# Fronius state 107 no AC grid detected: what it means and what to do

Fronius state 107 "No AC grid detected" means the inverter is not producing because it cannot detect a stable AC grid. Fronius notes that 107 also shows if the grid was only temporarily absent, for example during a power failure or shutdown. Grid codes like this clear by themselves once the grid is back within limits; if 107 stays on while your home has power, Fronius advises contacting your installer.

## Common causes

- A power outage or utility shutdown, even a brief one.
- The circuit breaker for the solar system switched off.
- A grid-side problem: Fronius states that the cause of class 1 codes lies in the grid, not the inverter.

## Safe steps to try

1. **Check whether there was a power outage** See whether your home has power, or check your utility's outage map.
2. **Wait for the inverter to reconnect** Fronius explains that after a grid code the inverter monitors the grid for a set period and then resumes feeding power by itself.
3. **Call if it stays on with power in the house** Fronius asks owners to make sure the circuit breaker is on. If you suspect the breaker, tell your technician rather than working in the electrical panel yourself. Do not open the inverter, a disconnect, a junction box or any conduit, and do not touch the panels, racking or wiring.

## When to call a professional

Call if your home has normal power and 107 does not clear within a few hours. Fronius advises contacting your installer if the error is permanent.

## Frequently asked questions

### Is state 107 an inverter fault?

Usually not. Fronius classes it as a class 1 code, which it describes as typically temporary with the cause lying in the grid. No device fault has occurred.

### Why is power coming back slowly after the code cleared?

Depending on the grid settings, Fronius inverters ramp their output up gradually after a shutdown caused by an AC error. That is normal.

Canonical page: https://otovo.com/repair/fronius/107