When this code appears, the drive is notifying you that a motor identification routine has been scheduled or is currently running. This routine is essential for the inverter to learn the electrical characteristics of the connected motor (such as resistance and inductance) to ensure precise control.
Apply a (start signal) to initiate the routine. siemens fault 0a7991
If you are performing a without the final motor, attaching a smaller spare motor can sometimes bypass identification faults by providing enough feedback for the drive to initialize. Alarms A 7991 and A8526 - SiePortal - Siemens When this code appears, the drive is notifying
: The alarm typically disappears automatically once the identification routine completes successfully. If you are performing a without the final
Either the network connection (profibus/profinet?) between the PLC controlling the drive is powered off, network connection lost ( Siemens SiePortal How can resolve the alarm Code A7991 - SiePortal - Siemens
Ensure the motor is safe to move if a "Rotating Measurement" was selected. Once finished, the alarm will clear itself. 2. Manually Disable the Routine
Set (Control mode: V/f standard) if advanced vector control isn't needed immediately. 3. Resolving Persistent Alarms (A07991 + A8526)