{"schemaVersion":1,"slug":"iec-double-spark-gap","name":"Double spark gap","kind":"symbol","abbreviation":"F","aliases":["two-gap spark gap","three-electrode spark gap","double protective gap"],"category":"connections-wiring","drawingTypes":["Schematic"],"referenceFamilies":["IEC","Manufacturer"],"summary":"A spark gap form with two gaps sharing a common electrode, used to protect two conductors against a common earth.","description":["The double spark gap places two gaps in one element, typically from each of two line conductors to a common centre electrode that is earthed. It protects a pair of conductors, such as a telecom pair, with a single component so that both lines are diverted together.","The symbol does not state breakdown voltages or whether both gaps are matched. If one gap breaks down before the other, a transverse voltage can appear across the protected pair. Check the product data where balanced breakdown matters."],"readingNotes":["Identify the common electrode connection to earth.","Check breakdown matching between the two gaps."],"drawingChecklist":["Show both line connections and the common earth.","State breakdown voltage.","Keep the earth lead short."],"distinction":"A double spark gap protects two conductors to a common electrode; a single spark gap protects one path.","facts":[{"label":"Graphic cue","value":"Two facing gaps sharing a centre electrode"},{"label":"Publisher form","value":"Spark Gap, Double (HFU1_S00372 Autodesk identifier)"},{"label":"Preview","value":"Original educational illustration; consult the publisher and applicable standard for the exact graphic"}],"references":[{"sourceId":"pub-symbol-earthing-surge","relevance":"Public IEC-oriented preview listing the double spark gap form."},{"sourceId":"autodesk-index","relevance":"Public directory of IEC-oriented symbol families."}],"related":["spark-gap-protective-element","ansi-spark-gap","gas-discharge-protection-tube"],"artwork":"s28-iec-double-spark-gap","publishedOn":"2026-10-28","updatedOn":"2026-10-28","provenance":"independent-public-research","symbolVariant":{"convention":"IEC","form":"Spark Gap, Double","reference":"Autodesk IEC-60617 Symbol Preview: Miscellaneous; vendor family reference, not certified IEC geometry.","counterpart":"spark-gap-protective-element"},"plainEnglish":{"title":"What does Double spark gap mean?","introduction":"The double spark gap places two gaps in one element, typically from each of two line conductors to a common centre electrode that is earthed. It protects a pair of conductors, such as a telecom pair, with a single component so that both lines are diverted together.","example":"The symbol does not state breakdown voltages or whether both gaps are matched. If one gap breaks down before the other, a transverse voltage can appear across the protected pair. Check the product data where balanced breakdown matters.","drawings":"Identify the common electrode connection to earth. Check breakdown matching between the two gaps. A double spark gap protects two conductors to a common electrode; a single spark gap protects one path.","terms":[{"name":"Rating","meaning":"A value stating the conditions for which equipment is specified."},{"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":"AutoCAD Electrical: Earthing, sources and surge protection","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-1E3FDEAE-B4B2-417C-8075-108AA2C6E509.htm"},{"label":"IEC-60617 symbol preview directory","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-7871E6EF-24D5-467E-9B74-321FEDC9DFDA.htm"}],"detail":"A spark gap form with two gaps sharing a common electrode, used to protect two conductors against a common earth. A double spark gap protects two conductors to a common electrode; a single spark gap protects one path.","profileId":"reviewed-symbol-20261028"},"url":"https://eloragrid.ai/symbols/iec-double-spark-gap","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/iec-double-spark-gap.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 IEC-oriented preview listing the double spark gap form."},{"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."}]}