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Century COMFORT-AIRE VMH-SG Series Service Manual

Single zone mini-splits
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Service Manual - VMHxxSG
Service Manual
VMH-SG Series
Single Zone Mini-Splits
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VMH30, 36 SG Series
www.marsdelivers.com

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Summary of Contents for Century COMFORT-AIRE VMH-SG Series

  • Page 1 Service Manual - VMHxxSG Service Manual VMH-SG Series Single Zone Mini-Splits Model VMH30, 36 SG Series www.marsdelivers.com...

  • Page 2: Table Of Contents

    Service Manual - VMHxxSG Table of Contents §. Safety Precautions Precautions Information servicing(For flammable materials) §. Specifications Model Reference Pipe length and the Drop Height Electrical Wiring Diagrams §. Product Features Display Functions Safety Features Basic Features §. Maintenance First Time Installation Checks Refrigerant Recharge Re-Installation §.
  • Page 3 Service Manual - VMHxxSG Table of Contents §. Troubleshooting Safety Caution General Troubleshooting Complain Record Form Information Inquiry Error Diagnosis and Troubleshooting Without Error Code Quick Maintenance by Error Code Troubleshooting by Error Code Check Procedures Appendix Temperature Sensor Resistance Value Table for T1,T2,T3 and T4 (°C – K) Temperature Sensor Resistance Value Table for TP(for some units) (°C –...
  • Page 4 Service Manual - VMHxxSG Safety Precautions Contents Precautions ......................2 Information servicing(For flammable materials) ..........3...

  • Page 5: Safety Precautions

    Service Manual - VMHxxSG 1. Precautions CAUTION To prevent personal injury, or property or unit damage, • • While unpacking be careful of sharp edges around adhere to all precautionary measures and instructions the unit as well as the edges of the fins on the con- denser and evaporator.

  • Page 6: Information Servicing(For Flammable Materials)

    Service Manual - VMHxxSG 2. Information servicing(For • Prior to work taking place, the area around the equipment is to be surveyed to make sure that there are no flammable flammable materials) hazards or ignition risks. • NO SMOKING signs shall be displayed. Checks to the area Ventilated area •...
  • Page 7 Service Manual - VMHxxSG • that capacitors are discharged: this shall be done in shall also take into account the effects of aging or a safe manner to avoid possibility of sparking; continual vibration from sources such as compressors or fans. •...

  • Page 8: Specifications 5

    Service Manual - VMHxxSG • The refrigerant charge shall be recovered into the • Before attempting the procedure ensure that: correct recovery cylinders. The system shall be flushed • mechanical handling equipment is available, if with OFN to render the unit safe. This process may required, for handling refrigerant cylinders;...
  • Page 9 Service Manual - VMHxxSG • Empty recovery cylinders are evacuated and, if • The recovered refrigerant shall be returned to the possible, cooled before recovery occurs. refrigerant supplier in the correct recovery cylinder, and the relevant Waste Transfer Note arranged. Do not •...
  • Page 10 Service Manual - VMHxxSG Specifications Contents Model Reference ....................2 Pipe Length and Drop Height ................3 Electrical Wiring Diagrams ..................4...

  • Page 11: Model Reference

    Service Manual - VMHxxSG 1. Model Reference Refer to the following table to determine the specific indoor and outdoor unit model. Indoor Unit Model Outdoor Unit Model Capacity (Btu/h) Power Supply B-VMH30SG-1 A-VMH30SG-1 208/230~, 60Hz, 1Phase B-VMH36SG-1 A-VMH36SG-1  Specifications 2 ...

  • Page 12: Pipe Length And The Drop Height

    Service Manual - VMHxxSG 2. Pipe Length and Drop Height The length and elevation of connection pipe are shown in the table below. if the pipe length exceeds max pipe length, additional refrigerant should be charged to ensure nominal cooling/heating capacity. Capacity(Btu/h) Standard Length Max Pipe Length...

  • Page 13: Electrical Wiring Diagrams

    Service Manual - VMHxxSG 3. Electrical Wiring Diagrams Indoor and outdoor unit wiring diagram Indoor Unit Outdoor Unit IDU Model IDU Wiring Diagram ODU Model ODU Wiring Diagram B-VMH30SG-1 A-VMH30SG-1 16022000034669 16022000034529 B-VMH36SG-1 A-VMH36SG-1 Outdoor unit printed circuit board diagram Outdoor Unit ODU Model ODU Printed Circuit Board...
  • Page 14 Service Manual - VMHxxSG Indoor unit abbreviations Abbreviation Paraphrase Yellow-Green Conductor Positive and Negative Ion Generator Capacitor PLASMA Electronic Dust Collector LIVE NEUTRAL Outdoor unit abbreviations Abbreviation Paraphrase 4-WAY Gas Valve Assembly/4-WAY VALVE AC-FAN Alternating Current FAN DC-FAN Direct Current FAN COMP Compressor L-PRO...
  • Page 15 Service Manual - VMHxxSG 30k-36k INDOOR WIRING DIAGRAM 16022000034669 I NDOOR 5 (10) 5 (10) 5(3 or 2) PLASMA OR ION(12V) CN11 C N13 C N12 C N27 C N19 C N21 C N22 CN26 T ransformer or OR UVC Power board C N10 C N15...
  • Page 16 Service Manual - VMHxxSG 30k-36k Outdoor unit wiring diagram: 16022000034529 1 ------- 1 OPTIONAL : IT3T4TP ;-0PT10N� I �OPTIONAL: �� �;��RATURE I TF ;;tJ I I PROTECTION OF COMPRESSOR EEV 1 RED : :YELLOW ._ _ YELLOW CN29 CN42 BLACK BLUE RED I CN20...
  • Page 17 Service Manual - VMHxxSG 30k-36k Outdoor unit printed circuit board diagram: 17122000047742...
  • Page 18 Service Manual - VMHxxSG Name Meaning CN11 N_in: connect to N-line (208-230V AC input) Power Supply CN12 L_in: connect to L-line (208-230V AC input) EEV-A CN16 EEV-B CN13 EEV-C EEV-D CN15 connect to electric expansion valve EEV-E EEV-F CN17 EEV-G CN14 connect to pipe temp.
  • Page 19 Service Manual - VMHxxSG Name Meaning HEAT_D CN20 connect to the heater, 208-230V AC when is ON CN21 HEAT_Y CN36 4-WAY CN38 connect to 4 way valve, 208-230V AC when is ON. CN27 connect to key board CN1 Note: This section is for reference only. Please take practicality as standard.
  • Page 20 Service Manual - VMHxxSG Product Features Contents Display Functions s ....................2 Safety Features ......................3 Basic Functions .......................4 Abbreviation s....................4 Fan Mode ......................4 Cooling Mode ....................4 Heating Mode(Heat Pump Units) ..............5 Auto-mode ....................6 Drying Mode ....................7 Forced Operation Function ................7 Timer Function ....................7 Sleep Function ....................7 3.10 Auto-Restart Function ..................8 3.11 Active Clean function ..................8...

