SPARK GAP
Spark-gap protective element
A spark-gap element provides a documented breakdown path across separated electrodes.
SLD / Schematic
IEEE / ANSI · SG
ANSI/IEEE spark gap symbol
IEEE-oriented spark gap drawn as two facing electrodes separated by an air gap, which breaks down at high voltage.
In plain English
What does ANSI/IEEE spark gap mean?
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.
A simple 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.
What the drawings help you do
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.
This particular reference
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.
- Rating
- A value stating the conditions for which equipment is specified.
- Schematic
- A drawing showing function and connections rather than physical appearance.
Read the source: Autodesk IEEE Symbol Preview — Miscellaneous · IEEE/ANSI 315-1975: graphic symbols for electrical and electronics diagrams
IEEE / ANSI · Autodesk IEEE-oriented spark gap form
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.
Shown as an independently authored educational illustration. Use the cited publication and drawing legend to verify the required drafting form.
Schematic · SG
What it represents
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.
How to read it
- Check whether follow current could be sustained on the circuit.
- Read breakdown voltage from equipment data.
Information to show or reference
- State breakdown voltage.
- Show the protected and earthed sides.
- Use an arrester where follow current is a risk.
A distinction that matters
A spark gap is a simple breakdown element; a gas discharge tube encloses the gap in gas for a defined breakdown.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Autodesk IEEE Symbol Preview — Miscellaneous
Exact public IEEE-oriented category page listing the spark gap form.
IEEE/ANSI 315-1975: graphic symbols for electrical and electronics diagrams
Graphic-symbol standards context and official status; not a source of reproduced artwork.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. DXF uses unscaled drawing units; a GA envelope supplies no product dimensions, clearances or fabrication information. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
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