Warning What does this mean?

Your system is down or running degraded, but this is not an immediate safety danger. Work through the safe steps below.

Fronius Inverter STATE 457 Error: Meaning, Causes & Safe Fix

STATE 457 means the inverter's grid relay may be sticking, or the voltage between neutral and ground is too high. The inverter has stopped feeding power into the grid as a safety precaution.

What should I do first?

Two quick questions — we'll point you to the right starting point.

Is this code still showing on your inverter's display?

What this code means

Before feeding power to the grid, your Fronius inverter checks its internal grid relay and the neutral-to-ground voltage. STATE 457 appears when the relay does not switch cleanly ('sticking') or when the neutral-to-ground voltage exceeds the permitted limit (it must be under 30V). Either way, the inverter will not feed energy into the grid until the issue is resolved.

What is this downtime costing you?

Rough estimate while your system isn't producing. Adjust the numbers to match your setup.

System size (kW) Peak sun hours / day Electricity rate ($/kWh)

–per day

–per week

–per 30 days

≈ – kWh of lost production per day.

Estimate only — assumes ~80% real-world output vs. nameplate. Actual losses depend on weather, shading, panel direction, and your tariff.

Common causes

Internal grid relay sticking or wearing out
Neutral-to-ground voltage above 30V (a wiring or earthing issue)
Loose or corroded AC connections
A grid-side earthing problem at the property

Safe steps to try

Work top to bottom, ticking off each step as you complete it. 0 of 5 done.

Note the code and watch whether it clears on its own
Check your switchboard for a tripped breaker — look only, do not touch wiring
Try one AC reset: turn the AC circuit breaker off and back on
If the code returns, leave the system as it is and call your installer
Do not open the inverter or touch any AC terminals

Is your inverter still under warranty?

Before paying for a repair, check — your installer may fix this free.

Brand Year installed

Based on typical standard warranty terms — always confirm with your warranty card or installer paperwork, as terms vary by model, region, and purchase date.

When to call an electrician

Contact your local Fronius Service Partner if STATE 457 persists — relay faults and neutral-to-ground voltage issues require a trained technician with proper test equipment.

Frequently asked questions

Will my solar still work with STATE 457?

No — the inverter stops feeding power into the grid while this code is active. Your panels are not generating usable power until it is resolved.

What does 'neutral-ground voltage under 30V' mean?

It is a safety check: the voltage between your neutral wire and earth must stay below 30 volts. Measuring it involves live electrical work — strictly a job for your installer or electrician.

Can a power surge cause STATE 457?

Grid disturbances can contribute, but a sticking relay is usually internal wear. Either way, it needs professional diagnosis — do not open the inverter.

Need a professional?

This fault may need professional diagnosis. Contact a qualified solar electrician in your area.

Sources: meaning and troubleshooting verified against the manufacturer's documentation — Fronius Operating Instructions (Symo/Primo) — 'Status codes and remedy' / 'STATE CODES' tables (Fronius docs 42,0410,0192 & 42,0410,1909 series)