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.
Growatt Inverter AC F Outrange — A Plain-English Frequency Guide
AC F Outrange means the utility grid’s frequency has moved outside the range your Growatt inverter is permitted to operate in. The inverter disconnects from the grid as a protective response and waits for conditions to normalize. This is nearly always a grid-side event — not a fault in your inverter.
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?
Is your system producing power right now?
What this code means
Grid frequency — 50 Hz in most of the world, 60 Hz in the Americas — is the heartbeat of the power system, held steady by the balance of generation and demand across the whole grid. Your inverter watches it constantly, because feeding power into a grid whose frequency is off can be unsafe. Growatt’s manual defines this condition directly: ‘AC F Outrange / Error: 304 — Utility grid frequency out of permissible range.’
When frequency drifts too far, the inverter does exactly what it’s supposed to do: it stops feeding in and waits. In the large majority of cases this is transient — a distant grid disturbance, a switching event, or a shaky rural grid — and the inverter reconnects by itself once the frequency settles. The display may show the code for only a few minutes before the inverter quietly goes back to work. Unless you happen to be watching the screen — or you get an alert from your monitoring app — the first sign is often just a small dip in that day’s production graph.
Repeated AC F Outrange events tell a different story. They can indicate a genuinely unstable local grid, or — on a new installation — that the inverter’s country/grid standard setting doesn’t match your actual grid. That setting is installer-only; it defines the exact frequency window the inverter enforces, and changing it yourself can breach grid compliance rules. Your installer can check which grid standard is selected and whether it matches your local utility’s requirements.
Growatt’s documented response is measured: switch off the DC switch, check the AC wiring (especially neutral and ground) without touching anything live, verify the grid frequency complies with your local standard, then restart the inverter — and contact Growatt if the problem persists.
What is this downtime costing you?
Rough estimate while your system isn't producing. Adjust the numbers to match your setup.
≈ – 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
- Transient grid frequency disturbance (utility-side event).
- Unstable or weak grid, common in rural or remote areas.
- Major grid events — storms, large outages, or switching operations nearby.
- Incorrect country/grid-standard setting in the inverter (installer to verify).
- Loose neutral or ground connection in the AC wiring (qualified person to check).
- High local solar penetration causing local grid instability (rare).
Safe steps to try
Work top to bottom, ticking off each step as you complete it. 0 of 5 done.
Is your inverter still under warranty?
Before paying for a repair, check — your installer may fix this free.
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
Call your installer if AC F Outrange persists for hours, recurs daily, or appears alongside other grid errors. Never touch AC wiring, never attempt to change the grid standard or country setting yourself, and if you ever see signs of overheating or burning, switch off and call a professional immediately.
Frequently asked questions
Will AC F Outrange damage my inverter?
No — disconnecting is the protection working as designed. The inverter is built to ride out grid disturbances by stepping aside until conditions are safe.
How long before the inverter reconnects?
Once the frequency returns inside the permitted window and stays there for the inverter’s monitoring period, it reconnects automatically — typically within minutes. There’s nothing you need to reset in the normal case.
What’s the difference between AC F Outrange and AC V Outrange?
F is frequency (the 50/60 Hz heartbeat of the grid); V is voltage (the 230V level). Both are grid-quality protections, but they watch different things. You troubleshoot them similarly: confirm it’s grid-side, then call your installer if it keeps happening.
Can I widen the frequency range myself?
No. The permitted range comes from your country’s grid standard, and the setting is locked to installers for good reason — an incorrect setting can breach grid compliance and create safety risks. If you suspect the setting is wrong, your installer can verify it.
Who’s responsible for grid frequency?
Your utility or grid operator maintains frequency across the network; individual households can’t influence it. If your whole area sees frequent frequency events, it’s worth reporting to the utility — and telling your installer, who can confirm your system is riding through them correctly.
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 — Growatt MIN 2500-6000TL-XE/X Installation & Operation Manual (GR-UM-263-A-00), section 11 — Trouble shooting: ‘AC F Outrange / Error: 304 — Utility grid frequency out of permissible range. 1. Please switch off DC switch. 2. Check AC wiring, especially neutral and ground wire. 3. Check grid frequency is complied with local grid standard. 4. Restart inverter, if problem still exist, Contact Growatt.’ (official Growatt manual, tr.growatt.com; read and verified directly).