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Fronius · Fronius Symo 3.0–20.0 (three-phase grid inverter, SnapINverter) · Operation

What the Fronius Symo LEDs mean (red, orange, green)

Summary (editorial)

The manual explains the green, orange and red LED states and points to the status code on the display.

✎ editorial – written from the cited sources, not a manufacturer statement. Status: draft.

From the manufacturer's documentation (English source wording, with page)

  1. Initialisation LED (red) lights up during the initialisation phase when starting up the inverter, or if there is a continuous hardware fault in the initialisation phase[1]
  2. Status LED (orange) lights up: in the automatic startup or self-test phase (as soon as the solar modules are delivering sufficient power after sunrise); if status codes (State codes) are shown on the display; in standby mode; during software update[2]
  3. Operating status LED (green) lights up if the PV system is working correctly after the automatic startup phase, all the time while energy is being fed into the grid[3]
  4. The keys operate capacitively. Exposure to water may impair their function; if necessary, wipe the keys dry with a cloth[4]
  5. Keys: "left/up", "down/right", "menu/esc" (menu level, quit setup menu), "enter" (confirm)[5]
  6. Standby: manual activation/deactivation of standby mode – no energy is fed into the grid; the Startup LED shows steady orange; Standby / Enter are alternately displayed[6]
  7. Standby mode can only be terminated manually by pressing the "Enter" key; pressing Enter at any time will cause energy to resume feeding into the grid, as long as there is no error (State code)[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. [1] Fronius Symo 3.0-3 – 20.0-3, Fronius Eco 25.0-3 – 27.0-3 – Operating Instructions (42,0410,2028, ed. 044-12062025) (42,0410,2028 (044-12062025)) , p. 26 official manufacturer document quote verified initialisation led (red) lights up
  2. [2] Fronius Symo 3.0-3 – 20.0-3, Fronius Eco 25.0-3 – 27.0-3 – Operating Instructions (42,0410,2028, ed. 044-12062025) (42,0410,2028 (044-12062025)) , p. 26 official manufacturer document quote verified status led (orange) lights up
  3. [3] Fronius Symo 3.0-3 – 20.0-3, Fronius Eco 25.0-3 – 27.0-3 – Operating Instructions (42,0410,2028, ed. 044-12062025) (42,0410,2028 (044-12062025)) , p. 26 official manufacturer document quote verified operating status led (green) lights up
  4. [4] Fronius Symo 3.0-3 – 20.0-3, Fronius Eco 25.0-3 – 27.0-3 – Operating Instructions (42,0410,2028, ed. 044-12062025) (42,0410,2028 (044-12062025)) , p. 26 official manufacturer document quote verified the keys operate capacitively.
  5. [5] Fronius Symo 3.0-3 – 20.0-3, Fronius Eco 25.0-3 – 27.0-3 – Operating Instructions (42,0410,2028, ed. 044-12062025) (42,0410,2028 (044-12062025)) , p. 26 official manufacturer document quote verified key for switching to the menu level
  6. [6] Fronius Symo 3.0-3 – 20.0-3, Fronius Eco 25.0-3 – 27.0-3 – Operating Instructions (42,0410,2028, ed. 044-12062025) (42,0410,2028 (044-12062025)) , p. 34 official manufacturer document quote verified the startup led will show steady orange.
  7. [7] Fronius Symo 3.0-3 – 20.0-3, Fronius Eco 25.0-3 – 27.0-3 – Operating Instructions (42,0410,2028, ed. 044-12062025) (42,0410,2028 (044-12062025)) , p. 34 official manufacturer document quote verified standby mode can only be terminated manually by pressing the "enter" key.