Power transformer

What it represents

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.

Two-winding, three-winding and autotransformer arrangements describe different configurations. The SLD should identify the intended configuration clearly and link it to the transformer schedule and any associated protection or GA drawings.

How to read it

• Read the winding count and electrical connections before interpreting the rating labels.
• Use the equipment reference to distinguish a power transformer from an instrument transformer.

Information to show or reference

• Document the specified rating and winding connections.
• Reference earthing and protection arrangements.
• Link the equipment schedule and physical drawing.

Sources you can follow

These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.

About this graphic

This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.

SVG and DXF downloads contain this original artwork. DXF uses unscaled drawing units; a GA envelope supplies no product dimensions, clearances or fabrication information. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.

Entry JSON · Entry Markdown · Last editorial update: 13 October 2026