- Error code
- FS 40
- Category
- Grid undervoltage
- Manufacturer
- KACO
1What the error means
The voltage of one grid phase is too low and the inverter cannot feed in.
On the display or in the monitoring software it appears as FS 40.
2Possible causes
- Grid voltage drop or outage
- Tripped fuse or lost phase
- Loose or oxidised connection on the AC cable
3What to do
- Check the AC fuses and that all phases reach the inverter.
- Check the AC cable connections at the inverter and in the distribution board.
- If the grid is stable and the fault persists, check the measuring circuit.
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.