Review if the p1520 or p1521 torque limits are set too low.
, which may indicate that the PLC is not correctly signaling the drive to start or that the network connection is lost. Siemens SiePortal Are you experiencing this fault during initial setup or has it appeared on a running machine Fault A07991 cannot be cleared on SINAMICS G120C drive
). In Siemens Sinamics and Micromaster drive systems, fault and alarm codes typically follow a specific alphanumeric format, such as (Fault) or (Alarm) followed by several digits. Based on common Siemens documentation and user forums like Siemens SiePortal , here are the closest matches for your query: 1. Alarm A07991: Motor Data Identification Active The most likely match for your code is . This is a warning/alarm indicating that Motor Data Identification (Motor ID) is currently active. What it means: siemens fault 0a7991 best
By following the steps outlined in this guide, you can resolve the A07991 alarm effectively, ensuring your Siemens SINAMICS drive is configured for maximum reliability and performance.
This article provides the , most structured approach to diagnosing and resolving Fault 0A7991. We will move beyond the manual to explore why it happens, how to fix it permanently, and how to optimize your drive parameters to ensure it never returns. Review if the p1520 or p1521 torque limits are set too low
Give the drive a . The motor might whistle or hum for a short time but will not rotate normally. Once finished, the alarm should disappear automatically. Save the parameters from RAM to ROM (e.g., set p0971 = 1 ). To Disable/Skip Identification : Set p1900 = 0 (Inhibits Motor Data Identification). If using V/f control, set p1300 = 0 and then p1900 = 0 .
This fault often appears after changing motor data, encoder settings, or control modes. In Siemens Sinamics and Micromaster drive systems, fault
– Too many high-speed functions activated (e.g., multiple positioning tasks, high-frequency cyclic telegrams, simultaneous safety functions) exceeding the CU’s real-time capability.
In Siemens support forums, you will often see A07991 discussed alongside another alarm: (PROFINET: Cyclic connection not established). They commonly appear together during the initial setup, especially when using a PLC for control.
Siemens Fault 0A7991 is rarely a hardware failure. It is a . The very best way to resolve it is to remember the mantra: "Enable before you identify."