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Midea Atom X Series Manual
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Midea Atom X Series Manual

Midea Atom X Series Manual

Commercial air conditioners
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Service
Manual
Model:
Commercial Air Conditioners
Series
208/230V 60Hz
MDV V18WMN10T
MDV V24WMN10T
MDV V30WMN10T
MDV V36WMN10T
MDV V48WMN10T
MDV V60WMN10T
R454B

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Summary of Contents for Midea Atom X Series

  • Page 1 R454B Commercial Air Conditioners Service Manual Series Model: 208/230V 60Hz MDV V18WMN10T MDV V24WMN10T MDV V30WMN10T MDV V36WMN10T MDV V48WMN10T MDV V60WMN10T...
  • Page 2 Service Manual...
  • Page 3 AtomX Series VRF 60Hz CONTENTS Part 1 General Information ................ 3 Part 2 Component Layout and Refrigerant Circuits ........ Part 3 Control .................... 23 Part 4 Field Settings ................. 39 Part 5 Electrical Components and Wiring Diagrams ....... Part 6 Diagnosis and Troubleshooting ............. 6...
  • Page 4 AtomX Series VRF 60Hz...
  • Page 5 AtomX Series VRF 60Hz Part 1 General Information 1 Indoor and Outdoor Unit Capacities ............2 External Appearance .................. 5 3 Nomenclature .................... 4 Combination Ratio ..................5 Selection Procedure ................... 8...
  • Page 6 AtomX Series VRF 60Hz 1 Indoor and Outdoor Unit Capacities 1.1 Indoor Units Table 1-1.1: Indoor unit abbreviation codes Abbreviation Abbreviation Type Type code code Compact Four-way Cassette Medium Static Pressure Duct Four-way Cassette Wall-mounted Low Static Pressure Duct Table 1-1.2: Indoor unit capacity range Capacity Capacity kBtu/h...
  • Page 7 AtomX Series VRF 60Hz 2 External Appearance 2.1 Indoor Units Table 1-2.1: Indoor unit appearance Compact Four-way Cassette Four-way Cassette Low Static Pressure Duct Medium Static Pressure Duct Wall-mounted 2.2 Outdoor Units Table 1-2.2: Outdoor unit appearance MDV-V18WMN10T MDV-V30WMN10T MDV-V48WMN10T MDV-V24WMN10T MDV-V36WMN10T MDV-V60WMN10T...
  • Page 8 3.1 Indoor Units 3.1.1 Standard indoor units Indoor units H 07 G M N10 Legend No. Code Remarks Midea VRF indoor unit Function code H: HyperLink function 4 07 Capacity index (the capacity in kBtu/h) Indoor unit type Q4C: Compact Four-way Cassette...
  • Page 9 AtomX Series VRF 60Hz 4 Combination Ratio Sum of capacity indexes of the indoor Combination ratio = units Capacity index of the outdoor unit Table 1-4.1: Indoor and outdoor unit combination ratio limitations Units (kBtu/h) Minimum combination ratio Maximum combination ratio 18/24 130% 130%...
  • Page 10 AtomX Series VRF 60Hz 5 Selection Procedure 5.1 Procedure Step 1: Establish design conditions Design temperature and humidity (indoor and outdoor) Required heat load of each room System peak load Indoor unit specifications (type and quantity) Piping length, level differences Room( i) area Adjust the piping length, reduce the refrigerant charge...
  • Page 11 AtomX Series VRF 60Hz Provisionally select outdoor unit capacity based combination ratio limitations Confirm that the number of indoor units connected to the outdoor unit is within limitation Correct cooling and heating capacities of the outdoor unit for 1. Room(i) with larger airflow the following items: indoor units Outdoor air temperature / Indoor air temperature WB /...
  • Page 12 AtomX Series VRF 60Hz...
  • Page 13 AtomX Series VRF 60Hz Part 2 Component Layout an 1 Layout of Functional Components ............12 2 Piping Diagrams ..................Refrigerant Circu 3 Refrigerant Flow Diagrams ............... 19...
  • Page 14 AtomX Series VRF 60Hz 1 Layout of Functional Components 1.1 1.5/2.0ton layout of functional components Figure 2-1.1: 1.5/2.0ton layout of functional components Legend Parts name Compressor One way valve High pressure switch 4-way valve(ST1) Heat exchanger Electronic expansion valve (EEVA) Radiator Stop valve (liquid side) Stop valve (gas side)
  • Page 15 AtomX Series VRF 60Hz 1.2 2.5/3.0ton layout of functional components Figure 2-1.2: 2.5/3.0ton layout of functional components Legend Parts name Compressor High pressure switch Oil separator High pressure sensor One way valve 4-way valve(ST1) Heat exchanger Electronic expansion valve (EEVA) Radiator Stop valve (liquid side) Stop valve (gas side)
  • Page 16 AtomX Series VRF 60Hz 1.3 4.0/5.0ton layout of functional component Figure 2-1.3: 4.0/5.0ton layout of functional components Legend Parts name Compressor Oil separator High pressure switch High pressure sensor One way valve 4-way valve(ST1) Heat exchanger Electronic expansion valve (EEVA) Radiator Stop valve (liquid side) Stop valve (gas side)
  • Page 17 AtomX Series VRF 60Hz 2 Piping Diagrams 2.1 1.5/2.0ton piping diagram Figure 2-2.1: 1.5/2.0ton piping diagram Legend Parts name Parts name Compressor Electronic expansion valve (EEVD) One-way valve Services valve High pressure switch Fusible plug Four-way valve Low pressure switch 18.1-18.3 Filter High pressure sensor...
  • Page 18 AtomX Series VRF 60Hz 2.2 2.5/3.0ton piping diagram Figure 2-2.2: 2.5/3.0ton piping diagram Legend Parts name Parts name Compressor Gas-liquid separator High pressure switch Fusible plug Oil separator Low pressure sensor High pressure sensor Solenoid valve One-way valve Capillary tube Four-way valve 20.1-20.5 Filter...
  • Page 19 AtomX Series VRF 60Hz 2.3 4.0/5.0ton piping diagram Figure 2-2.3: 4.0/5.0ton piping diagram Legend Parts name Parts name Compressor Gas-liquid separator Oil separator Fusible plug High pressure switch Low pressure sensor High pressure sensor Solenoid valve One-way valve Capillary tube Four-way valve 20.1-20.5 Filter...
  • Page 20 AtomX Series VRF 60Hz 2.4 Key components 1. Oil separator: of the compressor and quickly returns it to the compressor. Separation Separates oil from gas refrigerant pumped out efficiency is up to 99%. 2. Gas-liquid separator: Separates liquid refrigerant from gas refrigerant, stores liquid refrigerant and oil to protect compressor liquid hammering.
  • Page 21 AtomX Series VRF 60Hz Refrigerant Flow Diagrams 3.1 Cooling operation Figure 2-3.1: Refrigerant flow during cooling operation...
  • Page 22 AtomX Series VRF 60Hz 3.2 Heating operation Figure 2-3.2: Refrigerant flow during heating operation...
  • Page 23 AtomX Series VRF 60Hz 3.3 Oil return operation in cooling mode Figure 2-3.3: Refrigerant flow during oil return operation in cooling mode...
  • Page 24 AtomX Series VRF 60Hz 3.4 Oil Return/Defrost operation in heating mode Figure 2-3.3: Refrigerant flow during oil return/defrost operation in heating mode...
  • Page 25 AtomX Series VRF 60Hz Part Control 1 Stop Operation ..................2 Standby Control ..................3 Startup Control ..................4 Normal Operation Control ............... 26 5 Special Control ..................
  • Page 26 AtomX Series VRF 60Hz 1 Stop Operation The stop operation occurs for one of the four following reasons: will makes a 'stop 1. Abnormal shutdown: in order to protect the compressors, if an abnormal state occurs, the system with thermos-off' operation and an error code will be displayed on the outdoor unit digital displays. 2.
  • Page 27 AtomX Series VRF 60Hz 3 Startup Control 3.1 Third-part AHU start control Outdoor unit receives 24V electrical signal from thermostat and determines operation mode. Continuous square sign from 30 to 80 Hz which lasts more than 3 seconds is effective signal. O type: When thermostat is set with O type, and run into cooling mode, it will send 24V electrical signal from O/B and Y port thermostat to B and Y port on signal board of outdoor unit.
  • Page 28 AtomX Series VRF 60Hz 4 Normal Operation Control 4.1 Component Control during Normal Operation Table 3-5.1: Outdoor unit component control during normal operation Function of Functional Part Part Name Symbol Cooling Heating Pressure control: Compressor is used to maintain constant evaporating pressure in cooling mode, and constant condensing pressure in heating mode Inverter compressor Protection control: High pressure protection, Low pressure protection, Discharge temperature...
  • Page 29 AtomX Series VRF 60Hz 4.2 Compressor Control Cooling operation Compressor frequency is controlled to keep IDU evaporating pressure (Te) at target pressure (Tes). , which could be changed by menu settings on main board; The default target pressure in cooling mode is 39.2 Target evaporating pressure would decrease if cooling capacity of indoor unit is too low;...
  • Page 30 AtomX Series VRF 60Hz Operating frequency ranges During normal operation, the minimum frequency is always 18Hz for all outdoor units and the maximum one is limited as the table below. Table 3-5.3: Outdoor unit frequency ranges during operation Frequency Range in Cooling or main Cooling Model Frequency Range in Heating or main Heating MDV-V18WMN10TM...
  • Page 31 AtomX Series VRF 60Hz 5.6 Outdoor Fan Control The speed of the outdoor unit fans is adjusted in steps, as shown in Table 3- Table 3-5.9: Outdoor fan speed steps Fan speed (rpm) Fan speed index 2.5/3.0ton 1.5/2.0ton 2.5/3.0ton FANA FANB...
  • Page 32 AtomX Series VRF 60Hz 5 Special Control 7.1 Oil Return Operation In order to prevent compressors from running out of oil, the oil return operation is conducted to recover oil that has flowed out of the compressor and into the piping system. This operation is performed for all units including units that are in standby.
  • Page 33 AtomX Series VRF 60Hz 7.2 Defrosting Operation In order to recover heating capacity, the defrosting operation is conducted when the outdoor unit heat excha performing as an evaporator. The defrosting operation is controlled according to outdoor ambient temperature, outd heat exchanger temperature, indoor heat exchanger temperature and outdoor units running time. When the outdoor df”.
  • Page 34 AtomX Series VRF 60Hz 3. Refrigerant auto-charging is available only after successfully commissioning. Do not enter auto-charging mode w system is initializing. 4. The refrigerant auto-charging function is only available in cooling operation. Before entering auto-charging mode Table 3-7.4: Indoor unit operation mode during auto-charging mode please Indoor unit operation mode Operation...
  • Page 35 AtomX Series VRF 60Hz 7. Turn on refrigerant supply, the system will charge refrigerant automatically in 30 to 60 minutes. The refrigerant amount OK” for 5s to quit auto- charged should be calculated and recorded. 8. When refrigerant auto-charging is over successfully, the LED will display “END”, then press “ charging mode.
  • Page 36 AtomX Series VRF 60Hz 7.4 Chassis electric heating belt control Chassis electric heating belt control is used to prevent chassis from being freeze by condensate water and ice rain, ambient temperature is less than 89.6 . Accumulated ice on chassis would block drain hole and damage condenser, which Ambient temperature T4 is less than 35.6 .
  • Page 37 AtomX Series VRF 60Hz 7.6 Test Operation Control Test operation is used to debug malfunction because of incorrect installation. Press “1-1-2 operation. ” on PCB to enter test Basic procedure of test operation Before entering test operation, please debug malfunction in stop mode, such as temperature sensor error, communication Function menu Settings to the the system will perform a test operatin g.
  • Page 38 AtomX Series VRF 60Hz Refrigerant and electrical Refrigerant and electrical signal are not matching signal are matching...
