IGBT temperature

What does F31 mean?

The IGBT Inverter Bridge over-temperature protection has activated due to an excessively high short-term overload current. This indicates the power semiconductors are being stressed beyond their safe operating limits. Repeated trips can degrade the IGBTs.

• Sustained heavy overload on the motor, causing the IGBTs to conduct excessive current and generate heat beyond their cooling capacity.
• Inadequate cooling of the drive's IGBT module due to clogged heatsink fins, failed cooling fans, or high ambient temperature.
• Rapid acceleration/deceleration or frequent starts/stops with high inertia loads, leading to transient current peaks.
• Drive operating outside its specified output current rating (Ih) or duty cycle (e.g., parameter P1-54 'Motor rated torque' set too high).
• Faulty internal IGBT temperature sensor or gate drive circuit issues.

Click steps to track your progress.

1. 1

   Allow the drive to cool down. Measure ambient temperature in the control cabinet and verify it is within the drive's specified operating range (e.g., 0°C to 50°C).

2. 2

   Inspect the drive's cooling fans for proper operation and check heatsink fins for dust, debris, or blockages. Clean with compressed air if necessary (ensure power off).

3. 3

   Verify the motor load current (e.g., Menu 1-04 'Motor Current') is not consistently exceeding the drive's nominal output current (Ih) rating for extended periods.

4. 4

   Increase acceleration and deceleration ramp times (e.g., P3-41 'Acceleration ramp 1 time', P3-42 'Deceleration ramp 1 time') to reduce current peaks during transients.

5. 5

   Check if the motor and drive are correctly sized for the application. Compare motor nominal current (P1-50) and drive nominal current (Ih) values.

6. 6

   Verify the drive's IGBT temperature reading in the diagnostics menu (e.g., Menu 1-30 'Heatsink temperature') and compare to observed conditions.