# Circuit-breaker undervoltage ride-through interface Canonical URL: https://eloragrid.ai/symbols/circuit-breaker-undervoltage-ride-through-interface Publisher: Elora Grid Updated: 2026-11-03 Lookup label: CURI Drawing use: Schematic Reference families: Manufacturer Representation: Functional block Installation focus: switchgear Input: Supply disturbance and support circuit Output: Documented delayed release Represents the defined delay or support circuit associated with an undervoltage release. ## In plain English ### What this block does Represents the defined delay or support circuit associated with an undervoltage release. ### A simple example In a medium-voltage switchgear drawing, the operating reference helps the reader distinguish the interrupting device from its isolation, earthing and auxiliary-control interfaces. For this reference, the drawing identifies “Supply disturbance and support circuit” at the input and “Documented delayed release” at the output. Permitted delay must follow the selected release unit. ### What the drawings help you do Start at the named input: Supply disturbance and support circuit. Identify its source device or document and the state represented on the drawing. Follow the named output: Documented delayed release. Cross-reference its destination and separate the command from confirmation that the equipment responded. ### Terms - Input: Supply disturbance and support circuit - Output: Documented delayed release - Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections. Concept diagram: Supply disturbance and support circuit → CURI → Documented delayed release A reading guide. The entry's original illustration and input/output facts describe this application. - [High-voltage circuit breakers](https://www.siemens-energy.com/global/en/home/products-services/product-offerings/circuit-breakers.html) ## What it represents Represents the defined delay or support circuit associated with an undervoltage release. A switching-device operating reference adds the specific mechanism or duty context needed to interpret its place in a power circuit. The same basic switching outline can serve different equipment constructions, so the added description must remain attached to its device tag. In a medium-voltage switchgear drawing, the operating reference helps the reader distinguish the interrupting device from its isolation, earthing and auxiliary-control interfaces. For this reference, the drawing identifies “Supply disturbance and support circuit” at the input and “Documented delayed release” at the output. Permitted delay must follow the selected release unit. Use the device schedule for its actual construction, operating duty and ratings. These original functional illustrations describe the named role and do not certify a standard glyph or product footprint. The functional block 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: Supply disturbance and support circuit. Identify its source device or document and the state represented on the drawing. - Follow the named output: Documented delayed release. Cross-reference its destination and separate the command from confirmation that the equipment responded. - Permitted delay must follow the selected release unit. - Use the device schedule for its actual construction, operating duty and ratings. These original functional illustrations describe the named role and do not certify a standard glyph or product footprint. ## Information to show or reference - Label the source and connection reference for supply disturbance and support circuit. - Identify the destination and defined state of documented delayed release. - Record the equipment or control-document revision supporting this functional block. - Check this application limit in the project design: Permitted delay must follow the selected release unit. ## Important distinction Permitted delay must follow the selected release unit. 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: Functional block - Installation focus: Switchgear - Input / boundary: Supply disturbance and support circuit - Output / connection: Documented delayed release - Lookup label: CURI is a library lookup label, not a standard device designation. ## Public references - [High-voltage circuit breakers](https://www.siemens-energy.com/global/en/home/products-services/product-offerings/circuit-breakers.html) — Siemens Energy. Public technical context for switching-device operating references. Circuit-breaker construction and interruption families. 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.