  • Page 21: Product Features

    Service Manual - VMHxxSG 1. Display Function Unit display functions Display Function ECO function (available on select units only) when Wireless Control feature is activated(some units) Temperature value Temperature Timer ON is set. Activation of , Fresh, Swing, Turbo, ECO, Breeze away, ECO (3s) intelligent or Silence Timer OFF is set.

  • Page 22: Safety Features

    Service Manual - VMHxxSG 2. Safety Features Compressor three-minute delay at restart Compressor functions are delayed for up to ten seconds upon the fi rst startup of the unit, and are delayed for up to three minutes upon subsequent unit restarts. Automatic shutoff based on discharge temperature If the compressor discharge temperature exceeds a certain level for a period of time, the compressor ceases operation.

  • Page 23: Basic Functions

    Service Manual - VMHxxSG 3. Basic Functions frequency(FminC). • Compressor runs at FminC more than 10 minutes. Abbreviation • T1 is lower than or equal to (Tsc-CDIFTEMP). Note: CDIFTEMP is EEPROM setting parameter. It is 2°C Unit element abbreviations usually. Abbreviation Element 3) If one of the following conditions is satisfied, not judge...

  • Page 24: Heating Mode(Heat Pump Units)

    Service Manual - VMHxxSG For AC fan motor units: level per 1 minute. • Hold: Keep the current frequency. • Resume: No limitation for frequency. Heating Mode(Heat Pump Units) 3.4.1 Compressor Control 1) Reach the configured temperature • If the following conditions are satisfied, the compressor ceases operation.
  • Page 25 Service Manual - VMHxxSG 2) Auto fan defrosting ends and the machine switches to normal heating mode: For DC fan motor units: • T3 rises above TCDE1°C. • Rise curve • T3 maintained above TCDE2°C for 80 seconds. • When T1-Tsc is higher than -1.5°C, fan speed •...

  • Page 26: Auto-Mode

    Service Manual - VMHxxSG • Decrease: Decrease the running frequency to the lower following signals: level per 20 seconds. • Switch on • Hold: Keep the current frequency. • Switch off • Resume: No limitation for frequency. • Timer on •...

  • Page 27: Auto-Restart Function

    Service Manual - VMHxxSG • The operational process for sleep mode is as follows: you press “Follow Me,” the function turns off. The unit regulates temperature based on its own sensor • When cooling, the temperature rises 1°C (to not and settings.

  • Page 28: Breeze Away Function(Optional)

    Service Manual - VMHxxSG 3.17 Breeze Away function (Optional) • This feature avoids direct airflow blowing on the body. • NOTE: This feature is available under cooling mode, fan-only mode and drying mode. 3.18 Wireless Control (Optional) • Wireless control allows you to control your air conditioner using your mobile phone and a Wireless connection.
  • Page 29 Service Manual - VMHxxSG Maintenance Contents First Time Installation Check .................2 Refrigerant Recharge ....................4 Re-Installation .......................5 Indoor Unit ....................5 Outdoor Unit ....................7...

  • Page 30: First Time Installation Check

    Service Manual - VMHxxSG 1. First Time Installation Check Air and moisture trapped in the refrigerant system affects To prevent air and moisture from affecting the air the performance of the air conditioner by: conditioner’s performance, the indoor unit, as well as the pipes between the indoor and outdoor unit, must be be •...
  • Page 31 Service Manual - VMHxxSG Procedure: • If the pressure successfully reaches -0.1 MPa Tighten the flare nuts of the indoor and outdoor (14.5 Psi), fully close the Handle Lo valve, then units, and confirm that both the 2- and 3-way valves cease vacuum pump operations.

  • Page 32: Refrigerant Recharge

    Service Manual - VMHxxSG 2. Refrigerant Recharge mA A Procedure: Close both 2- and 3-way valves. 3-way valves. Slightly connect the Handle Lo charge hose to the Operate the air conditioner in cooling mode to charge 3-way service port. the system with liquid refrigerant. Connect the charge hose to the valve at the bottom When the electronic scale displays the correct of the cylinder.

  • Page 33: Re-Installation

    Service Manual - VMHxxSG 3. Re-Installation Indoor Unit Collecting the refrigerant into the outdoor unit Procedure: Confirm that the 2- and 3-way valves are opened. Close the 3-way valve so that the gauge rests between 0.3 MPa (43.5 Psi) and 0.5 MPa (72.5 Psi). Connect the charge hose with the push pin of Handle Lo to the 3-way valve’s gas service port.
  • Page 34 Service Manual - VMHxxSG Air purging with vacuum pump Procedure: • If the pressure successfully reaches -0.1 MPa Tighten the flare nuts of the indoor and outdoor (14.5 Psi), fully close the Handle Lo valve, then units, and confirm that both the 2- and 3-way valves cease vacuum pump operations.

