Heatsink Overheat

What does OH mean?

The OH condition indicates that the inverter's heatsink temperature has risen above the set OH Pre-Alarm Level (L8-02). This is a warning that the inverter is approaching an over-temperature condition. If the temperature continues to rise, the inverter will likely trip to protect its internal power components.

• Ambient temperature inside the control cabinet exceeding the inverter's maximum specified operating temperature (e.g., 40°C).
• Blocked heatsink fins or cooling fan vents due to dust, lint, or debris accumulation.
• Failure of the inverter's internal cooling fan, preventing adequate heat dissipation.
• Insufficient cabinet ventilation, leading to poor heat exchange with the surrounding environment.
• Inverter mounted too closely to other heat-generating equipment or within an unventilated enclosure.

Click steps to track your progress.

1. 1

   1. Measure the ambient temperature inside the control cabinet using a calibrated thermometer and compare it to the inverter's specification.

2. 2

   2. Thoroughly clean the inverter's heatsink fins and cooling fan inlets/outlets using compressed air or a soft brush.

3. 3

   3. Verify the operation of the inverter's cooling fan by observing rotation or measuring its supply voltage (e.g., 24VDC).

4. 4

   4. Check the control cabinet's ventilation system (e.g., exhaust fans, air filters) for proper airflow and replace any clogged filters.

5. 5

   5. Confirm the heatsink over-temperature pre-alarm level (e.g., Parameter L8-02) is set appropriately for the application.