Siemens SINUMERIK codes
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Siemens SINUMERIK Controller

Servo/Axis · Intermediate · 30-120 minutes

Alarm 300727

Siemens 300727 - Axis drive reactance less than or equal to zero

This alarm occurs when the value in MD 1139, MD 1140, or MD 1141 is set to less than or equal to zero, typically due to incorrect parameter configuration. Fix by ensuring valid positive values are entered for reactance parameters.

Siemens SINUMERIKServo/AxisIntermediate30-120 minutes

300727

Siemens 300727 - Axis drive reactance less than or equal to zero

Axis drive reactance less than or equal to zero

The value in MD 1139: $MD_STATOR_LEAKAGE_REACTANCE (stator leakage reactance) or MD 1140: $MD_ROTOR_LEAKAGE_REACTANCE (rotor leakage reactance) or MD 1141: $MD_MAGNETIZING_REACTANCE (magnetizing reactance) is less than or equal to zero Control reaction: NC not ready. The NC switches to follow-up mode. Channel not ready. NC Start disable in this channel. Interface signals are set. Alarm display. NC Stop on alarm.

Root Cause Summary

This alarm occurs when the value in MD 1139, MD 1140, or MD 1141 is set to less than or equal to zero, typically due to incorrect parameter configuration. Fix by ensuring valid positive values are entered for reactance parameters.

Safety

  • Drive/power/encoder circuit: hazardous voltages may remain in the DC link after power-off. Lock out / tag out, wait for discharge per the drive documentation, and use qualified personnel only.

Causes and Fixes

  1. 1

    Access machine data

    Navigate to the machine data parameters via the CNC control interface.

  2. 2

    Check reactance values

    Verify the values in MD 1139 (stator leakage), MD 1140 (rotor leakage), and MD 1141 (magnetizing reactance) are positive.

  3. 3

    Correct and save

    Enter valid positive values, save changes, and reset the control.

DIY Feasiblehigh confidence

Call a technician if:

  • ·If the alarm persists after correcting parameter values
  • ·If access to machine data is restricted or unclear

Prevention

  • Double-check parameter values during setup
  • Use simulation to validate program changes

Common Mistakes

  • Overlooking negative or zero values in parameters
  • Failing to save changes after editing machine data

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