In Siemens SINAMICS drives (such as the G120, S120, or G120XA), fault code F7902 (or F07902) indicates a "Motor Stalled" condition.
This fault occurs when the drive detects that the motor is not rotating properly—or is rotating too slowly—despite being given a command to run. Core Causes
The drive triggers this fault when the deviation between the calculated motor speed and the actual speed exceeds a specific threshold for a set amount of time. sinamics drive motor fault 7902 - SiePortal - Siemens
In Siemens SINAMICS drives (like the G120 or S120), Fault F07902 indicates a Motor Stalled condition. This happens when the drive detects that the motor has stopped rotating for longer than the set delay time, even though the drive is trying to run it.
Here are three post options tailored for different audiences:
Option 1: Quick Troubleshooting (Best for LinkedIn/Professional Forums)
Headline: Dealing with Siemens Fault F07902? Here’s the fix. 🛠️
If your SINAMICS drive just threw a "Motor Stalled" error, don't panic. Here is a rapid-fire checklist to get back up and running:
Mechanical Check: Is the motor actually jammed? Check for obstructions or a locked brake.
Motor Data: Ensure your motor parameters (p304–p311) match the nameplate exactly. siemens drive fault code 7902
Identification: Redo the motor data identification (p1900=2) and static optimization.
Flying Restart: If this happens during an OFF/ON cycle, try activating the "Flying Restart" function (p1200=1).
Thresholds: If the motor is fine but the load is heavy, you might need to increase the current setpoint (p1610) or the stall delay time (p2178).
For more detailed steps, check the Official Siemens Support Portal. #Automation #Siemens #SINAMICS #Maintenance #Engineering
Option 2: Technical/Deep Dive (Best for a Blog or internal wiki)
Title: Troubleshooting the SINAMICS F07902 "Motor Stalled" Fault
The F07902 fault occurs when the difference between the set speed and actual speed exceeds the tolerance for a specific time limit. Common Causes & Fixes:
G120XA solution to warning F7902 motor out of step - Siemens
This is a diagnostic and troubleshooting report for Siemens Drive Fault Code 7902. In Siemens SINAMICS drives (such as the G120,
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
Date: [Insert current date]
Firmware reference: SINAMICS parameter manual, List Manual (LH1)
The Siemens drive fault code indicates that motor has stalled or is out of step
. This typically occurs when the drive loses synchronism with the motor, meaning the motor is unable to rotate at the speed commanded by the inverter. Common Causes Missing Motor Data Identification
: The most frequent cause is a lack of motor data identification and static optimization, particularly with asynchronous motors. Mechanical Overload
: The load on the motor exceeds its torque capability, physically preventing it from turning. Incorrect Parameter Settings
: Limits for stall detection (such as speed or current thresholds) may be set too strictly for the specific application. Acceleration/Deceleration Rates
: Ramp times that are too aggressive (too short) can cause the drive to lose control of the motor rotor position. Recommended Troubleshooting Steps Perform Motor Identification
: Re-run the motor data identification routine (often called "MotID") to ensure the drive accurately understands the electrical characteristics of the motor. Check Mechanical Load Official Siemens Definition (from List Manual):
: Inspect the connected machinery for jams, broken bearings, or excessive friction that could be stalling the shaft. Adjust Stall Protection Parameters
: Verify and potentially increase the stall detection time or torque limits if the application involves high-inertia loads. Review Ramp Times
: Increase the acceleration (P1120) and deceleration (P1121) times to allow the motor more time to reach the setpoint without losing synchronism. Verify Power Supply
: Ensure the input voltage is stable, as a significant voltage drop can reduce the motor's available torque.
For detailed parameter lists and specific drive models, you can refer to the Siemens SiePortal Support F7902 Technical FAQ specific parameter numbers for a particular Siemens drive series, such as the SINAMICS G120
Subject: G120XA solution to warning F7902 motor out of step - Siemens
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.
To avoid future occurrences of fault code 7902: