Recently we had a customer that we helped with troubleshooting a Fanuc servo A20B-1003-0090 board that he was installing into a A06B-6058-H005 drive. Fanuc lists some troubleshooting options in the manual that we wanted to repost to help anyone who is having similar issues.
Troubleshooting for the DCAI alarm:
- Setting S2 for the S series
- Machine load
- Check connection of separate discharge unit
A. Check amplifier setting S2. If the setting is incorrect, go to Cause 1. If the setting is correct, go to A-0.
A-0: Check whether a separate discharge unit is being used. If it is being used, go to A-1. If not being used, go to A-2.
A-1: Check the connection of the separate discharge unit. If the connection is incorrect, go to Cause 2. If connection is correct, go to A-2.
A-2: Check the acceleration/deceleration frequency. If the frequency is too high, go to Cause 3. If the frequency is low enough, go to A-3.
A-3: Replace the servo amplifier. If a DCAL alarm no longer occurs, go to Cause 4. If a DCAL alarm still occurs, go to Cause 3.
1). If the setting S2 of the S series servo amplifier is incorrect, a DC alarm is caused.
2). If the separate discharge unit is connected incorrectly, a DC alarm occurs.
3). Compared to the regenerative power of the amplifier, the regenerative energy of the motor is too large. (The inertia is too large or the acceleration/deceleration frequency is too high.) In this case, try to decrease the acceleration/deceleration frequency or install a separate discharge unit.
4). The discharge transistor (Q1) in the servo amplifier is defective.