# Star-delta transformer

Canonical URL: https://eloragrid.ai/symbols/star-delta-transformer
Publisher: Elora Grid
Updated: 2026-10-13
Lookup label: TX Y-D
Drawing use: SLD, Schematic
Reference families: IEC, Manufacturer

A star-delta transformer connects one winding set in star and the other in delta.

## What it represents

A star-delta transformer connects one winding set in star and the other in delta. The notation identifies winding topology; a clock-number or equivalent phase-displacement designation is still needed where system phase relationships matter.

## How to read it

- Read which side is star from the declared primary and secondary labels.
- The preview is an original explanation of this function. Match the actual drawing convention to its legend and the selected equipment documentation.

## Information to show or reference

- Identify winding sides
- State complete vector group
- Show neutral availability

## Important distinction

Y-D topology alone does not specify a complete transformer vector group.

## Facts

- Drawing role: Winding connection
- Representation scope: Functional concept; not an official standard graphic or a product footprint
- Public vendor block reference: HXF1P3SD, VXF1P3SD (Autodesk identifiers; not IEC symbol numbers)
- Identifier status: The short label is a functional lookup label, not an assigned IEC or IEEE symbol number. Any separately listed Autodesk code is a verified vendor block name.

## Public references

- [Power, potential and autotransformer symbols](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-C1FE1690-DBF4-4F69-85C4-28E41F0A6392.htm) — Autodesk. Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic.
- [AutoCAD Electrical: Three-phase transformer connections](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-EB13DB13-01EE-4541-BED7-19B9001BE8FC.htm) — Autodesk. Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic.

## Graphic scope

Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.