22016

Navigate to Diagnostics > Machine Data > [Spindle Channel] and locate MD 35220 ACCEL_REDUCTION. Document the current value and cross-reference against the motor nameplate maximum continuous torque and peak torque ratings.

Do not assume the value was correctly set during commissioning; verify against actual motor specifications.

Reduce MD 35220 by 10-15% increments. Start with conservative value (typically 0.5-0.7 for servo spindles). Re-test the program block that triggered alarm.

Excessive reduction will limit spindle performance; iterate methodically.

Monitor actual spindle current draw via HMI Spindle > Actual Values during test run. Confirm peak current remains below motor FLA + 20% safety margin.

If alarm persists after optimization, check MD 35210 (SPINDLE_TYPE) confirms 'FOLLOWING' mode and MD 35230 (POSITION_RANGE_LIMIT) is not improperly restricting motion envelope.

Access NCK menu path: Diagnostics > Spindle [n] > Motor Parameters. Cross-reference Rated Power (MD 35100), Rated Speed (MD 35110), and Rated Torque against the actual motor nameplate in the electrical cabinet.

Mismatched MD entries will cause the control to miscalculate acceleration headroom.

Obtain the motor datasheet and verify continuous torque curve. Compare the commanded acceleration profile from the NC program block (G01 F-rate for following spindle) against motor continuous torque availability.

Peak torque is not usable for sustained following; only continuous rating applies.

If motor is undersized, contact machine builder for spindle replacement options. Alternatively, modify NC program block to reduce feed rate (F-word) for following spindle motion to stay within motor capability.

Navigate to Diagnostics > Spindle [n] > Control Parameters. Review MD 35240 (SERVO_GAIN_P), MD 35245 (SERVO_GAIN_I), and MD 35250 (SERVO_GAIN_D). Compare against Siemens commissioning template values for your spindle motor size class.

Excessively high gains can cause oscillation; excessively low gains cause lag.

Enable oscilloscope or trace recording (NCK Diagnostics > Scope) and capture Position Command vs. Position Actual for the alarm block. Observe if actual position lags command by >10% of interpolation cycle time.

If lag detected, increase MD 35240 incrementally (5-10% steps) and re-test. If overshooting occurs, increase MD 35245 (integral action) instead. Document all parameter changes with date/engineer initials.

Tuning changes must be validated on test part before production run.

Verify MD 35260+ (notch filter, low-pass filter) are not disabled. These filters suppress resonance peaks that can trigger servo instability and force larger corrective moves.