Siemens drives do not rely solely on external sensors. They use internal at the inverter’s output stage. When the motor is running, the drive expects balanced currents. If one phase deviates by more than a programmable tolerance (typically set via parameter p3230 in Sinamics), the drive triggers fault 7902.
The stall detection thresholds (such as stall speed and stall time) configured in the parameters may be too tight for the specific application dynamics.
Siemens drive fault code 7902 indicates a condition . This fault occurs when the drive detects that the motor is unable to rotate or maintain its speed despite receiving current. It is a protective mechanism designed to prevent permanent damage to both the motor windings and the drive's internal power electronics. Technical Context: What Does Fault 7902 Mean? siemens drive fault code 7902
Ensure that the wiring matches the voltage levels supplied by the drive. For example, a 230V/400V motor must be wired in Delta for a 230V drive output, and Star for a 400V drive output.
) are too low for the application, preventing sufficient torque. Recommended Solutions Siemens drives do not rely solely on external sensors
Increase the low-speed voltage boost parameters ( to p1312 ) if using U/f control to inject extra torque at startup.
If you want to dive deeper into a specific part of this issue, please let me know: If one phase deviates by more than a
Ensure your SINAMICS drive control units are updated to the latest stable firmware version, as Siemens regularly optimizes vector control algorithms and motor model calculations via software updates.
This diagnostic parameter tells you how the stall was detected.
The motor is drawing maximum allowable current ( p0640p 0640