Schneider Electric · ALTIVAR 28 Variable Speed Drive
This fault indicates an internal malfunction within the drive controller, potentially stemming from environmental electromagnetic interference or an improper connection/disconnection of the local control option while powered. Ignoring this can result in total drive failure and loss of control.
Click steps to track your progress.
1. Cycle drive power (turn off, wait 30 seconds, turn on) to clear transient conditions.
2. Verify control wiring shielding is properly terminated at the drive ground terminal and not at both ends (ground loop).
3. Measure incoming control power supply (e.g., 24VDC) stability with an oscilloscope for voltage dips or spikes.
4. Perform a factory reset (e.g., Parameter P9-01 = 1) to clear corrupted configuration, then re-enter essential motor parameters.
5. Check for loose internal connections by physically inspecting the drive's control board connections.