- Error code
- 404
- Category
- Grid fault
- Manufacturer
- SMA
- Models
- Sunny Tripower (STP)
1What the error means
The inverter disconnected from the grid because it detected islanding or a very fast change in frequency. It is a safety function: it is not allowed to feed a section of the grid that has been cut off.
2Possible causes
- Brief outage or oscillation of the grid
- Unstable AC connection
- Wrong country setting in the parameters
3What to do
- Check the AC connection and the fuses.
- Confirm that the correct country setting is selected.
- If it recurs with no obvious cause on the grid, the inverter needs to be checked.
Same code group
Code 404 belongs to the same group as 401, 402, 403 — they share the same cause and the same remedy.
4Repair by Aineas
You send the inverter to our lab in Thessaloniki. We diagnose it, inform you of the fault and the cost, and the repair starts only after you approve it. Every inverter is tested under simulated operating conditions before delivery.