- Error code
- 6404
- Category
- Self-diagnosis / Internal fault
- Manufacturer
- SMA
1What the error means
Code 6404 belongs to the event group 6001 to 6438, which SMA documents as "Self-diagnosis – Interference of device". It means that the inverter's internal self-test has detected a malfunction in its own hardware, and the inverter stops feeding in power for protection. SMA does not publish a separate description for each code in this group. The exact cause is identified by diagnosis in the workshop.
2Possible causes
- Fault on the power board
- Wear of the grid relays
- Fault in the measuring circuit or on the control board
- Ageing of electronic components due to thermal stress
3What to do
- Perform a full restart: disconnect the AC side at the fuse and the DC side at the DC switch, wait a few minutes and reconnect according to the manufacturer's instructions.
- Check that the AC fuses are switched on and that the area around the inverter is freely ventilated.
- If the fault persists after the restart, the inverter needs to be checked in the workshop.
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.