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["FFailure LED5 Failure description: code Discharging temperature sensor: Outdoor Indoor unit LED status 20 times Td1and Td2 failure digital Outdoor unit LED status display tube: LED1 LED2 23-0,1 Indoor wired Normal Normal controller: 17 Failure diagnosis and troubleshooting Troubleshooting Diagnosis 1. Model MRV 5 series 2. Abnormity detection method Check if the corresponding N Replace it correctly by after- connector of sensor is normal sales personnel on site. \u25c6 Check if the sensor connection is normal; Y \u25c6 Check if resistance characteristic of the sensor is normal; \u25c6 Check if the temperature loop acquired by the PCB is normal. conditions Check if resistance N Replace it correctly by after- characteristic of the sensor sales personnel on site. It is detected that the AD value is normal is below 11 (open circuit) or Y Replace it correctly by after- above 1012 (short circuit) for Y sales personnel on site. 60 seconds continuously. If Ta\u2264-10\u00b0C the open circuit is Check if the temperature detected after 3 minutes of loop acquired by the compressor operation (AD computer board is normal value is below 11). 4. Possible causes \u25c6 The connection of sensor is not secure; \u25c6 The sensor is broken; \u25c6 The sensor is with resistance drift; \u25c6 The temperature acquired by PCB is not accurate. 198","Failure code Indoor unit LED status LED5 Failure description: Outdoor 20 times Oil temperature sensor: digital display Th, Toil1 and Toil2 failure tube: 24-0, 1, 2 Outdoor unit LED status LED1 LED2 Indoor wired Normal Normal Troubleshooting controller: 18 Failure diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the corresponding N Replace it correctly by after- connector of sensor is normal sales personnel on site. \u25c6 Check if the sensor connection is normal; Y N Replace it correctly by after- \u25c6 Check if resistance sales personnel on site. characteristic of the sensor is Check if resistance normal; characteristic of the sensor \u25c6 Check if the temperature is normal loop acquired by the PCB is normal. Y conditions It is detected that the AD value is below 11 (open circuit) or above 1012 (short circuit) for 60 seconds continuously, when Ta\u2264-10\u00b0C, no alarm is given; when ET\u2264-10\u00b0C, no alarm is given within 5 minutes. 4. Possible causes \u25c6 The connection of sensor is Check if the temperature Y Replace it correctly by after- loop acquired by the sales personnel on site. not secure; computer board is normal \u25c6 The sensor is broken; \u25c6 The oil temperature sensor is with resistance drift; \u25c6 The temperature acquired by PCB is not accurate. 199","Failure code LED5 Failure description: Outdoor Heat exchanger inlet temperature: digital Indoor unit LED status 20 times Toci1 failure display tube: Outdoor unit LED status 25-0 LED1 LED2 Troubleshooting Indoor wired controller: Normal Normal 19 Failure diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the corresponding N Replace it correctly by after- connector of sensor is normal sales personnel on site. \u25c6 Check if the sensor connection is normal; Y N Replace it correctly by after- \u25c6 Check if resistance sales personnel on site. characteristic of the sensor is Check if resistance normal; characteristic of the sensor \u25c6 Check if the temperature is normal loop acquired by the PCB is normal. Y Y Replace it correctly by after- sales personnel on site. conditions Check if the temperature loop acquired by the It is detected that the AD value computer board is normal is below 11 (open circuit) or above 1012 (short circuit) for 60 seconds continuously, the cooling mode operates the sensor abnormity without troubleshooting it, and no alarm is given during defrosting and within 3 minutes at the end of defrosting. 4. Possible causes \u25c6 The connection of sensor is not secure; \u25c6 The sensor is broken; \u25c6 The sensor is with resistance drift; \u25c6 The temperature acquired by PCB is not accurate. 200","Failure code LED5 Failure description: Outdoor Communication between indoor unit and digital Indoor unit LED status 20 times outdoor unit failure display tube: Outdoor unit LED status 26-0, 1, 2 LED1 LED2 Indoor wired controller: Normal Normal 1A 1. Model Failure diagnosis and troubleshooting MRV 5 series Diagnosis Troubleshooting 2. Abnormity detection method Check if the communication Y Replace it correctly by after- wire of outdoor unit is shorted sales personnel on site. \u25c6 Grounded short-circuit of communication wire, or N Y Replace it correctly by after- disconnected communication sales personnel on site. wire P and Q; Check if the communication wire \u25c6 Incorrect wiring of of outdoor unit is disconnected Y Replace it correctly by after- communication wire P and Q; sales personnel on site. \u25c6 Uniform indoor unit power N supply, and partial indoor unit being powered off. Check if the communication \u25c6 Larger interference and wire P and Q of indoor and unstable communication signal. outdoor unit is incorrect \u25c6 Failure in PCB of indoor and outdoor unit results in unstable communication. conditions It is not detected that there N Y Adjust it correctly by after- is indoor unit connection for Check if there is same indoor unit No. sales personnel on site. 200 rounds continuously; it is detected that the number N of indoor units is less than set number for 270 seconds continuously; it is detected that the number of indoor units is more than set number for 170 seconds continuously. 4. Possible causes Check if the computer board N Adjust it correctly by after- communication port of indoor sales personnel on site. and outdoor unit is correct \u25c6 Poor communication wire: Y Y Eliminate the interference Check if there is interference source source. short circuit and disconnection; \u25c6 Incorrect wiring of N Replace indoor or outdoor computer board communication wire P and Q P and Q; \u25c6 Poor PCB results poor communication; \u25c6 Larger interference of normal communication. 201","Failure code LED5 Failure description: Outdoor Outdoor compressor oil temperature too digital Indoor unit LED status 20 times high failure(Toil1 and Toil2) display tube: Outdoor unit LED status 27-0, 1 LED1 LED2 Indoor wired controller: Normal Normal 1B 1. Model Failure diagnosis and troubleshooting MRV 5 series Diagnosis Troubleshooting 2. Abnormity detection method Check if the resistance of oil N Replace the oil temperature temperature sensor is correct sensor by after-sales personnel \u25c6 Check if the temperature on site. detected by the oil temperature Y sensor is correct; Y Replace it correctly by after- \u25c6 Check the unit for leakage Check if the refrigerant in the sales personnel on site and ensure refrigerant is enough. \u25c6 Check if the outdoor unit SV31, SV32, LEVb, etc. can be normally turned on; \u25c6 Check the outdoor heat blockage and inlet & outlet air N blockage. \u25c6 Check the indoor heat blockage and inlet & outlet air Check if the outdoor heat N Replace it correctly by after- blockage when cooling. exchange is normal when cooling, sales personnel on site. and check if the indoor conditions heating is normal when heating Toil1\/Toil2\u2265120\u00b0C. 4. Possible causes Y Check if the outdoor unit LEVb, SV31 N Troubleshoot and replace and SV32 can be turned on normally it correctly by after-sales \u25c6 The oil temperature sensor personnel on site. is with resistance drift; Y \u25c6 The refrigerant in the system Check if it is beyond the \u25c6 The outdoor unit LEVb, allowed operation range of unit. SV31, SV32, etc. cannot be turned on normally; Y \u25c6 The unit condensation Use the unit in accordance side is with poor heat transfer with its allowed range. function. \u25c6 The operation environment is beyond the allowed range. 202","Failure code LED5 Failure description: Outdoor High pressure sensor Pd failure digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 28 LED1 LED2 Indoor wired controller: Normal Normal 1C Failure diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the corresponding N Replace it correctly by after- connector of sensor is normal sales personnel on site. \u25c6 Check if the sensor connection is normal; Y N Replace it correctly by after- \u25c6 Check if voltage sales personnel on site. characteristic of the sensor is Check if the voltage normal; characteristic of the sensor \u25c6 Check if the pressure loop is normal acquired by the PCB is normal. Y conditions It is detected that the AD value is below 11 (open circuit) or above 1012 (short circuit) for 30 seconds continuously, and no alarm is given during defrosting and within 3 minutes at the end of defrosting. 