106 on a Fronius International GmbH Fronius SnapINverter: AC frequency too low
Short answer
On a Fronius International GmbH inverter, 106 means: AC frequency too low. The inverter stops until the fault clears or is reset. An engineer is needed to fix the cause.
Reviewed 24 September 2026 · 1 source
What it means
The manual says: AC frequency too low.
Part involved: grid monitoring.
When it shows: Class 1 status code.
Likely causes:
- Inverter resumes feeding in after careful testing once grid conditions are within range; check grid connections; if recurring contact your system fitter.
Is it safe?
| Does the inverter stop? | Yes |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
| Engineer needed? | Yes |
The inverter stops until the fault clears or is reset.
Resetting itself: yes.
Manual reset: Automatic when condition clears.
What you can check
- Read the state code on the inverter display or in Fronius Solar.web and note date/time for your installer.
- Class 1 codes are normally caused by the public grid and clear on their own.
- If it keeps recurring, contact your installer.
What the engineer will check
- Check grid connection and AC voltage at inverter (230 V +10%/-5% depending on country setup); log grid; DNO liaison; check country setup.
Who to ask for: Fronius-trained PV installer / Fronius Service Partner.
Certification: Installer liaison with the DNO; any change to grid-protection settings needs DNO agreement (G98/G99) and the manufacturer's installer/grid code.
What you might notice
Sources
- Fronius Primo 3.0-1 - 8.2-1 Operating Instructions (HTML) ↗ · 42,0410,2165 online edition · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026