This 56-minute DVD explains how common types of overhead transformers can be connected together. Covers both single-phase and three-phase transformers, with emphasis on three-phase connections of three single-phase transformers. Presents connection theory using phasor diagrams and demonstrates how each of the connections is made. Covers how to make three-phase connections in the following configurations: delta-wye, wye-delta, alternative delta-delta, and alternative wye-delta. Also shows these connections using phasor diagrams. Explains how to connect transformers to form an open bank in delta-delta and wye-delta.
Introduction - 7 minutes
Describes the basic requirements for connecting units together to form a three-phase bank. Explains connection principles and theory using phasor diagrams. Demonstrates and explains why delta-wye and wye-delta three-phase connections have angular displacements of 30 degrees.
Delta-Wye Connections - 10 minutes
Demonstrates and explains how a delta-wye three-phase connection produces 30 degrees of angular displacement, using subtractive-polarity transformers.
Wye-Delta Connections - 9 minutes
Demonstrates and explains how a three-phase wye-delta connection produces 30 degrees of angular displacement.
Alternative Connections - 12 minutes
Demonstrates and explains: phasor diagrams and angular displacement using alternative connections, how an alternative delta-delta three-phase connection producing 180 degrees of angular displacement can be made, and how an alternative wye-delta three-phase connection producing 210 degrees of angular displacement can be made.
Open Banks - 9 minutes
Demonstrates and explains: an open delta-delta connection producing 0 degrees of angular displacement and an open wye-delta three-phase connection producing 30 degrees of angular displacement.
Additional Three-Phase Connections - 9 minutes
Demonstrates and explains one example of a three-phase transformer.