W
Screened conductor with earthed screen
A screened conductor whose screen tail is drawn to an earth symbol, recording where the shield is earthed.
IEC
IEC · W
Screened conductor
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.
- Signal
- Electrical information passed between devices, rather than necessarily the main power supply.
- Schematic
- A drawing showing function and connections rather than physical appearance.
Read the source: Autodesk IEC-60617 preview: Cable identification and twisted-pair annotation · IEC-60617 symbol preview directory
IEC · Screened single-conductor form
Independent IEC-context illustration; consult IEC 60617 for the exact screen outline.
Shown as an independently authored educational illustration. Use the cited publication and drawing legend to verify the required drafting form.
Schematic · W
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.
A distinction that matters
A screened conductor has a conductive shield; a cable-core grouping outline only shows that several cores share one sheath and implies no shielding.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Autodesk IEC-60617 preview: Cable identification and twisted-pair annotation
Public IEC-60617 preview family for cable annotation used alongside screened-core forms.
IEC-60617 symbol preview directory
Public directory of IEC-oriented symbol families.
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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