Heidenhain TNC 620 Error Code 300

Heidenhain CNC Major Drive

Model: TNC 620 | Code: 300

Applicable Systems
TNC 620

Symptoms

Drive fault. The servo drive has reported a fault to the NC system.

Possible Causes

  • Drive overcurrent trip
  • Drive overvoltage on DC bus
  • Drive overtemperature
  • Drive communication with NC interrupted
  • Drive internal hardware fault

Troubleshooting Steps

  1. Step 1: Check the equipment status and fault indicators to confirm the active fault code
    Fault indicator or HMI displays code 300 as active
  2. Step 2: Verify all electrical connections, wiring harnesses, and connector seating
    All connections secure, no corrosion, loose pins, or damaged wires
  3. Step 3: Check motor cable connections at drive output terminals for correct phase sequence and tightness
    Cables securely connected, phase sequence correct, no loose terminals
  4. Step 4: Measure motor winding insulation resistance with a megger (500V DC minimum)
    Insulation resistance above minimum value (typically > 1 Megaohm)
  5. Step 5: Verify drive parameter settings match motor nameplate data (current, voltage, power, RPM)
    All motor nameplate parameters correctly entered in drive
  6. Step 6: Inspect motor for mechanical overload, bearing seizure, or driven equipment jam
    Motor rotates freely, no mechanical binding or excessive load
  7. Step 7: Reset the fault after fixing the root cause: clear the fault via HMI or power-cycle
    Fault clears and drive resumes normal operation without recurrence

How to Reset

To reset: 1) Identify and fix the root cause described in the fault symptoms. 2) Press RESET on the HMI or controller, or power-cycle the equipment. 3) If the fault recurs, contact manufacturer service. Caution: Document the fault code and context before resetting.

Frequently Asked Questions

  • Q: What does fault code 300 mean on the Heidenhain TNC 620?

    Fault 300 on the Heidenhain TNC 620 indicates: Drive fault. The servo drive has reported a fault to the NC system. Refer to the equipment manual and manufacturer support for specific troubleshooting steps.

  • Q: Can I continue operating the equipment with fault 300 active?

    No. The equipment has detected a fault condition and has taken protective action (typically stopping or derating). Continuing to operate without fixing the root cause may cause further damage. Always investigate and fix the fault before resuming operation.

Related Heidenhain Fault Codes

Source: Heidenhain TNC 620 Operating Manual, Heidenhain Documentation

Category: CNC