  • Page 35: Outdoor Unit

    Service Manual - VMHxxSG Outdoor Unit Evacuation for the whole system Procedure: Wait for 5 minutes then check whether the gauge Confirm that the 2- and 3-way valves are opened. needle moves after turning off the vacuum pump. If Connect the vacuum pump to the 3-way valve’s the gauge needle moves backward, check whether service port.
  • Page 36 Service Manual - VMHxxSG Refrigerant charging mA A Procedure: Close both 2- and 3-way valves. Fully open the Handle Lo manifold valve, 2- and 3-way valves. Slightly connect the Handle Lo charge hose to the 3-way service port. Operate the air conditioner in cooling mode to charge the system with liquid refrigerant.
  • Page 37 Service Manual - VMHxxSG Indoor Unit Disassembly Contents Dimension ......................2 Indoor Unit Disassembly ..................3 Front Panel ....................3 Electrical parts ....................7 Fan motor and fan ..................10 Step motor ....................12 Drain Hose ....................14 Evaporator ....................15...

  • Page 38: Dimension

    Service Manual - VMHxxSG 1. Dimension Capacity Body Code W(mm/inch) D(mm/inch) H(mm/inch) 3 3 0 0 k~36k 1140/44.88 275/10.83 370/14.57 Indoor Unit Disassembly 2  Indoor Unit Disassembly 2 ...

  • Page 39: Indoor Unit Disassembly

    Service Manual - VMHxxSG 2. Indoor unit Disassembly Front Panel Procedure Illustration 1) Put your hands at the 2 sides of filter, pull the filter gently along the verticall direction, and then remove it.(see CJ_EP_001) CJ_EP_001 2) Open the horizontal louver and push the locker towards right to open it.
  • Page 40 Service Manual - VMHxxSG Procedure Illustration 4) Open the panel assembly, move the slider to fix the panel. (see CJ_EP_003) CJ_EP_003 5) Open two stop blocks of panel frame assembly. (see CJ_EP_004) 6) Remove 1 fixing screw in the panel frame.
  • Page 41 Service Manual - VMHxxSG Procedure Illustration 7) pull two sides of the bottom panel along the direction indicated in right image to remove it. (see CJ_EP_005) CJ_EP_005 8) Pull the mandril of panel to remove it.(see CJ_EP_006) 9) Remove the panel assembly.(see CJ_EP_006) (Caution: If you want to close the panel, you must bend the middle of mandril,...
  • Page 42 Service Manual - VMHxxSG Procedure Illustration 10) Remove 1 screw of the display board. (see CJ_EP_007) 11) Rotate the display board subassembly in the direction shown in the right picture. (see CJ_EP_007) 12) Pull the four clips to remove the display board.(see CJ_EP_007) CJ_EP_007 Note: This section is for reference only.

  • Page 43: Electrical Parts

    Service Manual - VMHxxSG Electrical parts (Antistatic gloves must be worn.) Note: Open the front panel (refer to 2.1 Front panel) before disassembling electrical parts. Procedure Illustration 1) Pull the two lifts of the cover of electronic control box with thumbs and then open it.
  • Page 44 Service Manual - VMHxxSG Procedure Illustration 4) Disconnect the wires. (see CJ_EP_010) CJ_EP_010 5) Remove one screw used for the ground connection. (see CJ_EP_011) 6) Pull two clips of the electronic control box along the direction shown in the right picture to remove the main control board.
  • Page 45 Service Manual - VMHxxSG Procedure Illustration 7) Remove the other screw used for the ground connection.(see CJ_EP_012) 8) Collapse the mandril.(see CJ_EP_012) 9) Pull the cover of electronic control box along the direction indicated in right image to remove it.(see CJ_EP_012) Ground Screw CJ_EP_012 10) Remove one fixing screw then pull out...

  • Page 46: Fan Motor And Fan

    Service Manual - VMHxxSG Fan motor and fan Note: Remove the front panel (refer to 2.1 Front panel). before disassembling fan motor and fan. Procedure Illustration 1) Open two stop blocks of chassis assembly(below). (see CJ_EP_014) 2) Remove chassis assembly(below) along the direction shown in the right picture (see CJ_EP_014) CJ_EP_014...
  • Page 47 Service Manual - VMHxxSG Procedure Illustration 4) Remove the bearing sleeve (see CJ_ EP_016). CJ_EP_016 5) Remove the fixing screw (see CJ_EP_017). 6) Pull out the fan motor and fan assembly from the side. CJ_EP_017 Note: This section is for reference only. Actual unit appearance may vary. Indoor Unit Disassembly 11 ...

  • Page 48: Step Motor

    Service Manual - VMHxxSG Step motor Note: Remove the front panel and chassis assembly(below) (refer to 2.1 Front panel and 2.3 Fan motor and fan) before disassembling step motor. Procedure Illustration 1) Remove one screw to remove cover of louver motor.(see CJ_EP_018).(for some units) CJ_EP_018 2) Open the cover of louver motor, pull...
  • Page 49 Service Manual - VMHxxSG Procedure Illustration 3) Remove the two screws, then remove the horizontal swing motor(see CJ_EP_020). Note: The horizontal swing motor is located in panel assembly. swing motor CJ_EP_020 4) Remove 2 screws, then remove the vertical swing motor swing motor (see CJ_EP_021).(for some units) 5) Remove 1 screw, then remove the ionizer...

