Allen-Bradley PowerFlex 525 VFD
Allen-Bradley PowerFlex 525 VFD code F021: F021 Output Ph Loss
The drive stopped because one of the three output power phases to the motor is missing.
- Code
- F021
- Name
- F021 Output Ph Loss
- Controller
- Allen-Bradley PowerFlex 525 VFD
- Type
- General fault
- What it does
- Fault: the equipment trips and stops
- Risk
- YELLOW Booth plays by its own rules
- Reset
- Needs a manual reset
- Source
- The manufacturer's manual (subscribers see which manual and page)
Updated July 22, 2026
How to fix it
Subscribers get:
- What to do next, in plain words
- Which manufacturer manual it comes from, linked
- The 3 common causes listed for this code
- Booking a live video call with Ben, a master booth technician ($250/hr, paid per call)
Questions about this code
What does Allen-Bradley PowerFlex 525 VFD code F021 mean?
The drive stopped because one of the three output power phases to the motor is missing.
Is Allen-Bradley PowerFlex 525 VFD code F021 dangerous?
It is graded yellow: not hard, but a booth does it differently than the gear most techs know, so follow the checks in order.
How do I fix Allen-Bradley PowerFlex 525 VFD code F021?
The manual's fix and the step by step check for this code are in WERCS Diagnose, plans from $49 a month. For help right now, WERCS answers 24/7 at (877) 489-3727.
Other Allen-Bradley PowerFlex 525 VFD codes
F007 · F007 Motor OverloadF008 · F008 Heatsink OvrTmpF012 · F012 HW OverCurrentF013 · F013 Ground FaultF029 · F029 Analog In LossF038 · F038 Phase U to GndF041 · F041 Phase UV ShortF059 · F059 Safety OpenF070 · F070 Power UnitF081 · F081 DSI Comm Loss
All 16 Allen-Bradley PowerFlex 525 VFD codes · Every fault code