Siemens Fault 0a7991 Best -

This article provides the best, most comprehensive guide to understanding, fixing, and preventing the A7991 alarm, ensuring your motors are properly identified and your drive system operates at peak efficiency. What is Siemens Alarm 0A7991?

Executing these steps properly closes the loop on commissioning, ensuring your system runs optimally and free of active alarm codes.

: Visit the official Siemens support website. Siemens offers comprehensive support through their website, including manuals, FAQs, and forums where you can search for your specific fault code. siemens fault 0a7991 best

When this alarm appears, the drive is notifying you that a motor data identification (motor ID) routine is either running, active, or requested, which usually requires the motor to run for a few seconds. If this process is interrupted or fails, the drive will display 0A7991.

Depending on whether you are on a live site with a motor connected or conducting a Factory Acceptance Test (FAT) without a physical load, select the appropriate method below. Method 1: Execute the Planned Motor ID (Best Practice) This article provides the best, most comprehensive guide

Issue – Fault A07991 cannot be cleared on SINAMICS G120C drive

Parameter p1900 was actively set to 1 (Identification at standstill) or 2 (Rotating measurement). : Visit the official Siemens support website

: Carry out the motor ID at standstill as prompted by the system.

parameters). If this process is initiated but not completed, or if the drive expects it to run at the next start command, A7991 appears. Common Causes for 0A7991

This is the #1 cause. For safety, Siemens drives require a (ON/OFF1 command via terminal or fieldbus) before they perform motor identification. If the drive is inhibited, fault 0A7991 appears.

The drive is in a commissioning mode where it is measuring the motor's electrical characteristics (resistance, inductance, etc.) to optimize performance. Why it shows up: