J
Cable straight-through joint
A joint connecting two lengths of the same cable in line, drawn as a mark on the cable route.
IEC
IEC · J
Cable branch joint
A cable joint where a branch cable is taken off a main cable, drawn as a joint with a third cable leaving it.
In plain English
What does Cable branch joint mean?
A branch or tee joint connects a branch cable to a main cable without terminating the main cable at a switchboard. It is common on low voltage street mains and some legacy medium voltage networks, where services or spur cables are taken from the main along its route.
A simple example
The symbol shows the circuit arrangement but not the protection of the branch. A branch made by a joint generally has no switching or fault isolation at the tee, so faults on the branch affect the main circuit's protection. Readers should check protection grading and fault level at the branch cable.
What the drawings help you do
Check how the branch is protected, since there may be no device at the joint. Record joint location for fault finding. A branch joint connects a third cable mid-route; a one-line bus tap is a connection to a busbar, not a cable.
This particular reference
A cable joint where a branch cable is taken off a main cable, drawn as a joint with a third cable leaving it. A branch joint connects a third cable mid-route; a one-line bus tap is a connection to a busbar, not a cable.
- Normally open / normally closed
- The contact state in the normal condition defined for the drawing.
- 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: Elastimold underground cable accessories · IEC-60617 symbol preview directory
IEC · Branch cable joint
Independent IEC-context illustration; not certified IEC geometry.
Shown as an independently authored educational illustration. Use the cited publication and drawing legend to verify the required drafting form.
SLD / GA · J
What it represents
A branch or tee joint connects a branch cable to a main cable without terminating the main cable at a switchboard. It is common on low voltage street mains and some legacy medium voltage networks, where services or spur cables are taken from the main along its route.
The symbol shows the topology but not the protection of the branch. A branch made by a joint generally has no switching or fault isolation at the tee, so faults on the branch affect the main circuit's protection. Readers should check protection grading and fault level at the branch cable.
How to read it
- Check how the branch is protected, since there may be no device at the joint.
- Record joint location for fault finding.
Information to show or reference
- Show the branch cable size and type.
- Confirm protection covers the branch.
- Locate the joint on the route drawing.
A distinction that matters
A branch joint connects a third cable mid-route; a one-line bus tap is a connection to a busbar, not a cable.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Elastimold underground cable accessories
Manufacturer context for underground cable joints.
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.
Explore related references
Put the reference into a drawing workflow.
Elora Grid helps electrical teams work with drawings, specifications and equipment information. Explore the drafting workflow or join the early-access waitlist.