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 202 on the screen, with fault LED illuminated. Inverter shuts down DC input.
Technical Causes:
- PV string open-circuit voltage exceeds inverter maximum (typically 550V for single-phase, 1100V for three-phase models).
- Oversized string design not accounting for low-temperature voltage rise.
- Faulty MPPT detection.
Diagnostic Procedure:
- Immediately disconnect DC switch.
- Measure each string open-circuit voltage with multimeter under current conditions.
- Calculate maximum expected Voc considering local minimum temperatures and panel coefficients.
Resolution:
- Reduce number of panels per string to comply with inverter limits.
- If voltage normal but error persists, restart inverter.
- Reconfigure strings if design issue identified.
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.