{"schemaVersion":1,"slug":"open-delta-winding-connection","name":"Open-delta winding connection","kind":"symbol","abbreviation":"OPEN D","aliases":[],"category":"power-distribution","drawingTypes":["SLD","Schematic"],"referenceFamilies":["IEC","Manufacturer"],"summary":"An open-delta arrangement uses an incomplete delta connection for a specified transformer or measurement purpose.","description":["An open-delta arrangement uses an incomplete delta connection for a specified transformer or measurement purpose. The absent winding or open connection must be visible rather than interpreted as an accidental drawing omission."],"readingNotes":["Identify the actual application and its documented winding arrangement.","The preview is an original explanation of this function. Match the actual drawing convention to its legend and the selected equipment documentation."],"drawingChecklist":["Show open portion","Name connected terminals","Reference applicable rating or measurement scheme"],"distinction":"Open delta and broken-delta residual-voltage circuits describe different application contexts; the drawing must say which is intended.","facts":[{"label":"Drawing role","value":"Three-phase winding"},{"label":"Representation scope","value":"Functional concept; not an official standard graphic or a product footprint"},{"label":"Identifier status","value":"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."}],"references":[{"sourceId":"pub-symbol-windings","relevance":"Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic."}],"related":["power-transformer","generator"],"artwork":"edu-open-delta-winding-connection","publishedOn":"2026-10-13","updatedOn":"2026-10-13","provenance":"independent-public-research","url":"https://eloragrid.ai/symbols/open-delta-winding-connection","illustration":{"url":"https://eloragrid.ai/library/illustrations/open-delta-winding-connection.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"pub-symbol-windings","title":"AutoCAD Electrical: Winding arrangements and AC/DC indications","publisher":"Autodesk","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-3F5A759D-872A-4990-8AAE-7CCAFBBBD4C5.htm","type":"cad-reference","scope":"Public vendor catalogue naming and functional variants. Vendor block names are not IEC identifiers. Linked for reference; no graphics or CAD files are redistributed.","checkedOn":"2026-10-13","reuse":"link-only","relevance":"Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic."}]}