  • Page 50: Drain Hose

    Service Manual - VMHxxSG Drain Hose Procedure Illustration 1) Rotate the fixed wire clockwise indicated in right image. (see CJ_EP_022) 2) Pull up the drain hose to remove it. (see CJ_EP_022) CJ_EP_022 Note: This section is for reference only. Actual unit appearance may vary. Indoor Unit Disassembly 14 ...

  • Page 51: Evaporator

    Service Manual - VMHxxSG Evaporator Note: Remove the front panel, electrical parts and fan (refer to 2.1 Front panel, 2.2 Electrical parts and 2.3 fan motor and fan) before disassembling evaporator. Procedure Illustration 1) Remove the 2 screws then remove the panel frame assembly.(see CJ_EP_023) CJ_EP_023 2) Disassemble the pipe clamp board.(see...
  • Page 52 Service Manual - VMHxxSG Procedure Illustration 3) Remove the 1 screw on the evaporator located at the left fixed plate (see CJ_ EP_025). 4) Remove the 1 screw on the evaporator located on the right side. (see CJ_EP_025). CJ_EP_025 5) Bend the piping carefully, separate the chassis assembly(above) and the evaporator then take the evaporator out.
  • Page 53 Service Manual - VMHxxSG Outdoor Unit Disassembly Contents Outdoor Unit Table ....................2 Dimension ......................3 Outdoor Unit Disassembly ..................5 5 Panel Plate ....................5 Electrical Parts .....................9 Fan Assembly ....................11 Fan Motor ....................12 Sound blanket .....................13 Four-way valve .....................14 Compressor ....................15...

  • Page 54: Outdoor Unit Table

    Service Manual - VMHxxSG 1. Outdoor Unit Disassembly Outdoor Unit Table Outdoor Unit Model Panel Plate PCB Board A-VMH30SG-1 PCB Board 12 A-VMH36SG-1 PCB Board 12  Outdoor Unit Disassembly 2  Outdoor Unit Disassembly 2...
  • Page 55 Service Manual - VMHxxSG Panel Plate 30k-36k  Outdoor Unit Disassembly 11 Outdoor Unit Disassembly 3 ...
  • Page 56 Service Manual - VMHxxSG For US models: 30k-36k Outdoor Unit Disassembly 4  Outdoor Unit Disassembly 12 ...

  • Page 57: Panel Plate

    Service Manual - VMHxxSG 3. Outdoor Unit Disassembly Panel Plate 5. D30 3 3 0 0 k k - - 3 3 6 6 k k Procedure Illustration 1) Turn off the air conditioner and the Big Handle power breaker. 2) Remove the screws of the big handle and then remove the big handle (2 screws) (see CJ_D30_001).
  • Page 58 Service Manual - VMHxxSG Procedure Illustration 4) Remove the screws of the front right panel and then remove the front right panel (2 screws) (see CJ_D30_003). Front Right Panel CJ_D30_003 5) Remove the screws of the front panel and then remove the front panel (9 screws) (see CJ_D30_004).
  • Page 59 Service Manual - VMHxxSG Procedure Illustration 6) Remove the screws of water collecting cover and then remove the water collecting cover (2 screw) (see CJ_ D30_005). Water Collecting Cover CJ_D30_005 7) Remove the screws of the rear net and then remove the rear net (2 screws) CJ_D30_006).
  • Page 60 Service Manual - VMHxxSG Procedure Illustration 8) Remove the screws of the right panel and then remove the right panel (8 screws) (see CJ_D30_007). Right Panel CJ_D30_007 Note: This section is for reference only. Actual unit appearance may vary.  Outdoor Unit Disassembly 39 ...

  • Page 61: Electrical Parts

    Service Manual - VMHxxSG Electrical parts Antistatic gloves must be worn when you disassemble the electronic box. WARNING: Note: Remove the air outlet grille(refer to 3.1 Panel Plate) before disassembling electrical parts. PCB for ON-OFF Models 12. PCB board 12 Procedure Illustration 1) Unfix the hooks and then open the...
  • Page 62 Service Manual - VMHxxSG Procedure Illustration 3) Pull out the connectors (see CJ_ ODU_PCB_012-3 ). 4) Remove the 4 screws and then remove the electronic control board(see CJ_ODU_PCB_012-3 ). CJ_ODU_PCB_012-3 Note: This section is for reference only. Actual unit appearance may vary. ...

  • Page 63: Fan Assembly

    Service Manual - VMHxxSG Fan Assembly Note: Remove the panel plate (refer to 3.1 Panel Plate) before disassembling fan. Procedure Illustration 1) Remove the nut securing the fan with a spanner (see CJ_ODU_ FAN_001). 2) Remove the fan. D-cut CJ_ODU_FAN_001 Note: This section is for reference only.

  • Page 64: Fan Motor

    Service Manual - VMHxxSG Fan Motor Note: Remove the panel plate and the connection of fan motor on PCB (refer to 3.1 Panel Plate and 3.2 Electrical parts) before disassembling fan motor. Procedure Illustration 3) Remove the fixing screws of the fan motor (4 screws) (see CJ_ODU_MOTOR_001).

  • Page 65: Sound Blanket

    Service Manual - VMHxxSG Sound blanket Note: Remove the panel plate (refer to 3.1 Panel plate) before disassembling sound blanket. Procedure Illustration 1) Remove the sound blanket (side and top) (see CJ_ODU_BLANKET_001). Sound Blanket(top) Sound Blanket(side) CJ_ODU_BLANKET_001 Note: This section is for reference only. Actual unit appearance may vary. ...

  • Page 66: Four-Way Valve

    Service Manual - VMHxxSG Four-way valve (for heat pump models) WARNING: Evacuate the system and confirm that there is no refrigerant left in the system before removing the four-way valve and the compressor. (For R32 & R290, you should evacuate the system with the vacuum pump; flush the system with nitrogen;...

