{"schemaVersion":1,"slug":"iec-multi-lamp-fluorescent-luminaire","name":"Multi-tube fluorescent luminaire plan mark","kind":"symbol","abbreviation":"LF3","aliases":["three-tube fitting","multi-lamp linear luminaire","twin or triple tube luminaire"],"category":"installation-communications","drawingTypes":["GA"],"referenceFamilies":["IEC"],"summary":"Plan mark for a linear luminaire with several tubes, shown as parallel lines between common end bars.","description":["Multi-lamp linear luminaires, such as twin or triple tube troffers, are drawn with parallel lines between end bars, one line per lamp. Alternatively a single line with a numeral is used. The form helps lighting designers check that luminaire output matches the calculation.","Modular recessed fittings in a suspended ceiling grid are often drawn as a rectangle the size of the tile with internal lines for lamps. The plan then serves for coordinating ceiling tiles, sprinkler heads and diffusers. Line count does not show lamp wattage or ballast type. Read the schedule."],"readingNotes":["Count the lines or read the numeral.","Check grid coordination for recessed versions."],"drawingChecklist":["State number of lamps.","Tag fixture type.","Coordinate with ceiling services."],"distinction":"The single-line form shows one lamp; parallel lines show multi-lamp fittings.","facts":[{"label":"Graphic form","value":"Parallel lines between end bars"},{"label":"Count","value":"One line per lamp"},{"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 for installation plans; independently drawn here."},{"sourceId":"pub-object-engineering-design","relevance":"Installation design methodology covering lighting circuits and final distribution."}],"related":["iec-fluorescent-luminaire","iec-luminaire-general-plan-symbol"],"artwork":"s28-iec-multi-lamp-fluorescent-luminaire","publishedOn":"2026-10-28","updatedOn":"2026-10-28","provenance":"independent-public-research","symbolVariant":{"convention":"IEC","form":"Multi-lamp fluorescent luminaire","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 Multi-tube fluorescent luminaire plan mark mean?","introduction":"Multi-lamp linear luminaires, such as twin or triple tube troffers, are drawn with parallel lines between end bars, one line per lamp. Alternatively a single line with a numeral is used. The form helps lighting designers check that luminaire output matches the calculation.","example":"Modular recessed fittings in a suspended ceiling grid are often drawn as a rectangle the size of the tile with internal lines for lamps. The plan then serves for coordinating ceiling tiles, sprinkler heads and diffusers. Line count does not show lamp wattage or ballast type. Read the schedule.","drawings":"Count the lines or read the numeral. Check grid coordination for recessed versions. The single-line form shows one lamp; parallel lines show multi-lamp fittings.","terms":[{"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":"Electrical installation design methodology and references","url":"https://www.electrical-installation.org/enwiki/General_rules_of_electrical_installation_design"}],"detail":"Plan mark for a linear luminaire with several tubes, shown as parallel lines between common end bars. The single-line form shows one lamp; parallel lines show multi-lamp fittings.","profileId":"reviewed-symbol-20261028"},"url":"https://eloragrid.ai/symbols/iec-multi-lamp-fluorescent-luminaire","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/iec-multi-lamp-fluorescent-luminaire.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 for installation plans; independently drawn here."},{"id":"pub-object-engineering-design","title":"Electrical installation design methodology and references","publisher":"Schneider Electric — Electrical Installation Guide","url":"https://www.electrical-installation.org/enwiki/General_rules_of_electrical_installation_design","type":"manufacturer","scope":"Public design context. No universal working clearance, equipment dimension or project compliance conclusion is asserted.","checkedOn":"2026-10-13","reuse":"link-only","relevance":"Installation design methodology covering lighting circuits and final distribution."}]}