Old Hand Fault Finder

Allen-Bradley PowerFlex 525 F003: Power Loss

Cites the manual · line-by-line check pending

What it means DC bus dropped low enough to look like lost input power.

Likely causes

  • Utility dip
  • Blown fuse
  • Loose line terminal
  • Undersized supply

Checks, in order

  1. Measure all three input phases
  2. Check fuses and breakers
  3. Check for big motors starting on same feeder

Old Hand tip

Look at what else starts at the same time of day.

Source

Source (reworded, not copied): Rockwell Automation, PowerFlex 520-Series AC Drives User Manual, publication 520-UM001O-EN-E (September 2025), Chapter 4 Troubleshooting. Official manual (PDF). Fault numbers and names can differ between firmware versions.