{"schemaVersion":1,"slug":"motor-overload-alarm-no-contact","name":"Motor overload alarm NO contact","kind":"symbol","abbreviation":"OL NO","aliases":["HOL21","VOL21"],"category":"control-circuits","drawingTypes":["Schematic"],"referenceFamilies":["IEC","Manufacturer"],"summary":"An overload alarm NO contact closes on the documented overload relay operation.","description":["An overload alarm NO contact closes on the documented overload relay operation. The schematic identifies the alarm or feedback path independently of the motor-stopping contact."],"readingNotes":["Verify the contact behaviour after reset and after loss of auxiliary supply.","The preview is an original explanation of this function. Match the actual drawing convention to its legend and the selected equipment documentation."],"drawingChecklist":["Link overload device","Identify alarm destination","Reference contact terminal pair"],"distinction":"A trip alarm contact is different from a contactor position indication contact.","facts":[{"label":"Drawing role","value":"Contact state"},{"label":"Representation scope","value":"Functional concept; not an official standard graphic or a product footprint"},{"label":"Public vendor block reference","value":"HOL21, VOL21 (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-motor-control","relevance":"Public documentation of this equipment function or named vendor variant; the illustration is independently authored and is not the source graphic."}],"related":["normally-open-contact","normally-closed-contact"],"artwork":"edu-motor-overload-alarm-no-contact","publishedOn":"2026-10-13","updatedOn":"2026-10-13","provenance":"independent-public-research","url":"https://eloragrid.ai/symbols/motor-overload-alarm-no-contact","illustration":{"url":"https://eloragrid.ai/library/illustrations/motor-overload-alarm-no-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-motor-control","title":"AutoCAD Electrical: Motor control and overloads","publisher":"Autodesk","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-D74101D4-8702-418C-B349-B15EEAEFAA20.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."}]}