Fault Code 7902 — Siemens Drive

To fix the problem permanently, you must identify why the phase failure occurred. Causes fall into four main categories:

Understanding why the drive triggers a stall fault is the first step in troubleshooting. Common triggers include: SINAMICS G120XA fault F07902 - ID: 109773411 - Support siemens drive fault code 7902

| Root Cause | Solution | |------------|----------| | PLC in STOP | Set PLC to RUN or reconfigure drive to ignore missing telegram ( p2040 = 0 – not recommended for safety) | | p2040 too short | Increase p2040 to at least 2–3× bus cycle time | | Loose connector | Reseat or replace bus connector | | Wrong telegram type | Match p0922 with PLC configuration (e.g., standard telegram 1 for speed control) | | No termination | Activate termination on both ends of PROFIBUS segment | | EMI | Check cable routing, add ferrites, verify shield grounded at both ends | | Faulty option board | Replace communication board (e.g., CBE20 for PROFINET) | To fix the problem permanently, you must identify

| Step | Action | |------|--------| | 1 | Check (actual speed) — does it really exceed p2162? | | 2 | Verify p1082 (maximum speed) ≥ p2162 (overspeed threshold). | | 3 | Increase p2162 slightly (e.g., 1.1× p1082) if mechanical limits allow. | | 4 | Check encoder: cable shielding, terminal tightness, p0400 encoder type. | | 5 | Perform motor data identification (p1910 = 1) and speed controller optimization (p1960 = 1). | | 6 | Increase deceleration time p1121 to avoid regen overshoot. | | | 2 | Verify p1082 (maximum speed)

Are you using or is it in sensorless (V/f) control? sinamics drive motor fault 7902 - SiePortal - Siemens

the motor is moving, but the encoder or the motor model says otherwise". They started with the basics: Physical Obstruction