Allen-Bradley · PowerFlex 4M Adjustable Frequency
This fault indicates that an external auxiliary input, often configured as a safety interlock or enable signal, is currently open or inactive when the drive expects it to be closed. This condition prevents the drive from operating and is typically a protective measure. An unresolved open interlock will stop the drive, potentially indicating a safety bypass or an issue with an external control device.
Click steps to track your progress.
Verify all safety interlocks (e.g., E-stops, guard doors) are in their closed or 'safe' position.
Measure the voltage across the drive's auxiliary input terminals (e.g., D-IN0, COM) to confirm the presence of the expected signal (e.g., 24VDC).
Inspect the wiring from the auxiliary input device to the drive's input terminals for continuity and secure connections.
Manually actuate the auxiliary input device (if safe to do so) and confirm its contact closure using a multimeter.
If the input is controlled by a PLC, verify the PLC output status and confirm correct wiring to the drive's auxiliary input.