Grid Lost Fault on a Fox ESS H1 G2 single-phase hybrid inverter: Grid is lost

What it means

The manual says: Grid is lost.

Part involved: AC grid connection.

When it shows: Inverter no longer detects grid voltage.

Likely causes:

• Grid supply lost (power cut) or the inverter's AC supply isolated (AC isolator off / breaker tripped).

Is it safe?

The inverter stops until the fault clears or is reset.

Resetting itself: yes.

Manual reset: System reconnects automatically when the utility returns 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).
• Check whether there is a power cut in the house/street; the inverter reconnects on its own when the grid returns.
• If only the solar/battery breaker has tripped, reset it once; if it trips again leave it off and call your installer.

What the engineer will check

• Measure AC voltage at inverter grid terminals; check AC isolator/MCB/RCBO sizing and connections; confirm N/L wiring; check grid code setting.

Who to ask for: Qualified electrician / MCS PV installer.

Certification: None for homeowner checks; any grid-protection setting change needs installer and DNO consent (G98/G99).

What you might notice

• Inverter showing fault, red light or offline

What owners and engineers report

1 owner and engineer report mentions this.

• Solar or battery breaker/RCD keeps tripping on the H1 G2 single-phase hybrid inverter: 1 report

Sources

• H1(G2)/AC1(G2) Series User Manual ↗ · V1.0.8 · page 46 · Reviewed 24 September 2026

A code explains what the controller detected, not a confirmed root cause.

Reviewed: 24 September 2026