SolarEdge · PV inverters · SolarEdge SE3K–SE10K (three-phase inverter with power optimizers, SetApp)
Error 18x20Grid voltage is above the country limit.
Name in the manufacturer's documentation (fault list): Grid voltage is above the country limit.
[1]
In plain words (editorial)
The grid voltage is above the limit for the country set in the inverter. The manual says to verify that the inverter is set to the correct country and to consult the grid operator; grid protection values may only be changed if permitted by local authorities.
When to call a service technician: If it keeps recurring, contact your installer.
✎ editorial – written from the cited sources, not a manufacturer statement. Status: draft.
For technicians
Steps given by the manufacturer (source text)
- Verify that the inverter is set to the correct country[2]
- Turn OFF the inverters in the site and verify AC grid voltage[3]
- If the inverter is located far from the connection point to the grid, use a larger gauge AC wire[4]
- Consult the grid operator[5]
- If permitted by local authorities, change the grid protection values[6]
⚠ Work on refrigerant circuits, mains electricity and PV DC wiring is for qualified technicians only.
The Polish page has more detail (plain-language explanation, safe checks, guides): Read in Polish →
Sources
Every statement has a footnote to the document and PDF page. “Quote verified” means the quote was found automatically in the text of that page.
- [1] SolarEdge Inverters Error Codes and Troubleshooting – User Guide (Version 1.2, 2026-09) (se-inverter-installation-guide-error-codes (v1.2)) , p. 19 official manufacturer document quote verified
18x20 Grid voltage is above the country limit.
- [2] SolarEdge Inverters Error Codes and Troubleshooting – User Guide (Version 1.2, 2026-09) (se-inverter-installation-guide-error-codes (v1.2)) , p. 19 official manufacturer document quote verified
Verify that the inverter is set to the correct country
- [3] SolarEdge Inverters Error Codes and Troubleshooting – User Guide (Version 1.2, 2026-09) (se-inverter-installation-guide-error-codes (v1.2)) , p. 19 official manufacturer document quote verified
Turn OFF the inverters in the site and verify AC grid voltage
- [4] SolarEdge Inverters Error Codes and Troubleshooting – User Guide (Version 1.2, 2026-09) (se-inverter-installation-guide-error-codes (v1.2)) , p. 19 official manufacturer document quote verified
If the inverter is located far from the connection point to the grid, use a larger gauge AC wire
- [5] SolarEdge Inverters Error Codes and Troubleshooting – User Guide (Version 1.2, 2026-09) (se-inverter-installation-guide-error-codes (v1.2)) , p. 19 official manufacturer document quote verified
Consult the grid operator
- [6] SolarEdge Inverters Error Codes and Troubleshooting – User Guide (Version 1.2, 2026-09) (se-inverter-installation-guide-error-codes (v1.2)) , p. 19 official manufacturer document quote verified
If permitted by local authorities, change the grid protection values