What causes E01: Grid Freq Over Rating on my Delta Inverter?
- Ddavid43Sep 9, 2025
The E01 error on your Delta Inverter, indicating 'Grid Freq Over Rating', can be caused by the utility frequency being over the OFR setting, an incorrect country setting, or a detection circuit malfunction. You should check the utility frequency on the inverter terminal, verify the country setting, and inspect the detection circuit inside the inverter.