Locate parameter and adjust its data value back to 0 (Inhibited) . Ensure parameter p1910 is also adjusted back to 0 .
The most common solution is allowing the drive to do its job.
Set (Control mode: V/f standard) if advanced vector control isn't needed immediately. 3. Resolving Persistent Alarms (A07991 + A8526) siemens fault 0a7991
Diagnosing 0A7991 requires a systematic elimination of possibilities. Here are the five most common physical and parametric causes.
Alarm A08526 signifies that the VFD has lost its cyclic data link with the master PLC (such as an S7-1500) or has not yet been assigned a proper network device name. When both codes appear, the VFD is stuck: it cannot perform the motor ID run requested by A07991 because it is not receiving the execution bit (or control word) from the fieldbus network due to A08526. Locate parameter and adjust its data value back
After the alarm clears, remember to perform a to ensure settings are saved after a power cycle . Community Perspectives
The code (often appearing in logs as part of a longer string like 0a7991) is a Siemens drive alarm indicating that the motor identification has not yet been performed or completed. This typically occurs during the initial commissioning phase of a SINAMICS drive. Recommended Fixes Set (Control mode: V/f standard) if advanced vector
When a Siemens SINAMICS VFD displays A07991 , it means parameter (Motor data identification selection) or p1910 has been altered from its idle state ( 0 ). This triggers the inverter to lock normal operations until it can verify the physical characteristics of the motor.