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M thermal Mono

82 

200208

Midea 

ther

ma

l Mo

no

 Se

rvice M

an

ual

 

4.19

 

P5 Troubleshooting 

 

Digital display output 

4.19.1

 

Description 

4.19.2

High temperature difference between water side heat exchanger water inlet and water outlet
temperatures

 

protection.

Mono stops running.

Error code is displayed on hydronic system main control board for refrigerant system and user interface.

 

Possible causes 

4.19.3

Temperature sensor not connected properly or has malfunctioned.

Water piping contains air.

Insufficient water flow.

Hydronic system main PCB damaged.

Midea CAC Confidential

Mono

Summary of Contents for 06RY1

Page 1: ...SERVICEMANUAL MONO TYPE HEAT PUMP R32...

Page 2: ...Mono...

Page 3: ...ermal Mono 202008 1 CONTENTS CONTENTS Part 1 General Information 3 Part 2 Component Layout and Refrigerant Circuits 5 Part 3 Control 15 Part 4 Diagnosis and Troubleshooting 31 Midea CAC Confidential M...

Page 4: ...M thermal Mono 2 202008 Midea M thermal Mono Service Manual Midea CAC Confidential Mono...

Page 5: ...M thermal Mono 202008 3 Part 1 General Information Part 1 General Information 1 Unit Capacities and External Appearance 4 Midea CAC Confidential Mono...

Page 6: ...obtained by substituting the asterisk in the model name format given in the left hand column of the table above with the shortened model names given in the table For example the model name for the 8kW...

Page 7: ...08 5 Part 2 Component Layout and Refrigerant Circuits Part 2 Component Layout and Refrigerant Circuits 1 Layout of Functional Components 6 2 Piping Diagrams 11 3 Refrigerant Flow Diagrams 13 Midea CAC...

Page 8: ...M thermal Mono 6 202008 Midea M thermal Mono Service Manual 1 Layout of Functional Components KHC 06RY1 Figure 2 1 1 KHC 06RY1 top view Figure 2 1 2 KHC 06RY1 front view Midea CAC Confidential Mono...

Page 9: ...M thermal Mono 202008 7 Part 2 Component Layout and Refrigerant Circuits Figure 2 1 3 KHC 06RY1 Midea CAC Confidential Mono...

Page 10: ...M thermal Mono 8 202008 Midea M thermal Mono Service Manual KHC 08RY1 KHC 10RY1 Figure 2 1 1 KHC 08 10 RY1 top view Midea CAC Confidential Mono...

Page 11: ...M thermal Mono 202008 9 Midea CAC Confidential Figure 2 1 2 KHC 08 10 RY1 front view Part 2 Component Layout and Refrigerant Circuits Mono...

Page 12: ...M thermal Mono 10 202008 Midea M thermal Mono Service Manual Figure 2 1 5 KHC 12 14 16 RY3 front view Midea CAC Confidential KHC 12RY3 KHC 14RY3 KHC 16RY3 Figure 2 1 4 KHC 12 14 16 RY3 top view Mono...

Page 13: ...p Flow switch High pressure switch Expansion vessel Manometer Single way solenoid valve Capillary Discharge temp sensor DC motor T4 T3 Filter Suction temp sensor Filter Low pressure switch F d e s c C...

Page 14: ...erant system pressure When refrigerant system pressure rises above the upper limit or falls below the lower limit the high or low pressure switches turn off stopping the compressor 5 Air purge valve A...

Page 15: ...iagrams Heating and domestic hot water operation 4 6KW for example Figure 2 3 1 Refrigerant flow during heating or domestic hot water operation Cooling and defrosting operation 4 6KW for example Figur...

Page 16: ...M thermal Mono 14 202008 Midea M thermal Mono Service Manual Midea CAC Confidential Mono...

Page 17: ...ol Part 3 Control 1 Stop Operation 16 2 Standby Control 16 3 Startup Control 17 4 Normal Operation Control 19 5 Protection Control 21 6 Special Control 25 7 Role of Temperature Sensors in Control Func...