  • Page 39 AtomX Series VRF 60Hz 7.7 Heating prohibition control This control is used to set ambient temperature T4 for heating permitted temperature range. When T4 < T4set, the i units operating in heating mode with auxiliary heating source (please check function instruction of indoor unit) will tu “8-b-”...
  • Page 40 AtomX Series VRF 60Hz 7.8 Operation Limits Control Before compressors are about to start, the outdoor unit judge whether it’s suitable to operate or not by the value of ambient Cooling startup when 5°F T4 125°F temperature (T4). Heating startup when -22°F T 4 86°F Startup allowable Startup prohibited...
  • Page 41 AtomX Series VRF 60Hz Part Field 1. Overview ..................... 2. Digital display and button settings ............Settings 3. System Parameter Check ..............49...
  • Page 42 AtomX Series VRF 60Hz 1. Overview This chapter describes how the system configuration can be implemented once the installation is completed, and other relevant information. Implement field settings It contains the following information: Energy-saving and optimized operation Using the Check function 2.
  • Page 43 AtomX Series VRF 60Hz Menu mode selection flowchart: Figure 4-2.1 Menu mode selection flowchart: Menu mode function: Table 4-2.3 Menu mode function: First level menu Description Default Second level menu Query History error (last ten error codes) Specified menu mode Cleaning history error (History error) Query Indoor unit's address...
  • Page 44 AtomX Series VRF 60Hz Table 4-2.3 Menu mode function(continue) Default First level menu Second level menu Specified menu mode Description Automatic priority mode Cooling priority mode VIP indoor unit voting priority mode 0[1] In response to heating mode only In response to cooling mode only (Priority mode) Heating priority mode Capability requirements priority mode...
  • Page 45 AtomX Series VRF 60Hz Table 4-2.3 Menu mode function(continue) First level menu Description Default Second level menu Evaporation temperature setting (Ke0=-3) Specified menu mode Evaporation temperature setting (Ke0=0) Evaporation temperature setting (Ke0=2) Evaporation temperature setting (Ke0=4) Evaporation temperature setting (Ke0=6) (target evaporation Evaporation temperature setting (Ke0=8) temperature of the...
  • Page 46 AtomX Series VRF 60Hz Table 4-2.3 Menu mode function(continue) Specified menu mode Description Default First level menu Second level menu 28°F heataux operate temperature 36°F heataux operate temperature 43°F heataux operate temperature 50°F heataux operate temperature n8[1] 59°F heataux operate temperature (heat-auxiliary 68°F heataux operate temperature operate)
  • Page 47 AtomX Series VRF 60Hz 2.4 Function of switch ENC1 Switch Setting Switch positions Description Outdoor unit model setting (Valid at 0-5 ,default is 0) 0 - MDV-V18WMN10T ENC1 Model setting 1 - MDV-V24WMN10T 2 - MDV-V30WMN10T 3 - MDV-V36WMN10T 2.5 Special mode introduction 4 - MDV-V48WMN10T 2.5.1 Mode priority control 5 - MDV-V60WMN10T...
  • Page 48 AtomX Series VRF 60Hz If ODU receive cooling demand, ODU will stop and turn to operate in cooling mode. The indoor units with heating demand ”. are thermo-OFF and display “not priority ODU in cooling mode If ODU receive heating demand, ODU will continue to operate in cooling mode. The indoor units with heating deman thermo-OFF and display “not priority”.
  • Page 49 AtomX Series VRF 60Hz 2.5.2 System test Cooling Test Control Press “1-1-0” on PCB to enter cooling test mode, and all indoor units downstairs operate in cooling mode set at 62.6 with Cooling test control is used to check whether the system can operate cooling mode normally. high wind.
  • Page 50 AtomX Series VRF 60Hz Table 3-7.5: Error code during test operation Test item Object Malfunction reason Error code T1 < 109. Outdoor ambient T4 < -22 temperature T1 53 .6 and T 4 131 T1 < 53 .6 and T 4 86 4 131 Indoor ambient temperature...
  • Page 51 AtomX Series VRF 60Hz 3. System Parameter Check 3.1 UP / DOWN system check button Before pressing UP or DOWN button, allow the system to operate steadily for more than an hour. On pressing UP o DOWN Table 4-3.1 system check list: button, the parameters listed in below table will be displayed in sequence.
  • Page 52 AtomX Series VRF 60Hz Table 4-3.1 system check list(continue): DISP. CONTENT DESCRIPTION EEVD position Actual Value=DISP. *4 High pressure of unit Actual Pressure=DISP. /100 Unit: MPa Low pressure of unit Actual Pressure=DISP. /100 Unit: MPa Quantity of online IDUs Actual quantity Quantity of running IDUs Actual quantity [0] OFF...
  • Page 53 AtomX Series VRF 60Hz Part Electrical Components an 1. Outdoor Unit Electric Control Box Layout ..........2. Outdoor Unit Main Control Board ............53 3. Compressor & Fan drive board ............. 56 Wiring 4. Wiring Diagrams .................. Diagrams...
  • Page 54 AtomX Series VRF 60Hz 1. Outdoor Unit Electric Control Box Layout 1.1 1.5/2.0ton electric control box Figure 5-1.1: 1.5/2.0ton electric control box 1.2 2.5/3.0ton electric control box Figure 5-1.2: 2.5/3.0ton electric control box 1.3 4.0/5.0ton electric control box Figure 5-1.2: 4.0/5.0ton electric control box Note: The Compressor &...
  • Page 55 AtomX Series VRF 60Hz 2. Outdoor Unit Main Control Board 2.1 Outdoor unit main Control Board ports Figure 5-2.1: Outdoor unit main Control Board ports Table 5-2.1: Main Control Board port Notes: Label descriptions are given in...
  • Page 56 AtomX Series VRF 60Hz Table 5-2.1: Main Control Board port...
  • Page 57 AtomX Series VRF 60Hz 2.2 Outdoor unit main Control Board components 2.2.1 Layout Figure 5-2.2: Outdoor unit main Control Board components Function of buttons SW3 to SW6 2.2.2 Table 5-2.2: Function of buttons SW3 to SW6 Button Function In menu mode: previous and next buttons for menu SW3 (UP) modes.
