Growatt is one of the most widely installed inverter brands in India, and its fault messages are a frequent search. Exact codes and wording vary across models and firmware (MIN, MID, MOD, SPH), so always check your model's manual — but the messages fall into a few clear groups. Identifying the group tells you whether the problem is the grid, the solar array, the environment or the inverter itself.
Common Growatt error groups
- No AC Connection / AC V Outrange / AC F Outrange — the grid is absent, or its voltage or frequency is outside the inverter's limits.
- PV Isolation Low — insulation resistance on the DC (panel) side is too low, usually due to moisture or damaged cabling.
- Over-temperature warnings — the inverter is too hot and has derated or shut down.
- Residual I High — residual (leakage) current fault, often caused by moisture or damaged DC cabling.
- Numbered "Error" codes (for example relay or internal faults) — usually an internal hardware problem that needs a technician.
- Monitoring offline — the Wi-Fi / ShineLink dongle has lost connection to the inverter or the router.
What to check first, safely
- Is the grid supply present and stable?
- Are the AC breaker and DC isolator both ON?
- Did the error start after rain, cleaning or recent work on the site?
- Is the inverter in direct sun with blocked ventilation?
- Note the exact code and time it appears before restarting anything.
When it needs a technician
If the same Growatt error returns immediately after a correct restart, the fault is internal — relay, power supply, control board or power stage. Do not keep resetting: repeated restarts on a damaged power stage can turn a repairable fault into a total failure.
Frequently asked questions
Why does my Growatt inverter keep showing a grid fault?
Usually the grid voltage is outside the inverter's acceptable range — common at the far end of a feeder in the afternoon. If the grid reads normal at the terminals and the error persists, the inverter's relay or sensing circuit needs checking.
Can a Growatt isolation fault be fixed?
Yes. It is usually caused by damaged DC cable, water in a junction box or a failed MC4 connector. Finding and repairing the specific string resolves it.
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