What Are Delta WYE Connections?

What Does a Delta WYE Connection Do?

A Delta WYE connection is a transformer arrangement with three phases. (Some arrangements have only one phase.) Within this arrangement are three coils, also known as windings, that receive the electricity sent from a generator and adjust the voltage as necessary. Each winding takes in one of the phases of electricity. If you can imagine a set of power lines, you probably imagine three individual lines in your mind's eye. Each of those three power lines handles a different phase of electricity.

The WYE part of this connection within the transformer looks like the letter 'Y' when it's set up, hence the name. The two diagonal transformer windings, which look like the 'legs' of the letter Y, share a connection. The Delta part of this arrangement has three transformer windings taking the shape of a triangle. (In the Greek alphabet, the letter Delta is a triangle.) In essence, the Delta Wye is comprised of primary windings shaped like a triangle, backed up by secondary windings shaped like a 'Y.'

Three-phase electrical configurations are especially popular because they are so powerful. In fact, they can handle up to 173% more electrical power than a single-phase system can. Further, power produced using a three-phase system is easier to send over a long distance than power produced by windings in other configurations; you don't even need a large electrical conductor to be able to do so. It's also a smooth, reliable and efficient system, ideal for powering large pieces of industrial equipment.

Of all the possible three-phase electrical transformer connections, the world's most popular is the Delta WYE connection. The main reason for this is that the Delta WYE configuration is not only powerful, but also stable and reliable, which is critical for industries that don't want to risk electrical failure or overload. The main reason this setup is so stable is that the delta primary winding is able to balance electrical currents, and it frequently happens that a transformer can release an unbalanced electrical load.