in Siemens SINAMICS drives (such as the G120 or S120) indicates that Motor Data Identification is activated
fault No 7900: motor locked/ at high speed limit reached - SiePortal
Siemens Alarm A07991 (or A7991) on SINAMICS G120/S120 drives indicates that Motor Data Identification (ID) is active, requiring a motor ID run or manual adjustment to clear. The condition is resolved by running a motor identification, setting parameter P1900 to 0, or bypassing calculations via P340 during commissioning. For detailed solutions and forum discussions, visit Siemens SiePortal Dealing with Motor ID ( code 7991 ) - SiePortal - Siemens
- Exact product type and serial number (e.g., Sinamics G120, 6SL3120-1TE15-5AV0)
- Firmware version
- Full fault history and timestamps
- Photos of wiring and terminal labels
- Parameter set or backup file
- Any recent changes (software, wiring, maintenance)
Step 6: Check Hardware Configuration
Compare the actual installed modules against the configured modules in TIA Portal:
- Check communication connections: Verify that all communication cables and connections are secure and functioning properly.
- Restart the system: A simple reboot may resolve the issue.
- Review system configuration: Check the system's configuration and parameterization to ensure accuracy.
- Consult technical documentation: Refer to Siemens technical documentation or user manuals for troubleshooting guides.
- Contact Siemens support: Reach out to Siemens technical support for assistance with diagnosis and repair.
Give the drive a "Run" command. The motor may whistle or hum for about 10 seconds while it measures data.