Drive Controller Overheat

What does OHF mean?

This fault indicates that the drive controller's internal temperature or its I²t thermal model has exceeded safe operating limits, leading to an overheat condition. Continuous operation in this state will cause irreversible damage to the drive's sensitive electronic components.

• Cooling fan failure or obstruction preventing adequate airflow through the drive's heatsink.
• Ambient temperature in the enclosure exceeding the drive's specified maximum operating temperature (e.g., 50°C).
• Drive installed in a confined space with insufficient ventilation or clearance around heatsink fins.
• Excessive switching frequency (Parameter P1-05) setting, increasing internal power losses.
• Heavily loaded drive operating continuously at or above its rated current for extended periods.

Click steps to track your progress.

1. 1

   1. Inspect drive cooling fan operation; confirm fan spins freely and there is no debris obstructing airflow.

2. 2

   2. Measure ambient temperature inside the electrical enclosure; ensure it is below the drive's maximum rating (e.g., 40°C or 50°C).

3. 3

   3. Verify proper clearance (as per drive manual) around the drive's heatsink fins for optimal convection cooling.

4. 4

   4. Check drive internal temperature (display parameter P0-15 or similar) and compare to trip threshold.

5. 5

   5. Reduce the drive switching frequency (Parameter P1-05) if possible, considering audible noise and motor heating.