What is a servo press?

A servo press uses servo motors for precise force and position control during forming operations.

How do I calculate servo press tonnage?

Use our free tonnage calculator at servopress.club/tonnage-calculator.html

ABB ACS880 Fault 3281 on Servo Press: Motor Stall

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## Fault 3281 Definition

ABB ACS880 fault 3281 is motor stall — the drive has detected that the motor is not rotating despite being commanded to move. On a servo press, this typically means a mechanical jam or severe overload.

## Immediate Safety Check

Before any diagnosis: verify the press slide is not stuck in a position that could cause injury when released. If the slide is stuck mid-stroke with a die loaded, call a qualified press technician.

## Diagnosis

### Check for Mechanical Jam

- Inspect die area for foreign objects
- Check if slide moves freely by hand (with drive disabled and counterbalance air on)
- Check gib clearance — if gibs are too tight, slide can jam under load

### Check Drive Parameters

Fault 3281 is triggered when motor speed stays below parameter 25.11 (stall speed limit) for longer than parameter 25.12 (stall time limit).

Default values: 25.11 = 5% of rated speed, 25.12 = 20 seconds.

For a servo press with slow forming strokes, 5% of rated speed may be too close to normal forming speed. Check if the forming speed is above 25.11.

### Check Motor Feedback

If the encoder cable is damaged, the drive receives no speed feedback and assumes stall. Check encoder cable continuity and connector condition.

### Check Load

If the press is forming material that is significantly harder or thicker than designed, the motor may genuinely stall. Check material certificate against die design spec.

## Reset

Fix mechanical issue first. Then: fault reset via ACS880 control panel or fieldbus command.

anna_controls

Fault 3281 on a servo press almost always means a mechanical jam. The motor is trying to move but can't. Before touching any drive parameters, check: is the slide physically stuck? Is there material jammed in the die? Is a gib seized? I've seen shops spend hours troubleshooting the drive when the real problem was a broken bolt jamming the slide.

raj_maintenance

We got 3281 intermittently on a 300T press. Turned out the counterbalance pressure was low —the motor had to lift the full slide weight on the return stroke and stalled at TDC where mechanical advantage is lowest. Topped up the air pressure and the fault disappeared. Always check the simple stuff first.