This article is based on Siemens SINAMICS documentation and field experience. Always refer to the official List Manual for your exact drive series and firmware version before changing parameters.
The driven machinery (e.g., conveyors, pumps, fans, or gearboxes) may be physically jammed by debris, broken components, or lack of lubrication.
According to Siemens Support , you should follow these steps to resolve the fault:
The 7902 fault is rarely a hardware failure in the drive itself. Instead, it is typically related to improper motor parameterization or application issues: siemens drive fault code 7902
Run the motor identification routine (p1900 or p1910) to allow the drive to measure the motor resistance and inductance. Step 3: Adjust Acceleration and Torque Limits
Use a digital multimeter and, if available, a megohmmeter.
: The motor has already started moving and is operating above the p2175 threshold, but a sudden load change, mechanical failure, or tuning mismatch forces it to a halt or an unacceptable lag. Root Causes of Siemens Fault F07902 This article is based on Siemens SINAMICS documentation
F07902 is rarely caused by a random software glitch. It is typically a direct symptom of a mechanical, electrical, or parameter configuration issue. 1. Mechanical Overload or Jamming
The (frequently displayed as F07902 ) is a critical safety and operational alarm that indicates a Motor Stalled condition. This fault triggers across multiple families of the Siemens SINAMICS product ecosystem—including the G120, G120XA, G120X, G115D, and S120 drives. When the drive's control unit detects that the motor cannot maintain its designated speed under load for longer than a predefined window of time, it immediately generates this fault to prevent hardware degradation.
Verify the braking relay control voltage. If the brake doesn't receive voltage to release, the motor will stall. 4. Relevant Parameters Motor excitation time (increase if too low) p1745: Fault tolerance p2178: Motor blocked monitoring time p1610: Static torque setpoint p1200: Flying restart 5. Summary Table Suggested Action Fault at startup Perform static/rotating motor ID (p1900=2/3). Fault under load Increase p1610 (torque) or check mechanical load. Fault after power failure Enable flying restart (p1200=1). Motor brake locked Check brake relay and release voltage. To get a more specific solution, tell me: According to Siemens Support , you should follow
If there is an output contactor installed between the drive and the motor, ensure that it is commanded to close before the drive attempts the identification run. If the contactor remains open, the drive looks into an open circuit and triggers F7902.
Is the drive currently , or is it just showing a warning ?
: A factory-default or user-defined maintenance interval timer has run down to zero.
The drive activates a stall alarm if it detects either of the following conditions for longer than the delay set in :