Page 18: ...prevent refrigerant from mixing with compressor oil when the compressors are stopped The crankcase heater is controlled according to outdoor ambient temperature and the compressor on off state When t...

Page 19: ...MODE SETTING Menu and Part 3 7 6 HEAT MODE SETTING Menu 3 2 Compressor Startup Program In initial startup control and in re start control compressor startup is controlled according to outdoor ambient...

Page 20: ...FAN Fan runs at maximum speed 2 Electronic expansion valve EXV Position steps from 0 fully closed to 480 fully open controlled according to outdoor ambient temperature discharge temperature and suctio...

Page 21: ...EXV Position steps from 0 fully closed to 480 fully open controlled according to discharge temperature suction superheat and compressor speed Four way valve ST Off 4 2 Compressor Output Control The co...

Page 22: ...operating mode and outdoor ambient temperature After a further a few minutes the EXV is controlled according to suction superheat and discharge temperature Once a further a few minutes have elapsed th...

Page 23: ...the compressor from transient spikes in pressure Figure 3 5 1 High pressure protection control Notes 1 Pc Discharge pressure When the discharge pressure rises above 4 3MPa the system displays P1 prote...

Page 24: ...n temperature the compressor enters re start control 5 4 Compressor Current Protection Control This control protects the compressor from abnormally high currents Figure 3 5 5 Compressor current protec...

Page 25: ...150rpm for more than 90 seconds When DC fan motor protection control occurs the system displays the H6 error code and the unit stops running After 3 minutes the unit restarts automatically When H6 pro...

Page 26: ...Control When the module temperature rises at or above Tf2 the system displays C7 protection and the unit stops running When the module temperature drops at or below Tf0 1 the compressor enters re sta...

Page 27: ...e EXV 304 steps Four way valve ST Off Tables 3 6 2 show component control during oil return operation in heating and DHW modes Table 3 6 2 Outdoor unit component control during oil return operation in...

Page 28: ...n two zones control for cooling mode when the setting temperature of a certain zones is reached the zone and water pump of this zone will turn off In two zones control for heating mode the on off cont...

Page 29: ...eds at the same time Balance tank can store energy to provide hot water whilst heat pump runs heat mode cooling which can reduce the host selection and the initial investment 6 7 USB data transfer Con...

Page 30: ...ture Sensors in Control Functions Figure 3 7 1 Location of the temperature sensors on 6 16KW unit systems Notes 1 The names and functions of the temperature sensors labelled 1 to 12 in this figure are...

Page 31: ...ide heat exchanger water outlet temperature sensor Tw_out Heating Compressor output5 and on off control6 Freeze prevention control10 Cooling DHW 9 Backup electric heater water outlet temperature senso...

Page 32: ...M thermal Mono 30 202008 Midea M thermal Mono Service Manual Midea CAC Confidential Mono...

Page 33: ...o 202008 31 Part 4 Diagnosis and Troubleshooting 1 Outdoor Unit Electric Control Box Layout 32 2 Outdoor Unit PCBs 35 3 Error Code Table 49 4 Troubleshooting 52 5 Appendix to Part 4 110 Midea CAC Conf...

Page 34: ...nual 1 Outdoor Unit Electric Control Box Layout KHC 06RY1 Figure 4 1 1 Electric control box front view Main PCB for refrigerant system Main PCB for hydronic system Main PCB for refrigerant system Inve...

Page 35: ...RY1 KHC 10RY1 Figure 4 1 2 Electric control box front view Main PCB for refrigerant system Main PCB fort hydronic system Inverter module Outdoor unit power supply terminals Communication terminal bloc...

Page 36: ...Manual Midea CAC Confidential Figure 4 1 4 Electric control box front view Main PCB for refrigerant system Main PCB for hydronic system Inverter module Outdoor unit power supply terminals Communicati...

