239-02B1

Check ambient temperature conditions

Verify electrical cabinet temperature is within 0-45°C range. Check facility HVAC and ensure cabinet doors are properly sealed.

High cabinet temperatures can damage sensitive TNC electronics

Inspect cooling system operation

Verify all cooling fans in drive modules are operational. Clean air filters and check for blocked ventilation slots on servo drives.

TNC drives typically have internal temperature sensors - use HSC HEIDENHAIN Service Tool to monitor real-time thermal data

Verify motor cooling

Check servo motor cooling fan operation and clean motor housing fins. Ensure proper airflow around motor mounting area.

Liquid-cooled motors should show consistent coolant flow and temperature differential

Check axis load conditions

Access TNC Service menu → Axis diagnosis → Current monitoring to verify RMS current levels are within drive ratings during normal operation.

Compare actual vs. rated continuous current - sustained operation above 80% rated current will trigger thermal warnings

Inspect mechanical system

Check for mechanical binding, worn way covers, contaminated linear guides, or excessive backlash causing higher servo loads.

Disconnect power before manually checking axis movement

Review axis parameters

Verify servo parameters in TNC Setup → Machine Parameters → Axis-specific parameters. Check current limit settings and acceleration values.

Parameters like MP1020 (max. axis acceleration) and MP1030 (current limit) directly affect thermal loading

Access drive diagnostics

Use TNC Service menu → Drive diagnosis to check internal drive status, fault history, and thermal sensor readings.

HEIDENHAIN drives log thermal events - check fault buffer for recurring temperature warnings

Verify drive connections

Inspect power connections, motor cables, and feedback cable connections for looseness, corrosion, or damage causing increased resistance.

Always use lockout/tagout procedures when inspecting electrical connections

Test drive performance

Run axis through full travel range at reduced feedrates while monitoring temperature trends in TNC diagnostics.

Intermittent thermal warnings often indicate failing drive components requiring replacement

Check motor temperature sensor

Access TNC → Service → Encoder/Motor diagnosis to verify temperature sensor readings are realistic compared to actual motor housing temperature.

KTY84 sensors typically read 1kΩ at 25°C - use multimeter to verify sensor resistance

Inspect motor cable integrity

Check motor feedback cable for damage, especially at cable track entry points. Verify proper cable shielding and grounding.

Damaged encoder cables can cause erratic temperature readings and position feedback errors

Verify sensor parameter settings

Check TNC machine parameters for correct temperature sensor type and scaling factors specific to installed motor model.

Incorrect MP settings for thermal sensors can cause premature warnings - verify against motor nameplate specifications