10min Volt Fault on a Fox ESS H1 G2 single-phase hybrid inverter: The grid voltage is out of range for the last 10 Minutes
Short answer
On a Fox ESS inverter, 10min Volt Fault means: The grid voltage is out of range for the last 10 Minutes. The inverter stops until the fault clears or is reset.
Reviewed 24 September 2026 · 1 source
What it means
The manual says: The grid voltage is out of range for the last 10 Minutes.
Part involved: 10-minute average voltage protection.
When it shows: 10-minute rolling average voltage exceeds limit.
Likely causes:
- 10-minute average grid voltage above the limit (common on high-voltage rural/solar-saturated feeders).
Is it safe?
| Does the inverter stop? | Yes |
|---|---|
| Severity | Fault — clears by itself when the condition goes |
The inverter stops until the fault clears or is reset.
Resetting itself: yes.
Manual reset: System reconnects automatically when the utility is back to normal.
What you can check
- Read the full code and message on the inverter screen or in the FoxCloud app and note the date/time for your installer.
- Check the inverter's AC isolator next to the inverter and the solar/battery breaker in the consumer unit are ON (do not reset a breaker that trips again - call your installer).
- If it recurs on sunny days, ask your installer to log voltage - persistent high voltage is a network operator (DNO) matter.
What the engineer will check
- Check voltage rise on AC cable run; confirm 10-min average setting per G98/G99; request DNO voltage investigation.
Who to ask for: Installer, with DNO (network operator) if grid supply is at fault.
Certification: None for homeowner checks; any grid-protection setting change needs installer and DNO consent (G98/G99).
What you might notice
Sources
- H1(G2)/AC1(G2) Series User Manual ↗ · V1.0.8 · page 47 · Reviewed 24 September 2026
A code explains what the controller detected, not a confirmed root cause.
Reviewed: 24 September 2026