Page 37: ...the same on all Mono models The locations of each PCB in the outdoor unit electric control boxes are shown in Figures 4 1 1 to 4 1 4 in Part 4 1 Outdoor Unit Electric Control Box Layout 2 2 Main PCB f...

Page 38: ...wer port for room thermostat COM 18 CN35 Port for smart grid grid signal photovoltaic signal 19 CN36 Port for remote switch temperature board 20 CN19 Communicate port between indoor unit and outdoor u...

Page 39: ...stem Inverter Modules and filter board KHC 06RY1 KHC 08RY1 KHC 10RY1 Figure 4 2 2 KHC 06RY1 KHC 08RY1 KHC 10RY1 outdoor unit main PCB for refrigerant system 4 5 6 7 8 9 10 3 2 1 11 12 13 14 15 16 17 1...

Page 40: ...CN10 Input port for neutral wire 11 CN11 Input port for live wire 12 CN9 Port for outdoor ambient temp sensor and condenser temp sensor 13 CN24 Input port for 12V 9V 14 CN1 Port for suction temp sens...

Page 41: ...M thermal Mono 202008 39 Figure 4 2 3 KHC 06RY1 outdoor unit inverter module 1 2 3 8 7 4 5 6 9 Midea CAC Confidential Mono...

Page 42: ...M thermal Mono 40 200208 Midea M thermal Mono Service Manual Figure 4 2 3 KHC 08RY1 KHC 10RY1 outdoor unit inverter module 1 2 3 8 7 4 5 6 9 Midea CAC Confidential Mono...

Page 43: ...Figure 4 2 5 Code Content 1 U Compressor connection port U 2 V Compressor connection port V 3 W Compressor connection port W 4 CN20 Output port for 12V 5V 5 CN19 Port for fan 6 CN32 Port for communic...

Page 44: ...Service Manual KHC 12RY3 KHC 14RY3 KHC 16RY3 Figure 4 2 6 KHC 12RY3 KHC 14RY3 KHC 16RY3 outdoor unit main PCB for refrigerant system 1 1 2 3 4 5 6 7 8 3 2 1 9 10 11 12 13 28 27 26 25 24 23 22 21 20 1...

Page 45: ...tion with INVERT MODULE BOARD 13 CN6 Port for pressure sensor 14 CN36 Port for communication with MAIN CONTROL BOARD FOR REFRIGERANT SYSTEM CN36 15 CN4 Port for temp sensor Tp CN4 16 CN8 Port for temp...

Page 46: ...4 Output port for 15V 2 W Compressor connection port W 3 V Compressor connection port V 4 U Compressor connection port U 5 L1 Power Input port L1 6 L2 Power Input port L2 7 P_out Input port P_out for...

Page 47: ...2 CN200 Power supply L3 3 CN203 Power supply N 4 CN212 Power supply port of 310VDC 5 CN211 Power supply port for load 6 CN213 Port for FAN Reactor 7 CN214 Power supply port for Inverter module 8 PE3 G...

Page 48: ...per second Error or protection Error or protection code Error or protection code 2 5 DIP Switch Settings Modbus function will be available in 2020 5 30 The rotating coded switch S3 0 F on the main con...

Page 49: ...sor Th EA 11 Discharge pipe temperature sensor error User interface and refrigerant system main PCB Sensor Tp Ed 14 Water side heat exchanger water inlet temperature sensor error User interface and hy...

Page 50: ...Inverter module protection Refrigerant system main PCB L1 DC bus low voltage protection Refrigerant system main PCB L2 DC bus high voltage protection Refrigerant system main PCB L4 MCE error Refrigera...

Page 51: ...M thermal Mono 202008 51 Midea CAC Confidential Mono...

Page 52: ...and in accordance with all applicable legislation all national local and other laws standards codes rules regulations and other legislation that apply in a given situation Power off the outdoor units...

