Power Distribution Systems (1)

The type of transformer and the connection configuration feeding a drive plays an important role in its performance and safety. The following is a brief description of some of the more common configurations and a discussion of their virtues and shortcomings.

Delta / Wye with grounded Wye neutral:

This configuration is one of if not thee most common. It provides re-balancing of unbalanced voltage with a 30 degree phase shift. Depending on the output connections from the drive to motor, the grounded neutral may be a path for common mode current caused by the drive output.

Delta / Delta with grounded leg:

Another common configuration providing voltage re-balancing with no phase shift between input and output. Again, depending on the output connections from the drive to motor, the grounded
neutral may be a path for common mode current caused by the drive output.

to be continued........