{"schemaVersion":1,"slug":"ansi-dd6-transformer-connection-reference","name":"ANSI/IEEE Dd6 transformer connection reference form","kind":"symbol","abbreviation":"Dd6","aliases":["HXF1T22","VXF1T22","IEEE 3 Phase Dd6","ANSI Dd6 transformer connection reference"],"category":"power-distribution","drawingTypes":["SLD","Schematic"],"referenceFamilies":["IEEE / ANSI","Manufacturer"],"summary":"IEEE-library form of dd6 transformer connection reference: this reference identifies the publisher's Dd6 transformer connection form with delta/delta winding topology.","description":["This reference locates dd6 transformer connection reference in Autodesk's IEEE-oriented 3 phase transformers family. Dd6 combines an HV-side delta winding designation with an LV-side delta designation and clock group 6. 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. The public library uses HXF1T22 for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number.","Trace each winding, supply and accessible neutral through the complete machine or transformer connection diagram. Keep the phase arrangement, terminal labels and any clock notation attached to the device; neither the convention label nor this educational outline supplies its ratings.","A drafter should preserve the full Dd6 designation across the SLD, transformer schedule and protection references. Even when both windings use delta topology, the clock-group information remains a separate part of the connection designation. 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. 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. The linked functional counterpart explains the same operating role in its own drawing context; agreement of every detailed convention mark is not asserted."],"readingNotes":["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."],"drawingChecklist":["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."],"distinction":"The clock-group suffix is different from a voltage ratio, power rating or physical terminal number.","facts":[{"label":"Convention evidence","value":"Autodesk IEEE Symbol Preview: 3 Phase Transformers; published form: 3 Phase Dd6."},{"label":"Public vendor block","value":"HXF1T22. Vendor library token, not an IEEE symbol number."},{"label":"Information added","value":"Preserve the full group notation and verify the terminal/phase relationship in the selected transformer diagram."},{"label":"Preview","value":"Independent educational concept; consult the publisher and applicable standard for the exact graphic"},{"label":"HV winding topology","value":"delta"},{"label":"Artwork scope","value":"Original educational geometry. Exact standard graphics, product ratings and terminal pinouts are not certified."}],"references":[{"sourceId":"s28-ieee-3-phase-transformers","relevance":"Public IEEE-oriented 3 Phase Transformers table explicitly lists HXF1T22 as 3 Phase Dd6. This supports the vendor convention context, not reproduction of the publisher graphic."}],"related":["iec-dd6-transformer-connection-reference","power-transformer","voltage-transformer"],"artwork":"s28-ansi-dd6-transformer-connection-reference","publishedOn":"2026-10-28","updatedOn":"2026-10-28","provenance":"independent-public-research","symbolVariant":{"convention":"IEEE / ANSI","form":"3 Phase Dd6","reference":"Autodesk IEEE Symbol Preview: 3 Phase Transformers, block HXF1T22. Matching functional counterpart linked separately. Independently drawn educational geometry; not a certified IEEE glyph or database identifier.","counterpart":"iec-dd6-transformer-connection-reference"},"plainEnglish":{"title":"What does ANSI/IEEE Dd6 transformer connection reference form mean?","introduction":"This reference locates dd6 transformer connection reference in Autodesk's IEEE-oriented 3 phase transformers family. Dd6 combines an higher-voltage-side delta winding designation with an lower-voltage-side delta designation and clock group 6. The letters describe connection circuit arrangement; 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. The public library uses HXF1T22 for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number.","example":"Trace each winding, supply and accessible neutral through the complete machine or transformer connection diagram. Keep the phase arrangement, terminal labels and any clock notation attached to the device; neither the convention label nor this educational outline supplies its ratings.","drawings":"A drafter should preserve the full Dd6 designation across the single-line diagram, transformer schedule and protection references. Even when both windings use delta circuit arrangement, the clock-group information remains a separate part of the connection designation. 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. 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. The linked functional counterpart explains the same operating role in its own drawing context; agreement of every detailed convention mark is not asserted.","terms":[{"name":"Winding","meaning":"A coil of conductor inside an electrical machine or transformer."},{"name":"Coil","meaning":"A wound conductor that can produce a magnetic field when energised."},{"name":"Phase","meaning":"One of the related AC waveforms in a power system."}],"diagram":"flow","steps":["Identify the device and form","Read the connections and state","Check the equipment reference"],"caption":"A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram.","sources":[{"label":"Autodesk IEEE Symbol Preview: 3 Phase Transformers","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-EE75A5D4-8CBD-4E78-94A3-226A94E61817.htm"}],"detail":"IEEE-library form of dd6 transformer connection reference: this reference identifies the publisher's Dd6 transformer connection form with delta/delta winding circuit arrangement. The clock-group suffix is different from a voltage ratio, power rating or physical terminal number.","profileId":"reviewed-symbol-20261028"},"url":"https://eloragrid.ai/symbols/ansi-dd6-transformer-connection-reference","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/ansi-dd6-transformer-connection-reference.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"s28-ieee-3-phase-transformers","title":"Autodesk IEEE Symbol Preview: 3 Phase Transformers","publisher":"Autodesk","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-EE75A5D4-8CBD-4E78-94A3-226A94E61817.htm","type":"cad-reference","scope":"Public 3 phase transformers family names and vendor block tokens. Horizontal, vertical and rotated placements are not separate engineering functions. Exact standard geometry is not reproduced.","checkedOn":"2026-10-28","reuse":"link-only","relevance":"Public IEEE-oriented 3 Phase Transformers table explicitly lists HXF1T22 as 3 Phase Dd6. This supports the vendor convention context, not reproduction of the publisher graphic."}]}