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TROUBLE SHOOTINGDC Inverter VRF System DC Inverter Module Unit adopts intelligent control, which can detect every parameter and the working condition of each functional part and once functional parts go wrong, the system will give the clue to user to deal with the fault in time in several ways and carry on some protection actions itself.When the unit goes wrong, there are several ways to warn of user:

Three-bit digital display tube on the outdoor main electric control board indicates faults and protections with special characters;Indicating lamps on the lamp board of indoor units flash in special order;The operation panel of indoor units indicates faults and protections with special characters;1. Faults display Three-bit digital display tube on the outdoor main electric control board indicates faults and protections with special characters: The drawing of outdoor digital display tube is as follows:A. LED display on outdoor main PCB

three-bit digital display tubeWhen the system goes wrong or enters to the protection state, three-bit digital display tube on the outdoor main electric control board indicates faults and protections with special characters and the table below will list all codes and their meanings:Table 1: Outdoor protection codes and fault codes tableNo.CodesFaultsProtection codes and Faults codes of Inverter compressor1E01Inverter module goes wrong (fault).2P01The A.C input of Inverter compressor is so large that the compressor breaks down.5P02The exhaust temperature of Inverter compressor is too high.6P03The exhaust temperature sensor of Inverter compressor is wrong.7E02The D.C generatrix sampling voltage of outdoor unit is abnormal (fault).8E03Communication between outdoor main CMOS chip and Inverter driven CMOS chip goes wrong.System Protection codes an d Faults codes9P04The high pressure (exhaust pressure) switch breaks.10P05The low pressure (suction pressure) switch breaks.11P06Protection for the system exhaust pressure is too high.12P07Protection for the system suction pressure is too low.13P08At capacity reduced protection state for too low suction pressure.14P09At capacity reduced protection state for too high exhaust pressure.15P10At capacity reduced protection state for too high exhaust temperature.16P11The exhaust pressure sensor goes wrong.17P12The suction pressure sensor goes wrong.18E04Lack of Freon or the reversing valve goes wrong.19P13The condensing temperature is too high in cooling mode.20P14The condenser temperature sensor is wrong.21P15The outdoor ambient temperature sensor is wrong.22P16At protection state for too low voltage of A.C.Table 1: Outdoor protection codes and fault codes table (cont.)No.CodesFaultsSystem Protection codes an d Faults codes23E05The three-phase A.C power is lack of phase or the phase sequence is wrong.24P17The communicating circuitry among outdoor units goes wrong.25E06The addresses of outdoor units clash.26E07The addresses of outdoor units are wrong.27E08The communication among the main machine and all indoor units go wrong.28E09Module capacity dial code goes wrong.29E10Module amount dial code goes wrong.30E11The fault for the module amount is reduced.31E12The fault for the module amount is increased.32E13The driven of module condensing fan goes wrong.33E14The compressor operating is not kept in balanceProtection codes and Faults codes of Fixed-frequency compressor34P18The current input of #1 Fixed-frequency compressor is so large that the compressor breaks down.35P19The exhaust temperature of #1 Fixed-frequency compressor is too high.36P20The exhaust temperature sensor of #1 Fixed-frequency compressor is wrong.37P21The current input of #2 Fixed-frequency compressor is so large that the compressor breaks down.38P22The exhaust temperature of #2 Fixed-frequency compressor is too high.39P23The exhaust temperature sensor of #2 Fixed-frequency compressor is wrong.40P24Protection for the ambient temperature of the outdoor unit too low.B. Indicating lamps on the lamp board of indoor units This is especially for ceiling cassette type. Indicating lamps on the lamp board of indoor units flash in special order The conventional diagram of the lamp board is as follows:

It includes: Power lamp, run lamp, timer lamp, protection lamp, receiving window and emergency button. The details are as follows:(1) Power lamp: Red, it will lighten when the air conditioner is supplied with the power;(2) Run lamp: Green, it will lighten when the air conditioner runs and be off when the air conditioner stops;(3) Timer lamp: Yellow, it will lighten when the air conditioner enters to the timing state;(4) Protection lamp: Red, it will lighten when the air conditioner enters to the protection state;(5) Emergency button: It will display the power of indoor unit in horsepower.Fig 2: The conventional diagram of the lamp boardAs for DC Inverter VRF system, if the system goes wrong or enters to the protection state during operating, indicating lamps on the lamp board of indoor units flash in special order and the table below will list flashing ways and their meanings:Table 2: Indicating codes table of the indoor lamp board

Remark 1: Flashing ways above are: It keeps flash for one second every other second lashes N times continually with 5 seconds idle.Remark 2: Outdoor units with fault cue means that outdoor units are operating with the fault, that is, when the outdoor sensor goes wrong or the module is shielded, outdoor units are kept operating; However, Outdoor unit fault means that outdoor units go wrong and the system is shut down. Besides, the indoor unit will not display the corresponding code when outdoor units enter to the protection state.Table 2: Indicating codes table of the indoor lamp board (cont.)