  • Page 67: Compressor

    Service Manual - VMHxxSG Compressor WARNING: Evacuate the system and confirm that there is no refrigerant left in the system before removing the four-way valve and the compressor. (For R32 & R290, you should evacuate the system with the vacuum pump; flush the system with nitrogen;...
  • Page 68 Service Manual - VMHxxSG Procedure Illustration 3) Remove the hex nuts and washers securing the compressor, located on the bottom plate (see CJ_ODU_COMP_003). CJ_ODU_COMP_003 Suction Pipe 4) Heat up the brazed parts and then remove the the discharge pipe and the suction pipe (see CJ_ODU_COMP_004).
  • Page 69 Service Manual - VMHxxSG Troubleshooting Contents Safety Caution .......................3 General Troubleshooting ..................4 Complain Record Form ..................6 Information Inquiry ....................8 Error Diagnosis and Troubleshooting Without Error Code .......11 Remote maintenance ...................11 Field maintenance ..................12 Quick Maintenance by Error Code ..............17 Troubleshooting by Error Code ................17 TS01 EEPROM Parameter Error Diagnosis and Solution TS02 Indoor and Outdoor Unit Communication Error Diagnosis and Solution TS03 Zero-crossing Signal Detection Error Diagnosis and Solution...
  • Page 70 Service Manual - VMHxxSG Contents TS09 IPM Malfunction or IGBT Over-strong Current Protection Diagnosis and Solution TS10 Over Voltage or Too Low Voltage Protection Diagnosis and Solution TS11 Top temperature Protection of Compressor or High Temperature Protection of IPM Module or High Pressure Protection Diagnosis and Solution TS12 Inverter Compressor Drive Error Diagnosis and Solution TS13 Low Pressure Protection Diagnosis and Solution TS14 Indoor units mode conflic Diagnosis and Solution...

  • Page 71: Safety Caution

    Service Manual - VMHxxSG 1. Safety Caution WARNING Be sure to turn off all power supplies or disconnect all wires to avoid electric shock. While checking indoor/outdoor PCB, please equip oneself with antistatic gloves or wrist strap to avoid damage to the board. WARNING Electricity remains in capacitors even when the power supply is off.
  • Page 72 Service Manual - VMHxxSG When the indoor unit encounters a recognized error on different models , 1. the running LED with flash in a corresponding series, the timer LED may turn on or begin flashing; 2. an error code will be displayed; 3.
  • Page 73 Service Manual - VMHxxSG Top temperature protection of compressor or High temperature 3 times FLASH PC 02 TS11-S-INV protection of IPM module or High pressure protection 5 times FLASH Inverter compressor drive error TS12-S PC 04 1 time FLASH Current overload protection TS08-S PC 08 Communication error between outdoor main chip and compressor...

  • Page 74: Complain Record Form

    Service Manual - VMHxxSG 3. Complain Record Form Complain Record Form Request No.: Date: Installation Date: Service Date: Customer Information Name Telephone No. Home Address Email Product Information Indoor Unit Model Outdoor Unit Model Serial No. of indoor unit Serial No. of outdoor unit Working Mode □Cooling □Heating...
  • Page 75 Service Manual - VMHxxSG Parameter Checking information by Remote controller Displaying code Displaying code meaning Display value Display value meaning Room temperature Indoor coil temperature Outdoor coil temperature Ambient temperature Discharge temperature Targeted Frequency Actual Frequency Compressor current Outdoor AC voltage Indoor capacity test Reserve Outdoor fan speed...

  • Page 76: Information Inquiry

    Service Manual - VMHxxSG 4. Information Inquiry • To enter engineer mode, in power-on or standby mode, and in non-locked state, press the key combination “ON/OFF + Air Speed” for 7s: • After entering the engineer mode, the remote control will display icons of “Auto, Cool, Dry, Heat”, and the Battery icon;...
  • Page 77 Service Manual - VMHxxSG Error code Display Error Information EH 00/EH 0A Indoor unit EEPROM parameter error EL 01 Indoor / outdoor unit communication error Zero-crossing signal detection error EH 02 Over low voltage protection of indoor external fan EH 30 Over voltage protection of indoor external fan EH 31 The indoor fan speed is operating outside of the normal range...
  • Page 78 Service Manual - VMHxxSG Compressor discharge temperature protection PC 06 Outdoor current protection PC 08 PH 09 Anti-cold air in heating mode PFC module malfunction PC 0F Outdoor ambient tempreture too low pc 0l Evaporator coil temperature over high protection PH 90 Evaporator coil temperature over low Protection PH 91...

  • Page 79: Error Diagnosis And Troubleshooting Without Error Code

    Service Manual - VMHxxSG 5. Error Diagnosis and Troubleshooting Without Error Code WARNING Be sure to turn off unit before any maintenance to prevent damage or injury. Remote maintenance SUGGESTION: When troubles occur, please check the following points with customers before field maintenance. Problem Solution Unit will not start...

  • Page 80: Field Maintenance

    Service Manual - VMHxxSG Field maintenance Problem Solution Unit will not start 15-16 Compressor will not start but fans run 15-16 Compressor and condenser (outdoor) fan will not start 15-16 Evaporator (indoor) fan will not start 15-16 Condenser (Outdoor) fan will not start 15-16 Unit runs, but shortly stops 15-16...
  • Page 81 Service Manual - VMHxxSG 1.Remote Maintenance Electrical Circuit Refrigerant Circuit Possible causes of trouble Unit will not start ☆ ☆ ☆ ☆ The power switch is on but fans will not start ☆ ☆ ☆ The temperature on the display board cannot be set ☆...
  • Page 82 Service Manual - VMHxxSG 1.Remote Maintenance Others Possible causes of trouble Unit will not start The power switch is on but fans will not start ☆ The temperature on the display board cannot be set Unit is on but the wind is not cold(hot) Unit runs, but shortly stops The unit starts up and stops frequently ☆...
  • Page 83 Service Manual - VMHxxSG 2.Field Maintenance Refrigerant Circuit Others Possible causes of trouble Unit will not start Compressor will not start but fans run ☆ Compressor and condenser (outdoor) fan will not start Evaporator (indoor) fan will not start Condenser (Outdoor) fan will not start Unit runs, but shortly stops ☆...
  • Page 84 Service Manual - VMHxxSG 2.Field Maintenance Electrical Circuit Possible causes of trouble Unit will not start ☆ ☆ ☆ ☆ ☆ ☆ Compressor will not start but fans run ☆ ☆ ☆ ☆ ☆ Compressor and condenser (outdoor) fan will not start ☆...