4. Possible causes \u25c6 The connection of pressure Check if the pressure loop Y Replace it correctly by after- acquired by the computer sales personnel on site. sensor is not secure; board is normal \u25c6 The pressure sensor is broken; \u25c6 The pressure acquired by PCB is not accurate. 203","Failure code LED5 Failure description: Outdoor Low pressure sensor Ps failure digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 29 LED1 LED2 Indoor wired controller: Normal Normal 1D Failure diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the corresponding N Replace it correctly by after- connector of sensor is normal sales personnel on site. \u25c6 Check if the sensor connection is normal; Y N Replace it correctly by after- \u25c6 Check if voltage sales personnel on site. characteristic of the sensor is Check if the voltage normal; characteristic of the sensor \u25c6 Check if the pressure loop is normal acquired by the PCB is normal. Y conditions It is detected that the AD value is below 11 (open circuit) or above 1012 (short circuit) for 30 seconds continuously, and no alarm is given during defrosting and within 3 minutes at the end of defrosting. 4. Possible causes \u25c6 The connection of pressure Check if the pressure loop N Replace it correctly by after- acquired by the computer sales personnel on site. sensor is not secure; board is normal \u25c6 The pressure sensor is broken; \u25c6 The pressure acquired by PCB is not accurate. 204","Failure code LED5 Failure description: Outdoor High pressure switch HPS1 and HPS2 fail- digital Indoor unit LED status 20 times ure display tube: Outdoor unit LED status 30-0, 1 LED1 LED2 Indoor wired controller: Normal Normal 1E 1. Model Failure diagnosis and troubleshooting MRV 5 series Diagnosis Troubleshooting 2. Abnormity detection method Check if the corresponding connector N Replace it correctly by after- of pressure switch is normal Y sales personnel on site. \u25c6 Check if the pressure switch connection is normal; Y Replace it correctly by after- \u25c6 Check if the pressure switch sales personnel on site. signal loop acquired by the Check if the pressure switch PCB is normal; signal loop acquired by the \u25c6 Check if the pressure switch computer board is normal is turned off usually and the pressure exceeds 4.0MPa N when disconnection; \u25c6 Check if the high pressure Check if the high pressure reaches 4.0MPa side of the system is blocked; when the pressure switch is turned off \u25c6 Check the outdoor fan for normal operation when cooling. conditions The high pressure switch is Y turned off for 2s. 4. Possible causes Check if the high pressure stop Y Rectify it correctly by after- valve is turned on or the high sales personnel on site. pressure side is blocked \u25c6 The connection of pressure N N Rectify it correctly by after- Check the outdoor fan for Y sales personnel on site. switch is not secure; normal operation when cooling Y \u25c6 Pressure switch is broken; Rectify it correctly by after-sales \u25c6 The pressure switch Y personnel on site. Check if the refrigerant is excessive gases enter the system. signal acquired by the PCB is N Notify the user to use it within the incorrect; Check if it is out of the operating range of units. operating range of units by after- \u25c6 The high pressure side of sales personnel. the unit is blocked; \u25c6 The outdoor fan stops operating when cooling; \u25c6 The refrigerant is excessive; \u25c6 It is out of the operating range of units. 205","FFailure LED5 Failure description: code Defrosting temperature sensor failure: Outdoor Indoor unit LED status 20 times Tsco and Tliqsc digital Outdoor unit LED status display tube: LED1 LED2 32-0, 1 Indoor wired Normal Normal controller: 20 Failure diagnosis and troubleshooting Troubleshooting Diagnosis 1. Model MRV 5 series 2. Abnormity detection method Check if the corresponding N Replace it correctly by after- connector of sensor is sales personnel on site. \u25c6 Check if the sensor normal connection is normal; \u25c6 Check if resistance Y characteristic of the sensor is normal; Check if resistance \u25c6 Check if the temperature temperature characteristic of N Replace it correctly by after- loop acquired by the PCB is sales personnel on site. abnormal. the sensor is normal conditions Y N Replace it correctly by after- sales personnel on site. It is detected that the AD value Check if the temperature loop is below 11 (open circuit) or acquired by the computer above 1012 (short circuit) board is abnormal for 60 seconds continuously, the cooling mode operates the sensor abnormity without troubleshooting it, and no alarm is given during defrosting and within 3 minutes at the end of defrosting. 4. Possible causes \u25c6 The connection of sensor is not secure; \u25c6 The sensor is broken; \u25c6 The sensor is with resistance drift; \u25c6 The temperature acquired by PCB is not accurate. 206","Failure code Indoor unit LED status LED5 Failure description: Outdoor 20 times AT24C04 EEPROM communication failure digital display AT24C04 EEPROM data check failure tube: 33-0, 2, 3 Outdoor unit LED status LED1 LED2 IM EEPROM data or communication failure Indoor wired Normal Normal controller: 21 Troubleshooting Diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Turn BM1_1 and M1_2 to \\\"OFF\\\",energize again, and then \u25c6 Incorrect EEPROM data. check if the failure is cleared. conditions Y EEPROM communication Replace EE. error; EEPROM data check error (model ID, checksum, etc.); EEPROM data logic error (wider data range, wrong order, etc.) 4. Possible causes \u25c6 EEPROM is an old version, while the program is a new version. 207","Failure code LED5 Failure description: Outdoor Outdoor compressor discharging tempera- digital Indoor unit LED status 20 times ture (Td1, Td2).too high failure display tube: Outdoor unit LED status 34-0, 1 LED1 LED2 Troubleshooting Indoor wired N Replace the discharging controller: Normal Normal 22 temperature sensor by after- sales personnel on site. 1. Model Diagnosis and troubleshooting N Replace it correctly by after- MRV 5 series Diagnosis sales personnel on site and ensure the refrigerant is enough. 2. Abnormity detection method Check if the resistance of discharging temperature N Replace it correctly by after- \u25c6 Check if the temperature sensor is correct. sales personnel on site. detected via a discharging temperature sensor is correct. Y \u25c6 Check the unit for leakage \u25c6 Check if the outdoor unit Check if the refrigerant in the SV31, SV32, LEVb, etc. can be Y normally turned on; \u25c6 Check the outdoor heat blockage and air inlet & outlet short circuit when cooling. \u25c6 Check the indoor heat blockage and air inlet & outlet Check if the outdoor heat short circuit when heating. exchange is normal when cooling, and check if the conditions indoor heat exchange is Toil1\/Toil2\u2265120\u00b0C. normal when heating. 4. Possible causes Y \u25c6 The oil temperature sensor Check if the outdoor unit N Troubleshoot and replace is with resistance drift; LEVb, SV31 and SV32 cannot it correctly by after-sales \u25c6 The refrigerant in the system be turned on normally. personnel on site. \u25c6 The outdoor unit LEVb, Y SV31 and SV32 cannot be turned on normally. Check if the allowed operation \u25c6 The unit condensation range is exceeded. side is with poor heat transfer function; Y \u25c6 The operation environment Use the unit in accordance with is beyond the allowed range. its allowed operation range. 208","Failure code LED5 Failure description: Outdoor Four-way valve reversing failure digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 35-0, 1 LED1 LED2 Indoor wired controller: Normal Normal 23 Diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the difference between Y Replace it correctly after high and low pressure of Y sales on site and ensure the \u25c6 Check if the difference system exceeds 0.6MPa after Y refrigerant is enough. between high and low pressure start and before failure alarm N of system exceeds 0.6MPa after Troubleshoot if the detection start and before failure alarm; N value of Tsuc or Tdef1\/2 sensor \u25c6 Check if the unit lack of is correct and if the connection is refrigerant. Check if the refrigerant in the system correct. \u25c6 Check the four-way valve of Rectify it correctly by after-sales unit for normal switching and N personnel on site. \u25c6 Check if the detection value of Check if the detection value of low Troubleshoot and rectify high\/low pressure sensor is correct. pressure sensor is correct. it correctly by after-sales \u25c6 Check if the unit is beyond personnel on site. the operation range. N Replace the driver module conditions Check if the four-way valve of correctly. In case of meeting one of the compressor is blocked. following conditions after the four-way valve is energized N for 3min and lasts for 10s, it is judged as switching Check if it operates normally completion: after replacing with a normal \u2022Tsuc-Tdef\u226510\u00b0C driver module. \u2022Pd-Ps\u2265\u03b2Mpa (Tao>-10\u00b0C, \u03b2=0.60;Tao\u2264-10\u00b0C, Y \u03b2=0.40), otherwise, it is judged as failure. Check if the allowed operation range is exceeded. 