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What Causes an Input Phase Loss (PHF) Fault on the ATV12 and How to fix It?

Resolution:
The PHF (Input Phase Loss) fault on the Altivar Machine ATV12 drive indicates that one or more input phases are missing or unstable. This fault is only detected when the drive is running under load.

This issue can occur due to:

  • Incorrect power supply connection or a blown fuse
  • Loss of one input phase
  • Using a 3-phase ATV12 drive on a single-phase supply
  • Unbalanced power supply or load conditions

Follow these steps to resolve the PHF fault:

  1. Verify Power Supply

    • Check that all input phases are correctly connected
    • Inspect and replace any blown fuses
  2. Ensure Proper Supply Type

    • Confirm the drive is connected to a suitable 3-phase power source (if required)
  3. Inspect Motor and Output Circuit

    • Check motor wiring and connections
    • Verify all intermediate devices (contactors, circuit breakers, isolators) are functioning properly
  4. Adjust Protection Setting (if needed)

    • Disable input phase loss detection by setting parameter IPL = nO (see user manual, page 94)
    • Only disable this protection if it is safe and appropriate for your application

For further information, consult the ATV12 User Manual

If this article does not answer your question, check out our FAQ database that has answers to more commonly asked questions:

Frequently Asked Questions - Schneider Electric (se.com)

If this FAQ did not solve your issue, you can call us at 1-888-778-2733 Option 2 and then 4 or e-mail us atdrive.products.support@se.comto create a case with our Technical Support Team.

If you are not located in North America, please contact your local Customer Care Center for assistance:

Support | Schneider Electric Global (se.com)

Schneider Electric Canada

Attachment(s)
ATV12_user_manual_EN_BBV28581_04.pdf [3.62 MB]
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