Siemens Drive Fault Code 7902 //free\\ May 2026

Understanding and Resolving Siemens Drive Fault Code 7902 The Siemens Drive Fault Code 7902 (often displayed as F07902) is a critical error indicating a "Motor Stalled" condition. This fault occurs when the drive’s control logic determines that the motor is not rotating as expected despite receiving power, or when the deviation between the calculated motor speed and the actual measured speed exceeds defined limits.

While this fault is common across various series including SINAMICS S120, G120, G120XA, and G115D, its root causes can range from simple mechanical blockages to complex parameterization errors. Primary Causes of Fault 7902

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

The Siemens drive fault code 7902 (often displayed as F07902 or A07902 depending on the drive series) typically indicates a motor overspeed condition.

Here is the breakdown and common solutions for this fault. siemens drive fault code 7902

8. Recommendation

Begin with verifying that the PLC master is actively exchanging cyclic data with the drive’s configured station address. Then check hardware integrity of the bus cable and termination. If the issue persists, match telegram settings exactly between the drive (P0922) and the master’s hardware configuration.

Report prepared for: Siemens Drive Maintenance / Automation Engineer
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Firmware reference: SINAMICS parameter manual, List Manual (LH1)

In industrial automation, encountering a Siemens Drive Fault Code 7902—specifically F07902: Motor Stalled—can bring production to a grinding halt. This fault is common across various Siemens Sinamics series, including the G120, S120, and G120XA models. Understanding what this code means and how to systematically troubleshoot it is essential for minimizing downtime. What is Siemens Fault 7902?

Fault F07902 indicates that the drive has detected a motor stall. This occurs when the actual speed of the motor deviates from the speed setpoint by more than a specified threshold for a set period. Understanding and Resolving Siemens Drive Fault Code 7902

While related to F07900 (Motor Blocked), F07902 typically triggers at higher speeds or under specific torque conditions where the drive is attempting to move the motor, but the feedback or calculated model indicates it is not following the command. Common Causes of Fault 7902 sinamics drive motor fault 7902 - SiePortal - Siemens

In Siemens SINAMICS drives, fault code F07902 indicates a motor stall caused by mechanical overload, incorrect motor data, or improper configuration. Troubleshooting involves verifying motor nameplate data (p304-p311), running identification (p1900=2), and adjusting stall parameters like p2178 to prevent nuisance trips. For detailed troubleshooting steps, visit Siemens Support. sinamics drive motor fault 7902 - SiePortal - Siemens

Siemens drive fault code 7902 typically indicates a "Drive: Communication board (CB) link error" or a loss of communication via the PROFINET/PROFIBUS interface.

Here is a detailed breakdown of the fault, causes, and solutions. Begin with verifying that the PLC master is

Diagnostic Approach: Step by Step

When fault 7902 appears, do not simply reset and restart. Follow this systematic diagnostic sequence.

1. Which drive series?

  • SINAMICS G120, G120C, G120P, G130, G150, S120
  • Masterdrives (rarely, as 4-digit codes differ slightly)

Step 4: Check for Intermittent Bus Errors

  • In STARTER/Startdrive → Trace function → record r2060.0 (Telegram received bit) and r0722 (bus status).
  • If bit toggles sporadically, bus is unstable – check grounding, shielding, and routing away from power cables.

Real-World Case Study

Scenario: A automotive paint line conveyor trips with F07902 every Monday morning but runs fine for the rest of the week.

Investigation: Technicians found no cable breaks. The motor windings tested OK. The clue was the timing – every Monday after weekend shutdown.

Root Cause: A magnetic contactor between the drive and motor had a pitted auxiliary contact that overheated slightly on the first start of the week, dropping one phase for 50ms. As the day progressed, thermal expansion improved contact – until the next Monday.

Solution: Replaced contactor and implemented weekly starter torque check. Fault 7902 eliminated.