This is the complete fault table for the DEYE SUN G04/G05/G06 3-Phase Inverter family — 68 codes shared by 35 model numbers, transcribed from the official manual. On DEYE units, a fault code means the unit has cut its output and the red LED stays solid; a warning flashes the red LED while the unit keeps running.
Last checked against the official manuals on July 11, 2026.
The inverter detected that a PV string is connected to the DC input with reversed polarity.
CauseA PV string's plus and minus conductors are swapped at the DC input.
Recommended fixCheck the PV input polarity and reconnect the string correctly.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
Insulation resistance between the PV array (DC side) and ground is permanently below the protection limit.
CauseA poor or broken protective-earth connection, or degraded PV/DC wiring insulation, keeps the PV-to-ground insulation impedance below the limit.
Recommended fixCheck the grounding cable of the inverter.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
Leakage (residual) current on the DC side exceeded the protection limit.
CauseResidual-current monitoring measured DC-side leakage current above the limit, typically from damaged insulation creating a current path to ground.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
The ground-fault detector/interrupter (GFDI) detected a ground fault on the PV output.
CauseA PV output conductor is leaking or shorted to ground, tripping the GFDI protection.
Recommended fixCheck the solar panel output connection.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
Failure in reading the internal memory (EEPROM).
CauseThe controller could not read stored data from the EEPROM memory chip.
Recommended fixRestart the inverter; if the fault still exists, contact your installer or Deye service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
Failure in writing the internal memory (EEPROM).
CauseThe controller could not write data to the EEPROM memory chip.
Recommended fixRestart the inverter; if the fault still exists, contact your installer or Deye service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
The fuse of the ground-fault detector/interrupter (GFDI) circuit has blown.
CauseA ground-fault current large enough to blow the GFDI protection fuse has passed, or the fuse circuit itself failed.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
The GFDI circuit reports a grounding-contact failure.
CauseBad contact in the GFDI grounding path prevents the ground-fault protection from working properly.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
An IGBT power transistor was damaged by an excessive voltage drop.
CauseExcessive voltage drop measured across an IGBT indicates the power switch is damaged or overstressed.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
The auxiliary switching power supply of the inverter failed.
CauseThe internal DC 12 V auxiliary supply that feeds the control electronics is absent.
Recommended fixRestart the inverter; if the fault still exists, contact your installer or Deye service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
The AC main contactor (grid relay) did not operate correctly.
CauseThe main AC contactor failed to open or close as commanded, or its feedback signal is wrong.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
The AC auxiliary contactor did not operate correctly.
CauseThe auxiliary AC contactor failed to open or close as commanded, or its feedback signal is wrong.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
Reserved code; in practice it indicates loss of one grid phase, an AC voltage-detection failure, or relays not closed.
CauseLoss of one phase, a failure of the AC voltage detection part, or relays not closed.
Recommended fixRestart the inverter; if the error still exists, contact your installer or Deye service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
DC current exceeded the firmware (software) over-current limit.
CauseThe measured DC input current went above the firmware-set protection threshold.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
AC current exceeded the firmware (software) over-current limit.
CauseThe internal AC sensor or detection circuit on the control board, or its connection wire, may be loose and giving an over-current reading, or the AC current genuinely exceeded the software limit.
Recommended fixRestart the inverter; if the error still exists, contact your installer or Deye service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
The GFCI/RCD function measured continuous (average) leakage current above the limit.
CauseThe average leakage current is over 300 mA, caused by a DC-supply or solar-panel insulation problem, or by a faulty leakage-current sensor or its circuit.
Recommended fixCheck whether the DC power supply and solar panels are OK; check the 'Test data' -> 'diL' value (about 40; requires the big LCD); check the leakage-current sensor and its circuit. Restart the inverter; if the error still exists, contact your installer or Deye service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 57
Over-current detected on the three-phase output current measurement.
CauseThe three-phase output current exceeded the protection limit.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 57
The hardware over-current protection on the AC side tripped.
CauseThe AC sensor or detection circuit on the control board or its connection wire is faulty, or a real AC over-current occurred.
Recommended fixCheck the AC sensor and detection circuit on the control board and its wiring. Restart the inverter or perform a factory reset; if the error still exists, contact your installer or Deye service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 57
Combined (synthesized) hardware failure signal; several hardware protections asserted together.
CauseMultiple hardware fault signals were present at the same time.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 57
The DC-side hardware over-current protection tripped.
CauseSolar-panel output current outside the allowed range, a faulty DC current sensor or its detection circuit, or a firmware version not suitable for the hardware.
Recommended fixCheck that the solar panel output current is within the allowed range; check the DC current sensor and its detection circuit; check that the inverter firmware version suits the hardware. Restart the inverter; if the error still exists, contact your installer or Deye service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 57
Leakage current flow detected on the DC side.
CauseDC leakage-current monitoring detected current flowing to ground above the limit.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 57
The inverter was stopped by the emergency stop function (models with a stop button).
CauseThe stop button was pressed or the crash-stop input was triggered.
Recommended fixContact your installer for help.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 57
A sudden (transient) jump of leakage current above the limit was detected.