Page 53: ...E0 error occurs a manual system restart is required before the system can resume operation Mono stops running Error code is displayed on hydronic system main control board for refrigerant system and...

Page 54: ...switch is damaged Yes Replace the water flow switch No Internal circulator pump fuse backup electric heater fuse or hydronic system main PCB fuse has blown3 Yes Replace the blown fuse No Replace hydro...

Page 55: ...pplies to 3 phase models Mono stops running Error code is displayed on refrigerant system main control board for refrigerant system and user interface Possible causes 4 3 3 Power supply phases not con...

Page 56: ...ments If the phase sequence is inverted the compressor will operate inversely If the wiring connection of each outdoor unit is in A B C phase sequence and multiple units are connected the current diff...

Page 57: ...board for refrigerant system and user interface Possible causes 4 4 3 Communication wires between outdoor unit and user interface not connected properly Communication wiring X Y E terminals misconnec...

Page 58: ...0V or higher wires Yes Ensure the communication wires and high voltage wires are separated No Communication wires are close to a source of electromagnetic radiation such as transformer or strong fluor...

Page 59: ...heat exchanger water inlet temperature sensor error HA indicates a water side heat exchanger water outlet temperature sensor error H5 indicates a room temperature sensor error H9 indicates a zone 2 w...

Page 60: ...the hydronic system main PCB labeled 8 in Figure 4 2 1 in Part 4 2 2 Main PCB for Hydronic System Domestic hot water tank temperature sensor connection is port CN13 on the hydronic system main PCB la...

Page 61: ...ambient temperature sensor error E9 indicates a suction pipe temperature sensor error EA indicates a discharge temperature sensor error Mono stops running Error code is displayed on refrigerant syste...

Page 62: ...rt CN8 on the KHC 06 08 10 RY1 outdoor unit refrigerant system main PCB labeled 15 in Figure 4 2 2 in Part 4 2 1 Main PCBs for Refrigerant System Inverter Module port CN4 on the KHC 12 14 16 RY3 outdo...

Page 63: ...ssible causes 4 7 3 Hydronic system main PCB EEPROM is not connected properly Hydronic system main PCB damaged Procedure 4 7 4 EE Hydronic system EEPROM1 is not connected properly Yes Ensure the EEPRO...

Page 64: ...system main control board for refrigerant system and user interface Possible causes 4 8 3 The DC bus voltage is too low Procedure 4 8 4 F1 Power supply is abnormal Yes Provide normal power No LED ligh...

Page 65: ...rly Yes Ensure the EEPROM is connected properly No Replace refrigerant system main PCB Notes 1 Refrigerant system main PCB EEPROM is designated IC23 on the refrigerant system main PCBs labeled 29 in F...

Page 66: ...er supply No A transformer has malfunctioned2 Yes Replace the transformer No There is a source of electromagnetic radiation near the unit such as high frequency transmitter or other high strength radi...

Page 67: ...er has malfunctioned2 Yes Replace the transformer No There is a source of electromagnetic radiation near the unit such as high frequency transmitter or other high strength radiation device Yes Remove...

Page 68: ...uired before the system can resume operation The cause of an HH error should be addressed promptly in order to avoid system damage Mono stops running Error code is displayed on refrigerant system main...

Page 69: ...ain PCB Notes 1 Refer to Figures 4 1 1 to 4 1 7 in Part 4 1 Outdoor Unit Electric Control Box Layout and to the Mono Engineering Data Book Part 2 5 Wiring Diagrams 2 Only applies to single phase power...

Page 70: ...g Error code is displayed on refrigerant system main control board for refrigerant system and user interface Possible causes 4 13 3 Power supply voltage not within 10 of rated voltage or a phase is mi...

Page 71: ...er supply terminals are loose Yes Ensure the wires are connected properly No Outdoor unit powered on immediately after being powered off Yes Power off the unit and wait for at least 3 minutes before p...

Page 72: ...on refrigerant system main PCB is loose Yes Ensure the sensor is connected properly No High pressure sensor has short circuited or failed1 Yes Replace the sensor No Replace refrigerant system main PCB...

