Isolator
Disconnector
A switching device providing an electrical isolation function.
SLD / Schematic
GA objects · RMU
Ring main unit
A secondary-distribution switchgear assembly with a selected combination of switching functions.
GA · RMU
What it represents
A ring main unit is a compact secondary-distribution switchgear assembly with a manufacturer-defined combination of switching functions. Its electrical configuration and physical envelope depend on the chosen product, rather than on the abbreviation RMU alone.
The original envelope illustration is unscaled and has no manufacturer dimensions. Follow the cited public resources to the exact product, then use its current drawing and installation information for engineering work.
How to read it
- Identify the number and function of the selected ways.
- Keep the electrical configuration linked to the manufacturer GA.
Information to show or reference
- Reference the exact unit configuration.
- Check cable interfaces and installation information.
- Match the SLD ways to physical sections.
A distinction that matters
RMU does not specify one universal technology, dimension or combination of breaker, switch and fused ways.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Secondary-distribution switchgear and ring main units
Public ring-main-unit and secondary-distribution equipment 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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