{"schemaVersion":1,"slug":"iec-overhead-line","name":"Overhead line","kind":"symbol","abbreviation":"OHL","aliases":["aerial line","overhead conductor","pole line"],"category":"connections-wiring","drawingTypes":["SLD","GA"],"referenceFamilies":["IEC"],"summary":"A line or route mark identifying conductors carried overhead on poles or towers rather than buried or enclosed.","description":["The overhead line form identifies a circuit section strung in air between supports. On network single-line diagrams it distinguishes overhead feeders from underground cable sections, which matters because the two have different impedance, fault behaviour, auto-reclose practice and lightning exposure.","The symbol does not tell you the conductor type, span lengths, earth wire arrangement or structure type. Line data sheets and route drawings carry those. Where a feeder changes from overhead to underground, look for a cable sealing end or transition point drawn at the junction."],"readingNotes":["Note where the feeder changes between overhead and underground sections.","Check whether auto-reclose is applied to feeders with overhead sections."],"drawingChecklist":["Identify conductor type and route length.","Mark transition points to underground cable.","Reference structure and earth-wire details on route drawings."],"distinction":"An overhead line is strung in air; an underground cable is buried and has very different capacitance and fault characteristics.","facts":[{"label":"Graphic cue","value":"Line with pole or support marks along its length"},{"label":"Engineering impact","value":"Impedance, lightning exposure and reclosing practice"},{"label":"Preview","value":"Original educational illustration; consult the publisher and applicable standard for the exact graphic"}],"references":[{"sourceId":"autodesk-index","relevance":"Public directory of IEC-oriented symbol families."},{"sourceId":"s28-eig-building-lightning-protection","relevance":"Public installation-guide context on lightning exposure of external conductors."}],"related":["iec-underground-cable","iec-multicore-cable-sealing-end","surge-arrester"],"artwork":"s28-iec-overhead-line","publishedOn":"2026-10-28","updatedOn":"2026-10-28","provenance":"independent-public-research","symbolVariant":{"convention":"IEC","form":"Overhead line route form","reference":"Independent IEC-context illustration; not certified IEC geometry."},"plainEnglish":{"title":"What does Overhead line mean?","introduction":"The overhead line form identifies a circuit section strung in air between supports. On network single-line diagrams it distinguishes overhead feeders from underground cable sections, which matters because the two have different impedance, fault behaviour, auto-reclose practice and lightning exposure.","example":"The symbol does not tell you the conductor type, span lengths, earth wire arrangement or structure type. Line data sheets and route drawings carry those. Where a feeder changes from overhead to underground, look for a cable sealing end or transition point drawn at the junction.","drawings":"Note where the feeder changes between overhead and underground sections. Check whether auto-reclose is applied to feeders with overhead sections. An overhead line is strung in air; an underground cable is buried and has very different capacitance and fault characteristics.","terms":[{"name":"Terminal","meaning":"An identified point where a conductor connects."},{"name":"Schematic","meaning":"A drawing showing function and connections rather than physical appearance."}],"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":"IEC-60617 symbol preview directory","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-7871E6EF-24D5-467E-9B74-321FEDC9DFDA.htm"},{"label":"Building protection system","url":"https://www.electrical-installation.org/enwiki/Building_protection_system"}],"detail":"A line or route mark identifying conductors carried overhead on poles or towers rather than buried or enclosed. An overhead line is strung in air; an underground cable is buried and has very different capacitance and fault characteristics.","profileId":"reviewed-symbol-20261028"},"url":"https://eloragrid.ai/symbols/iec-overhead-line","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/iec-overhead-line.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"autodesk-index","title":"IEC-60617 symbol preview directory","publisher":"Autodesk","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-7871E6EF-24D5-467E-9B74-321FEDC9DFDA.htm","type":"cad-reference","scope":"Public reference directory of named symbol categories. Vendor graphics and CAD library files are not redistributed here.","checkedOn":"2026-10-13","reuse":"link-only","relevance":"Public directory of IEC-oriented symbol families."},{"id":"s28-eig-building-lightning-protection","title":"Building protection system","publisher":"Schneider Electric, Electrical Installation Guide","url":"https://www.electrical-installation.org/enwiki/Building_protection_system","type":"manufacturer","scope":"Lightning capture devices, down-conductors, earth leads and equipotential bonding of a building protection system.","checkedOn":"2026-10-28","reuse":"link-only","relevance":"Public installation-guide context on lightning exposure of external conductors."}]}