Fronius Inverter Error Codes & Troubleshooting Guide
Fronius inverters are renowned for their reliability and efficiency in converting solar energy into usable electricity. However, like all sophisticated electronic devices, they may occasionally display error codes—known as STATE codes—to indicate operational issues. Understanding these codes is crucial for timely troubleshooting and maintaining optimal system performance.
If you encounter issues with your Fronius inverter, try restarting it first. This simple step can often resolve common problems.
If restarting your inverter doesn’t resolve the issue, refer to the list below of a comprehensive table of common Fronius inverter error codes, their descriptions, and suggested remedies.
| Error Code | Description | Suggested Remedy |
|---|---|---|
| STATE 101 | Grid voltage beyond permitted limits | Check grid voltage and circuit breakers; adjust service menu settings; contact SolarWide if issue persists. |
| STATE 104 | Mains frequency beyond permitted limits | Verify mains frequency; adjust service menu settings; consult SolarWide if necessary. |
| STATE 107 | Sync with public mains supply not possible | Ensure mains power is connected; check circuit breakers; adjust settings; contact SolarWide if issue continues. |
| STATE 108 | Islanding detected | Automatic correction; if problem persists, contact SolarWide. |
| STATE 201 | Grid voltage beyond permitted limits | Check grid voltage and circuit breakers; adjust settings; contact SolarWide if issue persists. |
| STATE 202 | Grid voltage is lower than the specified limit | Verify grid voltage; contact SolarWide if necessary. |
| STATE 203 | Grid frequency is higher than the specified limit | Check grid frequency; consult SolarWide if issue continues. |
| STATE 204 | Grid frequency is lower than the specified limit | Verify grid frequency; contact SolarWide if necessary. |
| STATE 301 | Overcurrent (AC) | Fault is rectified automatically; if persistent, notify SolarWide. |
| STATE 302 | Overcurrent (DC) | Fault is rectified automatically; if persistent, notify SolarWide. |
| STATE 303 | Power stage set over temperature | Ensure ventilation slots are clear; if issue persists, contact SolarWide . |
| STATE 304 | Internal temperature too high | Check for adequate ventilation; if problem continues, consult SolarWide. |
| STATE 306 | Low PV output | Common during low sunlight; if it occurs in daylight, contact SolarWide. |
| STATE 307 | Low PV voltage | Common during low sunlight; if it occurs in daylight, contact SolarWide. |
| STATE 401 | No communication with power stage set | Inverter will retry; if issue persists, contact SolarWide. |
| STATE 406 | Temperature sensor faulty | Contact SolarWide for sensor inspection or replacement. |
| STATE 408 | DC feeding into grid detected | Consult SolarWide for diagnosis. |
| STATE 412 | Fixed voltage mode set incorrectly | Adjust voltage settings; if issue persists, contact SolarWide. |
| STATE 415 | Safety cut out via option card | Inverter stops feeding energy; contact SolarWide if issue continues. |
| STATE 560 | Derating from over-frequency | Inverter reduces output; resumes when frequency normalises. |
| STATE 567 | Grid Voltage Dependent Power Reduction | Inverter reduces output due to high grid voltage; contact SolarWide if recurring. |
| STATE 705 | Inverter number setting conflict | Correct inverter number via setup menu. |
| STATE 721 | EEPROM reinitialised or faulty | Acknowledge code; if persistent, contact SolarWide. |
| STATE 731 | Unsupported USB stick | Check/replace USB stick; verify file system format. |
| STATE 743 | Error during update | Repeat update; check USB; contact SolarWide if issue persists. |
| STATE 751 | Time lost | Reset time/date on inverter; contact SolarWide if issue continues. |
| STATE 1001 | Insulation measurement triggered | No action required; inverter resumes after test. |
| STATE 1024 | Settings changed – restart needed | Inverter restarts automatically; no extra action needed. |
| STATE 1030 | Wired Shut Down (WSD) triggered | Check for emergency stop; otherwise contact SolarWide . |
| STATE 1036 | Grid frequency high on reconnect | Wait for frequency to stabilise; no action needed. |
| STATE 1112 | Mains voltage-dependent power reduction | Inverter reduces output due to high voltage; no action required. |
| STATE 1175 | Not enough DC power for feed-in | Normal during early morning or late afternoon; inverter resumes when power returns. |
| STATE 1196 | Inverter setup values not received | Typical during startup; can usually be ignored. |
How to Restart Your Fronius Inverter (Step-by-Step)
If your Fronius inverter is showing an error or not functioning as expected, restarting the unit can often resolve minor issues. Follow these steps to safely shut down and restart your Fronius solar inverter:
- Turn Off the Solar Supply Main Switch
Locate the Solar Supply Main Switch in your switchboard (also known as the PV array isolator) and turn it OFF. This disconnects the inverter from the panels. - Turn Off the Inverter AC Isolator (If Present)
Some systems include a separate AC isolator next to or beneath the inverter. If yours has one, switch it OFF. - Turn Off the Inverter
Press the power button on the inverter (if it has one) or simply allow it to power down after the DC and AC isolators are turned off. - Wait 1–2 Minutes
Give the inverter a minute to fully shut down. This pause helps clear residual errors and allows internal systems to reset. - Turn the Inverter Back On
Now restart the system in reverse order:
- Turn the AC isolator (if applicable) back ON
- Turn the Solar Supply Main Switch back ON
The inverter should power up and begin its normal startup sequence. Watch the display screen for any error messages or status updates.
