Verified fault code

Siemens SINAMICS G120 F30003

Siemens SINAMICS G120 F30003: Power unit: DC-link voltage undervoltage.

Siemens SINAMICS G120 F30003 means Power unit: DC-link voltage undervoltage. The code applies to the product family named here; model and firmware differences must be checked against the documentation supplied for the device.

Safe diagnostic context

Treat the code as technical evidence, not a complete diagnosis. Make the asset safe under approved site procedures, capture operating state and event history, then use the OEM instructions for the exact device and firmware revision.

Manufacturer source

Siemens OEM documentation ↗

Source last verified: 01.09.2026