{"schemaVersion":1,"slug":"iec-frame-or-chassis-connection","name":"Frame or chassis connection","kind":"symbol","abbreviation":"-","aliases":["chassis connection","frame connection","mass connection"],"category":"connections-wiring","drawingTypes":["Schematic"],"referenceFamilies":["IEC"],"summary":"A connection to the metal frame or chassis of equipment, which may or may not itself be connected to earth.","description":["The frame or chassis connection shows that a circuit point is connected to the metal structure of a device, drawn as a line ending in a comb or hatched mark. It is common on electronics, vehicle and machine wiring, where the chassis is used as a common reference or return.","A chassis connection is not automatically an earth connection. Equipment on a vehicle or isolated supply may have a chassis that is not connected to earth at all. Where the chassis is also protectively earthed, the protective earth symbol should be shown separately so the safety function is clear."],"readingNotes":["Do not assume the chassis is earthed.","Look for a separate protective earth connection on the frame."],"drawingChecklist":["Show whether the chassis is earthed.","Separate chassis returns from protective earthing.","Identify the chassis bonding point."],"distinction":"A chassis connection ties to the equipment frame; a protective earth connection ties to the installation earthing system.","facts":[{"label":"Graphic cue","value":"Line ending in a comb-like mark"},{"label":"Earthing implied","value":"No; check separately"},{"label":"Preview","value":"Original educational illustration; consult the publisher and applicable standard for the exact graphic"}],"references":[{"sourceId":"pub-symbol-earthing-surge","relevance":"Public IEC-oriented earth and bonding forms."},{"sourceId":"autodesk-index","relevance":"Public directory of IEC-oriented symbol families."}],"related":["ansi-chassis-ground","protective-earth","functional-equipotential-bonding"],"artwork":"s28-iec-frame-or-chassis-connection","publishedOn":"2026-10-28","updatedOn":"2026-10-28","provenance":"independent-public-research","symbolVariant":{"convention":"IEC","form":"Frame or chassis connection","reference":"Independent IEC-context illustration; not certified IEC geometry."},"plainEnglish":{"title":"What does Frame or chassis connection mean?","introduction":"The frame or chassis connection shows that a circuit point is connected to the metal structure of a device, drawn as a line ending in a comb or hatched mark. It is common on electronics, vehicle and machine wiring, where the chassis is used as a common reference or return.","example":"A chassis connection is not automatically an earth connection. Equipment on a vehicle or isolated supply may have a chassis that is not connected to earth at all. Where the chassis is also protectively earthed, the protective earth symbol should be shown separately so the safety function is clear.","drawings":"Do not assume the chassis is earthed. Look for a separate protective earth connection on the frame. A chassis connection ties to the equipment frame; a protective earth connection ties to the installation earthing system.","terms":[{"name":"Terminal","meaning":"An identified point where a conductor connects."},{"name":"Schematic","meaning":"A drawing showing function and connections rather than physical appearance."}],"diagram":"flow","steps":["Identify the device and form","Read the connections and state","Check the equipment reference"],"caption":"A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram.","sources":[{"label":"AutoCAD Electrical: Earthing, sources and surge protection","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-1E3FDEAE-B4B2-417C-8075-108AA2C6E509.htm"},{"label":"IEC-60617 symbol preview directory","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-7871E6EF-24D5-467E-9B74-321FEDC9DFDA.htm"}],"detail":"A connection to the metal frame or chassis of equipment, which may or may not itself be connected to earth. A chassis connection ties to the equipment frame; a protective earth connection ties to the installation earthing system.","profileId":"reviewed-symbol-20261028"},"url":"https://eloragrid.ai/symbols/iec-frame-or-chassis-connection","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/iec-frame-or-chassis-connection.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-earthing-surge","title":"AutoCAD Electrical: Earthing, sources and surge protection","publisher":"Autodesk","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-1E3FDEAE-B4B2-417C-8075-108AA2C6E509.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 IEC-oriented earth and bonding forms."},{"id":"autodesk-index","title":"IEC-60617 symbol preview directory","publisher":"Autodesk","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-7871E6EF-24D5-467E-9B74-321FEDC9DFDA.htm","type":"cad-reference","scope":"Public reference directory of named symbol categories. Vendor graphics and CAD library files are not redistributed here.","checkedOn":"2026-10-13","reuse":"link-only","relevance":"Public directory of IEC-oriented symbol families."}]}