Disclaimer: This content is for informational and educational purposes only. The diagnostic steps described are suggestions, not an official service manual.
Phenomenon: The inverter displays Error 408 on the screen, with fault LED illuminated. Power output derated or halted.
Technical Causes:
- High ambient temperature exceeding inverter rating.
- Restricted airflow due to poor installation location or obstructions.
- Internal fan failure or dust accumulation.
Diagnostic Procedure:
- Verify ambient temperature around inverter (<60°C recommended).
- Check for obstructions and ensure minimum clearance per manual.
- Listen for fan operation during inverter activity.
Resolution:
- Improve ventilation: Clear obstructions, ensure shaded/cool location.
- Clean heatsink and fan if accessible externally.
- Restart inverter once temperature normalizes.
WARNING: Maintenance and repair of PV systems, high-voltage DC, and AC components must only be performed by certified professionals with valid electrical qualifications (e.g., SEP/G1 in Poland, or local European equivalents). Unauthorized opening of the inverter housing will void the warranty and carries a risk of electric shock or fire.
In case of persistent hardware failure, the only authorized path for repair is contacting the official Growatt Service Department.