thank you so much for helping narrowing down the problem.
Yes the machine is connected to main electricity.
I measured the voltages at the main transformator.
Main-electricity comming in from the street---main_transformator---machine
You wrote the motor has tripped. google translation translates "tripped" to "stumbeled". Do you mean the motor is damaged? Or does the motor have
a fault in the connection or wiring?
Would it make sense to start measuring the voltage at the motor and going backwards to main electricity?
Is there already flowing a current through the motor even with this Motor-Alarm-LED on?
The contactors have a black square on top. I'm not near to the machine right now so I can't take a look on the real thing. Does this square somehow
show the switching-state of the contactor. When I was at the machine the last time I pressed the red buttons but nothing happened. No click in the contactors no changes in the machine-state.
Is this alarm the spindle-motor or could it be any of the servomotors
(axis or spindle)?
How can I make the contactors switch manually? To see what changes then
or should I not do that for some reason?