Siemens Fault 0a7991 Verified -

: In some cases, changing the control mode to basic V/f control can also bypass the need for precise motor identification. 3. Resolving Persistent Alarms (The A8526 Connection)

If you do not wish to perform the identification (e.g., during bench testing without a motor), you can disable it via the Siemens Parameter List : siemens fault 0a7991

Issue – Fault A07991 cannot be cleared on SINAMICS G120C drive : In some cases, changing the control mode