WYE Start Delta Run motors are commonly used when a reduced Start-Up current is desired. The installation of a higher horsepower motor in a lower voltage environment such as a 1000 HP motor installed on a 480v distribution system is a common case. The potential problems are compounded if the motor and starter are a great distance from each other. Without the WYE start, excessive current may be drawn from the motor on startup, which could result in large voltage drops below the minimum voltage specification for a variety of loads on the distribution system. However, if your application does not require the WYE start and the starter is reconfigured for a straight Delta operation, make sure you minimize Power Circuit Anomalies by transferring the delta connection to the motor connection box rather than at the starter.
Visit the PdMA YouTube Channel at https://www.youtube.com/watch?v=qqvRNV9smqM to listen to an actual case study on this very topic and the problems that resulted from the Delta connection at the starter.
