Siemens Drive Fault Code 7902 !!install!! Official
Lock out and tag out (LOTO) the drive following local safety protocols.
When the internal speed adaptation controller output surpasses standard operation thresholds for longer than the set delay time, the drive determines that the rotor cannot keep up with the electrical field under its current load profile and drops into a fault state. Technical Mechanism: How F7902 is Triggered
Siemens drive systems are industry standards for precision motor control. However, like all sophisticated automation hardware, they occasionally trigger faults to protect the equipment from catastrophic failure. One common error encountered by automation engineers and maintenance technicians using SINAMICS drives (such as the G120, S120, or V90 series) is , which stands for "Motor stalled." siemens drive fault code 7902
If you are using an encoder, ensure the is correct. If the inverter spins the motor in the opposite direction of the encoder feedback, a 7902 or 7801 fault will occur.
Consult the official Siemens manual for your specific drive model (function diagrams 8010–8020 for output monitoring). For hands-on help, Siemens Technical Support can provide remote diagnostic assistance using Starter or STARTER software to trace current waveforms in real time. Lock out and tag out (LOTO) the drive
Disclaimer: This information is based on standard SINAMICS G120/S120 documentation and community feedback within the Siemens SiePortal .
) forces the drive to hit its current limit immediately. If it cannot accelerate the load to the target speed before the stall timer expires, F07902 trips. 5. Sensorless Vector Control Issues at Low Speeds Consult the official Siemens manual for your specific
Check for mechanical obstructions (brake locked, jammed load). Check motor cable connectivity.
If the fault occurs on a SINAMICS G120XA, follow this Siemens recommended procedure : the converter to factory settings. Set (V/f) or (Vector). Enter motor nameplate data ( p0304p 0304 p0311p 0311 Set (Quick commission). Set (Ident. at standstill). Start the motor in Hand mode to run the motor ID. Critical Parameters to Review p0346p 0346
Set (Motor data identification at standstill/Static Optimization).
If the mechanics are fine and the motor simply takes longer to accelerate due to high inertia, you may need to desensitize the stall detection logic.
