# Screened conductor

Canonical URL: https://eloragrid.ai/symbols/iec-screened-conductor
Publisher: Elora Grid
Updated: 2026-10-28
Lookup label: W
Drawing use: Schematic
Reference families: IEC

## Symbol convention

Convention: IEC
Form: Screened single-conductor form
Independent IEC-context illustration; consult IEC 60617 for the exact screen outline.

A single conductor enclosed by a drawn screen outline, showing that the core has a conductive shield around it.

## In plain English

### What does Screened conductor mean?

A screened conductor symbol adds an outline around one conductor to show a conductive screen, braid or foil surrounding the core. It is used for analogue instrument signals, encoder and thermocouple extension wiring and other circuits where capacitively coupled interference must be kept off the signal.

### A simple example

The outline alone does not show where or whether the screen is earthed. Earthing at one end, both ends or through a capacitor is a design decision that should be drawn explicitly with an earth or bonding symbol at the screen tail. The symbol also does not distinguish foil, braid or combined screens, which belong in the cable schedule.

### What the drawings help you do

Find the screen tail and confirm where it is terminated. Check whether a cable marker applies to the screened core and any others in the same cable. A screened conductor has a conductive shield; a cable-core grouping outline only shows that several cores share one sheath and implies no shielding.

### This particular reference

A single conductor enclosed by a drawn screen outline, showing that the core has a conductive shield around it. A screened conductor has a conductive shield; a cable-core grouping outline only shows that several cores share one sheath and implies no shielding.

### Terms

- Signal: Electrical information passed between devices, rather than necessarily the main power supply.
- 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 IEC-60617 preview: Cable identification and twisted-pair annotation](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-37A08C35-43A3-484D-B0EB-0BBCBC4BE709.htm)
- [IEC-60617 symbol preview directory](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-7871E6EF-24D5-467E-9B74-321FEDC9DFDA.htm)


## What it represents

A screened conductor symbol adds an outline around one conductor to show a conductive screen, braid or foil surrounding the core. It is used for analogue instrument signals, encoder and thermocouple extension wiring and other circuits where capacitively coupled interference must be kept off the signal.
The outline alone does not show where or whether the screen is earthed. Earthing at one end, both ends or through a capacitor is a design decision that should be drawn explicitly with an earth or bonding symbol at the screen tail. The symbol also does not distinguish foil, braid or combined screens, which belong in the cable schedule.

## How to read it

- Find the screen tail and confirm where it is terminated.
- Check whether a cable marker applies to the screened core and any others in the same cable.

## Information to show or reference

- Show the screen termination point explicitly.
- Record the screen type in the cable schedule.
- Keep screen drain terminals numbered on the terminal plan.

## Important distinction

A screened conductor has a conductive shield; a cable-core grouping outline only shows that several cores share one sheath and implies no shielding.

## Facts

- Graphic cue: Outline drawn around a single conductor with a short screen tail
- Does not show: Screen earthing point, screen material or coverage
- Preview: Original educational illustration; consult the publisher and applicable standard for the exact graphic

## Public references

- [Autodesk IEC-60617 preview: Cable identification and twisted-pair annotation](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-37A08C35-43A3-484D-B0EB-0BBCBC4BE709.htm) — Autodesk. Public IEC-60617 preview family for cable annotation used alongside screened-core forms.
- [IEC-60617 symbol preview directory](https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-7871E6EF-24D5-467E-9B74-321FEDC9DFDA.htm) — Autodesk. Public directory of IEC-oriented symbol families.

## 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.