Heat sink overtemperature

What does OH mean?

This fault indicates that the drive's heat sink temperature has exceeded its safe operating limit, typically due to insufficient cooling or excessive loading. By default, this critical condition triggers a full TRIP, inhibiting all ignition pulses and resetting the Ready signal to protect the drive's power semiconductors from thermal damage. Manual reset is required after the drive has cooled down and the cause is addressed.

• Blocked ventilation openings or obstructed cooling fins on the drive's heat sink, preventing adequate airflow.
• Failure of the drive's internal cooling fan(s) (e.g., seized motor, broken blades, electrical fault).
• Ambient temperature inside the electrical cabinet exceeding the drive's maximum operating temperature (e.g., 50°C).
• Continuous operation of the drive at or above its rated output current (e.g., P0-02) for extended periods.
• Insufficient clearance around the drive in the enclosure, leading to recirculation of hot air and poor heat dissipation.

Click steps to track your progress.

1. 1

   Perform a lockout/tagout procedure. Clean all dust and debris from the drive's heatsink fins and ventilation openings using compressed air.

2. 2

   Verify the operation of all internal cooling fans on the drive; replace any non-functional fans.

3. 3

   Measure the ambient temperature inside the electrical cabinet near the drive's air intake; ensure it is within the drive's specified operating range.

4. 4

   Check for proper air circulation within the enclosure; verify intake and exhaust fans (if external) are operational and sized correctly.

5. 5

   Reduce the drive's output current (e.g., by reducing mechanical load or motor speed) if operating continuously at high load.

6. 6

   Monitor the drive's internal heatsink temperature (P6-01) in real-time to identify thermal trends.