  • Page 85: Quick Maintenance By Error Code

    Service Manual - VMHxxSG 6. Quick Maintenance by Error Code If you do not have the time to test which specific parts are faulty, you can directly change the required parts according the error code. You can find the parts to replace by error code in the following table. Error Code Part requiring EH 00/...
  • Page 86 Service Manual - VMHxxSG TS01-IDU: Indoor EEPROM parameter error diagnosis and solution Description: Indoor PCB main chip does not receive feedback from EEPROM chip. Recommended parts to prepare: • Indoor PCB Troubleshooting and repair: Shut off the power supply and turn it on 2 minutes later.
  • Page 87 Service Manual - VMHxxSG TS01-ODU: Outdoor EEPROM parameter error or Compressor driven chip EEPROM parameter error diagnosis and solution Description: Outdoor PCB main chip does not receive feedback from EEPROM chip or compressor driven chip. Recommended parts to prepare: • Outdoor PCB Troubleshooting and repair: Shut off the power supply and turn it on 2 minutes later.
  • Page 88 Service Manual - VMHxxSG TS02-S-INV: Indoor and outdoor unit communication error diagnosis and solution Description: Indoor unit can not communicate with outdoor unit Recommended parts to prepare: • Indoor PCB • Outdoor PCB • Short-circuited component Troubleshooting and repair: Power off, then restart the unit after 2 minutes.
  • Page 89 Service Manual - VMHxxSG Remarks: • Use a multimeter to test the DC voltage between 2 port(or S or L2 port) and 3 port(or N or S port) of outdoor unit. The red pin of multimeter connects with 2 port(or S or L2 port) while the black pin is for 3 port(or N or S port) . •...
  • Page 90 Service Manual - VMHxxSG TS03: Zero crossing detection error diagnosis and solution Description: When PCB does not receive zero crossing signal feedback for 4 minutes or the zero crossing signal time interval is abnormal. Recommended parts to prepare: • Connection wires •...
  • Page 91 Service Manual - VMHxxSG TS04-S-IDU: The Indoor fan speed is operating outside of normal range diagnosis and solution) Description: When indoor fan speed keeps too low or too high for a certain time, the LED displays the failure code and the AC turns off.
  • Page 92 Service Manual - VMHxxSG Index: 1. DC Fan Motor(control chip is in fan motor) Power on and when the unit is in standby, measure the voltage of pin1-pin3, pin4-pin3 in fan motor connector. If the value of the voltage is not in the range showing in below table, the PCB must has problems and need to be replaced. •...
  • Page 93 Service Manual - VMHxxSG Troubleshooting...
  • Page 94 Service Manual - VMHxxSG TS04-ODU: The outdoor fan speed is operating outside of normal range diagnosis and solution) Description: When outdoor fan speed keeps too low or too high for a certain time, the LED displays the failure code and the AC turns off. Recommended parts to prepare: •...
  • Page 95 Service Manual - VMHxxSG Index: 1. DC Fan Motor (control chip is in outdoor PCB) Release the UVW connector. Measure the resistance of U-V, U-W, V-W. If the resistance is not equal to each other, the fan motor must has problems and need to be replaced. otherwise the PCB must has problems and need to be replaced. 2.
  • Page 96 Service Manual - VMHxxSG 3. DC Fan Motor(for some double fan models) Power on and when the unit is in standby, measure the voltage of CON1, pin1-pin2 and pin3-pin2 of CN1 in DC motor driver board. If the value of the voltage is not in the range showing in below tables, the outdoor main PCB must has problems and need to be replaced.
  • Page 97 Service Manual - VMHxxSG TS05-IDU: Open circuit or short circuit of indoor temperature sensor(T1, T2) diagnosis and solution Description: If the sampling voltage is lower than 0.06V or higher than 4.94V, the LED displays the failure code. Recommended parts to prepare: •...
  • Page 98 Service Manual - VMHxxSG TS05-ODU: Open circuit or short circuit of outdoor temperature sensor(T3, T4, TP, T2B,TH) diagnosis and solution Description: If the sampling voltage is lower than 0.06V or higher than 4.94V, the LED displays the failure code. Recommended parts to prepare: •...
  • Page 99 Service Manual - VMHxxSG Troubleshooting...
  • Page 100 Service Manual - VMHxxSG TS07: Indoor PCB / Display board communication error diagnosis and solution Description: Indoor PCB does not receive feedback from the display board. Recommended parts to prepare: • Communication wire • Indoor PCB • Display board Troubleshooting and repair: Power off, then restart the unit 2 minutes later...
  • Page 101 Service Manual - VMHxxSG TS08-S: Current overload protection diagnosis and solution Description: An abnormal current rise is detected by checking the specified current detection circuit. Recommended parts to prepare: • Connection wires • Reactor • Outdoor fan • Outdoor PCB Troubleshooting and repair: Was the protection activated...
