TX
Power transformer
Equipment transferring electrical power between winding circuits.
SLD / Schematic
IEC · Yd11
Yd11 transformer connection reference
This reference identifies the publisher's Yd11 transformer connection form with star/delta winding topology.
IEC · Yd11 transformer connection reference
Autodesk IEC-60617 Symbol Preview — Three-phase transformer and vector-group forms; vendor family reference, not certified IEC geometry or database identifier.
Shown as an independently authored educational illustration. Use the cited publication and drawing legend to verify the required drafting form.
SLD / Schematic · Yd11
What it represents
Yd11 combines an HV-side star winding designation with an LV-side delta designation and clock group 11. The letters describe connection topology; the final number identifies the phase relationship recorded with the transformer connection diagram. It is different from the voltage ratio or the number of terminals.
A drafter should preserve the full Yd11 designation across the SLD, transformer schedule and protection references. Two devices with the same winding letters but a different clock number are not the same connection reference. Check the selected transformer terminal diagram and the protection application documentation; the concept preview does not specify polarity tests, parallel-operation suitability or relay settings.
How to read it
- Preserve the full group notation and verify the terminal/phase relationship in the selected transformer diagram.
- The clock-group suffix is different from a voltage ratio, power rating or physical terminal number.
Information to show or reference
- Identify the associated device, circuit or diagram boundary.
- Preserve the full group notation and verify the terminal/phase relationship in the selected transformer diagram.
- Cross-reference the equipment data, terminal mapping or operating-state legend needed to interpret the form.
A distinction that matters
The clock-group suffix is different from a voltage ratio, power rating or physical terminal number.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
AutoCAD Electrical: Three-phase transformer connections
Official public publisher family name and reference context; vendor identifiers and graphics are distinct from licensed IEC database content.
Transformer vector-group interpretation in protection application
Manufacturer application context explains why winding type and clock number must be kept distinct in transformer protection documentation. No relay settings are prescribed here.
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.
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