F021Type 1 fault (auto-reset) · Motor / loadUsually repairable
PowerFlex 525 F021: Output Ph Loss
What F021 means
One of the three output phases to the motor is missing (when output-phase-loss detection is turned on).
Symptoms
Motor hums, runs rough or will not start, then the drive trips.
Is it repairable?
Yes: open windings are rewound and failed output stages are repaired.
Common causes
- Loose or burnt motor terminal
- Broken motor cable
- An output contactor with a bad contact
- An open motor winding
- A failed output transistor
Safe checks
- 1With power off, check every connection between drive and motor
- 2Measure motor winding resistance phase to phase
Drives hold dangerous voltage after power-off. Checks should only be done by qualified personnel, with power isolated and the DC link discharged.
Reviewed by AutomIQ repair technicians. Code and name from the PowerFlex 520-Series Adjustable Frequency AC Drive User Manual.
Related PowerFlex 525 faults
- F004UnderVoltage
- F005OverVoltage
- F007Motor Overload
- F008Heatsink OvrTmp
- F012HW OverCurrent
- F013Ground Fault