Siemens SINAMICS G120 Error Code F31108

Siemens PLC & VFD Major Encoder

Model: SINAMICS G120 | Code: F31108

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

Symptoms

Encoder overspeed: speed exceeds encoder rated limit.

Possible Causes

  • Excessive motor speed
  • Encoder speed limit too low
  • Speed feedback fault

Troubleshooting Steps

  1. Step 1: Check motor speed
    Speed within rated range
  2. Step 2: Verify encoder speed limit
    Limit appropriate for encoder
  3. Step 3: Check speed feedback signal
    Signal accurate

How to Reset

Reset via operator panel after speed is controlled.

Related Siemens Fault Codes

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Source: Siemens SINAMICS G120 List Manual

Category: PLC & VFD

Published: 2026-10-25