Cause : PHASE FAIL comes when one of the phases in the three-phase power supply may be missing or disconnected, leading to a phase loss condition. This means a missing input phase, for Frame K, L and M drives. Disable this trip for DC fed units.

PHASE FAIL fault in a Parker AC30 drive indicates that there is a problem with the power supply phases. This fault occurs when the drive detects an issue with the incoming three-phase power supply, which could be due to phase loss, phase imbalance, or phase reversal.

Possible Causes and Solutions:

1. Phase Loss:

   • Cause: One of the phases in the three-phase power supply may be missing or disconnected, leading to a phase loss condition.
   • Solution:
     • Check the power supply: Use a multimeter or other testing equipment to verify that all three phases are present and properly connected. Address any issues with phase loss by repairing or reconnecting the missing phase.

2. Phase Imbalance:

   • Cause: There may be an imbalance in the voltages of the three phases, which can cause the drive to detect a fault.
   • Solution:
     • Measure phase voltages: Check the voltages of each phase to ensure they are balanced and within the specified range. If there is an imbalance, identify and correct the source of the imbalance, such as an issue with the power supply or transformer.

3. Phase Reversal:

   • Cause: The sequence of the phases may be incorrect, leading to phase reversal.
   • Solution:
     • Verify phase sequence: Confirm the correct phase sequence using a phase sequence tester or similar tool. Reconnect the phases in the correct sequence if they are reversed.

4. Faulty Wiring or Connections:

   • Cause: Wiring issues or loose connections can cause phase failure.
   • Solution:
     • Inspect wiring and connections: Check all wiring and connections related to the power supply phases. Ensure that all connections are secure and that there are no signs of damage or wear.

5. Power Supply Problems:

   • Cause: Problems with the external power supply, such as voltage fluctuations or faults, can lead to phase failures.
   • Solution:
     • Check the power supply: Ensure that the power supply is stable and within the specified voltage range. Address any issues with voltage fluctuations or faults in the power supply.

6. Drive Internal Issues:

   • Cause: Internal faults within the drive, such as damaged components or internal circuitry problems, may cause a phase fail fault.
   • Solution:
     • Inspect the drive: If external checks do not reveal the issue, consider inspecting the drive for internal faults. This may require professional service or support from Parker.