  • Page 58 AtomX Series VRF 60Hz 3. Compressor & Fan drive board 3.1 1.5/2.0ton Compressor & Fan drive board Figure 5-3.1: 1.5/2.0ton compressor & Fan drive board...
  • Page 59 AtomX Series VRF 60Hz 3.2 2.5/3.0ton Compressor & Fan drive board of 35A Figure 5-3.2: 2.5/3.0ton compressor & Fan drive board of 35A...
  • Page 60 AtomX Series VRF 60Hz 3.3 4.0/5.0ton Compressor & Fan drive board Figure 5-3.5: 4.0/5.0ton compressor & Fan drive board ports of 50A...
  • Page 61 AtomX Series VRF 60Hz 4. Wiring Diagrams Figure 5.4.1: 1.5/2.0Ton model wiring diagram Legend Code Name Code Name COMP Compressor High pressure sensor EEVA/D Electronic expansion valve Low pressure sensor DC Fan Heat exchanger middle temperature sensor HEAT Crankcase heater Outdoor ambient temperature sensor HEATB Chassis electric heating belt...
  • Page 62 AtomX Series VRF 60Hz Figure 5-4.2: 2.5/3.0Ton model wiring diagram Legend Code Name Code Name COMP Compressor Low pressure sensor EEVA/D Electronic expansion valve Heat exchanger temperature sensor DC Fan Outdoor ambient temperature sensor HEAT Crankcase heater Liquid pipe temperature sensor HEATB Chassis electric heating belt Suction temperature sensor...
  • Page 63 AtomX Series VRF 60Hz Figure 5-4.3: 4.0/5.0Ton model wiring diagram Legend Code Name Code Name COMP Compressor Low pressure sensor EEVA/D Electronic expansion valve Heat exchanger temperature sensor FAN_UP/ DC Fan Outdoor ambient temperature sensor FAN_DOWN HEAT Crankcase heater Liquid pipe temperature sensor HEATB Chassis electric heating belt Suction temperature sensor...
  • Page 64 AtomX Series VRF 60Hz...
  • Page 65 AtomX Series VRF 6 Part Diagnosis and 1 Error Code Table ..................2 Error in Main Control ................Troubleshooting 3 Error in Compressor Driver ............... 4 Error in Fan Driver .................. 5 Error in Shut-off Device ................6 Appendix ....................
  • Page 66 AtomX Series VRF 60Hz 1 Error Code Table 1.1 Outdoor Error code table Table 6-1.1 Outdoor Error code table Manual re-start Error code Error description require Emergency stop Indoor unit refrigerant leakage Recover refrigerant after refrigerant leakage and shut down Refrigerant shut-off device error Communication error between indoor and outdoor unit Number of indoor units detected by the outdoor unit has decreased...
  • Page 67 AtomX Series VRF 6 Table continued on next page … Table 6-1.1 Outdoor Error code table (continued) Error code Error description Manual re-start require 1P32 Compressor high DC bus current protection (software protection) 1P33 1P32 protection occurs 3 times in 100 minutes High AC voltage protection Low AC voltage protection DC bus low voltage protection...
  • Page 68 AtomX Series VRF 60Hz Table continued on next page … Table 6-1.2 Compressor driver error code (continued) Error code Error description Manual re-start require 1L3E Low bus voltage error 1L31 High bus voltage error 1L32 Serious over voltage error of bus 1L43 Abnormal current sampling 1L45...
  • Page 69 AtomX Series VRF 6 Table 6-1.4 Status code Error code Error description Manual re-start require Oil return running, x represents oil return operation steps Defrost running, x represents defrosting operation steps Refrigerant judgment, no result Refrigerant quantity judgment, Significantly excessive Refrigerant quantity judgment, Slightly excessive Refrigerant quantity judgment, normal Refrigerant quantity judgment, Slightly insufficient...
  • Page 70 AtomX Series VRF 60Hz 2 Error in Main Control 2.1 A01: Emergency Stop Digital display output Description Possible causes The emergency stop signal is detected Controller send emergency signal to outdoor unit Defective main board Check whether the controller send Contact house holder to confirm the emergency signal to outdoor unit reason of emergency stop...
  • Page 71 AtomX Series VRF 6 2.2 A11: Refrigerant leakage error Digital display output Description Refrigerant leak detected in some indoor units The fan of the indoor unit with refrigerant leakage is detected running at the highest air speed and the electronic expansion valve is closed (note: re-powering the unit does not lift the fault), while the buzzer on the displa board of the faulty indoor unit and the buzzer on the line control connected to the faulty indoor unit continuously chirp...
  • Page 72 AtomX Series VRF 60Hz 2.3 1b01/4b01: Electronic expansion valve (EEVA/D) error Digital display output Description All units stop running Possible causes Error code is displayed on the outdoor unit with the error. The electronic expansion valve signal was not detected by the mainboard for 2 minutes Supposed causes: The electric expansion valve (EEVA/D) winding is mismatching...
  • Page 73 AtomX Series VRF 6 2.4 C21: Communication error between indoor units and outdoor unit Digital display output Description Communication error between IDU and ODU Error code is only displayed on the outdoor unit. All units stop running. Possible causes Communication cables between ODU and IDUs are unstably or wrongly connected, or in short circuit. Communication cables between communication board and main board are unstably or wrongly connected, or in short circuit.
  • Page 74 AtomX Series VRF 60Hz 2.5 C26/C28: Number of indoor units detected by the outdoor unit has decreased/increased Digital display output Description All units stop running. The number of online indoor units is smaller/greater than the configured number Error code is only displayed on the outdoor unit Possible causes Repetitive addresses are exist for the IDUs in the refrigerant system Power supply abnormal for some IDUs...
  • Page 75 AtomX Series VRF 6 2.6 1C41: Communication error between main control chip and inverter driver chip Digital display output Description The communication between the main control board and inverter driver board is error Error code is displayed on the unit with the error Possible causes All units stop running.
