Voltronic ESS510 Error Codes: Causes & Fixes (39 codes)

This is the complete fault table for the Voltronic ESS510 Energy storage system — all 39 codes from the official manual on one page. On this Voltronic device, a fault code means the unit has entered protection and stopped normal operation; a warning leaves it running. The exact indication (LED pattern or display code) is listed per code below.

Last checked against the official manuals on July 27, 2026.

How to read the severity labels

  • Fault(29)— operation stops until cleared
  • Warning(10)— unit keeps running · needs attention

Fault codes (29)operation stops until cleared

01Fault

DC bus voltage exceeds the upper threshold.

Fault

Fault code 01 shown on the display with the fault icon on: DC bus voltage exceeds the upper threshold..

CauseDC bus voltage exceeds the upper threshold.

Recommended fixDisconnect AC circuit breaker first. Then, disconnect DC circuit breaker. Until LCD screen completely shuts down, turn on DC breaker first. It will show "No Utility" in LCD screen. Then, turn on AC breaker. After 300 seconds, the system will automatically connect to the grid. If the error message still remains, please contact your installer.

Source:ESS510-manual.pdf· page 68

02Fault

DC bus voltage falls below the lower threshold.

Fault

Fault code 02 shown on the display with the fault icon on: DC bus voltage falls below the lower threshold..

CauseDC bus voltage falls below the lower threshold.

Recommended fixDisconnect AC circuit breaker first. Then, disconnect DC circuit breaker. Until LCD screen completely shuts down, turn on DC breaker first. It will show "No Utility" in LCD screen. Then, turn on AC breaker. After 300 seconds, the system will automatically connect to the grid. If the error message still remains, please contact your installer.

Source:ESS510-manual.pdf· page 68

03Fault

DC bus voltage soft-start is timeout.

Fault

Fault code 03 shown on the display with the fault icon on: DC bus voltage soft-start is timeout..

CauseDC bus voltage soft-start is timeout.

Recommended fixDisconnect AC circuit breaker first. Then, disconnect DC circuit breaker. Until LCD screen completely shuts down, turn on DC breaker first. It will show "No Utility" in LCD screen. Then, turn on AC breaker. After 300 seconds, the system will automatically connect to the grid. If the error message still remains, please contact your installer.

Source:ESS510-manual.pdf· page 68

04Fault

Inverter soft-start is timeout.

Fault

Fault code 04 shown on the display with the fault icon on: Inverter soft-start is timeout..

CauseInverter soft-start is timeout.

Recommended fixDisconnect AC circuit breaker first. Then, disconnect DC circuit breaker. Until LCD screen completely shuts down, turn on DC breaker first. It will show "No Utility" in LCD screen. Then, turn on AC breaker. After 300 seconds, the system will automatically connect to the grid. If the error message still remains, please contact your installer.

Source:ESS510-manual.pdf· page 68

05Fault

An inverter overcurrent event is detected.

Fault

Fault code 05 shown on the display with the fault icon on: An inverter overcurrent event is detected..

CauseAn inverter overcurrent event is detected.

Recommended fixDisconnect AC circuit breaker first. Then, disconnect DC circuit breaker. Until LCD screen completely shuts down, turn on DC breaker first. It will show "No Utility" in LCD screen. Then, turn on AC breaker. After 300 seconds, the system will automatically connect to the grid. If the error message still remains, please contact your installer.

Source:ESS510-manual.pdf· page 68

06Fault

Over temperature fault.

Fault

Fault code 06 shown on the display with the fault icon on: Over temperature fault..

CauseThe internal temperature is higher than specified temperature.

Recommended fixLeave inverter to cool down to room temperature. If the error message still remains, please contact your installer.

Source:ESS510-manual.pdf· page 68

07Fault

Relay failure is detected.

Fault

Fault code 07 shown on the display with the fault icon on: Relay failure is detected..

CauseRelay failure is detected.

Recommended fixDisconnect AC circuit breaker first. Then, disconnect DC circuit breaker. Until LCD screen completely shuts down, turn on DC breaker first. It will show "No Utility" in LCD screen. Then, turn on AC breaker. After 300 seconds, the system will automatically connect to the grid. If the error message still remains, please contact your installer.

Source:ESS510-manual.pdf· page 68

08Fault

DC component in the output current exceeds the upper threshold.

Fault

Fault code 08 shown on the display with the fault icon on: DC component in the output current exceeds the upper threshold..

CauseDC component in the output current exceeds the upper threshold.