CauseThe leakage current rose above 30 mA suddenly, from the DC supply or solar panels, or from a faulty leakage-current sensor or its circuit.
Recommended fixCheck whether the DC power supply and solar panels are OK; check the 'Test data' -> 'diL' value (about 40; requires the big LCD); check the leakage-current sensor and its circuit. Restart the inverter; if the fault still exists, contact your installer or Deye service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 57
PV-to-ground insulation resistance measured below the protection limit.
CauseVery often a PV-side problem: PV panel frames or the inverter not grounded well, the internal ground cable not fixed well on the shell, AC/DC cables or terminal blocks shorted to ground, or damaged insulation; it can also be the Vpe resistance on the main board or its detection on the control board.
Recommended fixCheck the Vpe resistance on the main board and its detection on the control board; check the PV panels (many times this is a PV problem); check that the panel frames and the inverter are grounded well and the inside ground cable is fixed well on the shell; check the AC/DC cables and terminal blocks for shorts to ground or damaged insulation. Restart the inverter; if the fault still exists, contact your installer or Deye service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 57
Reverse (feedback) energy flow detected on the DC side.
CauseCurrent fed back into the DC input instead of flowing from the PV array into the inverter.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 57
The two halves of the split DC bus are at unequal voltages.
CauseThe 'BUSN' cable or the driver-board power-supply cable is loose, unbalancing the split DC bus.
Recommended fixCheck whether the 'BUSN' cable or the driver-board power-supply cable is loose. Restart the inverter; if the fault still exists, contact your installer or Deye service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 57
Insulation error detected at the DC end.
CauseThe insulation impedance at the DC terminal end fell below the limit.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 57
Inverter power stage 1 measured an excessively high DC component.
CauseThe DC component measured on inverter power stage 1 exceeded its limit.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 57
The AC load switch failed.
CauseThe AC-side load switch (output relay path) did not switch correctly.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 57
The AC main contactor failed to operate.
CauseFaulty relays or missing AC voltage across them, a relay driver-circuit fault, or software not suitable for this inverter (old inverters have no relay detection function).
Recommended fixCheck the relays and the AC voltage of the relays; check the relay driver circuit; check whether the software is suitable for this inverter. Restart the inverter; if the fault still exists, contact your installer or Deye service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 57
At least one grid relay cannot close (open circuit detected).
CauseA relay or its driver signal is faulty, so at least one relay cannot be closed (old inverters have no relay detection function).
Recommended fixCheck the relays and their driver signals. Restart the inverter; if the fault still exists, contact your installer or Deye service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
Inverter power stage 2 measured an excessively high DC component.
CauseThe DC component measured on inverter power stage 2 exceeded its limit.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
Over-current detected on the AC output.
CauseThe AC output current exceeded the protection limit.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
The AC output current exceeded the rated load (overload).
CauseThe load or output current stayed above the inverter's rated current.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
No grid detected on the AC side.
CauseA grid outage, an AC connector in poor condition, abnormal grid voltage, or a faulty AC voltage-detection circuit.
Recommended fixCheck the AC grid voltage and the AC voltage detection circuit; check that the AC connector is in good condition and that the AC grid voltage is normal. Restart the inverter; if the fault still exists, contact your installer or Deye service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
Wrong grid phase relationship detected.
CauseIncorrect phase sequence or phase connection of the AC grid, or a phase-detection error.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
The three grid phase voltages are unbalanced beyond the allowed range.
CauseThe three grid phase voltages differ from each other by more than the allowed unbalance.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
The three output phase currents are unbalanced beyond the allowed range.
CauseThe three output phase currents differ from each other by more than the allowed unbalance.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
Over-current detected within a single grid cycle.
CauseA one-cycle over-current event on the AC output, or a faulty AC current sensor or its circuit.
Recommended fixCheck the AC current sensor and its circuit. Restart the inverter; if the fault still exists, contact your installer or Deye service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
The DC input current exceeded the protection limit.
CausePV input current above the DC over-current protection threshold.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
The line voltage between phases W and U is above the protection setting.
CauseGrid W-U line voltage above the protection setting, or an AC cable that is too thin causing extra voltage rise at the inverter terminals.
Recommended fixCheck the AC voltage protection setting; check if the AC cable is too thin; check the voltage difference between the LCD and a meter.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
The line voltage between phases W and U is below the protection setting.
CauseGrid W-U line voltage below the protection setting, or AC cables not firmly and correctly connected.
Recommended fixCheck the AC voltage protection setting; check the voltage difference between the LCD and a meter; check that all AC cables are firmly and correctly connected.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
The line voltage between phases V and W is above the protection setting.
CauseGrid V-W line voltage above the protection setting, or an AC cable that is too thin causing extra voltage rise at the inverter terminals.
Recommended fixCheck the AC voltage protection setting; check if the AC cable is too thin; check the voltage difference between the LCD and a meter.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
The line voltage between phases V and W is below the protection setting.
CauseGrid V-W line voltage below the protection setting, or AC cables not firmly and correctly connected.
