Solar · Error codes
Why does my SMA inverter say 'Waiting for DC start conditions'?
Short answer
SMA Events 3901 and 3902 mean the panels are not yet producing enough voltage for the inverter to start feeding in. It is normal at dawn, dusk and on very dull days, or when panels are snow-covered. In bright sunshine, ask your installer to check string design and the start-voltage setting (SMA manual, checked 24 September 2026).
Last checked 24 September 2026 · 1 source
In more detail
- Related: 3302/3303 'Unstable operation' - not enough DC power.
- Installer may adjust 'Critical voltage to start feed-in' if frequent in the morning.
The facts, dated
- 01SMA Event 3901 = Waiting for DC start conditions — 3901 event
manufacturer · n/a · checked 24 September 2026 · files.sma.de
Sources
- files.sma.de — files.sma.de/downloads/SBxx-1AV-41-BE-en-21.pdf
Last checked: 24 September 2026