{"schemaVersion":1,"slug":"key-operated-normally-closed-switch","name":"Key-operated normally-closed switch","kind":"symbol","abbreviation":"KEY NC","aliases":["HPB12KS","VPB12KS"],"category":"control-circuits","drawingTypes":["Schematic"],"referenceFamilies":["IEC","Manufacturer"],"summary":"A key-operated NC switch opens its reference closed contact through the key mechanism.","description":["A key-operated NC switch opens its reference closed contact through the key mechanism. Its access and switching functions must be documented separately."],"readingNotes":["Read the reference position from the operator schedule.","The preview is an original explanation of this function. Match the actual drawing convention to its legend and the selected equipment documentation."],"drawingChecklist":["Define normal key position","State contact action","Reference key-removal restrictions"],"distinction":"NC identifies the contact reference state, not a guarantee of tamper-proof control.","facts":[{"label":"Drawing role","value":"Manual operation"},{"label":"Representation scope","value":"Functional concept; not an official standard graphic or a product footprint"},{"label":"Public vendor block reference","value":"HPB12KS, VPB12KS (Autodesk identifiers; not IEC symbol numbers)"},{"label":"Identifier status","value":"The short label is a functional lookup label, not an assigned IEC or IEEE symbol number. Any separately listed Autodesk code is a verified vendor block name."}],"references":[{"sourceId":"pub-symbol-misc-switches","relevance":"Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic."}],"related":["pushbutton-no","pushbutton-nc"],"artwork":"edu-key-operated-normally-closed-switch","publishedOn":"2026-10-13","updatedOn":"2026-10-13","provenance":"independent-public-research","url":"https://eloragrid.ai/symbols/key-operated-normally-closed-switch","illustration":{"url":"https://eloragrid.ai/library/illustrations/key-operated-normally-closed-switch.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"pub-symbol-misc-switches","title":"AutoCAD Electrical: Level, flow, keyed and measurement switches","publisher":"Autodesk","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-1FB94435-C954-4479-BD97-25796DB8F728.htm","type":"cad-reference","scope":"Public vendor catalogue naming and functional variants. Vendor block names are not IEC identifiers. Linked for reference; no graphics or CAD files are redistributed.","checkedOn":"2026-10-13","reuse":"link-only","relevance":"Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic."}]}