Heatsink Overtemperature

What does OH2 mean?

An OH2 fault occurs when any of the heatsink thermistors measure a temperature exceeding the level set in L8-02. This indicates that the drive's heatsink is overheating, typically due to insufficient cooling, excessive ambient temperature, or prolonged overload on the drive. Sustained high temperatures can severely degrade the lifespan of the drive's power components and lead to premature failure.

• Insufficient cooling air flow due to clogged heatsink fins, blocked air vents, or a failing cooling fan (internal or external).
• Ambient temperature around the drive exceeding its specified operating limit (e.g., >50°C), leading to insufficient heat dissipation.
• Excessive drive loading, continuous operation at or above rated current for prolonged periods, causing high internal heat generation.
• Malfunctioning internal heatsink thermistor or its wiring, providing an inaccurate high temperature reading.
• Improper installation, such as mounting the drive in an enclosed space without adequate ventilation or spacing from other heat-generating equipment.

Click steps to track your progress.

1. 1

   Check and clean the heatsink fins and air vents thoroughly using compressed air (non-conductive) to remove dust, dirt, and debris.

2. 2

   Verify that all cooling fans (internal to drive, cabinet cooling fans) are operating correctly, checking for fan rotation and airflow.

3. 3

   Measure the ambient air temperature directly in front of and behind the drive's heatsink using a contact thermometer or IR thermometer.

4. 4

   Check parameter L8-02 (Heatsink Overtemperature Detection Level) and ensure it is set to the manufacturer's recommended value.

5. 5

   Monitor the drive's heatsink temperature (e.g., "Heatsink Temp" monitor value) during operation and compare it to the alarm threshold (L8-02).