{"schemaVersion":1,"slug":"breaker-open-disconnector-interlock","name":"Breaker-open disconnector interlock","kind":"symbol","abbreviation":"BDI","aliases":["Switchgear interlocking functions","switchgear Switchgear interlocking functions","switchgear","Switchgear","Breaker-open proof","Disconnector operation permission"],"category":"control-circuits","drawingTypes":["Schematic"],"referenceFamilies":["Manufacturer"],"summary":"Blocks disconnector movement until the specified breaker-open condition has been established.","description":["Blocks disconnector movement until the specified breaker-open condition has been established. An interlocking function permits or blocks an operation according to the positions and conditions of related equipment. Electrical, mechanical and trapped-key interlocks implement different parts of a coordinated operating philosophy.","In a switchgear feeder panel, a control diagram can prevent an incompatible combination of breaker, disconnector and earthing-switch positions. The physical equipment documents determine which restrictions are mechanically enforced. For this reference, the drawing identifies “Breaker-open proof” at the input and “Disconnector operation permission” at the output. Open-position proof is distinct from isolation verification.","Identify each initiating position, the action being blocked and the consequence of missing feedback. An illustrative logic diagram must not be treated as an operating procedure or proof of a complete safety system. 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."],"readingNotes":["Start at the named input: Breaker-open proof. Identify its source device or document and the state represented on the drawing.","Follow the named output: Disconnector operation permission. Cross-reference its destination and separate the command from confirmation that the equipment responded.","Open-position proof is distinct from isolation verification.","Identify each initiating position, the action being blocked and the consequence of missing feedback. An illustrative logic diagram must not be treated as an operating procedure or proof of a complete safety system."],"drawingChecklist":["Label the source and connection reference for breaker-open proof.","Identify the destination and defined state of disconnector operation permission.","Record the equipment or control-document revision supporting this functional block.","Check this application limit in the project design: Open-position proof is distinct from isolation verification."],"distinction":"Open-position proof is distinct from isolation verification. 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":[{"label":"Representation","value":"Functional block"},{"label":"Installation focus","value":"Switchgear"},{"label":"Input / boundary","value":"Breaker-open proof"},{"label":"Output / connection","value":"Disconnector operation permission"},{"label":"Lookup label","value":"BDI is a library lookup label, not a standard device designation."}],"references":[{"sourceId":"pi26-masterclad","relevance":"Public technical context for switchgear interlocking functions. Breaker control, mechanism, position contacts, racking interlocks and test interfaces. The application text and educational graphic are independently authored; the publisher does not certify this representation."}],"related":["iec-mechanical-interlock-between-devices","earthing-switch","disconnector-closed-breaker-interlock"],"artwork":"pi26-breaker-open-disconnector-interlock","publishedOn":"2026-11-03","updatedOn":"2026-11-03","provenance":"independent-public-research","representation":{"type":"functional-block","focus":"switchgear","family":"interlocks","input":"Breaker-open proof","output":"Disconnector operation permission"},"plainEnglish":{"title":"What this block does","introduction":"Blocks disconnector movement until the specified breaker-open condition has been established.","example":"In a switchgear feeder panel, a control diagram can prevent an incompatible combination of breaker, disconnector and earthing-switch positions. The physical equipment documents determine which restrictions are mechanically enforced. For this reference, the drawing identifies “Breaker-open proof” at the input and “Disconnector operation permission” at the output. Open-position proof is distinct from isolation verification.","drawings":"Start at the named input: Breaker-open proof. Identify its source device or document and the state represented on the drawing. Follow the named output: Disconnector operation permission. Cross-reference its destination and separate the command from confirmation that the equipment responded.","terms":[{"name":"Input","meaning":"Breaker-open proof"},{"name":"Output","meaning":"Disconnector operation permission"},{"name":"Application reference","meaning":"An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections."}],"diagram":"flow","steps":["Breaker-open proof","BDI","Disconnector operation permission"],"caption":"A reading guide. The entry's original illustration and input/output facts describe this application.","sources":[{"label":"Masterclad medium-voltage switchgear: circuit-breaker section interlocks","url":"https://productinfo.se.com/masterclad_mv_switchgear_ib/6055-30-masterclad-15kv-mv-switchgear-ib/English/6055-30%20Masterclad%20MV%20Switchgear%20Indoor%20%28bookmap%29_DD00646805.xml/%24/Section6-CircuitBreakerSectionInter-58DD6EC7"}],"profileId":"power-installation-interlocks"},"url":"https://eloragrid.ai/symbols/breaker-open-disconnector-interlock","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/breaker-open-disconnector-interlock.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"pi26-masterclad","publisher":"Schneider Electric","title":"Masterclad medium-voltage switchgear: circuit-breaker section interlocks","url":"https://productinfo.se.com/masterclad_mv_switchgear_ib/6055-30-masterclad-15kv-mv-switchgear-ib/English/6055-30%20Masterclad%20MV%20Switchgear%20Indoor%20%28bookmap%29_DD00646805.xml/%24/Section6-CircuitBreakerSectionInter-58DD6EC7","scope":"Breaker control, mechanism, position contacts, racking interlocks and test interfaces.","type":"manufacturer","checkedOn":"2026-11-03","reuse":"link-only","relevance":"Public technical context for switchgear interlocking functions. Breaker control, mechanism, position contacts, racking interlocks and test interfaces. The application text and educational graphic are independently authored; the publisher does not certify this representation."}]}