  • Page 76 AtomX Series VRF 60Hz 2.7 E41/F41/F43/F91/FC1/F81: T4/T3/T3B/T5/TL/Tg error (open/short) Digital display output Error code Error description Remarks Digital display output Outdoor ambient temperature sensor sensor error (T4) error(open/short) Main heat exchanger pipe temperature sensor error sensor (T3) error(open/short) Temperature sensor in the middle of the heat exchanger pipe (T3B) error sensor error (open/short)
  • Page 77 AtomX Series VRF 6 Procedure E41/F41/F43/F91/FC1/F81 Check whether T4/T3/T3B/T5/ TL/Tg sensor are seated to the specified Reset the sensor location and connected to the main board. Check whether the resistance of sensor is in the range of resistance Replace the fault sensor table (1).
  • Page 78 AtomX Series VRF 60Hz 2.8 F71: Discharge temperature sensor (T7C) error (open/short) Digital display output Description Temperature sensor error All units stop running. Error code is displayed on the unit with the error Detective voltage > 4.95V or < 0.05V Possible causes Contact failure between sensor and main board Temperature sensor failure...
  • Page 79 AtomX Series VRF 6 2.9 F62/F6A: Inverter module temperature (Tf) protection Digital display output Description F62: The temperature of the internal NTC of the compressor module board or fan module is higher than The temperature of the Tf/Ntc radiator is too high. 100°C.
  • Page 80 AtomX Series VRF 60Hz 2.10 F72/F7A: Discharge temperature (T7C) protection Digital display output Description F72: Discharge Temperature (T7C) 115 Discharge Temperature is over the limit. F7A: F72 protection occurs 3 times in 100 minutes All outdoor Unit stop running Error code is displayed on the unit with the error Possible causes Too high discharge temperature caused by little refrigerant remains in the system...
  • Page 81 AtomX Series VRF 6 2.11 F75: Compressor discharge insufficient superheat protection Digital display output Description The discharge temperature superheat of compressor is less than 43°F (6°C) for more than 60 minutes All units stop running. The error code is displayed on the outdoor unit with error. Determination during operation of outdoor unit.
  • Page 82 AtomX Series VRF 60Hz 2. Heating mode Is the discharge temperature sensor (T7C) seated Adjust the discharge temperature to correct location? Are these wirings properly sensor and its wiring connected to ODU main board? Comparing with the value of pressure gauge .
  • Page 83 AtomX Series VRF 6 2.12 P11: High pressure sensor malfunction Digital display output Description All units stop running. Open/short circuit error of high pressure sensor The error code is displayed on the Outdoor Unit with error. Possible causes The high pressure and low pressure are too low caused by less refrigerant in the system Misjudgment caused by faulty high pressure sensor Defective main board of outdoor unit The ambient temperature is extremely high and the value of temperature sensor (T4) is...
  • Page 84 AtomX Series VRF 60Hz 2.13 P12/P14: High pressure protection Digital display output Description P14: 3 times P12 in 100 minutes P12: The high pressure is over the limit. The detected high pressure is higher than 3.9 MPa All units stop running Error code is displayed on the unit with the Error Possible causes Extremely high pressure for too much refrigerant...
  • Page 85 AtomX Series VRF 6 2.14 P13: High pressure switch protection Digital display output Description All units stop running The detected high pressure is higher than 4.2 MPa Error code is displayed on the unit with the Error Possible causes The outdoor unit’s check valve is not open. The pressure switch is either not connected correctly or is damaged.
  • Page 86 AtomX Series VRF 60Hz Procedure The cut-off valve of the Open the outdoor unit stop outdoor unit is not opened valve High pressure switch not Connect the high pressure connected to module board [1] switch to the drive board Replace the high pressure High pressure switch failure switch Perform a partial refrigerant...
  • Page 87 AtomX Series VRF 6 2.15 P21: Low pressure sensor error Digital display output Description All units stop running. Open/short circuit Error in suction pressure sensor Error code is only displayed on the unit with the error. Possible causes There is air in the system. Low pressure sensor is not correctly connected to the main board.
  • Page 88 AtomX Series VRF 60Hz 2.16 P22/P25: Low pressure protection Digital display output Description P22: Low pressure protection; The detected low pressure is lower than 0.12 MPa P25: Low pressure protection occurs 3 times in 60 min. All units stop running. Error code is displayed on the unit with the error.
  • Page 89 AtomX Series VRF 6 2.17 1P32/1P33: Compressor high DC bus current protection Digital display output Description Compressor current is higher than 17A (single fan model)/24A (double fan model) Error code is displayed on the unit with the error. Possible causes All units stop running.
  • Page 90 AtomX Series VRF 60Hz 2.18 P51/P52: Power voltage protection Digital display output Description All units stop running The detected voltage of ODU is not within the range of accepted value Error code is displayed on the unit with the error. The voltage of ODU power supply is not within ±10% of rated voltage Possible causes Damaged drive board of ODU...
  • Page 91 AtomX Series VRF 6 2.19 1P56: Inverter module DC bus low voltage error Digital display output Description All units stop running. Inverter driver board DC bus voltage is too low Error code is displayed on the unit with the error Possible causes Under voltage or phase loss in the ODU power supply Loose internal wiring in the electric control box...
  • Page 92 AtomX Series VRF 60Hz 2.20 1P57/1P58: Inverter module DC bus high voltage error Digital display output Description over voltage All units stop running. Inverter driver board DC bus Error code is displayed on the unit with the error Possible causes ODU power supply overvoltage Driver board PCB damage 1P57/1P 58...
  • Page 93 AtomX Series VRF 6 2.21 1P59: Inverter module DC bus voltage drop protection Definition and inspection of faults Driver board DC bus over voltage Supposed causes Driver board PCB damage Under voltage or phase loss in the ODU power supply Loose internal wiring in the electric control box...
  • Page 94 AtomX Series VRF 60Hz 2.22 1P71: EEPROM error Digital display output Description EEPROM can’t communicate with main chip The EEPROM parameter of the ODU main control board is incorrect All units stop running Error code is displayed on the unit with the error Possible causes EEPROM is broken Wrong EEPROM model...
