Solar · Error codes
What does Fronius State 509 'No energy fed in for 24 hours' mean?
Short answer
Fronius State 509 means the inverter hasn't fed any energy into the grid in the past 24 hours. Snow, dirt or a long dull spell are typical causes. Acknowledge it on the display, check the DC switch is at 'I' as Fronius advises, and look for other state codes. If it keeps coming back, contact your installer (checked 24/09/2026).
Last checked 24 September 2026 · 1 source
In more detail
- Class 5 codes are warnings shown until acknowledged; inverter keeps running.
- Look for accompanying 306/307 or 1xx grid codes.
The facts, dated
- 01Fronius state 509 = no energy fed into the grid in the past 24 hours (class 5) — 509 state code
manufacturer · n/a · checked 24 September 2026 · manuals.fronius.com
Sources
- manuals.fronius.com — manuals.fronius.com/html/4204102165/en.html
Last checked: 24 September 2026