  • Page 102 Service Manual - VMHxxSG TS09-S: IPM malfunction or IGBT over-strong current protection diagnosis and solution Description: When the voltage signal the IPM sends to the compressor drive chip is abnormal, the LED displays the failure code and the AC turns off. Recommended parts to prepare: •...
  • Page 103 Service Manual - VMHxxSG Index: 1. IPM Continuity Check WARNING Electricity remains in capacitors even when the power supply is off. Ensure the capacitors are fully discharged before troubleshooting. 1. Turn off outdoor unit and disconnect power supply. 2. Discharge electrolytic capacitors and ensure all energy-storage unit has been discharged. 3.
  • Page 104 Service Manual - VMHxxSG 4. Compressor check Disconnect the compressor and check the resistance between U-V, V-W and U-W, and all 3 values should be equal. If not, the compressor is faulty and should be replaced. Note: The picture and the value are only for reference, actual condition and specific value may vary. ...
  • Page 105 Service Manual - VMHxxSG TS10-S: Over voltage or too low voltage protection diagnosis and solution Description: Abnormal increases or decreases in voltage are detected by checking the specified voltage detection circuit. Recommended parts to prepare: • Power supply wires • IPM module board •...
  • Page 106 Service Manual - VMHxxSG TS11-S-INV: Top temperature protection of compressor or High temperature protection of IPM module or High pressure protection diagnosis and solution Description: For some models with overload protection, If the sampling voltage is not 5V, the LED will display the failure. If the temperature of IPM module is higher than a certain value, the LED displays the failure code.
  • Page 107 Service Manual - VMHxxSG Check the fastening screws on the PCB and IPM radiator. Are they Replace the outdoor fixed tightly? control PCB. Tighten the screws and apply silicon grease. Note: For certain models, outdoor PCB could not be removed separately. In this case, the outdoor electric control box should be replaced as a whole.
  • Page 108 Service Manual - VMHxxSG High pressure protection High pressure protection Are the high pressure switch Are the high pressure switch Connect high pressure switch and Connect high pressure switch and and main control boar wired and main control boar wired mian control board mian control board correctly?
  • Page 109 Service Manual - VMHxxSG TS12-S: Inverter compressor drive error diagnosis and solution Description: An abnormal inverter compressor drive is detected by a special detection circuit, including communication signal detection, voltage detection, compressor rotation speed signal detection and so on. Recommended parts to prepare: •...
  • Page 110 Service Manual - VMHxxSG TS13-INV: Low pressure protection diagnosis and solution Description: Outdoor pressure switch cut off the system because low pressure is lower than 0.13 MPa, the LED displays the failure code. Recommended parts to prepare: • Connection wires •...
  • Page 111 Service Manual - VMHxxSG Low pressure protection Low pressure protection Are the low pressure protector Are the low pressure protector and main control board wired and main control board wired Reconnect the low pressure protector and main Reconnect the low pressure protector and main properly? properly? control board...
  • Page 112 Service Manual - VMHxxSG TS14: Indoor units mode conflict (match with multi outdoor unit) Description: The indoor units cannot work cooling mode and heating at same time. Heating mode has a priority. • Suppose Indoor unit A working in cooling mode or fan mode, and indoor unit B is set to heating mode, then A will change to off and B will work in heating mode.
  • Page 113 Service Manual - VMHxxSG TS33: Communication error between outdoor main chip and compressor driven chip diagnosis and solution Description: The main chip cannot detect the compressor driven chip Recommended parts to prepare: • Outdoor main PCB • Electric control box Troubleshooting and repair: Shut off the power supply and Shut off the power supply and...
  • Page 114 Service Manual - VMHxxSG 8. Check Procedures 8.1 Temperature Sensor Check WARNING Be sure to turn off all power supplies or disconnect all wires to avoid electric shock. Operate after compressor and coil have returned to normal temperature in case of injury. 1.
  • Page 115 Service Manual - VMHxxSG Resistance Value ASM135D23UFZ ATQ420D1UMU ASN98D22UFZ ATF235D22UMT ATQ360D1UMU Blue-Red Blue-Black 1.75Ω 0.37Ω Ω 0.75Ω 0.37Ω 1.57 Red-Black Resistance Value ATM115D43UFZ2 ATF250D22UMT ATF310D43UMT KSK103D33UEZ3(YJ) ASM98D32UFZ Blue-Red Blue-Black 1.87Ω 0.75Ω 0.65Ω 2.13Ω 2.2Ω Red-Black Resistance Value ASN140D21UFZ ASK89D29UEZD KSN140D21UFZ KTM240D57UMT KSK103D33UEZ3 Blue-Red...
