Undervoltage fault

What does F9 mean?

The DC-link voltage has dropped below acceptable limits, potentially triggering an undervoltage control supervision (S3). This could be caused by a low supply voltage, an internal frequency converter fault, a broken input fuse, or an open external charge switch. Prolonged undervoltage can cause erratic drive behavior and component stress.

Complete Troubleshooting Guide

1. 1

   If the supply voltage dip was temporary, reset the fault and attempt to restart the frequency converter.

2. 2

   Measure and verify the incoming supply voltage at the drive input terminals.

3. 3

   Check the functionality of the DC charge circuit and ensure the external charge switch is properly closed.

4. 4

   If the issue persists after these checks, contact your local distributor for further diagnostics.