4. Possible causes Y \u25c6 The detection value of high\/ Use the unit in accordance with low pressure sensor is incorrect; its allowed operation range. \u25c6 The refrigerant in the system \u25c6 The four-way valve cannot be \u25c6 suction pipe is blocked by foreign matters; \u25c6 The detection value of Tsuc or Tdef1\/2 sensor is incorrect; The power module cannot drive the compressor operating normally; \u25c6 The operation environment is beyond the allowed range. 209","Failure code LED5 Failure description: Outdoor Outdoor compressor oil temperature (Toil1, digital Indoor unit LED status 20 times Toil2) too low failure display tube: Outdoor unit LED status 36-0, 1 LED1 LED2 Troubleshooting Indoor wired controller: Normal Normal N Replace the oil temperature 24 sensor by after-sales personnel Diagnosis and troubleshooting on site. 1. Model Diagnosis Replace it correctly by after-sales MRV 5 series personnel on site. N [Note]: Check if it is inserted, 2. Abnormity detection method Check if the resistance of oil connected and intersected with temperature sensor is correct. another compressor, especially \u25c6 Check if the temperature when a single compressor operates. detected by the oil temperature Y sensor is correct. N Replace the poor valve (with \u25c6 Check if the outdoor unit Check if the sensor probe is secure leakage) and fan correctly by SV31, SV32, LEVb, etc. and if the position is correct. after-sales personnel on site. are with abnormal leakage and check if the detected Y N Replace the poor valve (with temperature is correct; leakage) and fan correctly by \u25c6 Check if the shutdown Check if the indoor unit LEV of \u201cOFF\u201d after-sales personnel on site. indoor unit LEV of unit is closed is closed tightly and if the indoor unit tightly, and if the running indoor fan of \u201cON\u201d is normal. N unit fan operates normally. Replace it correctly by after-sales Y personnel on site. conditions Check if the terminal of Check if the computer board Toil1\/Toil2-CT\u226410\u00b0C lasts for outdoor unit LEVb, SV31 N can normally control the related 5min. and SV32 is connected properly or is closed tightly. electronic expansion valve and 4. Possible causes solenoid valve, if not, replace it. Y \u25c6 The probe of oil temperature sensor falls off or is with Check if the outdoor unit LEVa1, 2 unsecure connection; and LEVb are connected properly \u25c6 The probe of oil temperature and correctly when heating. sensor is misplaced; \u25c6 The oil temperature sensor Y is with resistance drift; \u25c6 The outdoor unit LEVb, Check if the unit is filled with SV31 and SV32 are with excessive refrigerant. leakage; \u25c6 The terminal of outdoor Y unit LEVa1, 2 and LEVb is Fill with regular refrigerant in connected incorrectly; accordance with standard quantity. \u25c6 For the unit, there is LEV leakage in shutdown indoor unit and non-operation of fan in operating indoor unit; \u25c6 The system refrigerant is too much \u25c6 The operation environment is beyond the allowed range. 210","Failure code LED5 Failure description: Outdoor Low pressure sensor Ps too low protection digital Indoor unit LED status display tube: Outdoor unit LED status 20 times 39-0 Indoor wired LED1 LED2 controller: 27 Normal Normal 1. Model Diagnosis and troubleshooting MRV 5 series Diagnosis Troubleshooting 2. Abnormity detection method Check if the low pressure Y Replace it correctly by after- of system is below 0.05MPa sales personnel on site and \u25c6 Check if the low pressure of before failure alarm; ensure the refrigerant is enough. system is below 0.06MPa before failure alarm; Y N Rectify it correctly by after-sales \u25c6 Check if the unit lack of personnel on site. refrigerant. Check if the refrigerant in the system \u25c6 Check if the pipelines on the low pressure side or liquid side N of the unit are blocked; \u25c6 Check if the detection value Check if the detection value of low of low pressure sensor is correct. pressure sensor is correct. \u25c6 Check if the unit is beyond the operation range. conditions Alarm to shut down if the Y Y Troubleshoot and rectify it correctly followings are detected for by after-sales personnel on site. 5min: cooling: Ps< 0.10Mpa; Check if the pipelines on the heating: Ps< 0.05Mpa; oil low pressure side or liquid [Note]: Check if all stop valves can return: Ps<0.03Mpa after the side of the unit are blocked. compressor operates. (except be turned on and if the air-returning residual operation) 4. Possible causes N N Check if all the electronic expansion valves of the indoor unit \u25c6 The detection value of low Check if the allowed operation can be turned on normally. pressure sensor is incorrect; range is exceeded. \u25c6 The refrigerant in the system Y with air leakage; Use the unit in accordance with \u25c6 The pipelines on the low its allowed operation range. pressure side or liquid side of the unit are blocked; \u25c6 The outdoor unit cannot be turned on normally due to failure to open electronic expansion of outdoor heat exchanger when heating; \u25c6 The operation environment is beyond the allowed range. 211","Failure code LED5 Failure description: Outdoor Compressor ratio \u03b5 too high protection digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 39-1 LED1 LED2 Indoor wired controller: Normal Normal 27 Diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the system operating Y Use the unit in accordance with compression ratio is above 8 N its allowed operation range. \u25c6 Check if the operating before failure alarm. Y compression ratio of system is N Rectify it correctly by after-sales above 8 before failure alarm; Y personnel on site. \u25c6 Check if the unit lack of refrigerant. Check if the refrigerant in the system Troubleshoot and rectify it correctly \u25c6 Check if the pipelines on the by after-sales personnel on site. low pressure side or liquid side N [Note]: Simultaneously, check if all are blocked; stop valves can be turned on. \u25c6 Check if the detection value Check if the detection value of high- of high\/low pressure sensor is low pressure sensor is correct. Check if all the electronic correct. expansion valves of the indoor unit \u25c6 Check if the unit is beyond Y can be turned on normally. the operation range. Check if the pipelines on the conditions low pressure side or liquid side of the unit are blocked. Alarm to shut down if the compression ratio \u03b5 8.0 is N detected for continuous 5min after the compressor operates; Check if the allowed operation alarm to shut down if the range is exceeded. compression ratio \u03b5>9.0 or \u03b5>8.5 when cooling or heating Y for 1min separately. Use the unit in accordance with its allowed operation range. 4. Possible causes \u25c6 The detection value of high\/ low pressure sensor is incorrect; \u25c6 The refrigerant in the system with air leakage; \u25c6 The pipelines on the high pressure side or liquid side of the unit are blocked; \u25c6 The outdoor unit cannot be turned on normally due to failure to open electronic expansion of outdoor heat exchanger when heating; \u25c6 The operation environment is beyond the allowed range. 