Cause : Line phase failure in main circuit comes when the DC link voltage ripple has exceeded the permissible limit value.

Possible causes for this fault:

• A line phase has failed.
• The 3 line phases are inadmissibly unsymmetrical.
• The capacitance of the DC link capacitor forms a resonance frequency with the line inductance and the reactor integrated in the power unit.
• the fuse of a phase of a main circuit has ruptured.
• A motor phase has failed.

F30011 alarm in siemens 6RA80 DC Drive indicate Line phase failure in main circuit. This means the DC link voltage ripple has exceeded the drive limit value.

1. Check the main circuit fuses.
2. Check whether a single-phase load is distorting the line voltages.
3. Detune the resonant frequency with the line inductance by using an upstream line reactor.
4. Check the motor feeder cables.