Recommended fixDisconnect AC circuit breaker first. Then, disconnect DC circuit breaker. Until LCD screen completely shuts down, turn on DC breaker first. It will show "No Utility" in LCD screen. Then, turn on AC breaker. After 300 seconds, the system will automatically connect to the grid. If the error message still remains, please contact your installer.

Source:ESS510-manual.pdf· page 68

09Fault

PV input voltage exceeds the upper threshold.

Fault

Fault code 09 shown on the display with the fault icon on: PV input voltage exceeds the upper threshold..

CausePV input voltage exceeds the upper threshold.

Recommended fixCheck if the open circuit voltage of PV modules is higher than 500VDC. If PV open circuit voltage is less than 500VDC and the error message remains, please contact your installer.

Source:ESS510-manual.pdf· page 68

10Fault

Auxiliary power failed (auxiliary power means switch power supply).

Fault

Fault code 10 shown on the display with the fault icon on: Auxiliary power failed (auxiliary power means switch power supply)..

CauseAuxiliary power failed (auxiliary power means switch power supply).

Recommended fixTurn off the inverter. Then, restart the inverter. If the error message still remains, please contact your installer.

Source:ESS510-manual.pdf· page 68

11Fault

Over-current on PV input is detected.

Fault

Fault code 11 shown on the display with the fault icon on: Over-current on PV input is detected..

CauseOver-current on PV input is detected.

Recommended fixDisconnect AC circuit breaker first. Then, disconnect DC circuit breaker. Until LCD screen completely shuts down, turn on DC breaker first. It will show "No Utility" in LCD screen. Then, turn on AC breaker. After 300 seconds, the system will automatically connect to the grid. If the error message still remains, please contact your installer.

Source:ESS510-manual.pdf· page 68

12Fault

Leakage current exceeds the allowable range.

Fault

Fault code 12 shown on the display with the fault icon on: Leakage current exceeds the allowable range..

CauseThe ground voltage is too high.

Recommended fixPlease disconnect AC breaker first and then DC breaker. Check if grounding is connected properly after LCD screen completely shuts down. If grounding is correctly connected, turn on DC breaker. After it displays "No Utility" in LCD screen, turn on AC breaker. After 300 seconds, the system will automatically connect to the grid. If the error message still remains, please contact your installer.

Source:ESS510-manual.pdf· page 69

13Fault

PV insulation resistance is too low.

Fault

Fault code 13 shown on the display with the fault icon on: PV insulation resistance is too low..

CausePV insulation resistance is too low.

Recommended fixCheck if the impedance between positive and negative poles to the ground is greater than 1MΩ. If the impedance is lower than 1MΩ, please contact your installer.

Source:ESS510-manual.pdf· page 69

14Fault

Inverter DC component exceeds the allowable range.

Fault

Fault code 14 shown on the display with the fault icon on: Inverter DC component exceeds the allowable range..

CauseInverter DC component exceeds the allowable range.

Recommended fixDisconnect AC circuit breaker first. Then, disconnect DC circuit breaker. Until LCD screen completely shuts down, turn on DC breaker first. It will show "No Utility" in LCD screen. Then, turn on AC breaker. After 300 seconds, the system will automatically connect to the grid. If the error message still remains, please contact your installer.

Source:ESS510-manual.pdf· page 68

15Fault

A difference occurred in the readings from the main and secondary controllers.

Fault

Fault code 15 shown on the display with the fault icon on: A difference occurred in the readings from the main and secondary controllers..

CauseA difference occurred in the readings from the main and secondary controllers.

Recommended fixPlease disconnect AC breaker first and then disconnect DC breaker. After LCD screen is completely off, turn on DC breaker. Until it shows "No Utility" in LCD display, turn on AC breaker. After 300 seconds, the system will automatically connect to the grid. If error message remains, please contact your installer.

Source:ESS510-manual.pdf· page 69

16Fault

Leakage current CT failed.

Fault

Fault code 16 shown on the display with the fault icon on: Leakage current CT failed..

CauseLeakage current CT failed.

Recommended fixDisconnect AC circuit breaker first. Then, disconnect DC circuit breaker. Until LCD screen completely shuts down, turn on DC breaker first. It will show "No Utility" in LCD screen. Then, turn on AC breaker. After 300 seconds, the system will automatically connect to the grid. If the error message still remains, please contact your installer.

Source:ESS510-manual.pdf· page 68

17Fault

Communication with the main and secondary controllers is interrupted.

Fault

Fault code 17 shown on the display with the fault icon on: Communication with the main and secondary controllers is interrupted..