212","Failure code LED5 Failure description: Outdoor High pressure sensor Pd too high protec- digital Indoor unit LED status 20 times tion display tube: Outdoor unit LED status 40 LED1 LED2 Troubleshooting Indoor wired N Replace it correctly by after- controller: Normal Normal 28 sales personnel on site. Diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the voltage characteristic of the corresponding pressure sensor is normal. \u25c6 Check if the high pressure Y N Replace it correctly by after- acquired by the PCB is sales personnel on site. correct; Check if the pressure sensor \u25c6 Check if the voltage signal acquisition loop of the characteristic corresponding computer board is normal. to the pressure sensor is correct; Y \u25c6 Check if the high pressure side of the system is blocked; Check if the high pressure reaches \u25c6 Check the outdoor fan 4.0MPa upon failure alarm. for normal operation when cooling. conditions Y Y Rectify it correctly by after-sales Check if the high pressure stop personnel on site. The high pressure switch is valve is turned on or the high turned off for 2s. pressure side is blocked. N Rectify it correctly by after-sales personnel on site. 4. Possible causes N Rectify it correctly by after-sales \u25c6 The pressure sensor is Check the outdoor fan for normal Y personnel on site. broken; operation when cooling. \u25c6 The pressure sensor signal including the noncondensable gas acquired by the PCB is incorrect; Y \u25c6 The high pressure side of the Check if the refrigerant is excessive. Notify the user to use it within the unit is blocked; Y operating range of units by after- \u25c6 The outdoor fan stops N operating when cooling; sales personnel. \u25c6 The refrigerant is excessive; Check if the allowed operation \u25c6 It is out of the operating range range is exceeded of units. 213","Failure code LED5 Failure description: Outdoor Outdoor unit compressor discharging tem- digital Indoor unit LED status 20 times perature (Td1, Td2) too low failure display tube: Outdoor unit LED status 43-0, 1 LED1 LED2 Indoor wired controller: Normal Normal 2B Diagnosis and troubleshooting Troubleshooting 1. Model Diagnosis N Replace the discharging MRV 5 series temperature sensor by after- sales personnel on site. 2. Abnormity detection method Check if the resistance of discharging temperature sensor is correct. \u25c6 Check if the temperature Y Replace it correctly by after-sales detected by the oil temperature sensor is correct. Check if the sensor probe is secure personnel on site. \u25c6 Check the outdoor unit and if the position is correct. SV31, SV32, LEVb, etc. for N [Note]: Check if it is inserted, abnormal leakage and check Y connected and intersected with if the detected temperature is correct; Check if the indoor unit LEV of \u201cOFF\u201d another compressor, especially \u25c6 Check if the shutdown is closed tightly and if the indoor unit indoor unit LEV of unit is closed fan of \u201cON\u201d is normal. when a single compressor operates. tightly, and if the running indoor unit fan operates normally. Y N Replace the poor valve (with leakage) and fan correctly by after- conditions Check if the terminal of outdoor unit sales personnel on site. terminal LEVb, SV31 and SV32 is Td1\/Td2-CT\u226410\u00b0C lasts for connected properly or is closed tightly. N Replace the poor valve (with 5min. leakage) and fan correctly by after- Y sales personnel on site. 4. Possible causes Check if the outdoor unit LEVa1, N Replace it correctly by after-sales \u25c6 The probe of oil temperature 2 and LEVb are connected personnel on site. sensor falls off or is with properly and correctly. unsecure connection; N Check if the computer board \u25c6 The probe of oil temperature Y can normally control the related sensor is misplaced; Check if the unit is filled with \u25c6 The oil temperature sensor excessive refrigerant. electronic expansion valve and is with resistance drift; \u25c6 The outdoor unit LEVb, Y solenoid valve, if not, replace it. SV31 and SV32 are with Fill with refrigerant in leakage; accordance with standard \u25c6 The terminal of outdoor quantity. unit LEVa1, 2 and LEVb is connected incorrectly; \u25c6 For the unit, there is LEV leakage in shutdown indoor unit and non-operation of fan in operating indoor unit; \u25c6 excessive refrigerant. \u25c6 The operation environment is beyond the allowed range. 214","Failure code LED5 Failure description: Outdoor Communications between outdoor units digital Indoor unit LED status 20 times failure. display tube: Outdoor unit LED status 45 LED1 LED2 Troubleshooting Indoor wired N Replace it correctly by after- controller: Normal Normal 2D sales personnel on site. 1. Model Diagnosis and troubleshooting MRV 5 series Diagnosis 2. Abnormity detection method Check if the communication wire between the outdoor units is normal. \u25c6 Incorrect order of outdoor Y N Reset it correctly by after- communication wire; sales personnel on site. \u25c6 Incorrect wiring of outdoor Check if the address DIP switch communication wire; of outdoor unit is correct. Clear the interference \u25c6 Incorrect terminal source. connection of outdoor Y communication wire; \u25c6 Incorrect setting of address Check if there is interference source in the Y dip switch of outdoor unit; position where the outdoor unit is installed. conditions No communication for 30s (E) 4. Possible causes \u25c6 Poor communication N Power off the outdoor unit and research it. wire: short circuit or N disconnection; Replace the outdoor unit PCB \u25c6 Non-corresponding communication wire A, B and C; \u25c6 Incorrect connection of outdoor unit communication port of PCB; \u25c6 Interference source, which causes unstable communication of outdoor unit. 215","Failure code LED5 Failure description: Outdoor Communication with INV1 and INV2 module digital Indoor unit LED status 20 times board failure display tube: Outdoor unit LED status 46-0, 1 LED1 LED2 Troubleshooting Indoor wired N controller: Normal Normal 2E Replace it correctly by after- sales personnel on site. 1. Model Diagnosis and troubleshooting MRV 5 series Diagnosis 2. Abnormity detection method Check if the interface board is connected with the wiring harness of variable frequency board correctly. \u25c6 Check if the communication Y wire correspondence of inverter module is correct; \u25c6 Check if the communication wire is disconnected; conditions Check if the communication wire Y Replace it correctly by after- No communication for 30s is disconnected; sales personnel on site. 4. Possible causes N \u25c6 Poor communication wire: Test if the voltage of the two Y Replace the interface central needles of CN28 and board of outdoor unit. disconnection; CN57 changes by a multimeter. \u25c6 Incorrect correspondence of INV1 and INV2; incorrect connection of outdoor unit communication port of PCB; \u25c6 Poor inverter board or connection board 216","Failure code LED5 Failure description: Outdoor Communication with fan motor module digital Indoor unit LED status 20 times board 1, 2 failure display tube: Outdoor unit LED status 46-4, 5 LED1 LED2 Troubleshooting Indoor wired N controller: Normal Normal 2E Replace it correctly by after- sales personnel on site. 1. Model Diagnosis and troubleshooting Y Replace it correctly by after- MRV 5 series Diagnosis sales personnel on site. 2. Abnormity detection method Check if the connection of fan motor communication wire and \u25c6 Check if the communication compressor module wire is correct wire correspondence of fan motor is correct; Y \u25c6 Check if the communication wire is disconnected; Check if the communication wire \u25c6 Check if the driver module of fan motor is disconnected; whitch power supply to the fan motor is powered conditions Fan motor has a host computer N or compressor inverter, no communication for 30s 4. Possible causes Test if the voltage of the two N Replace the interface central needles of CN28 and CN57 changes by a multimeter. board of outdoor unit. \u25c6 Poor communication wire: Y disconnection; Check if the compressor module \u25c6 Incorrect correspondence connected with the fan motor is OK of INV1 and INV2; incorrect N connection of outdoor unit communication port of PCB; \u25c6 Poor inverter board or connection board Replace the compressor module 217","Failure code LED5 Failure description: Outdoor Communication with wireless communicai- digital Indoor unit LED status 20 times ton module failure display tube: Outdoor unit LED status 47 LED1 LED2 Troubleshooting Indoor wired controller: Normal Normal 2F Diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method \u25c6 Check if the dip switch of Check if the dip switch of BM2-1 and N Change the dip switch by BM2-1 and BM2-2 is correct BM2-2 is OFF position after-sales personnel on site. conditions Can\u2019t detect the wireless communication module within 120 seconds continuously, alarm 4. Possible causes \u25c6 The dip switch of BM2-1 and BM2-2 is wrong 218","Failure code LED5 Failure description: Outdoor LEVa1,2 and LEVb,c over current protection digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 51-0,1,2,3 LED1 LED2 Indoor wired controller: Normal Normal 33 Diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method \u25c6 LEV driver chip detection Check if the wires of electronic Y Replace electronic expansion expansion valve coil is short valve coil conditions circuit LEV driver chip detection Y 4. Possible causes N Replace PCB \u25c6 The wires of electronic Check if