Heidenhain codes
HeidenhainPower SupplyIntermediate30-120 minutes

238-101D

HEIDENHAIN 238-101D - 101D UVR configured DC-link voltage too low

101D UVR configured DC-link voltage too low

The configured DC-link voltage in MP_dcLinkVoltage is too low. It must exceed the rectified value of the live line voltage.

Root Cause Summary

The Heidenhain 238-101D alarm typically occurs when the configured DC-link voltage in MP_dcLinkVoltage is set too low compared to the rectifier value of the live line voltage. The most likely fix involves adjusting the parameter CfgSupplyModule3xx/MP_dcLinkVoltage to a value greater than the rectified line voltage, such as increasing it to DC 720 V for a 3AC 480 V line voltage.

Safety

  • Refer to Heidenhain service manual
  • Ensure qualified technician performs repairs

Causes and Fixes

  1. 1

    Access Parameter Settings

    Using the control panel, navigate to the machine parameters under CfgSupplyModule3xx and locate MP_dcLinkVoltage.

    Ensure you have the correct access code or password to modify parameters; consult the machine manual if needed.

    Ensure the machine is powered down or in a safe mode before accessing parameters to avoid electrical hazards.

  2. 2

    Measure Line Voltage

    Use a multimeter to measure the actual line voltage (e.g., 3AC 480 V) and calculate the rectified value (approximately 1.414 times the AC voltage).

    Double-check multimeter settings for AC voltage to avoid incorrect readings.

    High voltage present; only qualified personnel should perform this measurement.

  3. 3

    Adjust DC-link Voltage

    Set MP_dcLinkVoltage to a value greater than the rectified line voltage (e.g., DC 720 V for 3AC 480 V). Save the changes and restart the system.

    Incrementally increase the value if unsure, testing after each adjustment to ensure stability.

    Incorrect settings can damage components; refer to the Heidenhain manual for recommended values.

DIY Feasiblemedium confidence

Call a technician if:

  • ·If adjusting MP_dcLinkVoltage does not resolve the alarm after multiple attempts
  • ·If line voltage fluctuations persist despite installing stabilizers or if power supply unit testing indicates hardware failure

Prevention

  • Regularly monitor and log line voltage to detect fluctuations early
  • Schedule periodic parameter audits to ensure correct DC-link voltage settings
  • Perform routine maintenance on power supply units to prevent hardware failures

Common Mistakes

  • Setting MP_dcLinkVoltage without measuring actual line voltage, leading to incorrect configurations
  • Ignoring minor voltage fluctuations, which can escalate into recurring alarms over time

Related Alarms

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