Parker Drive Heatsink Overheat Fault

Heatsink Overheat Fault in a Parker AC Drive indicates that the temperature of the inverter heatsink has exceeded the allowable operating limit. Parker drives continuously monitor the heatsink temperature using an internal temperature sensor. If the heatsink temperature rises above the protection threshold, the drive generates a Heatsink Overheat Fault and shuts down the inverter output to protect the power semiconductors (IGBTs) from thermal damage.

This fault generally indicates a problem with the drive cooling system, ambient temperature, ventilation, cooling fan, or excessive load, rather than a failure of the motor itself.

Possible Causes

• High ambient temperature.
• Cooling fan failure.
• Cooling fan running at reduced speed.
• Blocked ventilation openings.
• Dirty or clogged heatsink fins.
• Restricted airflow around the drive.
• Drive mounted with insufficient clearance.
• Continuous operation at excessive load.
• Frequent starts and stops causing excessive heating.
• Overloaded motor drawing excessive current.
• Drive undersized for the application.
• Dust, oil, or contamination reducing cooling efficiency.
• Defective heatsink temperature sensor.
• Internal IGBT overheating.
• Internal drive hardware failure.

Solutions

• Allow the drive to cool before restarting.
• Check the ambient temperature and keep it within the specified operating range.
• Inspect the cooling fan for proper operation.
• Replace the cooling fan if defective.
• Clean the heatsink and ventilation openings.
• Remove dust and debris from the cooling path.
• Ensure adequate clearance around the drive for airflow.
• Reduce the mechanical load if possible.
• Verify that the motor current is within the drive's rated capacity.
• Check for overloaded machinery.
• Confirm the drive is correctly sized for the application.
• Inspect the heatsink temperature sensor if the fault occurs at normal temperatures.
• Replace the drive or repair the power section if an internal hardware fault is found.
• Contact Parker technical support if the fault persists.

Additional Information

Parker AC drives use an internal heatsink temperature sensor to continuously monitor the temperature of the inverter power module.

The Heatsink Overheat Fault is generated when the measured heatsink temperature exceeds the drive's protection limit.

Common causes include:

• Poor ventilation.
• Cooling fan failure.
• High ambient temperature.
• Excessive motor current.
• Continuous heavy-duty operation.

Unlike a Motor Overtemperature Fault, which protects the motor, a Heatsink Overheat Fault protects the drive's power electronics, particularly the IGBT modules, from excessive thermal stress.

If this fault occurs repeatedly, the cooling system or application load should be investigated before returning the drive to service.

Common Symptoms

• Drive trips with Heatsink Overheat Fault.
• Motor stops unexpectedly.
• Cooling fan may not be operating.
• Drive enclosure feels unusually hot.
• Fault occurs during prolonged operation.
• Fault appears during high ambient temperatures.
• Drive operates normally after cooling but trips again under load.
• Reduced cooling airflow around the drive.
• No visible motor fault.
• Drive requires a reset after cooling.

Recommended Troubleshooting Sequence

1. Stop the drive and allow it to cool.
2. Check the ambient temperature around the drive.
3. Inspect the cooling fan for proper operation.
4. Clean the heatsink and ventilation openings.
5. Verify adequate airflow around the drive.
6. Measure the motor current under load.
7. Check for excessive mechanical load.
8. Confirm the drive is correctly sized for the application.
9. Inspect the heatsink temperature sensor.
10. Check the inverter power section for overheating.
11. Restart the drive after corrective actions.
12. Monitor the heatsink temperature during operation.
13. Confirm the fault has cleared.
14. Replace defective cooling components if necessary.
15. Contact Parker technical support if the fault persists.

Heatsink Overheat Check Table

Check Point	Action
Ambient temperature	Verify within specified operating limits
Cooling fan	Check operation and replace if faulty
Heatsink	Clean dust and debris
Ventilation	Ensure airflow is unobstructed
Drive clearance	Verify adequate installation spacing
Motor current	Measure and compare with drive rating
Mechanical load	Check for overload
Temperature sensor	Inspect for correct operation
Power section	Check for overheating or damage
Parker technical support	Contact if the fault remains after inspection

Preventive Maintenance Tips

• Clean the heatsink and cooling fan regularly.
• Inspect cooling fans during scheduled maintenance and replace worn fans before failure.
• Maintain adequate clearance around the drive for proper airflow.
• Keep the drive enclosure free from dust, oil, and debris.
• Monitor ambient temperature and avoid operating above the specified limits.
• Ensure the drive is correctly sized for the application.
• Reduce continuous overload conditions where possible.
• Periodically check motor current and load levels.
• Tighten power terminals during routine maintenance.
• Record recurring Heatsink Overheat Fault events to assist long-term diagnostics.

Proper inspection of the cooling fan, heatsink, ventilation, ambient temperature, motor load, heatsink temperature sensor, and inverter power section, together with routine preventive maintenance and correct drive sizing, will help prevent recurring Heatsink Overheat Faults in Parker drives, ensuring effective thermal protection, reliable inverter operation, and dependable long-term performance of the drive system.