# ANSI/IEEE Three-phase AC source form Canonical URL: https://eloragrid.ai/symbols/ansi-three-phase-ac-source Publisher: Elora Grid Updated: 2026-10-28 Lookup label: AC 3PH Drawing use: SLD, Schematic Reference families: IEEE / ANSI, Manufacturer ## Symbol convention Convention: IEEE / ANSI Form: Power Source 3 Phase Autodesk IEEE Symbol Preview: Miscellaneous, block HPW1_3PH. Matching functional counterpart linked separately. Independently drawn educational geometry; not a certified IEEE glyph or database identifier. Related representation: [Three-phase AC source](https://eloragrid.ai/symbols/three-phase-ac-source) IEEE-library form of three-phase ac source: a three-phase AC source identifies a documented three-phase supply boundary. ## In plain English ### What does ANSI/IEEE Three-phase AC source form mean? This reference locates three-phase ac source in Autodesk's IEEE-oriented miscellaneous family. A three-phase AC source identifies a documented three-phase supply boundary. Its nominal voltage, phase sequence and neutral availability must be stated where the design relies on them. The public library uses HPW1_3PH for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number. ### A simple example Use the surrounding circuit labels and the project legend to identify the intended operating condition and connection. Carry the same device reference into the schedule or equipment document so the symbol can be reconciled with its real terminals, function and operating limits. ### What the drawings help you do Locate the source boundary before interpreting upstream ownership or available fault data. Three-phase source designation does not establish an accessible neutral conductor. 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 form of three-phase ac source: a three-phase AC source identifies a documented three-phase supply boundary. Three-phase source designation does not establish an accessible neutral conductor. ### Terms - AC: Alternating current: electricity whose direction changes periodically. - 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 — Miscellaneous](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-34282BFD-7B8E-48F3-A6ED-93ADBDDDFBD3.htm) ## What it represents This reference locates three-phase ac source in Autodesk's IEEE-oriented miscellaneous family. A three-phase AC source identifies a documented three-phase supply boundary. Its nominal voltage, phase sequence and neutral availability must be stated where the design relies on them. The public library uses HPW1_3PH for its horizontal representation; this is a vendor block name, not an IEEE standards symbol number. Use the surrounding circuit labels and the project legend to identify the intended operating condition and connection. Carry the same device reference into the schedule or equipment document so the symbol can be reconciled with its real terminals, function and operating limits. Locate the source boundary before interpreting upstream ownership or available fault data. Three-phase source designation does not establish an accessible neutral conductor. 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 - Locate the source boundary before interpreting upstream ownership or available fault data. - 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 - Name supply origin - State voltage and phase sequence - Reference neutral/earthing arrangement ## Important distinction Three-phase source designation does not establish an accessible neutral conductor. ## Facts - Convention evidence: Autodesk IEEE Symbol Preview: Miscellaneous; published form: Power Source 3 Phase. - Public vendor block: HPW1_3PH. Vendor library token, not an IEEE symbol number. - Drawing role: Supply or network role - 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 — Miscellaneous](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-34282BFD-7B8E-48F3-A6ED-93ADBDDDFBD3.htm) — Autodesk. Public IEEE-oriented Miscellaneous table explicitly lists HPW1_3PH as Power Source 3 Phase. 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.