PowerFlex Fault F070 — Power Loss
What This Fault Means
F070 indicates the drive detected a drop in the DC bus voltage below the minimum operating level, typically caused by a momentary or sustained loss of input AC power.
Common Causes
- Incoming power interruption (utility sag, transfer switch)
- Loose input power connections
- Blown input fuse or tripped breaker
- Contactor in the power feed opening unexpectedly
- Power supply voltage too low for the drive rating
Recommended Fix
- Check the incoming power — measure voltage at the drive's L1/L2/L3 terminals.
- Inspect input fuses and the upstream breaker.
- Tighten all input power connections.
- If using a contactor ahead of the drive, verify it stays closed during operation.
- For frequent sags, consider enabling the ride-through function (kinetic buffering) if supported.
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