Danfoss · VLT AutomationDrive FC 301/302
This warning/alarm is active when the supply voltage to the drive is lost. It is only issued if parameter 14-10 Mains Failure is not configured to [0] No function.
Click steps to track your progress.
1. Verify the status of the upstream circuit breaker (e.g., QF1) and fuses in the main power distribution panel.
2. Measure the incoming AC line-to-line voltages (L1-L2, L2-L3, L3-L1) at the drive's input terminals to confirm stable three-phase supply (e.g., 400VAC ±10%).
3. Inspect and tighten all power connections at the drive's L1, L2, L3 input terminals using a torque wrench to specified values (e.g., 5 Nm).
4. Check the setting of parameter P14-10 (Mains Failure) on the drive's LCP; if it's set too sensitively, consider adjusting it to [2] Alarm if appropriate for the application.
5. Examine the operation of any upstream main contactor (e.g., KM1) and its control circuit for proper engagement and coil voltage (e.g., 110VAC or 24VDC).