CauseCommunication with the main and secondary controllers is interrupted.

Recommended fixPlease disconnect AC breaker first and then disconnect DC breaker. After LCD screen is completely off, turn on DC breaker. Until it shows "No Utility" in LCD display, turn on AC breaker. After 300 seconds, the system will automatically connect to the grid. If error message remains, please contact your installer.

Source:ESS510-manual.pdf· page 69

20Fault

Discharge circuit fault.

Fault

Fault code 20 shown on the display with the fault icon on: Discharge circuit fault..

CauseDischarge circuit fault.

Recommended fixPlease disconnect AC breaker first and then disconnect DC breaker. After LCD screen is completely off, turn on DC breaker. Until it shows "No Utility" in LCD display, turn on AC breaker. After 300 seconds, the system will automatically connect to the grid. If error message remains, please contact your installer.

Source:ESS510-manual.pdf· page 69

21Fault

Soft start in battery discharge fails.

Fault

Fault code 21 shown on the display with the fault icon on: Soft start in battery discharge fails..

CauseSoft start in battery discharge fails.

Recommended fixPlease disconnect AC breaker first and then disconnect DC breaker. After LCD screen is completely off, turn on DC breaker. Until it shows "No Utility" in LCD display, turn on AC breaker. After 300 seconds, the system will automatically connect to the grid. If error message remains, please contact your installer.

Source:ESS510-manual.pdf· page 69

22Fault

Charging voltage is too high.

Fault

Fault code 22 shown on the display with the fault icon on: Charging voltage is too high..

CauseCharging voltage is too high.

Recommended fixCheck if the connection between battery and inverter is good. Make sure battery condition is ok. Then, restart the inverter. If error message remains, please contact your installer.

Source:ESS510-manual.pdf· page 69

23Fault

Overload fault.

Fault

Fault code 23 shown on the display with the fault icon on: Overload fault..

CauseOverload fault.

Recommended fixRemove excessive loads. Be sure the total power consumption of the connected loads is less than the maximum which this inverter can support. Then, restart the inverter.

Source:ESS510-manual.pdf· page 69

24Fault

Battery disconnected.

Fault

Fault code 24 shown on the display with the fault icon on: Battery disconnected..

CauseBattery disconnected.

Recommended fixCheck if battery cable is connected firmly. If error message remains, please contact your installer.

Source:ESS510-manual.pdf· page 69

25Fault

Inverter current is too high for a long time.

Fault

Fault code 25 shown on the display with the fault icon on: Inverter current is too high for a long time..

CauseInverter current is too high for a long time.

Recommended fixRemove excessive loads. Then, restart the inverter.

Source:ESS510-manual.pdf· page 69

26Fault

Short circuited on inverter output.

Fault

Fault code 26 shown on the display with the fault icon on: Short circuited on inverter output..

CauseShort circuited on inverter output.

Recommended fixTurn off the inverter. Disconnect AC circuit breaker first. Then, disconnect DC circuit breaker and then disconnect the loads. Please check if load circuit is ok. After removing the error, turn on the PV DC breaker and battery breaker. Turn on the inverter. If error message remains, please contact your installer.

Source:ESS510-manual.pdf· page 70

27Fault

Fan fault.

Fault

Fault code 27 shown on the display with the fault icon on: Fan fault..

CauseFan fault.

Recommended fixPlease check if fans are running ok. If fans are running ok, please shut down inverter first and then restart it. If fans stop running or error message remains after restart the inverter, please contact your installer.

Source:ESS510-manual.pdf· page 70

28Fault

OP current sensor fault.

Fault

Fault code 28 shown on the display with the fault icon on: OP current sensor fault..

CauseOP current sensor fault.

Recommended fixShut down the inverter completely. Restart the inverter to see if it's ok. If error message still remains, please contact your installer.

Source:ESS510-manual.pdf· page 70

29Fault

Charger failure.

Fault

Fault code 29 shown on the display with the fault icon on: Charger failure..

CauseCharger failure.

Recommended fixShut down the inverter completely. Restart the inverter to see if it's ok. If error message still remains, please contact your installer.

Source:ESS510-manual.pdf· page 70

30Fault

Version mismatch between controller board and power board.

Fault

Fault code 30 shown on the display with the fault icon on: Version mismatch between controller board and power board..

CauseVersion mismatch between controller board and power board.

Recommended fixShut down the inverter completely. Restart the inverter to see if it's ok. If error message still remains, please contact your installer.

Source:ESS510-manual.pdf· page 70

31Fault

Reverse connection of input and output wires.

