Solar · Error codes
What does Growatt Error 203 'PV Isolation Low' mean?
Short answer
Error 203 means low insulation resistance between the PV wiring and earth. Growatt's MIN manual gives a threshold of more than 25 kΩ, or 500 kΩ under VDE 0126. Wet DC isolators, poor earthing or damaged cables can cause it, and it may clear once things dry out. Recurring 203s need a PV installer to test the strings.
Last checked 24 September 2026 · 1 source
In more detail
- On MIN/MIC, Warning 203 (PV1/PV2 short) is a different condition from Error 203.
- SPH lists Error 203 with 'check the PV panel enclosure is properly grounded'.
The facts, dated
- 01Growatt PV-to-ground impedance requirement — >25 kOhm (or 500 kOhm VDE 0126)
manufacturer · UK · checked 24 September 2026 · midsummerwholesale.co.uk
Sources
- midsummerwholesale.co.uk — midsummerwholesale.co.uk/pdfs/min-2500-6000-tl-x-user-manual-general-en-202206.p…
Last checked: 24 September 2026