{"schemaVersion":1,"slug":"on-delay-normally-open-contact","name":"On-delay normally-open contact","kind":"symbol","abbreviation":"TON NO","aliases":[],"category":"control-circuits","drawingTypes":["Schematic"],"referenceFamilies":["IEC","Manufacturer"],"summary":"An on-delay NO contact changes from its unoperated open state only after the associated timing condition has persisted for the documented delay.","description":["An on-delay NO contact changes from its unoperated open state only after the associated timing condition has persisted for the documented delay. The contact tag links it to the timer element."],"readingNotes":["The delay applies to the indicated operating transition, not automatically to both directions.","The preview is an original explanation of this function. Match the actual drawing convention to its legend and the selected equipment documentation."],"drawingChecklist":["Match timer tag","Label delayed closing","Reference reset behaviour"],"distinction":"A timed contact adds transition information to the basic normally-open state.","facts":[{"label":"Drawing role","value":"Timed operation"},{"label":"Representation scope","value":"Functional concept; not an official standard graphic or a product footprint"},{"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-timers","relevance":"Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic."}],"related":["relay-coil","normally-closed-contact"],"artwork":"edu-on-delay-normally-open-contact","publishedOn":"2026-10-13","updatedOn":"2026-10-13","provenance":"independent-public-research","url":"https://eloragrid.ai/symbols/on-delay-normally-open-contact","illustration":{"url":"https://eloragrid.ai/library/illustrations/on-delay-normally-open-contact.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-timers","title":"AutoCAD Electrical: Time-delay relays","publisher":"Autodesk","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-DA927086-EEAF-48CB-B9B1-634A4B48C8C7.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."}]}