239-0007

Access electrical cabinet safely

Power down the machine following proper lockout/tagout procedures. Open the electrical cabinet and locate the CC modules (typically mounted on the left side of the control cabinet).

Ensure main power is disconnected and capacitors are discharged before accessing CC modules. Wait minimum 5 minutes after power-off.

Identify the affected CC module

The alarm parameter %2 indicates the CC module number. Locate this specific module - CC modules are numbered sequentially and labeled on the front panel. Verify the module label matches the alarm number.

Take a photo of the alarm screen showing all parameters (%1, %2, %6, %7) before acknowledging - this helps track the exact component and temperature values.

Inspect cooling fan operation

With power restored (cabinet open, safety observed), verify the cooling fan on the identified CC module is rotating. Fans should spin immediately at power-on. Check for obstructions, damaged blades, or bearing noise indicating imminent failure.

Keep hands and tools clear of rotating fans. Use a non-conductive tool to check blade rotation if needed.

Verify airflow direction and filter condition

Confirm airflow is moving from bottom to top through the heat sink (typical configuration). Check cabinet intake filters for blockage - restricted intake causes all CC modules to overheat. Clean or replace filters per maintenance schedule.

Hold a tissue near the fan exhaust to visually confirm airflow direction and strength. Weak airflow with fan running indicates blocked heat sink fins.

Replace failed cooling fan

If fan is not rotating or shows mechanical damage, order replacement fan using the CC module part number (fan is module-specific). Replacement requires CC module removal - document all cable connections before disconnecting.

Heidenhain CC modules typically use 24VDC fans. Verify fan voltage at the connector with a multimeter before replacing - no voltage indicates control board issue, not fan failure.

Measure cabinet ambient temperature

Use a calibrated thermometer to measure air temperature at the CC module intake area (lower section of cabinet). Document temperature and compare to specification (typically 45°C maximum for continuous operation).

Measure during actual machining operations when heat load is highest - idle conditions may not reveal thermal issues.

Check cabinet heat exchanger operation

Verify the cabinet air conditioning unit or heat exchanger is functioning. Check refrigerant cooling units for proper compressor operation, clean condenser coils, and verify temperature setpoint (typically 35°C). For air-to-air heat exchangers, clean both sides of the heat exchanger core.

Do not set cabinet cooling below ambient dew point - condensation will damage electronics. Maintain minimum 5°C above dew point.

Inspect cabinet sealing and heat sources

Verify cabinet doors seal properly and all cable entries are sealed. Identify any heat sources inside the cabinet (transformers, brake resistors, PLCs) that may be adding thermal load. Ensure brake resistors are mounted with adequate clearance.

Use a thermal imaging camera to identify hot spots inside the cabinet - this quickly reveals inadequate heat sink contact, failed components, or airflow dead zones.

Evaluate machine environment

Assess shop floor temperature, especially if machine is located near heat-generating equipment (furnaces, welders) or in direct sunlight. If ambient exceeds 35°C, improved environmental cooling or cabinet relocation may be required.

Temporary solutions include adding external fans to increase cabinet ventilation or shading cabinet from direct sun. Long-term solution requires upgrading cabinet cooling capacity.

Review axis load in Position Monitor

Access Machine > Position Monitor (or press POS key twice). Observe the 'Following error' and 'Lag' values during operation. Switch to Service > Diagnosis > Axis Monitor to view real-time current consumption (%) for each axis. Sustained operation above 70-80% indicates overload.

Enable the load recording function (MOD > Service > Diagnosis > Axis Load) to capture peak and average load over time - this identifies intermittent overload conditions.