  • Page 116 Service Manual - VMHxxSG Note: The picture and the value are only for reference, actual condition and specific value may vary. 8.3 IPM Continuity Check WARNING Electricity remains in capacitors even when the power supply is off. Ensure the capacitors are fully discharged before troubleshooting. 1.
  • Page 117 Service Manual - VMHxxSG Note: The picture and the value are only for reference, actual condition and specific value may vary. Troubleshooting  Troubleshooting ...
  • Page 118 Service Manual - VMHxxSG 8.4 4-way Valve Check 1. Power on, use a digital tester to measure the voltage, when the unit operates in cooling, it is 0V. When the unit operates in heating, it is about 230VAC. If the value of the voltage is not in the range, the PCB must have problems and need to be replaced. 2 Turn off the power, use a digital tester to measure the resistance.
  • Page 119 Service Manual - VMHxxSG 8.5 EXV Check WARNING Electricity remains in capacitors even when the power supply is off. Ensure the capacitors are fully discharged before troubleshooting. 1. Disconnect the connector from outdoor PCB. 2. Measure the resistance value of each winding using a multi-meter. 3.
  • Page 120 Service Manual - VMHxxSG Appendix Contents Temperature Sensor Resistance Value Table for T1, T2, T3, and T4 (°C – K) ..2 Temperature Sensor Resistance Value Table for TP (for some units)(°C --K) ..3 iii) Pressure On Service Port ..................4...
  • Page 121 Service Manual - VMHxxSG i) Temperature Sensor Resistance Value Table for T1,T2,T3 and T4 (°C – K) °C °F K Ohm °C °F K Ohm °C °F K Ohm °C °F K Ohm 115.266 12.6431 2.35774 0.62973 108.146 12.0561 2.27249 0.61148 101.517 11.5...
  • Page 122 Service Manual - VMHxxSG ii) Temperature Sensor Resistance Value Table for TP(for some units) (°C --K) °C °F K Ohm °C °F K Ohm °C °F K Ohm °C °F K Ohm °C °F K Ohm °C °F K Ohm °C °F K Ohm...
  • Page 123 Service Manual - VMHxxSG iii) Pressure On Service Port Cooling chart(R410A): ODU(DB) °F(°C) 0(-17) 5(-15) 95 (35) (-9.44) (7.22) (23.89) (29.44) (40.56) (46.11) (48.89) IDU(DB/WB) 70/59 (21.11/15) 10.1 10.6 75/63 (23.89/17.22) 10.7 11.2 80/67 (26.67/19.44) 11.2 11.9 90/73 (32.22/22.78) 10.5 10.3 10.0 10.6...
  • Page 124 Service Manual - VMHxxSG Heating chart(R410A): ODU(DB/WB) 57/53 47/43 37/33 27/23 17/13 (-8.33/- 0/-2 -17/-18 °F(°C) (13.89/11.67) (8.33/6.11) (2.78/0.56) (-2.78/-5) 10.56) (-17/-19) (-27/-28) IDU(DB) 55(12.78) 30.3 28.5 25.3 22.8 20.8 18.5 16.5 65(18.33) 32.5 30.0 26.6 25.4 23.3 20.5 19.0 75(23.89) 33.8 31.5...
  • Page 125 Service Manual - VMHxxSG Cooling chart(R22): ODU(DB) °F(°C) 0(-17) 5(-15) 95 (35) (-9.44) (7.22) (23.89) (29.44) (40.56) (46.11) (48.89) IDU(DB/WB) 70/59 (21.11/15) 75/63 (23.89/17.22) 80/67 (26.67/19.44) 90/73 (32.22/22.78) 70/59 (21.11/15) 75/63 (23.89/17.22) 80/67 (26.67/19.44) 90/73 (32.22/22.78) 70/59 (21.11/15) 0.40 0.41 0.46 0.50 0.51...
  • Page 126 Service Manual - VMHxxSG Heating chart(R22): ODU(DB/WB) 57/53 47/43 37/33 27/23 17/13 (-8.33/- 0/-2 -17/-18 °F(°C) (13.89/11.67) (8.33/6.11) (2.78/0.56) (-2.78/-5) 10.56) (-17/-19) (-27/-28) IDU(DB) 55(12.78) 18.9 17.8 15.8 14.3 13.0 11.6 10.3 65(18.33) 20.3 18.8 16.6 15.9 14.6 12.8 11.9 75(23.89) 21.1 19.7...
  • Page 127 Service Manual - VMHxxSG Cooling chart(R32): ODU(DB) °F(°C) 0(-17) 5(-15) 95 (35) (-9.44) (7.22) (23.89) (29.44) (40.56) (46.11) (48.89) IDU(DB/WB) 70/59 (21.11/15) 10.3 10.8 75/63 (23.89/17.22) 10.9 11.4 80/67 (26.67/19.44) 11.4 12.1 90/73 (32.22/22.78) 10.7 10.5 10.2 10.8 12.6 13.3 70/59 (21.11/15) 75/63 (23.89/17.22) 80/67 (26.67/19.44)
  • Page 128 Service Manual - VMHxxSG Heating chart(R32): ODU(DB/WB) 57/53 47/43 37/33 27/23 17/13 (-8.33/- 0/-2 -17/-18 °F(°C) (13.89/11.67) (8.33/6.11) (2.78/0.56) (-2.78/-5) 10.56) (-17/-19) (-27/-28) IDU(DB) 55(12.78) 30.9 29.1 25.8 23.3 21.2 18.9 16.8 65(18.33) 33.2 30.6 27.1 25.9 23.8 20.9 19.4 75(23.89) 34.5 32.1...
  • Page 129 Service Manual - VMHxxSG System Pressure Table-R22 Pressure Temperature Pressure Temperature °C °F °C °F 14.5 -41.091 -41.964 1600 41.748 107.146 21.75 -32.077 -25.739 1650 16.5 239.25 43.029 109.452 -25.177 -13.319 1700 246.5 44.281 111.706 36.25 -19.508 -3.114 1750 17.5 253.75 45.506 113.911...
  • Page 130 Service Manual - VMHxxSG System Pressure Table-R410A Pressure Temperature Pressure Temperature °C °F °C °F 14.5 -51.623 -60.921 2350 23.5 340.75 38.817 101.871 21.75 -43.327 -45.989 2400 39.68 103.424 -36.992 -34.586 2450 24.5 355.25 40.531 104.956 36.25 -31.795 -25.231 2500 362.5 41.368 106.462...
  • Page 131 Service Manual - VMHxxSG System Pressure Table-R32 Pressure Temperature Pressure Temperature °C °F °C °F 14.5 -51.909 -61.436 1850 18.5 268.25 28.425 83.165 21.75 -43.635 -46.543 1900 275.5 29.447 85.005 -37.323 -35.181 1950 19.5 282.75 30.448 86.806 36.25 -32.15 -25.87 2000 31.431 88.576...
  • Page 132 Service Manual - VMHxxSG 1900 Wellworth Ave., Jackson, MI 49203 • Ph. 517-787-2100 • www.marsdelivers.com 5/2022...

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