service panel Refer to section 1 2 Disconnect the following connectors Inverter P C board CN931 C...

Страница 44: ...he suction and the discharge pipe connected with compressor 6 Remove the compressor nuts 7 Remove the compressor 8 Detach the brazed parts of 4 way valve and pipe Photo 13 Photo 12 Photo 13 44 Brazed part of the discharge pipe Brazed part of the suction pipe Discharge temperature thermistor Brazed parts of 4 way valve Copyright 2021 MITSUBISHI ELECTRIC CORPORATION Issued Jun 2021 No OBH875 REVISED...

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