{"schemaVersion":1,"slug":"ansi-spark-gap","name":"ANSI/IEEE spark gap symbol","kind":"symbol","abbreviation":"SG","aliases":["IEEE spark gap","ANSI protective gap","air gap"],"category":"connections-wiring","drawingTypes":["Schematic"],"referenceFamilies":["IEEE / ANSI","Manufacturer"],"summary":"IEEE-oriented spark gap drawn as two facing electrodes separated by an air gap, which breaks down at high voltage.","description":["A spark gap is a pair of electrodes separated by a gap that flashes over when the voltage exceeds its breakdown level. It appears in surge protection of telecom and control circuits and on older equipment as coordinating gaps. The publisher's IEEE miscellaneous preview lists a spark gap form, the counterpart of the existing IEC page.","This illustration is independent and not the IEEE graphic. A plain spark gap can sustain follow current after breakdown on power circuits, which is why power arresters use other technology. The breakdown voltage depends on gap spacing and conditions, and must be specified."],"readingNotes":["Check whether follow current could be sustained on the circuit.","Read breakdown voltage from equipment data."],"drawingChecklist":["State breakdown voltage.","Show the protected and earthed sides.","Use an arrester where follow current is a risk."],"distinction":"A spark gap is a simple breakdown element; a gas discharge tube encloses the gap in gas for a defined breakdown.","facts":[{"label":"Convention evidence","value":"Autodesk IEEE Symbol Preview: Miscellaneous (Spark Gap)"},{"label":"Public vendor block name","value":"HFU1_S00371 (Autodesk identifier; not an IEEE symbol number)"},{"label":"Standards context","value":"IEEE/ANSI 315-1975 covers diagram graphics; IEEE lists this edition as Inactive-Reserved."},{"label":"Preview","value":"Original educational illustration; consult the publisher and applicable standard for the exact graphic"}],"references":[{"sourceId":"ansi-autodesk-34282bfd-7b8e-48f3-a6ed-93adbdddfbd3","relevance":"Exact public IEEE-oriented category page listing the spark gap form."},{"sourceId":"ieee-315","relevance":"Graphic-symbol standards context and official status; not a source of reproduced artwork."}],"related":["spark-gap-protective-element","ansi-gas-discharge-tube","ansi-surge-arrester"],"artwork":"s28-ansi-spark-gap","publishedOn":"2026-10-28","updatedOn":"2026-10-28","provenance":"independent-public-research","symbolVariant":{"convention":"IEEE / ANSI","form":"Autodesk IEEE-oriented spark gap form","reference":"Autodesk publishes this block under IEEE Symbol Preview: Miscellaneous. The counterpart is the matching functional concept; no equivalence of every detailed standard graphic is asserted.","counterpart":"spark-gap-protective-element"},"plainEnglish":{"title":"What does ANSI/IEEE spark gap mean?","introduction":"A spark gap is a pair of electrodes separated by a gap that flashes over when the voltage exceeds its breakdown level. It appears in surge protection of telecom and control circuits and on older equipment as coordinating gaps. The publisher's IEEE miscellaneous preview lists a spark gap form, the counterpart of the existing IEC page.","example":"This illustration is independent and not the IEEE graphic. A plain spark gap can sustain follow current after breakdown on power circuits, which is why power arresters use other technology. The breakdown voltage depends on gap spacing and conditions, and must be specified.","drawings":"Check whether follow current could be sustained on the circuit. Read breakdown voltage from equipment data. A spark gap is a simple breakdown element; a gas discharge tube encloses the gap in gas for a defined breakdown.","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":"Autodesk IEEE Symbol Preview — Miscellaneous","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-34282BFD-7B8E-48F3-A6ED-93ADBDDDFBD3.htm"},{"label":"IEEE/ANSI 315-1975: graphic symbols for electrical and electronics diagrams","url":"https://standards.ieee.org/ieee/315/515/"}],"detail":"IEEE-oriented spark gap drawn as two facing electrodes separated by an air gap, which breaks down at high voltage. A spark gap is a simple breakdown element; a gas discharge tube encloses the gap in gas for a defined breakdown.","profileId":"reviewed-symbol-20261028"},"url":"https://eloragrid.ai/symbols/ansi-spark-gap","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/ansi-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":"ansi-autodesk-34282bfd-7b8e-48f3-a6ed-93adbdddfbd3","title":"Autodesk IEEE Symbol Preview — Miscellaneous","publisher":"Autodesk","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-34282BFD-7B8E-48F3-A6ED-93ADBDDDFBD3.htm","type":"cad-reference","scope":"Verified public IEEE-oriented vendor catalogue. Block names identify vendor symbols, not IEEE standard symbol numbers. Linked only; graphics and CAD files are not redistributed. IEEE/ANSI 315-1975 is a historical graphics reference with Inactive-Reserved status; this page does not certify current standards compliance.","checkedOn":"2026-10-14","reuse":"link-only","relevance":"Exact public IEEE-oriented category page listing the spark gap form."},{"id":"ieee-315","title":"IEEE/ANSI 315-1975: graphic symbols for electrical and electronics diagrams","publisher":"IEEE Standards Association","url":"https://standards.ieee.org/ieee/315/515/","type":"standard","scope":"Graphic symbols and designation letters. IEEE lists this edition as Inactive-Reserved; it is a historical reference, not a claim of current compliance.","checkedOn":"2026-10-13","reuse":"link-only","relevance":"Graphic-symbol standards context and official status; not a source of reproduced artwork."}]}