Fronius State 567 Error – Meaning, Causes & Fix
Fronius State 567 is a fault code that appears on Fronius solar inverter displays (Symo, Primo, and GEN24 series) and indicates an AC grid-related issue — most commonly that the inverter has detected the grid voltage or frequency is outside the acceptable range configured for its region, causing it to disconnect from the grid as a protective measure. This is a safety-driven shutdown built into all grid-tied inverters to comply with utility interconnection standards, rather than necessarily indicating a hardware fault within the inverter itself. This guide explains what State 567 means, its common causes, and the correct troubleshooting approach. For related backup power system issues, see our Generac Error Code 1505 guide and our Tesla Powerwall Backup Gateway Offline guide.
What it means
The Fronius inverter has detected an AC grid parameter (voltage or frequency) outside its configured acceptable range and has disconnected from the grid as a required safety response.
Severity
ModerateCan you fix it yourself?
Yes for transient grid fluctuations that self-resolve; persistent occurrences may require a licensed electrician or utility involvement.
Call a technician when
Contact a licensed solar installer or electrician if State 567 persists across multiple days or occurs at a consistent time, as it may indicate a genuine grid voltage issue at your home requiring utility involvement.
What Does State 567 Mean?
Fronius inverters are required by grid interconnection standards (such as IEEE 1547 in the US, or local equivalents elsewhere) to disconnect automatically if the utility grid's voltage or frequency drifts outside a defined safe window. State 567 specifically flags this type of AC grid anomaly detection.
Common underlying triggers include:
1. Momentary grid voltage fluctuation: Utility grids naturally fluctuate slightly, and brief excursions outside the inverter's tight tolerance window trigger a temporary disconnect. 2. Persistent high grid voltage: In areas with many solar installations feeding back into a local transformer, voltage on that circuit can run consistently high, especially at midday. 3. Loose AC wiring connection: A loose connection at the inverter's AC terminal or the main panel can cause voltage readings to fluctuate erratically. 4. Long or undersized wire runs: Excessive voltage drop or rise across long AC wiring runs between the inverter and the electrical panel. 5. Utility-side transformer or grid equipment issue: Rare, but genuine utility equipment problems can cause sustained abnormal voltage.
This grid-protective shutdown behavior is functionally similar to how the Tesla Powerwall Backup Gateway manages its connection to the grid, both prioritizing safety disconnection over continued operation during abnormal conditions.
What Causes This Error?
- Momentary utility grid voltage or frequency fluctuation outside the inverter's configured tolerance
- Persistently high grid voltage on the local circuit, common in neighborhoods with high solar adoption
- Loose or corroded AC wiring connection at the inverter's grid terminal
- Undersized or excessively long AC wiring run causing voltage drop or rise
- Utility-side equipment issue such as a failing transformer
- Incorrect country/grid code setting configured in the inverter during installation
- Nearby heavy electrical loads (well pumps, large motors) causing brief voltage sags on the local circuit
- Firmware requiring an update to properly handle regional grid code changes
How to Fix State 567
- 1
Check the Fronius Solar.web portal or inverter display for the full event log. Review the timestamp and frequency of State 567 occurrences. A single brief occurrence that self-clears is usually a harmless transient grid event; frequent or daily occurrences suggest a persistent issue worth investigating further.
- 2
Wait for automatic reconnection. Fronius inverters are designed to automatically attempt reconnection to the grid after detecting stable conditions for a required time window (often 60-300 seconds depending on grid code). If the inverter resumes normal operation on its own, no further action may be needed for an isolated event.
- 3
Check AC wiring connections at the inverter (qualified personnel only). Since this involves opening electrical enclosures, only a licensed electrician or solar technician should inspect and tighten AC terminal connections at the inverter and disconnect switch.
- 4
Monitor grid voltage independently, if comfortable doing so safely. Some smart meters or a licensed electrician can measure grid voltage at your main panel over a day to identify whether voltage is running consistently high, particularly around midday when solar production peaks in your area.
- 5
Contact your utility if high grid voltage is confirmed. If measurements show your local grid voltage running high, especially during peak solar hours, report this to your utility company — they can adjust local transformer taps to bring voltage back within standard range.
- 6
Have a Fronius-certified installer review inverter settings and firmware. A certified installer can confirm the correct grid code/country setting is configured, check for available firmware updates addressing grid compliance, and adjust voltage ride-through settings within the limits allowed by local regulations.
When to Call a Professional
If State 567 occurs frequently, at a consistent time of day, or is accompanied by other grid-related codes, contact your Fronius-certified solar installer. Diagnosing a persistent grid voltage issue often requires coordination between the installer and your local utility company, since the root cause may be outside your property's electrical system entirely.
Can You Still Use the Device?
A Fronius inverter showing State 567 automatically resumes normal solar production once grid conditions return to acceptable parameters, so no permanent loss of function occurs from an isolated event. However, if this error recurs frequently, it will noticeably reduce your system's total energy production over time, as the inverter spends periods disconnected rather than generating power.
Official Resources
Disclaimer: This article is for informational purposes only and does not constitute professional repair advice. CodeExplain is not affiliated with Fronius or any other brand mentioned. Always consult a qualified technician for complex repairs.