Circuit arrangement · DDBA

Double-bus double-breaker bay 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.

Browse this installation focus

In plain English

What this arrangement shows

Provides separately switched breaker paths between the assigned circuit and two buses.

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 “Two breaker paths” at the input and “Dual-bus circuit connection” at the output. Each path needs defined protection and control.

Two breaker pathsDDBADual-bus circuit connection
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: Two breaker paths. Identify its source device or document and the state represented on the drawing. Follow the named output: Dual-bus circuit connection. Cross-reference its destination and separate the command from confirmation that the equipment responded.

Input
Two breaker paths
Output
Dual-bus circuit connection
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 · DDBADouble-bus double-breaker bay arrangement: original educational illustration
Original educational illustrationSee source and graphic notes

What it represents

Provides separately switched breaker paths between the assigned circuit and two buses. 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 “Two breaker paths” at the input and “Dual-bus circuit connection” at the output. Each path needs defined protection and control.

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: Two breaker paths. Identify its source device or document and the state represented on the drawing.
  • Follow the named output: Dual-bus circuit connection. Cross-reference its destination and separate the command from confirmation that the equipment responded.
  • Each path needs defined protection and control.
  • 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 two breaker paths.
  • Identify the destination and defined state of dual-bus circuit connection.
  • Record the equipment or control-document revision supporting this circuit arrangement.
  • Check this application limit in the project design: Each path needs defined protection and control.

A distinction that matters

Each path needs defined protection and control. 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

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.

Explore drafting