Cause : Over-current at stop comes when an over-current condition is detected even when the drive is not running. This issue can arise from various factors, such as electrical noise, grounding problems, or hardware faults. 

The ocS error code on your Delta MS300 drive indicates an Over-current at stop. This signifies that the motor current has exceeded a set limit for a specific duration.

1. Verify the wiring of the control circuit and the wiring/grounding of the main circuit to prevent interference.
2. Check if other error codes such as cd1–cd3 occur after cycling the power.