SA
Surge arrester
A surge arrester diverts a documented surge-related current through its protective path.
SLD / Schematic
Symbols · SC
Surge arrester counter
Counter in a surge arrester's earth lead that registers discharges and often shows leakage current.
In plain English
What does Surge arrester counter mean?
A surge counter is installed in the earth connection of a surge arrester, which must therefore be mounted on an insulating base. It increments each time the arrester discharges a significant surge, and many models include a milliammeter for leakage current, which helps assess arrester condition.
A simple example
On single-line diagrams the counter is drawn between the arrester and earth. The symbol does not tell you the counting threshold or whether leakage reading is total or resistive, and the insulating base must be shown so the counter is not bypassed.
What the drawings help you do
Check the arrester is on an insulating base. Note whether leakage current is shown. A surge counter records arrester operations; the surge arrester itself diverts the surge.
This particular reference
Counter in a surge arrester's earth lead that registers discharges and often shows leakage current. A surge counter records arrester operations; the surge arrester itself diverts the surge.
- 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.
Read the source: AutoCAD Electrical: Earthing, sources and surge protection
SLD / Schematic · SC
What it represents
A surge counter is installed in the earth connection of a surge arrester, which must therefore be mounted on an insulating base. It increments each time the arrester discharges a significant surge, and many models include a milliammeter for leakage current, which helps assess arrester condition.
On single-line diagrams the counter is drawn between the arrester and earth. The symbol does not tell you the counting threshold or whether leakage reading is total or resistive, and the insulating base must be shown so the counter is not bypassed.
How to read it
- Check the arrester is on an insulating base.
- Note whether leakage current is shown.
Information to show or reference
- Show counter in earth lead
- Show insulating base
- State counting threshold
A distinction that matters
A surge counter records arrester operations; the surge arrester itself diverts the surge.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
AutoCAD Electrical: Earthing, sources and surge protection
Public AutoCAD Electrical earthing and surge protection symbol family.
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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