{"schemaVersion":1,"slug":"iec-dimmer-switch","name":"Dimmer switch plan mark","kind":"symbol","abbreviation":"SD","aliases":["dimmer","light dimmer plan mark","dimming switch"],"category":"installation-communications","drawingTypes":["GA"],"referenceFamilies":["IEC"],"summary":"Plan mark for a switch that varies lamp brightness, drawn as a switch with an added variability arrow.","description":["A dimmer varies the power delivered to luminaires using phase-cut electronics or a control signal. IEC-style plans typically draw the switch mark with an oblique arrow or a small adjustment mark to show continuous variation, and the switching line links it to the dimmed group.","Dimmer compatibility with LED drivers is a frequent site problem, so the symbol is usually backed by a schedule stating the dimming method: leading edge, trailing edge, 0-10 V or DALI. The reader should check that every luminaire on the dimmed group is dimmable by that method.","The plan mark does not state the dimming technology or minimum load. A rotary or push dimmer looks the same on the plan."],"readingNotes":["Check the dimming method in the schedule.","Confirm every luminaire in the group is compatible."],"drawingChecklist":["State dimming method and rated load.","Link to the dimmed luminaire group.","Note minimum load for LED circuits."],"distinction":"A one-way switch has no variability mark; the dimmer adds continuous control of light output.","facts":[{"label":"Graphic cue","value":"Switch mark with an oblique variability arrow"},{"label":"Key schedule item","value":"Dimming method and load rating"},{"label":"Exact standard graphic","value":"Not reproduced here; confirm the form against IEC 60617 and the project legend"}],"references":[{"sourceId":"iec-diagrams","relevance":"IEC graphical symbol context; independently drawn here."},{"sourceId":"iec-public-operating","relevance":"Public IEC-oriented qualifier family showing how adjustability is added to a base symbol."}],"related":["iec-one-way-light-switch","iec-luminaire-general-plan-symbol"],"artwork":"s28-iec-dimmer-switch","publishedOn":"2026-10-28","updatedOn":"2026-10-28","provenance":"independent-public-research","symbolVariant":{"convention":"IEC","form":"Dimmer switch","reference":"IEC 60617 installation-plan style (architectural and topographical installation symbols); independently drawn, not certified IEC geometry or a database identifier."},"plainEnglish":{"title":"What does Dimmer switch plan mark mean?","introduction":"A dimmer varies the power delivered to luminaires using phase-cut electronics or a control signal. IEC-style plans typically draw the switch mark with an oblique arrow or a small adjustment mark to show continuous variation, and the switching line links it to the dimmed group.","example":"Dimmer compatibility with LED drivers is a frequent site problem, so the symbol is usually backed by a schedule stating the dimming method: leading edge, trailing edge, 0-10 V or DALI. The reader should check that every luminaire on the dimmed group is dimmable by that method.","drawings":"The plan mark does not state the dimming technology or minimum load. A rotary or push dimmer looks the same on the plan.","terms":[{"name":"Phase","meaning":"One of the related AC waveforms in a power system."},{"name":"Signal","meaning":"Electrical information passed between devices, rather than necessarily the main power supply."},{"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":"IEC graphical symbols for diagrams","url":"https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/"},{"label":"Autodesk IEC-60617 preview: Operating-device and function qualifiers","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-3598E18D-9F8A-48CE-83D0-4CEBA0AE869C.htm"}],"detail":"Plan mark for a switch that varies lamp brightness, drawn as a switch with an added variability arrow. A one-way switch has no variability mark; the dimmer adds continuous control of light output.","profileId":"reviewed-symbol-20261028"},"url":"https://eloragrid.ai/symbols/iec-dimmer-switch","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/iec-dimmer-switch.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"iec-diagrams","title":"IEC graphical symbols for diagrams","publisher":"IEC","url":"https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/","type":"standard","scope":"IEC 60617 and related symbol-design publications. Full database access requires a subscription.","checkedOn":"2026-10-13","reuse":"link-only","relevance":"IEC graphical symbol context; independently drawn here."},{"id":"iec-public-operating","title":"Autodesk IEC-60617 preview: Operating-device and function qualifiers","publisher":"Autodesk","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-3598E18D-9F8A-48CE-83D0-4CEBA0AE869C.htm","type":"cad-reference","scope":"Public publisher IEC-context family names and vendor block references. No vendor images or CAD library files are reproduced, and vendor tokens are not presented as verified IEC database identifiers.","checkedOn":"2026-10-14","reuse":"link-only","relevance":"Public IEC-oriented qualifier family showing how adjustability is added to a base symbol."}]}