If a drive's power supply is cut while a previously requested identification sequence is pending, the drive re-boots with the A07991 alarm pending until it receives a run command to perform the calculation. Understanding the Companion Alarm: A08526
If the alarm disappears but keeps coming back after a power cycle, try the following:
: While this alarm is active—especially if a rotating measurement is selected—you may be unable to save parameter assignments to the ROM until the process finishes. Common Troubleshooting Steps
is an informational alarm indicating that the Motor Data Identification (Motor ID) routine is actively enabled within a Siemens SINAMICS variable frequency drive. It commonly appears on popular drive platforms like the Siemens SINAMICS G120 series, G120C, G150, S120, and V70 lines. siemens fault 0a7991
To safely clear the warning and restore your machine to normal service, select one of the following validation methods based on whether you are working with an active motor on-site or performing testing in a lab environment. Method 1: Execute the Planned Motor Identification Routine
If you cannot perform the identification (e.g., for factory testing without a motor), set parameter to inhibit the measurement.
As a true alarm , it does not cause a drive trip or require manual acknowledgment; it automatically clears once the identification routine is successfully completed or manually deactivated by setting the relevant parameters to zero. If a drive's power supply is cut while
When code A07991 is active, the SINAMICS drive modifies its operational behavior in two key ways: 1. Intercepted Start Command
Some users have reported that this alarm can reappear after the drive's power supply is switched off and back on, even if the motors were previously commissioned.
Regardless of the formatting, the underlying cause and resolution remain identical. It commonly appears on popular drive platforms like
To avoid encountering in the future, implement these preventive strategies:
If the Basic Commissioning wizard in software like STARTER or TIA Portal had Motor ID selected as a step, the drive will output this alarm once the basic setup is complete.
Method 1: Allow the Identification Routine to Run (Recommended)