Siemens 25000 alarm: Spindle speed error

The actual speed of the spindle does not match the setpoint or the spindle does not reach speed. It is an alarm from the Spindle area, and in the catalog it is listed as “Spindle speed error”. On the machine you notice it like this: The spindle does not reach the commanded rpm, Failure to orient or during acceleration.

On the shop floor it almost always comes from one of these causes: Spindle encoder, Drive/motor, Carga excesiva, Parameters or orientation sensor. Rule out the most likely one on your machine first, before touching parameters or swapping anything.

Reset after removing setpoint/load and confirming that the spindle is stopped. Resetting without fixing the cause first only hides the problem: Siemens 25000 trips again and, in the meantime, you keep working with the machine in bad shape.

With the machine stopped and in a safe state, start with these checks: Note the commanded S and the actual rpm, Try low speed if the manual allows it, Check the drive alarms. That alone will tell you whether it is the program or whether you need to raise a maintenance job.

With Siemens 25000 active, avoid this: Do not perform machining if RPM is not maintained, Do not work on an energised drive. Skipping any of these points is what turns a minor stop into an expensive breakdown.

If it fails without load, there is noise or the drive reports an alarm. If you are not sure how far it goes, stop the machine and report it: a repeat alarm always works out cheaper than a crash.

It is critical: there is a real risk of damage to the machine, the tool or a person. Leave the machine stopped, do not keep resetting it to see if it goes away, and call maintenance before producing again. Confirm with Sinumerik/drive diagnosis and machine manufacturer's manual.