the PCB LED3 is expansion valve coil short expansion valve is operating circuit \u25c6 LEV drive output circuit anomalies 219","Failure code LED5 Failure description: Outdoor LEVa1,2 and LEVb,c open circuit digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 52-0,1,2,3 LED1 LED2 N Indoor wired controller: Normal Normal Reconnected by after-sales 34 personnel on site. Diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the electronic expansion valve coil terminal plug well \u25c6 LEV driver chip detection Y Y Replace the electronic expansion valve coil by after- conditions Check if the electronic expansion sales personnel on site. LEV driver chip detection valve coil harness, the terminal is 4. Possible causes good \u25c6 The electronic expansion valve coil connector is N disengaged or misplaced \u25c6 Electronic expansion valve Check whether the PCB LEV Y coil harness breaks circuit is damaged \u25c6 LEV drive circuit is open Replace PCB 220","Failure code LED5 Failure description: Outdoor Emergency stop function switch failure digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 74 LED1 LED2 Indoor wired controller: Normal Normal 4A Diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method \u25c6 Check if the CN18 is open circuit conditions If the PCB CN18 is short N Short circuit the CN18 circuit 4. Possible causes \u25c6 CN18 is open circuit 221","Failure code LED5 Failure description: Outdoor Pressure difference between high and low digital Indoor unit LED status 20 times pressure too low failure display tube: Outdoor unit LED status 75-0 LED1 LED2 Troubleshooting Indoor wired controller: Normal Normal 4B Diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the high-low pressure Y Replace it correctly by after-sales difference of system exceeds 0.4MPa personnel on site and ensure the \u25c6 Check if the difference after start and before failure alarm; refrigerant is enough. between high and low pressure of system exceeds 0.4MPa after N Rectify it correctly by after-sales start and before failure alarm; personnel on site. \u25c6 Check if the unit lack of Check if the refrigerant in the system Check if the corresponding pressure refrigerant. sensor is intersected with another \u25c6 Check the four-way valve of N N compressor, especially for a double unit for normal switching and Check if the detection value of low Y compressor system. pressure sensor is correct. \u25c6 Check if the detection value Troubleshoot and replace it correctly of high\/low pressure sensor is Y by after-sales personnel on site. correct. [Note]: Check if the suction pipe \u25c6 Check if the unit is beyond If the four-way valve of outdoor unit is filter of compressor is blocked, when the operation range. with backflow and if the suction pipe the discharging temperature rises obviously. conditions N N N Replace the driver module 75-0: Pd-Ps\u22640.1Mpa within 1min Check if it operates normally correctly. upon the INV compressor starts. after replacing a normal driver 75-4: Pd-Ps\u22640.4Mpa lasts for module. Replace the inverter compressor 3min. if the high-low pressure difference Y cannot reach 0.4MPa above before 4. Possible causes failure alarm. if the allowed operation range is exceeded. \u25c6 The detection value of high\/low pressure sensor is Y incorrect; Use the unit in accordance with \u25c6 The refrigerant in the system its allowed operation range. \u25c6 The four-way valve cannot be switched normally or with The power module cannot drive the compressor operating normally; \u25c6 The inverter compressor is with serious inter deterioration, difference between high and low pressure. \u25c6 The operation environment is beyond the allowed range. 222","Failure code LED5 Failure description: Outdoor Incorrect settings of quantity, address or digital Indoor unit LED status 20 times capacity for outdoor unit display tube: Outdoor unit LED status 76-0, 1, 2 LED1 LED2 Troubleshooting Indoor wired controller: Normal Normal 4C Diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the horse power of Y Research and lock the outdoor unit changes. outdoor unit. \u25c6 Check if the quantity of outdoor unit changes; (76-0) N Y \u25c6 Check if the address of Check if the quantity of Research and lock the outdoor unit changes; (76-1) outdoor unit changes. outdoor unit. \u25c6 Check if the horse power of outdoor unit changes.(76-2) N conditions Quantity of sub-unit setting does not conform to host EEPROM data; address of sub- unit setting does not conform to host EEPROM data; horse power setting of sub-unit does not conform to host EEPROM data. 4. Possible causes \u25c6 The quantity of connected Check if the address setting of Y Replace it correctly by after-sales outdoor unit is correct. personnel on site. Research and unit changes; lock the unit. \u25c6 The horse power of outdoor unit of the same system changes; \u25c6 The address setting of the same system changes; 223","Failure code LED5 Failure description: Outdoor Outdoor unit model are set incorrectly digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 83 LED1 LED2 Indoor wired controller: Normal Normal 53 Failure diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the dip switch setting is Y Adjusting the setting and re- correct search outdoor and locked conditions N N Replace the PCB Check if the BM3-1 \/ 2\/3 dip switch is conduction state Y Set the BM3-1 \/ 2\/3 dial repeatedly to ensure the disconnected status 4. Possible causes \u25c6 BM3-1 \/ 2\/3 dip switch setting wrong or bad continuity. 224","Failure code LED5 Failure description: Outdoor Compressor module hardware over current digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 110-0 ,1 LED1 LED2 N Rectify on site by after-sales Indoor wired controller: Normal Normal personnel. 6E Failure diagnosis and troubleshooting N Rectify on site by after-sales 1. Model Diagnosis personnel. MRV 5 series N Replace on site by after-sales personnel. 2. Abnormity detection method Check if the supply voltage is normal Y N \u25c6 Check if the modules are in Replace the compressor. normal conditions and if P and Check if the electrical cabinet and N are short-circuited to U, V compressor wires are secured, the N and W. UVW is correctly connected and Detect by exclusion. \u25c6 Check if the modules are the variable frequency board and module board are wired correctly. dissipation is good; \u25c6 Check if the compressor Y resistance is normal, Check if the power module is normal \u25c6 Check if the compressor wiring UVW is wrongly Y connected and if the inverter Check if there is other failure, board and module board are 112, and 114 wired securely. Y conditions Check if the compressor, resistance and insulation are normal Over current of module hardware Y Troubleshoot each failure. 4. Possible causes \u25c6 The module alarms FO failure due to poor heat dissipation; \u25c6 The module alarms failure as it is broken down; \u25c6 Liquid shock is found in compressor, which results in over current upon starting or operating; \u25c6 The winding resistance of compressor is large; \u25c6 UVW wiring is wrongly connected or the inverter board and module board are wired insecurely. 225","Failure code LED5 Failure description: Outdoor Fan motor module hardware over current digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 110-4, 5 LED1 LED2 N Rectify on site by after-sales Indoor wired controller: Normal Normal personnel. 6E Failure diagnosis and troubleshooting N Rectify on site by after-sales 1. Model Diagnosis personnel. MRV 5 series 2. Abnormity detection method Check if the supply voltage is normal \u25c6 Check if the motor DC +\/- Y loop is short circuit; Check if electrical box wiring is \u25c6 Check fan blade load is correct, the fan wire is securely stuck, rotation is smooth; connected \u25c6 Check if the compressor resistance is normal, \u25c6 Check the motor resistance is normal; conditions Y N Rotate the fan by hand, check if Replace fan motor Fan built-in drive hardware over- current rotation is smooth N Y Check the capacitor 4. Possible causes board voltage Left and right fan DC + (red \u25c6 The power supply of fan line), DC- (white line) voltage is N motor capacitor board is poor Detect by exclusion. \u25c6 Fan blade load is stuck. normal DC540V \u25c6 Motor built-in driver is not good Y Is there any other fault 112,114? 226","Failure code LED5 Failure description: Outdoor Compressor out of control digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 111-0 ,1 LED1 LED2 N Replace on site by after-sales Indoor wired controller: Normal Normal personnel. 6F N Replace on site by after-sales 1. Model Failure diagnosis and troubleshooting personnel. MRV 5 series Diagnosis N Replace the variable frequency control board. 2. Abnormity detection method Check if the supply voltage is normal N \u25c6 Check if the module is in Y Replace the power module. normal conditions and if P and N is short-circuited to U, V and Check if the electrical cabinet and N W; Measure with diode to see if compressor wires are secured, the Replace the compressor. there is a voltage drop between UVW is correctly connected and P\/N and U\/V\/W. the variable frequency board and \u25c6 Check if the module is module board are wired correctly. dissipation is good; Y \u25c6 Check if the compressor Check if the PWM signals winding is normal. from 6 channels on variable \u25c6 Check if the compressor frequency control board and wiring UVW is connected IPM driver board are normal. correctly and the inverter board and module board is securely wired. conditions Y Over current of module Check if the power module is normal hardware Y 4. Possible causes Check if the compressor, resistance \u25c6 The module alarms failure and insulation are normal as it broke down; \u25c6 Liquid shock is found in Y compressor which results in The compressor is overloading over current upon starting or and check for the causes. operating; \u25c6 The compressor winding is burned out; \u25c6 UVW wiring is wrongly connected or the inverter board and module board are wired insecurely. 227","Failure code LED5 Failure description: Outdoor Compressor module radiator temp. too high digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 112-0 ,1 LED1 LED2 Indoor wired controller: Normal Normal 70 Failure diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the cooling fan rotates N Troubleshoot the fan and PCB and the sensor is normal terminal for 220V voltage output. \u25c6 Check if the radiator is in normal conditions; Y N Secure the module and paint \u25c6 Check if the cooling fan is in with radiating silica gel evenly. normal conditions; Check if the module is \u25c6 Check if the radiator sensor secured and the cooling N is in normal conditions. silica gel is even up Replace the power module. conditions Y Raise failure alarm when Check if has 117 failure temperature \u226594\u00b0C. INV control board recovers Y automatically when Compressor overload to temperature \u226494\u00b0C. check the cause of over load 4. Possible causes \u25c6 The module is insecurely heat dissipation; \u25c6 The radiator sensor is broken which results in high detection temperature; \u25c6 The cooling fan fails to operate; \u25c6 There is no 220V output from the terminal of cooling fan of PCB. 228","Failure code LED5 Failure description: Outdoor Fan motor module radiator temp. too high digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 112- 4, 5 LED1 LED2 Indoor wired controller: Normal Normal 70 Failure diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if outdoor fan can rotate N Check whether the outdoor Y fan stuck, damaged, adjust the \u25c6 Check if the radiating of the replace fan fan motor aluminum radiator is good \u25c6 Check if the fan is good conditions Check if the fan rotation is N smooth Check the fan blocked reason Motor built-in IGBT bottom Y N radiator temperature reaches Replace fan motor 95.65 degree; When 112 fault occurs, whether the motor at high 4. Possible causes speed \u25c6 Motor built-in IGBT radiating Y poor; \u25c6 Outdoor fan does not turn or The motor is overloaded stuck and check the reason 229","Failure code LED5 Failure description: Outdoor Compressor module DC BUS under voltage digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 114-0 ,1 LED1 LED2 Indoor wired controller: Normal Normal 72 Failure diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the supply voltage is normal N Adjust the supply voltage or and the cabinet is wired correctly. N rewire the cabinet in accordance \u25c6 Check if the power with circuit diagram. voltage is too low and results Y in voltage decrease after Adjust or replace the power Check if the power relay and relay. \u25c6 Check if the PTC is in PTC is contacted. normal conditions; \u25c6 Check if the cabinet is correctly wired. conditions Y Y The detection circuit of variable frequency board is damaged, Raise failure alarm when Test if the voltage of DC bus is replace the board. power voltage<DC420V. below 420V. INV control board recovers automatically when voltage N >DC420V Replace and compare the neighboring electrical cabinet 4. Possible causes by troubleshooting. \u25c6 Incorrect wiring may result in under voltage alarm; \u25c6 PTC or relay damage may result in under voltage; \u25c6 Low power voltage may result in under voltage. 230","Failure code LED5 Failure description: Outdoor Fan motor module DC BUS under voltage digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 114-4, 5 LED1 LED2 Indoor wired controller: Normal Normal 72 Failure diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the supply voltage is normal N Adjust the supply voltage or and the cabinet is wired correctly. N rewire the cabinet in accordance \u25c6 Check the power supply with circuit diagram. voltage is too low, resulting Y in reduced voltage after Replace the compressor module Check if the PTC and SCR is \u25c6 Check if the PTC is in damaged. normal conditions; \u25c6 Check if the cabinet is correctly wired. conditions Y Y Replace the fan motor When the power voltage When the fan running, testing the <DC283V, fault and alarm. DC voltage between DC + (red Voltage> DC283V, the line), DC- (white line) if it less motor built-in control panel than 283? automatically restored N 4. Possible causes Check the rectifier bridge, \u25c6 Incorrect wiring may result reactor, electrolytic capacitor in under voltage alarm; of inverter main circuit \u25c6 PTC or SCR damage may result in under voltage; \u25c6 Low power voltage may result in under voltage. 231","Failure code LED5 Failure description: Outdoor Compressor module DC BUS over voltage digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 115-0, 1 LED1 LED2 Indoor wired controller: Normal Normal 73 Failure diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the supply voltage is normal. N Adjust the supply voltage. N \u25c6 Check if the power voltage Y Y Rewire the cabinet in accordance is too high and results in over Check if the cabinet is wired correctly. with wiring diagram. \u25c6 Check if the cabinet is Y The detection circuit of variable correctly wired. frequency board is damaged. Test if the voltage of DC bus is above 642V. Replace the board. conditions N Raise failure alarm when Replace and compare the power voltage>DC642V. neighboring electrical cabinet INV control board recovers by troubleshooting. automatically when voltage <DC642V. 4. Possible causes \u25c6 Incorrect connection may result in over voltage alarm; \u25c6 High power voltage may result in over voltage. 232","Failure code LED5 Failure description: Outdoor Compressor module software over current digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 117-0, 1 LED1 LED2 N Indoor wired controller: Normal Normal Adjust the supply voltage. 75 N 1. Model Failure diagnosis and troubleshooting accordance with the circuit diagram. MRV 5 series Diagnosis N 2. Abnormity detection method Replace the power module. Check if the supply voltage is normal. N Replace the variable frequency \u25c6 Check if the compressor is Y board. insecurely connected; Check if the electrical \u25c6 Check the system for liquid cabinet is wired correctly, the compressor matches shock. U, V and W correctly \u25c6 Check if the module is in and the variable frequency board and module board normal conditions and subject is connected securely. to short circuit. \u25c6 Check if the compressor is well. \u25c6 Check if the compressor wiring UVW is connected correctly and the inverter board and module board is securely wired. conditions Y Over current of module software Check if the power module is normal. 4. Possible causes Y Check if the detection circuit of variable frequency board is normal. \u25c6 The current detection Y loop of inverter board is in poor performance, which Check if the winding and insulation N results in rapid current rise of compressor; of compressor is normal. Replace the compressor. \u25c6 Damage or liquid shock is found in compressor, which Y results in over current; \u25c6 UVW wiring is wrongly Replace and compare the connected or the inverter board neighboring electrical cabinet and module board are wired by exclusion method insecurely. 