# ANSI/IEEE Double spark gap form Canonical URL: https://eloragrid.ai/symbols/ansi-double-spark-gap Publisher: Elora Grid Updated: 2026-10-28 Lookup label: F Drawing use: Schematic Reference families: IEEE / ANSI, Manufacturer ## Symbol convention Convention: IEEE / ANSI Form: Spark Gap, Double Autodesk IEEE Symbol Preview: Miscellaneous, block HFU1_S00372. Matching functional counterpart linked separately. Independently drawn educational geometry; not a certified IEEE glyph or database identifier. Related representation: [Double spark gap](https://eloragrid.ai/symbols/iec-double-spark-gap) IEEE-library form of double spark gap: a spark gap form with two gaps sharing a common electrode, used to protect two conductors against a common earth. ## In plain English ### What does ANSI/IEEE Double spark gap form mean? This reference locates double spark gap in Autodesk's IEEE-oriented miscellaneous family. 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 public library uses HFU1_S00372 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 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. Identify the common electrode connection to earth. A double spark gap protects two conductors to a common electrode; a single spark gap protects one path. 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 double spark gap: 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. ### Terms - Terminal: An identified point where a conductor connects. - Rating: A value stating the conditions for which equipment is specified. - Schematic: A drawing showing function and connections rather than physical appearance. 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 double spark gap in Autodesk's IEEE-oriented miscellaneous family. 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 public library uses HFU1_S00372 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. 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. Identify the common electrode connection to earth. A double spark gap protects two conductors to a common electrode; a single spark gap protects one path. 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 - Identify the common electrode connection to earth. - Check breakdown matching between the two gaps. ## Information to show or reference - Show both line connections and the common earth. - State breakdown voltage. - Keep the earth lead short. ## Important distinction A double spark gap protects two conductors to a common electrode; a single spark gap protects one path. ## Facts - Convention evidence: Autodesk IEEE Symbol Preview: Miscellaneous; published form: Spark Gap, Double. - Public vendor block: HFU1_S00372. Vendor library token, not an IEEE symbol number. - Graphic cue: Two facing gaps sharing a centre electrode - Publisher form: Spark Gap, Double (HFU1_S00372 Autodesk identifier) - Preview: Original educational illustration; consult the publisher and applicable standard for the exact graphic - 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 HFU1_S00372 as Spark Gap, Double. 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.