Circuit arrangement · NSBOA

Normally split busbar operating arrangement

Circuit arrangement · Switchyards

An independently authored application reference. The drawing shows the named function or circuit relationship; use the project legend and selected equipment documentation for its drafting form and connections.

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In plain English

What this arrangement shows

Shows the defined normal separation between bus sections that can be connected by switching.

A simple example

In a switchyard, a single-line arrangement helps identify the bay connections, tie devices and possible alternate supply paths. Normal open points must remain separate from the equipment's physical ability to close. For this reference, the drawing identifies “Bus sections and normal open point” at the input and “Split normal operating state” at the output. Normal position is not a permanent wiring difference.

Bus sections and normal openpointNSBOASplit normal operating state
A reading guide. The entry's original illustration and input/output facts describe this application.

What the drawings help you do

Start at the named input: Bus sections and normal open point. Identify its source device or document and the state represented on the drawing. Follow the named output: Split normal operating state. Cross-reference its destination and separate the command from confirmation that the equipment responded.

Input
Bus sections and normal open point
Output
Split normal operating state
Application reference
An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.

Read the source: SEL-451 protection, automation and bay control

SLD / Schematic · NSBOANormally split busbar operating arrangement: original educational illustration
Original educational illustrationSee source and graphic notes

What it represents

Shows the defined normal separation between bus sections that can be connected by switching. A busbar arrangement defines the available paths between incoming circuits, outgoing circuits and bus sections. Its switching devices and measurement boundaries determine how a circuit can remain connected when part of the installation is unavailable.

In a switchyard, a single-line arrangement helps identify the bay connections, tie devices and possible alternate supply paths. Normal open points must remain separate from the equipment's physical ability to close. For this reference, the drawing identifies “Bus sections and normal open point” at the input and “Split normal operating state” at the output. Normal position is not a permanent wiring difference.

Name each bus, bay and switching device. The arrangement illustrates electrical connectivity; reliability, fault levels, permitted switching and protection coordination require the actual network design. The circuit arrangement is an independent explanation of this named application. Equipment-specific ratings, terminal connections and operating conditions must be established in the project documentation.

How to read it

  • Start at the named input: Bus sections and normal open point. Identify its source device or document and the state represented on the drawing.
  • Follow the named output: Split normal operating state. Cross-reference its destination and separate the command from confirmation that the equipment responded.
  • Normal position is not a permanent wiring difference.
  • Name each bus, bay and switching device. The arrangement illustrates electrical connectivity; reliability, fault levels, permitted switching and protection coordination require the actual network design.

Information to show or reference

  • Label the source and connection reference for bus sections and normal open point.
  • Identify the destination and defined state of split normal operating state.
  • Record the equipment or control-document revision supporting this circuit arrangement.
  • Check this application limit in the project design: Normal position is not a permanent wiring difference.

A distinction that matters

Normal position is not a permanent wiring difference. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram.

Sources you can follow

These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.

SEL-451 protection, automation and bay control

Public technical context for switchyard busbar arrangements. Bus arrangements, breaker control and bay-level coordination. The application text and educational graphic are independently authored; the publisher does not certify this representation.

SEL · Public reference checked 3 November 2026 · Link only

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. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.

Entry JSON · Entry Markdown · Last editorial update: 3 November 2026

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