ydc Y-Delta Connection Fault fault in delta drive

ydc Y-Delta Connection Fault fault in delta drive troubleshooting

Description

ydc is specific to high-power drives that control an external Star-Delta (Y-Delta) contactor configuration for the motor winding switching. The drive logic controls the switchover; if the feedback from the contactors doesn't match the command, ydc trips.

Causes

1. Contactor Stuck: The Star contactor welded shut and didn't open when commanded.
2. Auxiliary Wiring: The feedback wire from the contactor aux block to the drive input is loose.
3. Timing: The mechanical interlock on the contactors is slowing down the switchover beyond the drive's timeout.

Solution

Contactor maintenance:
1. Inspect Contactors: Physically check if the contactors move freely.
2. Check Feedback: Verify the aux contact signal reaches the drive's input terminal.
3. Increase Delay: Increase the "Y-Delta Switchover Delay" parameter to account for slow, large contactors.