{"schemaVersion":1,"slug":"pushbutton-nc","name":"Normally closed pushbutton","kind":"symbol","abbreviation":"PB NC","aliases":["stop pushbutton","NC push button","momentary break pushbutton","HPB12","VPB12"],"category":"control-circuits","drawingTypes":["Schematic"],"referenceFamilies":["IEC","IEEE / ANSI"],"summary":"A pushbutton contact normally shown closed before actuation.","description":["A normally closed pushbutton has a contact closed in its specified normal state. Actuation changes that contact state according to the selected operator and contact block. Momentary, maintained, latching and positive-opening characteristics must be identified from device documentation.","A stop circuit is a common use, but the generic representation does not establish emergency-stop suitability or the required control-system behaviour. Operator labels, device specifications and the complete circuit remain necessary."],"readingNotes":["Identify the contact block and its parent operator.","Read mechanical and contact characteristics from the manufacturer information."],"drawingChecklist":["Show terminal designations.","State the mechanical operating mode.","Reference the complete circuit purpose and device selection."],"distinction":"An ordinary NC pushbutton and an emergency-stop device are not interchangeable solely because both drawings show a closed contact.","facts":[{"label":"Normal contact state","value":"Closed"},{"label":"Safety function","value":"Requires complete device and circuit assessment"},{"label":"Operating mode","value":"Device-specific"},{"label":"Public Autodesk reference names","value":"HPB12, VPB12 (vendor identifiers, not IEC symbol IDs)"}],"references":[{"sourceId":"autodesk-pushbuttons","relevance":"Public NC pushbutton and actuator variants."}],"related":["pushbutton-no","emergency-stop","normally-closed-contact","relay-coil"],"artwork":"push-nc","publishedOn":"2026-10-13","updatedOn":"2026-10-13","provenance":"independent-public-research","url":"https://eloragrid.ai/symbols/pushbutton-nc","illustration":{"url":"https://eloragrid.ai/library/illustrations/pushbutton-nc.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"autodesk-pushbuttons","title":"Pushbutton contact and actuator variants","publisher":"Autodesk","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-9E8890C7-7176-47DD-8700-E02A16C1670E.htm","type":"cad-reference","scope":"Momentary and latching pushbuttons, normal contact states and mushroom actuators.","checkedOn":"2026-10-13","reuse":"link-only","relevance":"Public NC pushbutton and actuator variants."}]}