{"schemaVersion":1,"slug":"gas-discharge-protection-tube","name":"Gas-discharge protection tube","kind":"symbol","abbreviation":"GDT","aliases":["HFU1_S00374","VFU1_S00374","gas discharge tube"],"category":"connections-wiring","drawingTypes":["SLD","Schematic"],"referenceFamilies":["IEC","Manufacturer"],"summary":"A gas-discharge tube provides a documented surge-protection path through gas breakdown.","description":["A gas-discharge tube provides a documented surge-protection path through gas breakdown. The schematic identifies its protected terminals and the intended discharge connection."],"readingNotes":["Check the tube arrangement and specified operating voltage from the selected component.","The preview is an original explanation of this function. Match the actual drawing convention to its legend and the selected equipment documentation."],"drawingChecklist":["Name protected terminals","State discharge-tube rating","Reference protective connection"],"distinction":"A gas-discharge tube is a protection component, not a fuse-link.","facts":[{"label":"Drawing role","value":"Earth or bonding role"},{"label":"Representation scope","value":"Functional concept; not an official standard graphic or a product footprint"},{"label":"Public vendor block reference","value":"HFU1_S00374, VFU1_S00374 (Autodesk identifiers; not IEC symbol numbers)"},{"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-earthing-surge","relevance":"Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic."}],"related":["protective-earth","earthing-switch"],"artwork":"edu-gas-discharge-protection-tube","publishedOn":"2026-10-13","updatedOn":"2026-10-13","provenance":"independent-public-research","url":"https://eloragrid.ai/symbols/gas-discharge-protection-tube","illustration":{"url":"https://eloragrid.ai/library/illustrations/gas-discharge-protection-tube.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-earthing-surge","title":"AutoCAD Electrical: Earthing, sources and surge protection","publisher":"Autodesk","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-1E3FDEAE-B4B2-417C-8075-108AA2C6E509.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."}]}