  • Page 95 AtomX Series VRF 6 2.23 Pb1: HyperLink overcurrent error Digital display output Description HyperLink overcurrent error Error code is displayed on master ODU. Possible causes All units stop running. The M1M2 communication wiring of the master ODU is short-circuited. The M1M2 communication wiring of the master ODU is connected to other communication wiring (not M1M2) of t IDU.
  • Page 96 AtomX Series VRF 60Hz 2.24 Pd1/Pd2: Anti-condensation protection Digital display output Description Anti-condensation protection Error code is displayed on the unit with the error Possible causes All units stop running. The ODU check valve is not opened. Piping and wiring are inconsistent. For example, the piping for system A is connected to system A and communication wiring is connected to system B.
  • Page 97 AtomX Series VRF 6 2.25 U13: Indoor unit type setting error Digital display output Description Error code is displayed on ODU. Anti-condensation protection Error code is displayed on the unit with the error Possible causes All units stop running. Indoor Unit is VRF unit, while system setting is unitary system.
  • Page 98 AtomX Series VRF 60Hz 3 Error in Compressor Driver 3.1 1L01: Compressor error occurs 3 times in 60 minutes Digital display output Description Compressor error occurs 3 times in 60 minutes Possible Cause Spot check to inquire about the code. Find out the cause by the error code. Procedure Spot check to inquire about the error code.
  • Page 99 AtomX Series VRF 6 3.2 1L1E: Hardware overcurrent Digital display output Description The compressor stops running after the error occurs. If the error disappears one minute later, the compressor sta The compressor current exceeds the protection value set for the hardware. again Impurities in the refrigerant system Possible causes...
  • Page 100 AtomX Series VRF 60Hz 3.3 1L11, 1L12: Compressor software overcurrent Digital display output by the software. Description The compressor will shutdowm when the error occurs. If the error disappears one minute later, the compressor w The compressor current exceeds the protection value set start again.
  • Page 101 AtomX Series VRF 6 3.4 1L2E: Compressor inverter module high temperature protection Digital display output 212 ). Description The compressor will stop when the error occurs. If the error disappears one minute later, the compressor will star The temperature of the compressor or fan drive board (IPM) exceeds the set value ( again Possible causes Poor heat dissipation due to uneven application of heat dissipation silicone gel on the module;...
  • Page 102 AtomX Series VRF 60Hz 3.5 1L43: Compressor current sampling bias is abnormal Digital display output 212 ). Description Once this fault occurs, the compressor cannot be started up, and the drive board must be The temperature of the compressor drive board (IPM) exceeds the set value ( checked.
  • Page 103 AtomX Series VRF 6 3.6 1L45: Compressor motor code mismatch Digital display output Description The compressor parameters set by the main control board do not match the compressor parameters of the drive board. Possible causes Once this fault occurs, the compressor cannot be started up, and the drive board must be checked. The capacity DIP switch or model DIP switch of the main control board is incorrectly set.
  • Page 104 AtomX Series VRF 60Hz 3.7 1L5E: Compressor startup failed Digital display output Description The compressor stops running after the error occurs. If the error disappears one minute later, the compressor sta The compressor fails to start again. Possible causes There is a pressure difference at system startup The stop valve is not open Compressor stuck, wear, system blockage Abnormal compressor drive board...
  • Page 105 AtomX Series VRF 6 3.8 1L51: Compressor zero speed protection Digital display output Description Compressor locked-rotor occurred Possible causes The system has impurities or lacks oil, causing compressor locked...
  • Page 106 AtomX Series VRF 60Hz 3.9 1L52: Compressor locked-rotor Protection Digital display output Description The compressor is blocked. again. The compressor stops running after the error occurs. If the error disappears one minute later, the compressor sta Possible causes Procedure The compressor is blocked due to impurities or lack of oil in the system. 1L52 Is the check Open the check valve...
  • Page 107 AtomX Series VRF 6 3.10 1L6E: Compressor motor phase loss protection Digital display output Description Compressor phase loss protection occurred Supposed causes 1L6E Poor contact of compressor wiring or terminal screw is not tightened Procedure Power off and check Secure the wiring if the UVW output terminals of the drive board or the UVW terminals of the compressor...
  • Page 108 AtomX Series VRF 60Hz 3.11 1L65: Compressor IPM short circuit Digital display output Description Supposed causes Compressor IPM short circuit Abnormal control board in outdoor unit: damaged 1L65 Procedure Replace the drive board in outdoor ack up and run unit and power it b Normal operation...
  • Page 109 AtomX Series VRF 6 3.12 1Lbe: High pressure switch protection Digital display output Description When the fault occurs, the compressor stops operation. If the fault disappears in 1 min, the compressor is started The high pressure switch connected to the drive board acts. again.
  • Page 110 AtomX Series VRF 60Hz 3.13 1LCE: PFC hardware overcurrent Digital display output Description Possible causes PFC hardware over current protection The PFC IGBT short circuit The PFC IGBT Open circuit The Power supply voltage fluctuation The Power supply voltage distortion Procedure 1LCE Is there a fault in...
  • Page 111 AtomX Series VRF 6 3.14 1LC1: PFC software overcurrent Digital display output Description Possible causes PFC software over current protection The PFC IGBT short circuit The PFC IGBT Open circuit The Power supply voltage fluctuation The Power supply voltage distortion Procedure 1LC1 Is there a fault in...
  • Page 112 AtomX Series VRF 60Hz 4 Error in Fan Driver 4.1 1J01: Fan error occurs 3 times in 60 minutes Digital display output Description Fan error occurs 3 times in 60 minutes Possible Cause Spot check to inquire about the code. Find out the cause by the error code. Procedure Spot check to inquire about the error code.
  • Page 113 AtomX Series VRF 6 4.2 1J1E: Fan hardware overcurrent Digital display output Description Possible Cause Fan error occurs 3 times in 60 minutes Spot check to inquire about the code. Find out the cause by the error code. Procedure Spot check to inquire about the error code. Refer to the process for the error code.
