A117 Armature current ripple alarm in ABB DCS800 drive indicates that the ripple in the armature current has exceeded a predefined limit. This means one or several thyristors may carry no current.

Troubleshooting Steps:

1. Verify that the power supply is stable and within the specified voltage and frequency range.
2. Visually inspect the motor for any signs of damage or overheating.
3. Check the motor's insulation resistance and winding resistance.
4. Review the drive's current control parameters, such as the PI gains and current limit.