If your solar system has stopped working or your inverter screen is flashing unfamiliar alerts, you're likely seeing one of many Aurora inverter error codes (also known as Power-One inverter fault codes). These messages are designed to help identify issues affecting your solar performance—ranging from minor warnings to major faults requiring urgent attention.

Below is a comprehensive breakdown of every known Aurora inverter fault code, what it means, and what you can do about it. If you're unsure or need hands-on help, call us at Solair Electrical on 0405 685 441—we’re fully qualified to inspect and repair Aurora and ABB inverters across Brisbane and surrounds.

RISO LOW

According to the ABB / Power-One Aurora user manual, a 'Riso Low' warning means the inverter has found low insulation resistance on the DC side of your solar system. This usually isn't a fault with the inverter itself, but rather something affecting the wiring or components connected to it. The issue could be with the solar panel cables, the DC isolators, or the panels themselves

W001 – Sun Low

Input voltage under threshold (usually early morning or poor light). Not a fault unless it persists during sunny hours.

E001 – Input OC

Input over current detected. Needs electrical investigation.

W002 – Input UV

Input under voltage. May indicate string voltage issue or shading.

E002 – Input OV

Input over voltage. Could mean your PV array is supplying too much voltage—switch off the DC isolator and call for service.

E003 – Internal Error

No parameters available—could indicate a software or board fault.

E004 – Bulk OV

Bulk over voltage detected. May point to a failing capacitor or circuit issue.

E005 – Communication Error

Internal communication failure between components.

E006 – Output OC

Output over current. Requires urgent inspection.

E007 – IGBT Sat

Insulated-gate bipolar transistor saturation. Suggests power stage fault.

W011 – Sun Low (Bulk Under Voltage)

Bulk voltage too low, usually due to early/late sunlight or panel mismatch.

E009 – Internal Error

Unspecified internal fault. Requires diagnosis.

W003 – Grid Fail

Grid voltage/frequency out of tolerance. Check grid or isolator.

E010 – Bulk Low

Voltage too low in bulk capacitor. May require capacitor replacement.

E011 – Ramp Fail

The inverter failed ramp-up during connection phase.

E012 – DC/DC Fail

DCDC board failure. Inverter may not operate.

E013 – Wrong Mode

Wrong input setting selected (single vs dual channel).

E014 – Over Temp.

Inverter internal temperature too high. Check for blocked airflow or direct sun exposure.

E015 – Cap Fault

Bulk capacitor fault detected—likely needs replacement.

E016 – Inv. Fault

General inverter failure revealed by DC/DC board.

E017 – Start Timeout

Inverter failed to start within the expected time.

E018 – Ground F.

Leakage current fault. Could be due to moisture or damaged cabling.

E020 – DCDC Relay Fail

DC/DC relay malfunction. Inverter will likely not start.

E021 – Inverter Relay Fail

Output relay error. Needs component-level inspection.

E022 – Auto test Timeout

Inverter failed internal self-test.

E023 – DC Injection Error

Excessive DC into the grid—safety risk. Disconnect system and contact a professional.

W004 – Grid OV

Grid over voltage—monitor, especially during peak export periods.

W005 – Grid UV

Grid under voltage. Check if power company is doing maintenance.

W006 – Grid OF

Grid over frequency.

W007 – Grid UF

Grid under frequency.

W008 – Z Grid HI

Grid impedance out of range. Could be poor connection or cable fault.

E024 – Unknown Error

Internal unidentified issue—likely firmware or board fault.

E025 – Riso Low (Log Only)

Low insulation resistance logged (no shutdown). Monitor system.

E026 – VRef Error

Reference voltage error. Needs circuit board inspection.

E028 – Fgrid Measures Fault

Grid frequency misread. Possibly faulty sensor.

E029 – Zgrid Measures Fault

Impedance sensor error.

E030 – ILeak Measures Fault

Leakage current reading error.

E031 – Wrong V Measure

Voltage sensor fault or misreading.

E032 – Wrong I Measure

Current sensor fault or misreading.

W010 – Fan Fail

Fan failure logged (no disconnection). Clean/inspect cooling fans.

E033 – Under Temperature

Inverter is operating below minimum temperature range. May delay startup.

E034 – Interlock Fail

Unused diagnostic—ignore unless persistent.

E035 – Remote Off

Inverter is off via external signal. Check smart meter or remote-control system.

E036 – Vout Avg.

Average output voltage is outside the expected range.

W012 – Clock Battery Low

Internal clock battery is low. Not urgent but may affect monitoring.

W013 – Clock Failure

Internal clock error. Not critical, but inverter may not log properly.

Need Help with Aurora Inverter Error Codes? Call Solair Electrical

While some warnings are harmless or self-correcting, many Aurora inverter error codes point to serious faults that can reduce your solar system’s efficiency or shut it down entirely. It’s not always easy to diagnose these issues without the right equipment or training.

At Solair Electrical, we specialise in Aurora/Power-One inverter repairs and diagnostics throughout Brisbane and the Gold Coast. Whether you're seeing a simple fan warning or a complete grid failure alert, we can help get your system back to full performance—safely and efficiently.

Call us now on 0405 685 441 to book your inverter inspection. Don’t risk damage or downtime—get your solar system checked by a professional today.