233","Failure code LED5 Failure description: Outdoor Fan motor module software over current digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 117- 4, 5 LED1 LED2 N Indoor wired controller: Normal Normal Adjust the supply voltage. 75 1. Model Failure diagnosis and troubleshooting MRV 5 series Diagnosis 2. Abnormity detection method Check if the supply voltage is normal. Y \u25c6 Check if the fan motor Check if the electrical N cabinet is wired correctly, accordance with the circuit diagram. strong electricity wire is the variable frequency board and module board insecurely connected; is connected securely. \u25c6 Fan rotation is smooth \u25c6 Check if the module is normal, if short circuit conditions Y N Double fan: fan running current Replace the fan motor value over 5.5A, single fan: fan Motor rotation is smooth, the sound running current value over 6A is normal N 4. Possible causes Y Replace the fan motor \u25c6 Fan motor is poor Running current value is normal \u25c6 Fan blade overload Y Replace and compare the neighboring electrical cabinet by exclusion method 234","Failure code Indoor unit LED status LED5 Failure description: Outdoor 20 times Current detecting circuit abnormal of com- digital pressor module display tube: Outdoor unit LED status LED1 LED2 119-0, 1 Normal Normal Troubleshooting Indoor wired controller77 Failure diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the inverter module is Correct the connection in connected to the three phase lines, N accordance with the wiring \u25c6 Check if the current U (red), V (white) and W (black) sensor is reversely correspondingly on compressor? diagram and ensure negative connected and U and W is in phase and phase loss are not reverse direction. Y found. \u25c6 Check if the current sensor is in reverse Check if the current sensor N Correct the connection in direction. (the arrow detects the current of U phase accordance with the wiring on sensor points at the and W phase? diagram. compressor) \u25c6 Check if the inverter Y N Correct the connection in board is well. Check if the screen printed accordance with the wiring \u25c6 Check if the current arrow on current sensor diagram. sensor is well. points to the compressor? N Correct the connection in conditions Y accordance with the wiring diagram. The current detection sensor Check if the harness terminal of inverter control board of current sensor is connected is in abnormal conditions, correspondingly to the inverter disconnected or connected controlling board? Is the incorrectly. connection reliable? 4. Possible causes Y \u25c6 The inverter board and After power on and before current sensor is anti- connected or the current operation, test the DC sensor is in incorrect direction. voltage between the second \u25c6 The inverter board or current sensor is damaged. pin (black, earth wire) and N Replace the current sensor third pin (brown, signal wire) with abnormal signal voltage. of the wiring harness terminal of the two current sensors, is within 3V\u00b10.2V? To be continued 235","Continued Indoor unit LED status LED5 Failure description: 20 times Current detecting circuit abnormal of com- Failure code pressor module Outdoor Outdoor unit LED status LED1 LED2 digital Normal Normal Troubleshooting display tube: 119-0, 1 Failure diagnosis and troubleshooting Indoor wired controller77 Diagnosis 1. Model MRV 5 series 2. Abnormity detection method Check if there is audible sound N Replace the inverter control when the compressor starts board with abnormal current \u25c6 Check if the current before the 119 failure alarm. detection loop. sensor is reversely (Note: the duration is about 1s.) connected and U and W is in reverse direction. Y \u25c6 Check if the current sensor is in reverse After power supply and N Replace the current sensor direction. (the arrow upon compressor start, test with abnormal signal voltage. on sensor points at the the DC voltage between the compressor) second pin (black, earth wire) \u25c6 Check if the inverter and third pin (brown, signal board is well. wire) of the wiring harness \u25c6 Check if the current terminal of the two current sensor is well. sensors, confirm if the signal voltage is between conditions 1V and 5V? The current detection sensor Y N Correct the wrong of inverter control board connection. is in abnormal conditions, between inverter control disconnected or connected board CN10 and module incorrectly. driver board CNDR15V1 is reliably connected? 4. Possible causes \u25c6 The inverter board and Y N current sensor is anti- Confirm if the wiring harness Correct the wrong connection. connected or the current between inverter control board sensor is in incorrect CN9 and module driver board direction. CNDR1 is reliably connected? \u25c6 The inverter board or current sensor is damaged. To be continued 236","Continued Indoor unit LED status LED5 Failure description: 20 times Current detecting circuit abnormal of Failure code compressor module Outdoor digital Outdoor unit LED status LED1 LED2 display tube: Normal Normal Troubleshooting 119-0, 1 Indoor wired Failure diagnosis and troubleshooting controller77 Diagnosis 1. Model MRV 5 series 2. Abnormity detection method \u25c6 Check if the current sensor Replace the corresponding Y Replace the abnormal is reversely connected and U control boards on failure unit inverter control board or and W is in reverse direction. with inverter control board module driver board. \u25c6 Check if the current sensor and module driver board is in reverse direction. (the respectively and check if the Y Replace the abnormal arrow on sensor points at the control board is in abnormal? compressor. compressor) \u25c6 Check if the inverter board is N well. \u25c6 Check if the current sensor Replace the compressor is well. on the failure unit to drive with compressor in conditions good performance and check if the compressor The current detection sensor is abnormal? of inverter control board is in abnormal conditions, disconnected or connected incorrectly. 4. Possible causes \u25c6 The inverter board and current sensor is anti-connected or the current sensor is in incorrect direction. \u25c6 The inverter board or current sensor is damaged. 237","Failure code LED5 Failure description: Outdoor Compressor module power supply abnor- digital display Indoor unit LED status 20 times mal tube: Outdoor unit LED status 120-0, 1 LED1 LED2 Troubleshooting 121-0, 1 N Indoor wired Normal Normal controller: 78, Adjust the power supply. 79 Failure diagnosis and troubleshooting Diagnosis N Reconnect or re-fix it in 1. Model accordance with circuit diagram. MRV 5 series N 2. Abnormity detection method Check if the supply voltage is normal Adjust or replace PTC or relay. \u25c6 Check if the supply voltage Y N The DC bus voltage of variable is abnormal. frequency board is abnormal, \u25c6 Check if the PTC or relay Check if the electrical replace the board. contacts or not. cabinet is correctly \u25c6 Check if the DC bus voltage connected is normal. Y \u25c6 Check if the DC power supply of inverter board is Check if the PTC or relay is contacted . normal. Y conditions Check if the voltage between P The power supply of inverter and N is less than 375V. control board is interrupted instantly. 4. Possible causes \u25c6 The supply voltage is found Y \u25c6 The PTC or relay does not Check the rectifier bridge, contact. electrolytic capacitor, electric \u25c6 The inverter control board is reactor in variable frequency in poor performance. loop. 238","Failure code Indoor unit LED status LED5 Failure description: Outdoor 20 times Radiator temp. sensor of compressor mo- digital dule is abnormal. display tube: Outdoor unit LED status LED1 LED2 122-0, 1 Normal Normal Troubleshooting Indoor wired controller: 7A Failure diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the sensor and N Adjust the connection variable frequency board is between temperature sensor \u25c6 Check if the temperature connected correctly. and variable frequency acquisition circuit of inverter board. board is normal. Y \u25c6 Check if the resistance of N temperature sensor is normal. Check if the sensor Replace the sensor. \u25c6 Check if they are connected resistance is normal. correctly Y conditions Replace the variable The temperature sensor is frequency board. disconnected or the resistance is incorrect. 4. Possible causes \u25c6 The resistance of temperature sensor is found with drift. \u25c6 The inverter board acquires inaccurate temperature. 239","Failure code LED5 Failure description: Outdoor Hardware instantaneous over current of the digital display Indoor unit LED status 20 times tube: Outdoor unit LED status Troubleshooting 123-0, 1 LED1 LED2 N Indoor wired controller: 78, Normal Normal Adjust the power supply. 7B Failure diagnosis and troubleshooting N Reconnect or re-fix it in 1. Model Diagnosis accordance with circuit diagram. MRV 5 series N 2. Abnormity detection method Check if the supply voltage is normal Replace the inverter module \u25c6 Check the module is normal, Y there is short circuit between P, Check if the electrical box connect N, U, V, W correctly, compressor wires connect \u25c6 Check whether the module reliably good; Y \u25c6 Check the compressor resistance is normal, Check if the inverter module is normal \u25c6 Check if the wiring of compressor UVW is correct, Y frequency converter board and module board connection is reliable. conditions If the resistance, insulation of the N Replace the compressor Hardware instantaneous over compressor is normal side Y If there are other failures 112,114 4. Possible causes Y \u25c6 Poor radiating caused the Solve the failure module burned; \u25c6 The module is punctured to cause a breakdown; \u25c6 Compressor winding resistance too large \u25c6 UVW wiring short circuit, or compressor line short circuit to ground \u25c6 The compressor has a liquid shock, causing starting current or operating current too high 240","Failure code LED5 Failure description: Outdoor Compressor module three-phase power digital display Indoor unit LED status 20 times failure tube: Outdoor unit LED status 124-0, 1 LED1 LED2 Troubleshooting Indoor wired N controller: 78, Normal Normal 7C Adjust the power supply. Failure diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Check if the power supply voltage too low or lack of phase \u25c6 Check if the modules' R, S, Y N Reconnect or re-fix it in T are correct, if missing phase accordance with wiring \u25c6 Check if the power supply of Check if the electrical box connect diagram. the electrical box lack of phase, correctly if the voltage is too low N Reconnect or re-fix it in Y accordance with wiring conditions diagram. Check if the inverter module connect Module three-phase power well N failure Y Replace the inverter module 4. Possible causes Check if the inverter module is normal \u25c6 Module three-phase voltage is too low Y \u25c6 Module three-phase power lack of phase or imbalance Replace the electrical box to compare 241","Failure code LED5 Failure description: Outdoor Compressor frequency un-match digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 125-0, 1 LED1 LED2 Indoor wired controller: Normal Normal 7D Failure diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Whether the power supply voltage is N Adjust the power supply. \u25c6 Check if the communication Y circuits of power module and N Reconnect or re-fix it in inverter board are securely Check if the electrical box connect accordance with wiring inserted and connected. correctly diagram. \u25c6 Check if the power module Y is well. \u25c6 Check if the inverter board is well. conditions Check if the inverter module is N Replace the inverter module normal N (current frequency \u2265 INV target frequency +3Hz) or Y Replace the compressor (target frequency \u22650 && actual frequency =0) for continuous 5 Compressor winding resistance, minutes insulation is normal 4. Possible causes \u25c6 The power module and inverter board are connected loosely, which results in detection failure of compressor rotation speed. \u25c6 The power module is damaged. 242","Failure code LED5 Failure description: Outdoor Fan motor speed un-match digital Indoor unit LED status 20 times display tube: Outdoor unit LED status Troubleshooting 125-4, 5 LED1 LED2 Indoor wired controller: Normal Normal 7D Failure diagnosis and troubleshooting 1. Model Diagnosis MRV 5 series 2. Abnormity detection method Whether the power supply voltage is N Adjust the power supply. \u25c6 Check if the compressor Y N Reconnect or re-fix it in module is damaged accordance with wiring \u25c6 Check if the fan rotation is Check if the electrical box connect diagram. smooth; correctly \u25c6 Check whether the fan N Replace the inverter module blade load is blocked; Y N conditions Check if the inverter module is Replace fan motor normal Hall signal logic built-in the fan motor is wrong too many times Y 4. Possible causes Exchange the left and the right fan motor, if the failure fan motor \u25c6 Fan blade overload \u25c6 Fan motor is bad is OK 243","23.2 Lack of refrigerant judgment method (1) Refer to the R410A system static balance pressure reference value form (2) Check if the temp. difference between coil pipe and ambient temp. less than 4oC, if yes, it means the system lack of refrigerant. R410A system static balance pressure reference value Outdoor ambient temp.\uff08\u2103\uff09 Pressure\uff08MPa\uff09 Outdoor ambient temp.\uff08\u2103\uff09 Pressure\uff08MPa\uff09 -23 0.258 16 1.198 -22 0.272 17 1.235 -21 0.287 18 1.273 -20 0.301 19 1.312 -19 0.317 20 1.352 -18 0.332 21 1.392 -17 0.349 22 1.433 -16 0.365 23 1.475 -15 0.383 24 1.518 -14 0.4 25 1.562 -13 0.419 26 1.607 -12 0.437 27 1.653 -11 0.456 28 1.699 -10 0.476 29 1.747 -9 0.496 30 1.795 -8 0.517 31 1.845 -7 0.538 32 1.895 -6 0.56 33 1.946 -5 0.582 34 1.999 -4 0.605 35 2.052 -3 0.629 36 2.106 -2 0.653 37 2.162 -1 0.677 38 2.218 0 0.703 39 2.276 1 0.729 40 2.334 2 0.755 41 2.394 3 0.782 42 2.455 4 0.81 43 2.516 5 0.839 44 2.579 6 0.868 45 2.643 7 0.898 46 2.709 8 0.928 47 2.775 9 0.959 48 2.843 10 0.991 49 2.911 11 1.024 50 2.981 12 1.057 51 3.053 13 1.091 52 3.125 14 1.126 53 3.199 15 1.162 244","23.3 The checking method for the valve 1. After the valve is energized, listen to the sound of valve action, if no action enter the next checking. For the solenoid valve: check if the PCB terminal has 220V output, if yes, change the solenoid valve coil, if not OK, change the solenoid valve body. For the electronic expansion valve: measure the resistance value. FUJIKOKI electronic expansion valve Resistance value: 1 and 5: 46\u00b14\u03a9 3 and 5: 46\u00b14\u03a9 1 and 3: 92\u00b18\u03a9 2 and 4: 92\u00b18\u03a9 23.4 The 4-way valve reversing condition After 4-Way valve powered on 3 minutes, if it satisfy one of the following condition lasting 10 seconds. Condition: --Tsuc-Tdef\u226510OC --Pd-Ps\u2265\u03b2MP (Tao>-10OC, \u03b2=0.60; Tao\u2264-10OC, \u03b2=0.4) 245","23.5 Fan motor detection standard Fan motor code: 0150401918 Expected readings of control Expected readings of DC fan PWB VDC outputs to DCFM motor circuit board resistances Multi meter test points for VDC Multi meter test points for \u03a9 Multimeter Multimeter PCB DC volts Multimeter Multimeter DCFM PWB red probe black probe black probe red probe resistance value 5V SE GND2 5V SE GND2 0.664M\u03a9 +5V GND2 5V +5V GND2 \u221e A2 GND2 A2 GND2 \u221e Wring of DC fan motor 1 GND2 Communication signal Blue public ground 2 SE Send or receive signal Gray wire 3 +5V 5V communication Yellow power supply 4 \/\/ \/ 5 A2 Communication White address Expected readings of control Expected readings of DC fan PWB VDC outputs to DCFM motor circuit board resistances Multi meter test points for VDC Multi meter test points for \u03a9 Multimeter Multimeter PCB DC volts Multimeter Multimeter DCFM PWB red probe black probe black probe red probe resistance value +540VDC GND 540V +540VDC GND 1.444M\u03a9 15V GND2 15V 15V GND2 102.6K\u03a9 Wring of DC fan motor 1 +540VDC Input DC high voltage Red positive 2 GND Input DC high voltage White negative 3 GND2 Input DC 15 voltage Brown negative 4 15V Input DC 15 voltage Orange positive 246","Fan motor code: 0150401919 Expected readings of control Expected readings of DC fan PWB VDC outputs to DCFM motor circuit board resistances Multi meter test points for VDC Multi meter test points for \u03a9 Multimeter Multimeter PCB DC volts Multimeter Multimeter DCFM PWB red probe black probe black probe red probe resistance value 5V SE GND2 5V SE GND2 0.662M\u03a9 5V +5V GND2 +5V GND2 \u221e A2 GND2 A2 GND2 \u221e Wring of DC fan motor 1 GND2 Communication signal Blue public ground 2 SE Send or receive signal Gray wire 3 +5V 5V communication power Yellow supply 4\/ \/ \/ 5\/ \/ \/ Expected readings of control Expected readings of DC fan PWB VDC outputs to DCFM motor circuit board resistances Multi meter test points for VDC Multi meter test points for \u03a9 Multimeter Multimeter PCB DC volts Multimeter Multimeter DCFM PWB red probe black probe 540V black probe red probe resistance value +540VDC GND +540VDC GND 1.46M\u03a9 15V GND2 15V 15V GND2 101.1K\u03a9 Wring of DC fan motor 1 +540VDC Input DC high voltage Red positive 2 GND Input DC high voltage White negative 3 GND2 Input DC 15 voltage Brown negative 4 15V Input DC 15 voltage Orange positive 247"]