Fault

Fault code 31 shown on the display with the fault icon on: Reverse connection of input and output wires..

CauseReverse connection of input and output wires.

Recommended fixShut down the inverter completely. Check if grid wires are connected to AC output terminals. If mis-connected, re-connect it correctly. And turn on the inverter again. If error message still remains, please contact your installer.

Source:ESS510-manual.pdf· page 70

Warning codes (10)unit keeps running · needs attention

W02Warning

Internal EEPROM failed.

Warning

Warning code 02 flashing on the display: Internal EEPROM failed..

CauseInternal EEPROM failed.

Recommended fixRestart the unit again. If problem still exists, please contact your installer.

Source:ESS510-manual.pdf· page 71

W04Warning

Battery low.

Warning

Warning code 04 flashing on the display: Battery low..

CauseBattery low.

Recommended fixRecharge or replace the battery.

Source:ESS510-manual.pdf· page 71

W07Warning

Overload.

Warning

Warning code 07 flashing on the display: Overload..

CauseOverload.

Recommended fixReduce connected load.

Source:ESS510-manual.pdf· page 71

W17Warning

Battery open.

Warning

Warning code 17 flashing on the display: Battery open..

CauseBattery open.

Recommended fixRe-connect the battery.

Source:ESS510-manual.pdf· page 71

W20Warning

Over temperature.

Warning

Warning code 20 flashing on the display: Over temperature..

CauseOver temperature.

Recommended fixCheck the ventilation around the unit and try to reduce connected load. Check if fans run normally.

Source:ESS510-manual.pdf· page 71

W32Warning

Communication lost between inverter and display panel.

Warning

Warning code 32 flashing on the display: Communication lost between inverter and display panel..

CauseCommunication lost between inverter and display panel.

Recommended fixRestart the unit again. If problem still exists, please contact your installer.

Source:ESS510-manual.pdf· page 71

W60Warning

BMS stops battery charging and discharging.

Warning

Warning code 60 flashing on the display: BMS stops battery charging and discharging..

CauseBattery status is not allowed to charge and discharge after the communication between the inverter and battery is successful, or the battery communication signal is lost (code 60 shows and the inverter stops charging and discharging the battery).

Recommended fixCheck the communication connection between the inverter and battery. If communication was established and then lost, the buzzer beeps immediately; after 10 minutes without communication the inverter stops charging and discharging the lithium battery.

Source:ESS510-manual.pdf· page 71

W69Warning

BMS stops battery charging.

Warning

Warning code 69 flashing on the display: BMS stops battery charging..

CauseBattery status is not allowed to charge after the communication between the inverter and battery is successful; code 69 shows to stop charging the battery.

Recommended fixFollow the battery BMS state; charging resumes when the battery allows it. If the warning persists, check the battery status and communication.

Source:ESS510-manual.pdf· page 71

W70Warning

BMS requests battery charging.

Warning

Warning code 70 flashing on the display: BMS requests battery charging..

CauseBattery status must be charged after the communication between the inverter and battery is successful; code 70 shows to charge the battery.

Recommended fixAllow the inverter to charge the battery as requested by the BMS.

Source:ESS510-manual.pdf· page 71

W71Warning

BMS stops battery discharging.

Warning

Warning code 71 flashing on the display: BMS stops battery discharging..

CauseBattery status is not allowed to discharge after the communication between the inverter and battery is successful; code 71 shows to stop discharging the battery.

Recommended fixFollow the battery BMS state; discharging resumes when the battery allows it. If the warning persists, check the battery status and communication.

Source:ESS510-manual.pdf· page 71

Still seeing a code on your ESS510?

Send us the code on your screen and a Voltronic technician will reply with the exact steps for your unit. Support is free for life — a first diagnosis never needs a callout.

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Common questions about ESS510 error codes

What is the difference between a fault and a warning on the ESS510?
A fault puts the unit into protection and stops normal operation — this page lists 29 of them for the ESS510. A warning leaves the unit running; there are 10 warning codes here. Resolve the cause of a fault before restarting; warnings can usually be cleared while the unit runs.
Does this page apply to other Voltronic models?
No — this table was transcribed specifically from the ESS510 manual. Other Voltronic devices have their own pages; start from the error-code hub to find the one matching the model number on your unit's label.
Where do these codes come from?
Every entry was transcribed from ESS510-manual.pdf — Voltronic's official documentation. Each row cites its source manual (and page where printed), so you can verify the wording before acting on it.

Compiled from official Voltronic user manuals. Always consult your device manual and a qualified technician before performing repairs.