Heatsink Overtemperature

What does OH mean?

The controller's heatsink temperature has exceeded its safe operating limit (either >85°C or >80°C), typically due to high ambient temperature, blocked airflow, or excessive drive load. A dirty heatsink or high currents during acceleration can also contribute. Sustained overtemperature will lead to derating, thermal shutdown, and reduced component lifespan.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Verify that the controller's ventilation openings are not obstructed.

2. 4

   Assess the drive dimensioning against the application load and duty cycle; consider reducing load or upsizing the drive.

3. 5

   Inspect the motor and mechanical load for any rough-running or defective bearings that could increase current draw.