# Double-bus double-breaker bay arrangement Canonical URL: https://eloragrid.ai/symbols/double-bus-double-breaker-bay-arrangement Publisher: Elora Grid Updated: 2026-11-03 Lookup label: DDBA Drawing use: SLD, Schematic Reference families: Manufacturer Representation: Circuit arrangement Installation focus: switchyards Input: Two breaker paths Output: Dual-bus circuit connection Provides separately switched breaker paths between the assigned circuit and two buses. ## 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. ### 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. ### Terms - 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. Concept diagram: Two breaker paths → DDBA → Dual-bus circuit connection A reading guide. The entry's original illustration and input/output facts describe this application. - [SEL-451 protection, automation and bay control](https://selinc.com/products/451/) ## 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. ## Important distinction 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. ## Facts - Representation: Circuit arrangement - Installation focus: Switchyards - Input / boundary: Two breaker paths - Output / connection: Dual-bus circuit connection - Lookup label: DDBA is a library lookup label, not a standard device designation. ## Public references - [SEL-451 protection, automation and bay control](https://selinc.com/products/451/) — SEL. 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. ## Graphic scope Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.