Side-by-side reference

Understand the difference.

Compare the meaning, drawing context and source references of two entries. A similar graphic or shared abbreviation does not establish equivalence.

First referenceCompare with

TX Y-Y-D

Symbols

Star-star-delta three-winding transformer

A star-star-delta transformer includes two star-connected winding sets and a delta tertiary winding. The schematic needs all three winding ratings and the intended tertiary connection.

Drawing use: SLD / Schematic
Application: Power distribution
Reference family: IEC / Manufacturer

A distinction that matters

A delta tertiary is a third winding, not an alternative connection of the main secondary.

Full reference

Symbols

Power transformer

A power-transformer representation identifies equipment transferring electrical power between winding circuits. The generic mark can show the relationship between windings, but voltage levels, winding connections, vector group, rating and earthing information require additional annotations and equipment references.

Drawing use: SLD / Schematic
Application: Power distribution
Reference family: IEC / IEEE / ANSI

A distinction that matters

A transformer used for voltage measurement is a VT or PT. Its function and secondary circuit differ from those of a power transformer.

Full reference

Original educational previews. Follow the source references on each full entry for the appropriate standard or selected product.