Page 73: ...cates P0 protection has occurred 3 times in 60 minutes When an HP error occurs a manual system restart is required before the system can resume operation Error code is displayed on refrigerant system...

Page 74: ...Notes 1 To check for insufficient refrigerant An insufficiency of refrigerant causes compressor discharge temperature to be higher than normal discharge and suction pressures to be lower than normal a...

Page 75: ...When the discharge pressure falls below 3 2MPa P1 is removed and normal operation resumes Error code is displayed on refrigerant system main control board for refrigerant system and user interface Po...

Page 76: ...e MHA V12 14 16 W D2N8 B outdoor unit refrigerant system main PCB labeled 16 in Figure 4 2 3 in Part 4 2 3 Main PCB for Refrigerant System Inverter Module port CN31 on the KHC 12 14 16 RY3 outdoor uni...

Page 77: ...W three phase model 14A the system displays P3 protection and Mono stops running When the current returns to the normal range P3 is removed and normal operation resumes Error code is displayed on refr...

Page 78: ...e heat exchanger water piping circulator pumps and water flow switch for dirt blockages In cooling mode check air side heat exchanger fan s and air outlets for dirt blockages 2 High pressure side bloc...

Page 79: ...ystem displays P4 protection and Mono stops running When the discharge temperature falls below 95 C P4 is removed and normal operation resumes Error code is displayed on refrigerant system main contro...

Page 80: ...perly No Temperature sensor has short circuited or failed3 Yes Replace the sensor No High pressure switch connection or pressure sensor connection on refrigerant system main PCB is loose4 Yes Ensure t...

Page 81: ...th the sensor s resistance characteristics table the sensor has failed Refer to Part 2 1 Layout of Functional Components and to Table 5 5 1 or 5 5 2 in Part 5 5 1 Temperature Sensor Resistance Charact...

Page 82: ...t exchanger water inlet and water outlet temperatures protection Mono stops running Error code is displayed on hydronic system main control board for refrigerant system and user interface Possible cau...

Page 83: ...iping or broken expansion vessel Yes Inspect the system and fix the error No Replace outdoor main PCB Notes 1 Water side heat exchanger water inlet temperature sensor and water side heat exchanger wat...

Page 84: ...ection Zero speed protection Excessive compressor frequency variation Actual compressor frequency differs from target frequency High pressure protection PED board self checking fail Specific error cod...

Page 85: ...ection Table 4 4 3 Errors indicated on LED single phase 4 10kW LED1 flashing pattern GREEN LED2 is always on RED Corresponding error Flashes 3 times and stops for 1 second then repeats P1 High pressur...

Page 86: ...erter module is damaged1 Yes Replace the inverter module2 Notes 1 Measure the resistance between each of U V and W and each of P and N on the inverter module All the resistances should be infinite If...

Page 87: ...tance between each of U V and W and each of P and N on the inverter module All the resistances should be infinite If any of them are not infinite the inverter module is damaged and should be replaced...

Page 88: ...e compressor No Replace the inverter module3 Notes 1 Refer to Figure 4 4 2 2 Use clip on ammeter to measure the compressor current if the current is normal indicates the inverter module is failed if t...

Page 89: ...appears immediately after the outdoor unit is powered on L1 L2 Power supply is abnormal Yes Re start the unit once the power supply has returned to normal No Replace the inverter module1 Notes 1 When...

Page 90: ...le PCB Refer to Figure 4 4 2 Figure 4 4 4 Relay location of main PCB for refrigerant system Single phase 4 6 8 10kW unit Single phase 12 14 16kW unit Relay L5 L8 L9 troubleshooting 4 20 8 L5 L8 L9 The...

Page 91: ...rotection Excessive compressor frequency variation Actual compressor frequency differs from target frequency High pressure protection Contactor stuck or 908 self checking fail Specific error codes for...

