10238

I2 Powering Down

Allen-Bradley · PowerFlex 750

What does 10238 mean?

This fault is asserted when the DC bus voltage drops to 80% of its rated value on port 2. This indicates a significant loss of DC bus voltage which can lead to drive shutdown and loss of control.

Common Causes

  • Loss of one or more phases of the 3-phase AC input supply (L1, L2, L3) to the rectifier on Port 2.
  • Excessive load current draw from the motor connected to Port 2, leading to rapid DC bus discharge.
  • Degradation or failure of the DC link capacitors on Port 2, resulting in reduced energy storage capacity.
  • Internal short circuit or ground fault within the DC bus section of Port 2, causing voltage collapse.
  • Faulty DC bus voltage sensing circuit on Port 2 providing an inaccurate low voltage reading to the controller.

Repair Steps & Checklist

Click steps to track your progress.

  1. 1

    Measure the 3-phase AC input voltage at terminals R, S, T (Port 2) to confirm nominal values are present and stable.

  2. 2

    Check the status of all upstream circuit breakers and fuses supplying power to the Port 2 input.

  3. 3

    Monitor the actual motor current (e.g., Parameter P3-01 for Port 2) to verify it is within the drive's rated limits.

  4. 4

    Inspect the DC link capacitors on Port 2 for physical signs of damage, such as bulging, leaking electrolyte, or discoloration.

  5. 5

    Using a multimeter, measure the DC bus voltage across the P+ and N- terminals (Port 2) and compare it to the value displayed on the drive.

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Verified technical data. Last updated: March 2026

Related Faults

Source: Allen-Bradley PowerFlex 750