Delta-Wye (Δ-Y) Connection — Transformer Glossary

A three-phase transformer connection where the primary winding is connected in delta (triangle) and the secondary in wye (star) configuration.

Backelectrical

Delta-Wye (Δ-Y) Connection

A three-phase transformer connection where the primary winding is connected in delta (triangle) and the secondary in wye (star) configuration.

Delta-wye (Dyn11 in IEC notation) is the most common connection for distribution transformers worldwide. The delta primary provides: harmonic current circulation (reducing harmonic distortion), no neutral required on the supply side. The wye secondary provides: a neutral point for single-phase loads, lower insulation requirements per phase. The '11' indicates a 30° phase shift between primary and secondary voltages — critical information for parallel operation. Other common connections include Yyn0 (wye-wye) and Dyn1.

Ready to Specify

Get a Quote Tailored to This Specification

Send us your application context — we'll come back with a sized solution, certified to IEC, IEEE/ANSI or UL, and a delivery slot from our Dubai factory.

Talk to Engineering

Secondary WindingThe winding connected to the load (output side) of a transformer. It receives energy from the magnetic field created by the primary winding.

Three-Phase PowerAn electrical power system using three alternating currents of equal frequency and amplitude, offset by 120° from each other.