The wired controller of indoor units indicates faults and protections with special characters (especially for duct type and floor & ceiling type indoor unit): When the system goes wrong or enters to the protection state or other operating states, LCD of the wire controller will display the corresponding code and give an alarm and the code display table is as follows: C. The wired of indoor units Table 3: Code display Table

Table 3: Code display Table (cont.)

Operation informationLED codesInstructionDefrost cueFlash onceThe running lamp flashing when the unit startsAnti cold air cueFlash twiceThe running lamp flashing when the unit startsNon-priority cueFlash three timesThe running lamp flashing and the unit is shut down.Outdoor units with fault cueFlash four timesThe running lamp flashing all the timeThe operation panel of indoor units indicates faults and protections with special characters (especially for wall-mounted unit): When the system goes wrong or enters to the protection state or other operating states, LED of the display will shows the corresponding code and give an alarm and the code display table is as follows: Table 4: Code display Table

D. The operation panel of indoor units Table 4: Code display Table (cont.)Fault information LED codesInstructionCommunication fault with outdoor unitE0It just displays at shutting down.Room temp. sensor faultE2It just displays at shutting down.The middle of indoor coil temp. sensor is fault (T2)E3It just displays at shutting down.Indoor coil frosting protectionE4It just displays at shutting down.The outlet of indoor coil temp. sensor is fault (T2B)E5It just displays at shutting down.Indoor fan motor fault (only when the motor is PG motor) E6It just displays at shutting down.Water pump faultE7It just displays at shutting down.Outdoor ambient temp.(T4) too lowE8It just displays at shutting down.Outdoor unit faultE9It just displays at shutting down.Zero passage protectionEAIt just displays at shutting down.EPROOM faultEBPower on 20s and displayHigh temp. protection of the middle of indoor coil (T2) in heating modeECIt just displays at shutting down.2. Troubleshooting2.1 Outdoor unit trouble shooting The followings will give an introduction for protection and faults codes separately and then explain how to deal with them.1) E01: Inverter module faultCause: external electromagnetism interruption the poor power Inverter module faultTroubleshooting: Please carry on maintaining following the flow below:

2) E02: The voltage of DC generatrix sampling is abnormalCauses: Power supply voltage of outdoor unit is extremely high or low Power supply is lack of phase Troubleshooting check the power supply3) E03: Communication fault between the outdoor main control board and inverter drive board Causes: electronic control board fault driving board fault communication wire open circuit strong electromagnetism interruptionTroubleshooting: Please carry on maintaining following the flow below:

4) E04: Lack of refrigerantCauses: System high pressure is lower than 0.35MPa at off state System low pressure switch trips 4 times in 45 minutes Troubleshooting: Please carry on maintaining following the flow below:

5) E05: Three-phase AC power is lack of phase or the sequence is wrongCauses: Power supply is lack of phase or the sequence is wrongTroubleshooting: Please carry on maintaining following the flow below:

6) E07: Addresses of outdoor units are wrongCauses: Outdoor unit is dialed to the wrong positionTroubleshooting: Please carry on maintaining following the flow below:

NOTE: In System Installation section, it give a detailed instruction for how to dial the address. Instruction for dialing outdoor address: The dialing address of main machine is 00 and that of #1 Secondary unit and #2 Secondary units are 01 and 10 separately, otherwise it means the dialing address is wrong and the system will display E07.7) E08: Communication fault between outdoor units and indoor unitsCauses: Communication wires between outdoor units and indoor units are connected wrong Some wires are not connected well outdoor main PCB fault indoor PCB faultTroubleshooting: Please carry on maintaining following the flow below:

8) E09: Module capacity dialing goes wrongCauses:The capacity dialing has been set before delivery and it cannot be modified at will, otherwise it will cause a bad incident.Troubleshooting:When E09 is indicated on the outdoor electric control board, please consult with the salesmen or the technical department of our company and then carry on maintaining following the flow after affirming the fault:

9) E10: Module amount dialing goes wrong E11: Module amount is reduced E12: Module amount is increased

Causes: The main machine of DC Inverter Module Unit can automatically inspect the actual amount of operating outdoor units and the amount set of outdoor units so that when the former is not in line with the latter, the system electric control will display the corresponding fault codes:Troubleshooting: When E10, E11 or E12 is indicated on the outdoor electric control board, please carry on maintaining following the flow below:

10) E13: Module condenser fan drive goes wrongCauses: Outdoor fan motor goes wrong or Overheating protection of outdoor fan Troubleshooting: Please carry on maintaining following the flow below:

