Cause : DEVICE OVER TEMPERATURE comes when the internal temperature of the drive has exceeded safe operating limits. This fault can be caused by various factors, including inadequate ventilation, high ambient temperature, excessive load, or malfunctioning cooling components.

The F0003 alarm code on your ABB ACS550 drive indicates a device over temperature fault. This means the drive's internal temperature has exceeded its safe operating limits.

1. Check for and correct Fan failure. 
2. Obstructions in the air flow.
3. Dirt or dust coating on the heat sink. 
4. Excessive ambient temperature. 
5. Excessive motor load.