Siemens SINAMICS G120 Error Code F30003

Siemens PLC & VFD Major Undervoltage

Model: SINAMICS G120 | Code: F30003

Applicable Systems
S7-1200 S7-1500 S7-300 S7-400 LOGO! SINAMICS

Symptoms

Power module DC link undervoltage.

Possible Causes

  • Input voltage too low
  • Input phase loss
  • Transient power loss

Troubleshooting Steps

  1. Step 1: Measure input voltage
    Voltage within rated range
  2. Step 2: Check input fuses
    All fuses intact
  3. Step 3: Verify DC link voltage
    Voltage above threshold

How to Reset

Auto-reset when voltage returns or reset via panel.

Related Siemens Fault Codes

Source: Siemens SINAMICS G120 List Manual

Category: PLC & VFD