11) P01: AC current input of Inverter compressor is so large that the compressor breaks down Causes: When AC current input of Inverter compressor is more than 16A result from the large loads or other factors.Troubleshooting: Please carry on maintaining following the flow below:

Troubleshooting (cont.)12) P02: The exhaust temperature of Inverter compressor is too high P19: The exhaust temperature of #1 Fixed-frequency compressor is too high P22: The exhaust temperature of #2 Fixed-frequency compressor is too highCauses: When the exhaust temperature of Inverter compressor gets to 120 during operating, the system will clue to the compressor entering to the protection from the exhaust temperature too high and the system electronic control will display the corresponding protection code:Troubleshooting: hen the compressor enters to the protection from the exhaust temperature too high, please carry on maintaining following the flow below:

17) P13: Condensing temperature is too high in cooling modeCauses: When the condensing humidity surpasses 62 , the system will clue to the condensing temperature too high.Troubleshooting: Please carry on maintaining by following the flow below:

18) P16: At protection state for too low or too high AC voltage inputCauses: When AC power supply voltage input is lower than 190V or higher than 270V (the normal voltage is 220V), the system will clue to entering the protection state for too low or too high AC voltage inputTroubleshooting: Please carry on maintaining by following the flow below:

9) P17: Communication fault among outdoor unitsCauses: When the communication wires among outdoor units are connected wrong or some wires are not connected well, it will lead the communication among them go wrong and the system electric control will display P17 to clue to users.Troubleshooting: Please carry on maintaining following the flow below:

19) P18: The current input of #1 Fixed-frequency compressor is so large that the compressor breaks down P21: The current input of #2 Fixed-frequency compressor is so large that the compressor breaks downCauses: As for DC Inverter VRF system, the electric control is kept inspecting the operating current of the compressor, when the current surpasses the setting value, the system electronic control will display the corresponding code and stop the compressor. As for the setting value, it is depended on the type of compressor.Troubleshooting: Please carry on maintaining following the flow below:

20) P24: Protection from outdoor ambient temperature too lowCauses: As for DC Inverter VRF system, the electronic control system is kept inspecting the outdoor ambient temperature, when the temperature is lower than -14 , the electric control system will forbid the unit to run and clue the unit enters to the protection state.Troubleshooting: Please carry on maintaining following the flow below:

2.2. Indoor unitCommunication fault between the unit and outdoor unit,Cause Communication line fault or some wires fault Electronic parts faultTroubleshooting is referred to the flow below

Trouble shooting (cont.)

2) Room temperature sensor faultCause Temperature sensor is loose Temperature sensor connecting wire fault or sensor fault Troubleshooting is referred to the flow below

3) Midpoint temperature sensor fault of the pipeCause Temperature sensor is loose Temperature sensor connecting wire fault or sensor faultTroubleshooting is referred to the flow below

4) Outdoor unit faultTroubleshooting:When the indoor unit clue that the outdoor unit goes wrong, it will stop the outdoor unit running and then inspect and maintain it according to the hint of the outdoor electric control.

5) Frosting protection of the indoor evaporatorCauses: When the indoor electric control inspects that the temperature in the middle of the evaporator keeps lower than 2 for 3 minutes, it will clue that the evaporator begins to frosting protection and stop the indoor unit running to prevent the indoor unit from frosting. During frosting protection, when the coil temperature of the evaporator is no lower than 7, the electric control will unlock the protection and restart up the indoor unit. The troubleshooting is referred to the flow below:

6) The outlet of indoor coil temp. sensor is fault Cause Temperature sensor is loose Temperature sensor connecting wire fault or sensor faultTroubleshooting is referred to the flow below

7) Indoor fan fault (it is applicable for the case that the indoor motor is PG motor):Cause fan wires loose, fan capacitor fault, fan jam fan fault, indoor PCB fault Troubleshooting is referred to the flow below

Troubleshooting (cont.)8) High temp. protection of the middle of indoor coil in heating mode Causes: When the indoor electric control inspects that the temperature in the middle of the evaporator keeps no lower than 62 in heating mode, it will clue to entering protection from too high the midpoint temperature of the pipe and when the coil temperature of the evaporator is no higher than 52, the electric control will unlock the protection. Sensor fault, indoor fan fault, indoor PCB fault, system abnormal, etc. Troubleshooting is referred to the flow below:

High temp. protection of the middle of indoor coil in heating mode 9) Water pump faultCauses: In cooling mode, when the indoor electric control inspects that the water level switch keeps in off-position for 5 minutes, the electric control will display the fault and shut down the unit. The unit will be restarted up after the fault is eliminated. Water float switch fault, water pump fault, etc.The troubleshooting is referred to the flow below:

Thank you!