# ANSI/IEEE Three-phase star autotransformer form Canonical URL: https://eloragrid.ai/symbols/ansi-three-phase-star-autotransformer Publisher: Elora Grid Updated: 2026-10-28 Lookup label: AT 3PH Y Drawing use: SLD, Schematic Reference families: IEEE / ANSI, Manufacturer ## Symbol convention Convention: IEEE / ANSI Form: 3 Phase Autotransformer Star Connected Autodesk IEEE Symbol Preview: Transformers, block HXF1T19. Matching functional counterpart linked separately. Independently drawn educational geometry; not a certified IEEE glyph or database identifier. Related representation: [Three-phase star autotransformer](https://eloragrid.ai/symbols/three-phase-star-autotransformer) IEEE-library reference for three-phase star autotransformer, with its operating meaning, connection notes and public vendor block identity. ## In plain English ### What does ANSI/IEEE Three-phase star autotransformer form mean? This reference locates three-phase star autotransformer in Autodesk's IEEE-oriented transformers family. A three-phase star-connected autotransformer has electrically shared winding portions arranged in a three-phase star connection. Its neutral and tap connections need explicit identification. The public library uses HXF1T19 for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number. ### A simple 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. ### What the drawings help you do Determine how the common star point and any accessible neutral are used by the design. A star autotransformer is electrically different from a star-star two-winding transformer. The linked functional counterpart explains the same operating role in its own drawing context; agreement of every detailed convention mark is not asserted. ### This particular reference IEEE-library reference for three-phase star autotransformer, with its operating meaning, connection notes and public vendor block identity. A star autotransformer is electrically different from a star-star two-winding transformer. ### Terms - Winding: A coil of conductor inside an electrical machine or transformer. - Phase: One of the related AC waveforms in a power system. - Terminal: An identified point where a conductor connects. Concept diagram: Identify the device and form → Read the connections and state → Check the equipment reference A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram. - [Autodesk IEEE Symbol Preview — Transformers](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-68D02867-7A98-47D1-A83F-DBAD1DDB616F.htm) ## What it represents This reference locates three-phase star autotransformer in Autodesk's IEEE-oriented transformers family. A three-phase star-connected autotransformer has electrically shared winding portions arranged in a three-phase star connection. Its neutral and tap connections need explicit identification. The public library uses HXF1T19 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. Determine how the common star point and any accessible neutral are used by the design. A star autotransformer is electrically different from a star-star two-winding transformer. The linked functional counterpart explains the same operating role in its own drawing context; agreement of every detailed convention mark is not asserted. ## How to read it - Determine how the common star point and any accessible neutral are used by the design. - The preview is an original explanation of this function. Match the actual drawing convention to its legend and the selected equipment documentation. ## Information to show or reference - Show star point - State winding voltage ratios - Reference tap terminals ## Important distinction A star autotransformer is electrically different from a star-star two-winding transformer. ## Facts - Convention evidence: Autodesk IEEE Symbol Preview: Transformers; published form: 3 Phase Autotransformer Star Connected. - Public vendor block: HXF1T19. Vendor library token, not an IEEE symbol number. - Drawing role: Winding connection - Identifier status: 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. - Artwork scope: Original educational geometry. Exact standard graphics, product ratings and terminal pinouts are not certified. ## Public references - [Autodesk IEEE Symbol Preview — Transformers](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-68D02867-7A98-47D1-A83F-DBAD1DDB616F.htm) — Autodesk. Public IEEE-oriented Transformers table explicitly lists HXF1T19 as 3 Phase Autotransformer Star Connected. This supports the vendor convention context, not reproduction of the publisher graphic. ## Graphic scope Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.