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 405 on the screen, with the fault LED illuminated. Inverter operation is halted.
Technical Causes:
- Internal relay failure or detection issue in the AC output circuit.
- Hardware fault in relay control circuit.
Diagnostic Procedure:
- Power cycle the inverter: Disconnect AC and DC supplies, wait 10 minutes, reconnect.
- Observe if the error persists after multiple restarts.
Resolution:
- Temporary clearance after restart may indicate intermittent issue; monitor closely.
- Persistent error indicates hardware fault requiring component replacement.
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.