BD
Feeder busway
A busway run used purely to carry power between two points, drawn as a distinct trunking line without tap-off points.
SLD / GA
Symbols · EF
Busway end feed unit
The point where incoming cables or a transformer connect to the end of a busway run, drawn as a feed box on the busway.
In plain English
What does Busway end feed unit mean?
An end feed unit is the cable or transformer connection box at the start of a busway run. On single-line diagrams it shows where the supply enters the busway and is often annotated with the incoming cable details. Centre feed units, used to reduce voltage drop on long runs, are a related variant.
A simple example
The symbol does not show whether the feed unit includes isolation. Many end feed units are simple cable boxes, so isolation for maintenance must be at the upstream switchboard. Check cable entry and gland plate sizes on the layout, because large parallel cable sets need substantial space.
What the drawings help you do
Confirm where isolation for the busway is provided. Read incoming cable data at the feed unit. An end feed unit brings supply into the busway; a tap-off connection takes supply out of it.
This particular reference
The point where incoming cables or a transformer connect to the end of a busway run, drawn as a feed box on the busway. An end feed unit brings supply into the busway; a tap-off connection takes supply out of it.
- Winding
- A coil of conductor inside an electrical machine or transformer.
- Terminal
- An identified point where a conductor connects.
- Rating
- A value stating the conditions for which equipment is specified.
Read the source: Canalis busbar trunking systems · IEC-60617 symbol preview directory
SLD / GA · EF
What it represents
An end feed unit is the cable or transformer connection box at the start of a busway run. On single-line diagrams it shows where the supply enters the busway and is often annotated with the incoming cable details. Centre feed units, used to reduce voltage drop on long runs, are a related variant.
The symbol does not show whether the feed unit includes isolation. Many end feed units are simple cable boxes, so isolation for maintenance must be at the upstream switchboard. Check cable entry and gland plate sizes on the layout, because large parallel cable sets need substantial space.
How to read it
- Confirm where isolation for the busway is provided.
- Read incoming cable data at the feed unit.
Information to show or reference
- Show the incoming cable or transformer connection.
- Identify upstream isolation.
- Reference the feed unit size and cable entry.
A distinction that matters
An end feed unit brings supply into the busway; a tap-off connection takes supply out of it.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Canalis busbar trunking systems
Manufacturer busbar trunking ranges including feed units.
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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