Measure the resistance across the motor phases to rule out open or short circuits.
If running in vector control mode, execute a new motor data identification routine ( or p1910 ) to allow the drive to map the motor’s electrical characteristics accurately. Prevention and Best Practices
Motor cables (U, V, W) are connected improperly, or the encoder signal is reversed (if applicable). Premature Startup: Motor excitation time ( p0346p 0346
: Inspect the connected machinery for jams, broken bearings, or excessive friction that could be stalling the shaft. Adjust Stall Protection Parameters siemens drive fault code 7902
Is this a or a fault that suddenly appeared on an existing machine? Share public link
Disconnect drive terminals and measure resistance at room temperature. Should be ~600Ω. Use a hairdryer to warm probe—resistance should increase smoothly.
: Physical blockage or high friction in the motor or driven equipment. Measure the resistance across the motor phases to
Siemens drive fault code F07902 is a protective feature designed to shield your equipment from catastrophic failure. While a sudden stall often points to an obvious mechanical jam, chronic or intermittent F07902 faults are usually cured by fine-tuning torque limits, adjusting the stall delay timer (p2177), or ensuring that the drive's internal motor model accurately matches the physical asset on the plant floor.
Check parameters to adjust the stall detection sensitivity. If using an encoder, check for "inverted" encoder signals. Specific Notes for G120XA Converters
If the drive is not accurately configured with the motor’s nameplate data, its internal mathematical models will calculate speed and torque incorrectly. Incorrect values for rated current, rated speed, or power factor ( ) frequently trigger false stall faults. 3. Torque and Current Limits Set Too Low If the current limit ( p0640p 0640 ) or torque limits ( p1520p 1520 p1521p 1521 Premature Startup: Motor excitation time ( p0346p 0346
The machinery the motor is driving is physically blocked or stuck.
To resolve Fault F7902 efficiently, technician teams should follow a structured, step-by-step diagnostic workflow. 1. Audit the Motor Nameplate Parameters
If you are currently looking at a live fault panel, tell me: