Cause : DC link voltage monitoring Vdc_Max comes when the monitoring of the DC link voltage p1284 has responded (only U/f control).

In a Siemens drive system, fault code F7404 indicates a "DC link voltage monitoring" issue. This means the voltage level in the drive's DC link circuit has exceeded the pre-set limits. The DC link is a vital part of the drive, responsible for storing and filtering the DC voltage from the rectified mains supply before it's converted into AC to power the motor.

- check the line supply voltage.
- check the braking module.
- adapt the device supply voltage.
- adapt the DC link voltage monitoring.