Siemens recommends re-performing the quick commissioning if the fault persists:
Faulty wiring, inverted encoder signals, or a damaged encoder can feed the drive incorrect speed data. siemens drive fault 7902
The Siemens drive fault code (often displayed as 7902 ) indicates a "Motor Stalled" condition. This fault occurs when the drive identifies that the motor has remained in a stalled state for a duration longer than the time set in the delay parameter. inverted encoder signals
This masks the problem. Do not leave permanent. a stuck brake
The motor is physically unable to rotate due to a jammed load, a stuck brake, or a load that exceeds the motor's torque capacity.