  • Page 114 AtomX Series VRF 60Hz 4.3 1J11, 1J12: Fan software overcurrent Digital display output Description will start again. The fan will stop when the error occurs. If the error disappears five seconds later, the fan The fan current exceeds the protection value set for the software. Possible causes Severe fan wear.
  • Page 115 AtomX Series VRF 6 4.4 1J2E: Fan inverter module high temperature protection Digital display output Description will start again. The fan will stop when the error occurs. If the error disappears five seconds later, the fan The fan current exceeds the protection value set for the software. Possible causes Severe fan wear.
  • Page 116 AtomX Series VRF 60Hz 4.5 1J43: Fan current sampling is abnormal Digital display output Description The temperature of the fan drive board (IPM) exceeds the set value Possible causes (212 ). The compressor and fan drive board is faulty. Procedure Replace the compressor and fan drive board.
  • Page 117 AtomX Series VRF 6 4.6 1J45: Fan motor code mismatch Digital display output Description The compressor parameters set by the main control board do not match the compressor parameters of the drive board. Possible causes Once this fault occurs, the fan cannot be started up, and the drive board must be checked. The capacity DIP switch or model DIP switch of the main control board is incorrectly set.
  • Page 118 AtomX Series VRF 60Hz 4.7 1J5E: Fan startup failed Digital display output Description The fan stops running after the error. If the error disappears after five seconds, the fan starts The fan fails to be started. again. Possible causes Fan motor stuck: Fan drive board is abnormal: Procedure XJ5E fault...
  • Page 119 AtomX Series VRF 6 4.8 1J51: Fan zero speed protection Digital display output Description Possible causes Fan zero speed protection The system has impurities or lacks oil, causing fan locked...
  • Page 120 AtomX Series VRF 60Hz 4.9 1J52: Fan locked-rotor Protection Digital display output Description The fan stops running after the error. If the error disappears after five seconds, the fan starts The fan is blocked. again. Possible causes Procedure 1J52 The fan shaft is stuck. Check whether the motor is blocked Replace the drive board...
  • Page 121 AtomX Series VRF 6 4.10 1J6E: Fan motor phase loss protection Digital display output Description The fan stops running after the error. If the error disappears after five seconds, the fan starts The fan has phase loss protection. again Possible causes The IPM of inverter drive board is damaged The compressor cable is in poor contact or the terminal screw is not tightened.
  • Page 122 AtomX Series VRF 60Hz 4.11 1J65: Fan IPM short circuit Digital display output Description Possible causes Fan IPM short circuit Abnormal control board in outdoor unit: damaged Procedure 1J65 Replace the drive board in outdoor unit and power it back up and run Normal operation...
  • Page 123 AtomX Series VRF 6 5 Error in Shut-off Device 5.1 3b01 : The electronic ball valve is in error Digital display output Description Shut-off device displays error code 3b01, the outdoor unit displays error code All units stop running Possible causes Electronic expansion valve EBVA/B is not connected to main control board coil is damaged.
  • Page 124 AtomX Series VRF 60Hz Notes: [1] All models of ODU have electronic ball valves A and B, which are connected to the main boards CN30 and CN [2] Schematic diagram of coil resistance measurement of electronic ball valve and reference range of resistance The coil Valve A/B Measurement point...
  • Page 125 AtomX Series VRF 6 5.2 C2A: Communication error between outdoor unit and refrigerant shut-off device. Digital display output Description All units stop running. Communication error between outdoor unit and refrigerant shut-off device. Shut-off device displays error code C2A, the outdoor unit displays error code Table 5-1.6 Error caused by communication table Possible causes Shut-off device...
  • Page 126 AtomX Series VRF 60Hz Procedure Corresponding to the actual installation of ODU Check whether the ODU interface, shut-off device interface, judging the communication is correct selection of communication protocol Check whether the ODU has ODU power on been powered on 1.The communication wiring is not tightened;...
  • Page 127 AtomX Series VRF 6 5.3 P71: Error in EEPROM Digital display output Description All units stop running The EEPROM parameter of the shut-off device main control board is incorrect Shut-off device displays error code Possible causes EEPROM units damaged: Main control board is damaged: Procedure Shut- off device power off and power on again to see...
  • Page 128 AtomX Series VRF 60Hz 5.4 Ab1: Error in power-down Digital display output Description All units stop running The power supply to the shut-off device is disconnected. Shut-off device displays error code Possible causes Power switch jumped turns; Loose power cord; Main control board is damaged: Procedure Shut-off device...
  • Page 129 AtomX Series VRF 6 5.5 P5d: Supercapacitor voltage over rated operational voltage Digital display output Description All units stop running. Supercapacitor voltage is seriously too high Shut-off device displays error code P5d, the outdoor unit displays error code Possible causes Main control board of refrigerant shut-off device is damaged Main control boa rd is Procedure...
  • Page 130 AtomX Series VRF 60Hz 5.6 P5E: Supercapacitor voltage lower than rated operational voltage Digital display output Description All units stop running. Supercapacitor voltage is seriously too low Shut-off device displays error code P5E, the outdoor unit displays error code Possible causes Main control board of refrigerant shut-off device is damaged Main control boa rd is Procedure...
  • Page 131 AtomX Series VRF 6 6 Appendix 6.1 Resistance characteristics of temperature sensor Table 6-6.1: Temperature probe symbol and position Temperature probe symbol and position The probe type Bottom of heat exchanger Type A Outdoor ambient temperature Type A Liquid pipe stop valve Type A T7C1/T7C2 Inverter compressor A discharge...
  • Page 132 AtomX Series VRF 60Hz 6.2 Resistance of Temperature sensor A Table 6-6.2: Temperature sensor temperature resistance characteristic table Rmin(K ) Rnom(K ) Rmax(K ) Rmin(K ) Rnom(K ) Rmax(K ) T( ) T( ) 337.762 388.619 446.732 37.558 40.376 43.365 315.441 362.171 415.45...