Recommended fixCheck the AC voltage protection setting; check the voltage difference between the LCD and a meter; check that all AC cables are firmly and correctly connected.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
The line voltage between phases U and V is above the protection setting.
CauseGrid U-V line voltage above the protection setting, or an AC cable that is too thin causing extra voltage rise at the inverter terminals.
Recommended fixCheck the AC voltage protection setting; check if the AC cable is too thin; check the voltage difference between the LCD and a meter.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
The line voltage between phases U and V is below the protection setting.
CauseGrid U-V line voltage below the protection setting.
Recommended fixCheck the AC voltage protection setting.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
The grid frequency is above the protection setting.
CauseGrid frequency measured above the configured over-frequency protection limit.
Recommended fixCheck the frequency protection setting.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
The grid frequency is below the protection setting.
CauseGrid frequency measured below the configured under-frequency protection limit.
Recommended fixCheck the frequency protection setting.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
The DC component of the U-phase grid current is too high.
CauseThe DC component injected in the U-phase output current exceeded its limit.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
The DC component of the V-phase grid current is too high.
CauseThe DC component injected in the V-phase output current exceeded its limit.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
The DC component of the W-phase grid current is too high.
CauseThe DC component injected in the W-phase output current exceeded its limit.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
The DC current through AC filter inductor phase A is too high.
CauseThe DC component of the current in AC inductor phase A exceeded its limit.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 58
The DC current through AC filter inductor phase B is too high.
CauseThe DC component of the current in AC inductor phase B exceeded its limit.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 59
The DC current through AC filter inductor phase C is too high.
CauseThe DC component of the current in AC inductor phase C exceeded its limit.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 59
The DC bus voltage exceeded its upper limit.
CausePV input voltage above the permitted limit (too many solar panels in series), or a problem in the Ubus voltage detection circuit.
Recommended fixCheck the PV voltage, the Ubus voltage, and its detection circuit; if the PV input voltage exceeds the limit, reduce the number of solar panels in series; check the Ubus voltage on the LCD display.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 59
The DC bus voltage is below its lower limit.
CauseThe PV input voltage is low - it always happens in the early morning; if F56 appears while the inverter is running, it may be loss of a driver or firmware that needs an update.
Recommended fixCheck the PV voltage and Ubus voltage; update the firmware if needed. Restart the inverter; if the fault still exists, contact your installer or Deye service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 59
Reverse power flow ('reverse irrigation') detected on the AC side.
CauseAC current flowed backwards into the inverter (reverse power flow on the AC side).
Recommended fixThe manual gives no remedy beyond identifying AC reverse power flow; contact your installer or Deye service if the fault persists.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 59
Over-current on the U-phase grid current.
CauseThe U-phase grid current exceeded its protection limit.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 59
Over-current on the V-phase grid current.
CauseThe V-phase grid current exceeded its protection limit.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 59
Over-current on the W-phase grid current.
CauseThe W-phase grid current exceeded its protection limit.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 59
Over-current through filter reactor phase A.
CauseThe current through reactor (filter inductor) phase A exceeded its limit.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 59
Over-current through filter reactor phase B.
CauseThe current through reactor (filter inductor) phase B exceeded its limit.
Recommended fixRestart the inverter; if the fault is not ruled out, contact the installer or manufacturer customer service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 59
A DC arc fault was detected on the PV side (AFCI protection).
CauseA sustained PV-side DC arc, typically from a loose, poor, or damaged PV module cable connection.
Recommended fixCheck the PV module cable connections and clear the fault; seek help from Deye if the inverter cannot go back to its normal state.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 59
The IGBT heat-sink temperature exceeded its limit.
CauseIGBT heat-sink over-temperature; it can also be a faulty temperature sensor, firmware not suitable for the hardware, or a wrong inverter model configuration.
Recommended fixCheck the temperature sensor; check that the firmware is suitable for the hardware and that the inverter is its right model. Restart the inverter; if the fault still exists, contact your installer or Deye service.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 59
Warning that the PV side of the inverter has caused an arc issue.
CauseAn arc was detected on the PV side of the inverter, usually from a loose or poor PV connection.
Recommended fixCheck the connection of the PV, then clear this fault through the ARC function in the operating parameters; the inverter can then resume operation.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
Firmware upgrade error warning.
CauseThe firmware was upgraded incorrectly.
Recommended fixUpgrade to the correct firmware.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
Cooling fan warning.
CauseUsually one or more fan cables are not properly connected, or a fan is broken.
Recommended fixCheck whether all fan cables are properly connected, or replace the faulty fan.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
Firmware version/prefix error after an upgrade.
CauseA version upgrade error corrupted the firmware version (prefix) data.
Recommended fixContact the after-sales engineer to send a command to fix it.
Source:063_BManual_SUN-6K-G06-LV-P1_20250923_en_30a96699.pdf· page 56
Send us the code on your screen and a DEYE technician will reply with the exact steps for your unit. Support is free for life — a first diagnosis never needs a callout.
Compiled from official DEYE user manuals. Always consult your device manual and a qualified technician before performing repairs.