Page 92: ...rotection Flashes 17 times and stops for 1 second then repeats L8 Compressor frequency variation greater than 15Hz within one second protection L9 Actual compressor frequency differs from target frequ...

Page 93: ...port between refrigerant system main control board for refrigerant system inverter module is port CN36 on refrigerant system main control board for refrigerant system port CN8 on inverter module 2 Mea...

Page 94: ...wire should run from the N terminal on the inverter module through the current sensor in the direction indicated by the arrow on the current sensor and end at the N terminal of capacitor Refer to Fig...

Page 95: ...wire from the inverter module to the correct compressor terminals as indicated by the labels on the compressor 2 Measure the voltage between each of W W V V U U and GND when the unit is in standby The...

Page 96: ...Yes Replace the compressor No Replace the inverter module2 Notes 1 When replacing an inverter module a layer of thermally conductive silica gel should be painted on the IPM module on the reverse side...

Page 97: ...or unit is powered on L1 L2 P N 15V wire on refrigerant system main PCB is not connected properly1 Yes Ensure P N 15V wire is connected properly No Voltage between N and 15 is abnormal2 Yes Check 15V...

Page 98: ...Put the red probe on the DC power output negative terminal terminal 5 and put the black probe onto each of the AC power input terminals terminals 1 2 and 3 in turn The voltage between terminal 5 and...

Page 99: ...is over current2 Yes Replace the compressor No Replace the inverter PCB Notes 1 Re start the unit use clip on ammeter to measure the compressor current if the current is normal indicates the compresso...

Page 100: ...ubleshooting Digital display output 4 22 1 Description 4 22 2 PED PCB failure Split stops running Error code is displayed on hydronic box main PCB and user interface Possible causes 4 22 3 Power suppl...

Page 101: ...an be recovered Yes Increase the power voltage to the required range No PED1 board broken Yes Replace PED PCB and power on again No IPM module broken Yes Replace IPM module and power on again Notes 1...

Page 102: ...r is connected properly No Water side heat exchanger water outlet temperature sensor water inlet temperature sensor or backup electric heater outlet water temperature sensor has short circuited or fai...

Page 103: ...stem displays Pd protection and Mono stops running When the air side heat exchanger refrigerant outlet temperature returns drops below 55 C Pd is removed and normal operation resumes Mono stops runnin...

Page 104: ...nt temperature sensor connections are port CN9 on the refrigerant system main PCB labeled 12 in Figure 4 2 2 in Part 4 2 3 Main PCBs for Refrigerant System Inverter Modules and Filter Boards labeled 5...

Page 105: ...ture in heating mode Mono stops running Error code is displayed on hydronic system main control board for refrigerant system and user interface If PP error occurs 3 times then Hb will appear Possible...

Page 106: ...nsor and water side heat exchanger water outlet temperature sensor connections are port CN6 on the hydronic system main PCB labeled 8 in Figure 4 2 1 in Part 4 2 2 Min PCB for Hydronic System 2 Measur...

Page 107: ...n hydronic system main PCB outdoor unit main PCB and user interface Possible causes 4 26 3 Temperature collecting plate Optional connection wire is not connected Temperature collecting plate Optional...

Page 108: ...licate Main board fuse is damaged Procedure 4 27 4 Hd SW9 DIP switch with wrong settings Yes Check SW9 setting Master unit ON Slave unit OFF No More than two units are connected to the wire controller...

Page 109: ...rmal Mono 202008 109 No Address code missing or address code setting duplicate Yes Reset address code by another controller No Main board fuse is damaged Yes Replace main board Midea CAC Confidential...

Page 110: ...18 94 769 22 11 496 62 2 181 102 0 574 17 89 353 23 10 971 63 2 102 103 0 558 16 84 278 24 10 473 64 2 026 104 0 542 15 79 521 25 10 65 1 953 105 0 527 14 75 059 26 9 551 66 1 883 13 70 873 27 9 125...

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