  • Page 133 AtomX Series VRF 6 Table 6-6.2: Temperature sensor temperature resistance characteristic table (continues) Rmin(K ) Rnom(K ) Rmin(K ) Rnom(K ) Rm ax(K ) T( ) Rmax(K ) T( ) 6.412 6.69 6.975 1.455 1.585 1.725 6.132 6.407 6.688 1.403 1.53 1.668 5.866...
  • Page 134 AtomX Series VRF 60Hz Table 6-6.2: Temperature sensor temperature resistance characteristic table (continues) Rmin(K ) Rnom(K ) Rmin(K ) Rnom(K ) Rmax(K ) T( ) Rmax(K ) T( ) 0.434 0.49 0.553 0.16 0.186 0.216 0.422 0.477 0.538 0.156 0.181 0.211 0.41 0.463...
  • Page 135 AtomX Series VRF 6 6.3 Resistance of Temperature sensor B Table 6-6.3: Temperature sensor temperature resistance characteristic table Rmin(K ) Rnom(K ) Rmax(K ) Rmin(K ) Rnom(K ) Rmax(K ) T( ) T( ) 1447.607 1780.01 2186.77 182.421 210.39 242.429 1357.115 1665.411 2041.903...
  • Page 136 AtomX Series VRF 60Hz Table 6-6.3: Temperature sensor temperature resistance characteristic table (continues) Rmin(K ) Rnom(K ) Rmin(K ) Rnom(K ) Rmax(K ) T( ) Rmax(K ) T( ) 34.655 37.967 41.558 8.048 8.427 8.817 33.284 36.419 39.814 7.788 8.147 8.515 31.973 34.942...
  • Page 137 AtomX Series VRF 6 Table 6-6.3: Temperature sensor temperature resistance characteristic table (continues) Rmin(K ) Rnom(K ) Rmin(K ) Rnom(K ) Rmax(K ) T( ) Rmax(K ) T( ) 2.328 2.452 2.58 0.841 0.912 0.989 2.262 2.384 2.511 0.825 0.896 0.972 2.198 2.319...
  • Page 138 AtomX Series VRF 60Hz 6.4 High Pressure Sensor Voltage Characteristics Table 6-6.4: High pressure sensor voltage characteristic table High pressure (MPa) High pressure (psi) Resistance (K ) Output voltage(V) 14.5 225.5555556 0.5869565 192.5806452 0.673913 43.5 167.1428571 0.7608696 146.9230769 0.8478261 72.5 130.4651163 0.9347826 116.8085106...
  • Page 139 AtomX Series VRF 6 4.673366834 4.326087 652.5 3.990147783 4.4130435 3.333333333 Measure the voltage between the middle and the lower pin (blue one) **Outdoor unit: high pressure sensor...
  • Page 140 AtomX Series VRF 60Hz 6.5 Low Pressure Sensor Voltage Characteristics Table 6-6.5: Low pressure sensor voltage characteristic table Low pressure Low pressure Resistance Output Low pressure Resistance Output (MPa) (psi) (K ) voltage(V) Low pressure (MPa) (psi) (K ) voltage(V) 14.5 184.285714 0.68...
  • Page 141 AtomX Series VRF 6 6.6 Quick Field Test Guide on Main Control Board Figure 6.6.4: Main Control Board Main control board Digital Display...
  • Page 142 AtomX Series VRF 60Hz Main Control Board Test: The Control board is powered from the Drive board. While Control board start working, the Digital Display and LED1 will light up. Normally, the Digital Display indicates running conditions of the unit. If the Digital Display or LED1 do not light up when the unit is powered on, check the wiring and input power.
  • Page 143 AtomX Series VRF 6 Figure 6.6.6: Main Control Board Port measurement guidelines Table 6-6.6: Main control board definition table Multimeter Multimeter System Multimeter Black Normal Value Notes Status Stalls Probe (+) Probe (+) Power off 0.3~0.7V 0V or are abnormal Rectifier bridge Power off 0.3~0.7V...
  • Page 144 AtomX Series VRF 60Hz 6.7 Quick Field Test Guide on Compressor & Fan Drive Board There three different drive boards for different outdoor units. The following items are three different drive boards diagrams. 1.5/2.0ton Compressor & Fan Drive Board Test Please look at the corresponding diagram to fing the test points, then refer to Table 4.8 for Normal Value.
  • Page 145 AtomX Series VRF 6 Test points of drive board, please refer to Figure 6.6.8 and Table 6.6.7 for test method and Normal Value. Figure 6.6.8: Main Control Board Port...
  • Page 146 AtomX Series VRF 60Hz 2.5/3.0ton Compressor & Fan Drive Board Test Figure 6.6.7: Compressor & Fan Drive Board...
  • Page 147 AtomX Series VRF 6 Test points of drive board, please refer to Figure 6.6.8 and Table 6.6.7 for test method and Normal Value. Figure 6.6.8: Main Control Board Port Note: The drive boards of 1.5/2.0ton and 2.5/3.0ton are installed upside down, it must be turned over to be test.
  • Page 148 AtomX Series VRF 60Hz 4.0/5.0ton Compressor & Fan Drive Board Test Figure 6.6.9: Compressor & Fan Drive Board...
  • Page 149 AtomX Series VRF 6 Test points of drive board, please refer to Figure 6.6.10 and Table 6.6.7 for test method and Normal Value. Figure 6.6.10: Main Control Board Port...
  • Page 150 AtomX Series VRF 60Hz Figure 6.6.11: Compressor & Fan Drive Board measurement guidelines Table 6-6.7: Compressor & Fan Drive Board definition table Normal Value Multimeter Multimeter Notes System Multimeter Black Status Stalls Probe (+) Power off Diodes 0.3~0.7V 0V or are abnormal Rectifier bridge Probe (+) 0.3~0.7V...
  • Page 151 AtomX Series VRF 6...
  • Page 152 Add.: Midea Headquarters Building, 6 Midea Avenue, Shunde, Foshan, Guangdong, China Postal code: 528311 mbt.midea.com / global.midea.com/ ics.midea.com Note: Midea reserves the right to change the specifications of the product, and to withdraw or replace products without prior notification or public announcement. Midea is constantly developing and improving its products.

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