F7404 fault in siemens sinamics V90 drive indicates the Upper DC link voltage threshold was reached. This means the internal DC bus voltage spiked too high during operation, typically caused by rapid motor deceleration feeding energy back into the drive.
Cause:
The DC link voltage monitoring is active and the upper DC link voltage threshold was reached in the “Operation” state.
Remedy:
- Check the line supply voltage.
- Check the infeed module or the brake module.
- Increase the upper DC link voltage threshold.
- Switch out (disable) the DC link voltage monitoring.
