GoodWe · PV inverters · GoodWe ET G2 6–15 kW (three-phase hybrid inverter)
F18Low Insulation Resistance
Name in the manufacturer's documentation (user manual): Low Insulation Resistance
[1]
In plain words (editorial)
The insulation between the PV side and protective ground is too low – the manual names a PV string short-circuited to ground or a long-term humid installation environment with poor line-to-ground insulation. The manual also lists low insulation of the battery port line to ground.
When to call a service technician: Have your installer check the PV strings and the inverter's protective ground wire. If the impedance is only too low in rainy weather, the manual allows the installer to reconfigure the insulation impedance protection point.
✎ editorial – written from the cited sources, not a manufacturer statement. Status: draft.
For technicians
Possible causes (source text)
Steps given by the manufacturer (source text)
- Check the impedance of the PV string/battery port to Protection ground. If a short circuit occurs, identify the short-circuit point and rectify it.[5]
- Check whether the inverter's Protection ground wire is correctly connected.[6]
- If it is confirmed that this impedance is indeed lower than the default value in rainy weather, please use Appto reset the inverter's“Insulation Impedance Protection Point”。 For inverters in the Australian and New Zealand markets，when an insulation impedance fault occurs, the following alarm methods are also available:[7]
⚠ 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] GoodWe Residential Smart Inverter Solutions – ET G2 6-15K (+ LX F / LX D) – User Manual V2.2 (2026-09-30) (V2.2-2026-09-30) , p. 197 official manufacturer document quote verified
- [2] GoodWe Residential Smart Inverter Solutions – ET G2 6-15K (+ LX F / LX D) – User Manual V2.2 (2026-09-30) (V2.2-2026-09-30) , p. 197 official manufacturer document quote verified
The PV string is short-circuited to Protection ground
- [3] GoodWe Residential Smart Inverter Solutions – ET G2 6-15K (+ LX F / LX D) – User Manual V2.2 (2026-09-30) (V2.2-2026-09-30) , p. 197 official manufacturer document quote verified
The PV string installation environment is humid for a long time, and the line-to- ground insulation is poor
- [4] GoodWe Residential Smart Inverter Solutions – ET G2 6-15K (+ LX F / LX D) – User Manual V2.2 (2026-09-30) (V2.2-2026-09-30) , p. 197 official manufacturer document quote verified
The battery port line has Low Insulation Resistance to ground
- [5] GoodWe Residential Smart Inverter Solutions – ET G2 6-15K (+ LX F / LX D) – User Manual V2.2 (2026-09-30) (V2.2-2026-09-30) , p. 197 official manufacturer document quote verified
Check the impedance of the PV string/battery port to Protection ground. If a short circuit occurs, identify the short-circuit point and rectify it
- [6] GoodWe Residential Smart Inverter Solutions – ET G2 6-15K (+ LX F / LX D) – User Manual V2.2 (2026-09-30) (V2.2-2026-09-30) , p. 197 official manufacturer document quote verified
Check whether the inverter's Protection ground wire is correctly connected
- [7] GoodWe Residential Smart Inverter Solutions – ET G2 6-15K (+ LX F / LX D) – User Manual V2.2 (2026-09-30) (V2.2-2026-09-30) , p. 197 official manufacturer document quote verified
If it is confirmed that this impedance is indeed lower than the default value in rainy weather, please use Appto reset the inverter's“Insulation Impedance Protection Point”。 For inverters in the Australian and New Zealan…