Input Phase Loss
Schneider Electric · Altivar 312 Variable Frequency Drive
What does PHF mean?
This fault occurs when one or more phases of the incoming power supply to the drive are lost or are significantly unbalanced, typically detected when the drive is under load. Potential causes include blown input fuses, incorrect wiring (e.g., 3-phase drive on a single-phase supply), or an unbalanced line. Operating with input phase loss can damage the drive's input rectifier and lead to erratic performance.
Additional Steps
Steps 1–2 are listed in Priority Fix.
- 3
Verify the input power lines are balanced and free from major voltage unbalance.
- 4
Reset the fault after the cause has been cleared. In specific scenarios, input phase loss detection can be disabled ([Input phase loss] (IPL) = [No] (nO), page 94), but this is not a fix for the underlying power issue.