Fronius – it’s an Austrian company, not an Australian one. But you probably know that already, right? Because if you’re here, your very own Fronius solar inverter is almost certainly showing you an error code that you just want a quick answer to – so you know what on earth to do about it. Well, stop stressing about your Fronius inverter problems, because we’re here to help.
Fronius was established in 1945, but it’s been one of the leading solar brands in the Brisbane and wider Australian solar market since 2000. In the solar world, that’s a long time ago – and could explain why your particular inverter is now playing up. The good news, however, is Fronius’ user-friendly error code system, which makes Fronius inverter troubleshooting a heck of a lot easier.
You’ll find these codes on the inverter’s screen, but you can also check them out via the very impressive Fronius Solar.web platform, providing users just like you with clear insights into system performance and potential issues.
Understanding Fronius error codes
All the time – while we work, play and sleep – Fronius inverters are monitirong their own performance and looking out for problems. When an issue is detected, the inverter displays a specific error code. But here’s the issue: There are almost too many Fronius error codes to count. Each one corresponds to an exact and particular issue, ranging from minor glitches to major faults.
Top 10 most common Fronius error codes & their solutions
Through extensive research, but also our own hands-on Brisbane solar repair experience of one of the most common inverter brands, we’ve identified the most frequently encountered Fronius fault codes – just for you. We outline the top 10 codes, what they mean, and what to do next:
1. Fronius State 509 – No energy fed to the grid in the last 24 hours
Meaning: The inverter has not exported any energy to the grid in the past day.
Possible causes: This could be due to low solar production, high self-consumption, or a system fault.
Recommended action: Check if the solar panels are receiving adequate sunlight and inspect for any shading or obstructions. Ensure the system is operational during daylight hours. If the issue persists, consult a professional technician.
2. Fronius Error 105 – AC frequency too high
Meaning: The alternating current (AC) frequency from the grid exceeds the inverter’s permissible limits.
Possible causes: Grid instability or fluctuations in the local power supply.
Recommended action: Monitor the grid frequency over time. If the error occurs frequently, contact your utility provider to report the issue.
3. State 307 Fronius – DC input voltage too low
Meaning: The direct current (DC) voltage from the solar panels is insufficient for the inverter to operate.
Possible causes: Poor weather conditions, shading on panels, or a fault in the solar array.
Recommended action: Inspect the panels for shading or debris. Ensure all connections are secure. If the problem continues, seek assistance from a solar technician.
4. Fronius Error 314 – Current sensor calibration timeout
Meaning: The inverter’s current sensor failed to calibrate within the expected timeframe.
Possible causes: Internal inverter malfunction or external electrical interference.
Recommended action: Restart the inverter to attempt recalibration. If the error persists, professional solar servicing may be required.
5. Fronius Error 102 – AC voltage too high
Meaning: The AC voltage from the grid is higher than the inverter’s acceptable range.
Possible causes: Voltage spikes or issues with the local power supply.
Recommended action: Monitor the voltage levels. If this error occurs frequently, contact your utility provider to address potential grid issues.
6. Fronius Error 475 – Solar panel ground fault/insulation fault
Meaning: A ground fault or insulation issue has been detected in the solar panel array.
Possible causes: Damaged or faulty wiring, moisture ingress, or degradation of panel insulation.
Recommended action: Immediately shut down the system and inspect for visible damage. Do not attempt repairs yourself; contact a certified solar technician to address the fault.
7. Fronius Error 401 – AC voltage too high
Meaning: Similar to Error 102, indicating the AC voltage exceeds safe operating limits.
Possible causes: Grid voltage anomalies or inverter settings misconfiguration.
Recommended action: Verify inverter settings align with local grid standards. If the error persists, consult with your utility provider or a professional technician.
8. Fronius State 523 – DC2 input voltage too low
Meaning: The second DC input voltage is below the required threshold for operation.
Possible causes: Issues with the second string of solar panels, such as shading, disconnection, or panel faults.
Recommended action: Inspect the second panel string for any issues. Ensure all connections are intact and panels are clean. If unresolved, seek professional assistance.
9. Fronius State 104 – Mains frequency beyond permitted limits
Meaning: The grid frequency is outside the inverter’s allowable range.
Possible causes: Grid instability or frequency fluctuations.
Recommended action: Monitor the frequency. If this error is frequent, contact your utility provider to investigate potential grid issues.
10. Fronius Error 103 – AC voltage too low
Meaning: The AC voltage from the grid is below the inverter’s operational threshold.
Possible causes: Undervoltage conditions in the local power supply.
Recommended action: Check for any issues with your electrical system. If the problem persists, consult your utility provider or a qualified local electrician.
Beyond the top 10 most common codes
We’ve taken a lot of time to research the Fronius error codes you’re most likely to encounter, based on the experiences of solar users just like you. But it would require a blog the length of your driveway to break them all down with the detail that we’ve just provided!
Seeing one of the Top 10 Fronius error codes? Or something we haven’t listed here? Either way, it’s essential to address them as soon as possible to ensure your solar system continues to run as smoothly as you expect. Here at Static Electrics, we absolutely specialise in solar inverter repairs and maintenance – and so much more in the solar and electrical fields across Brisbane and beyond.
Our friendly and certified solar professionals have worked on more Fronius inverters than we can count, helping homeowners and businesses just like you to diagnose and resolve the complete range of issues. So for expert advice or to schedule a service, give us a shout today – we’ll help you keep your solar system performing at its best!
