{"schemaVersion":1,"slug":"test-mode-output-blocking","name":"Test-mode output blocking","kind":"symbol","abbreviation":"TOB","aliases":["Switchgear interlocking functions","switchgear Switchgear interlocking functions","switchgear","Switchgear","Test-mode selection","Output block status"],"category":"control-circuits","drawingTypes":["Schematic"],"referenceFamilies":["Manufacturer"],"summary":"Separates a test initiation from the normal operating output under the documented test configuration.","description":["Separates a test initiation from the normal operating output under the documented test configuration. 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 “Test-mode selection” at the input and “Output block status” at the output. Any active unblocked path must remain visible.","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: Test-mode selection. Identify its source device or document and the state represented on the drawing.","Follow the named output: Output block status. Cross-reference its destination and separate the command from confirmation that the equipment responded.","Any active unblocked path must remain visible.","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 test-mode selection.","Identify the destination and defined state of output block status.","Record the equipment or control-document revision supporting this functional block.","Check this application limit in the project design: Any active unblocked path must remain visible."],"distinction":"Any active unblocked path must remain visible. 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":"Test-mode selection"},{"label":"Output / connection","value":"Output block status"},{"label":"Lookup label","value":"TOB 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","invalid-position-fail-block-gate"],"artwork":"pi26-test-mode-output-blocking","publishedOn":"2026-11-03","updatedOn":"2026-11-03","provenance":"independent-public-research","representation":{"type":"functional-block","focus":"switchgear","family":"interlocks","input":"Test-mode selection","output":"Output block status"},"plainEnglish":{"title":"What this block does","introduction":"Separates a test initiation from the normal operating output under the documented test configuration.","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 “Test-mode selection” at the input and “Output block status” at the output. Any active unblocked path must remain visible.","drawings":"Start at the named input: Test-mode selection. Identify its source device or document and the state represented on the drawing. Follow the named output: Output block status. Cross-reference its destination and separate the command from confirmation that the equipment responded.","terms":[{"name":"Input","meaning":"Test-mode selection"},{"name":"Output","meaning":"Output block status"},{"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":["Test-mode selection","TOB","Output block status"],"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/test-mode-output-blocking","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/test-mode-output-blocking.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."}]}