{"schemaVersion":1,"slug":"iec-time-delay-push-switch","name":"Time-delay push switch plan mark","kind":"symbol","abbreviation":"ST","aliases":["staircase timer push","timed push switch","timer light switch"],"category":"installation-communications","drawingTypes":["GA"],"referenceFamilies":["IEC"],"summary":"Plan mark for a push switch that turns lights on for a set period, commonly used in stairwells and common corridors.","description":["A time-delay push switch, often wired to a staircase timer, turns lighting on when pressed and lets it switch off after a set interval. Plans draw a push-button mark at each push position with a small clock or t tag, and show the timer location in the board where one is used.","Several push switches may be wired in parallel to one timer, so the switching line links them all to a common luminaire group. The electrician reads the plan to run a separate push conductor rather than switched-line wiring.","The plan symbol does not set the delay period or state whether the timer is in the switch or at the board. The specification should give both."],"readingNotes":["Look for the associated timer in the board schedule.","Expect several pushes wired in parallel on one landing group."],"drawingChecklist":["State delay time and adjustment range.","Show the timer location.","Link all pushes to the controlled group."],"distinction":"A momentary bell push is not connected to lighting; a time-delay push switch starts a lighting timer.","facts":[{"label":"Operation","value":"Momentary push starting a timed lighting period"},{"label":"Typical location","value":"Stairs and shared corridors"},{"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":"switching-devices","relevance":"Context for functional control switching."}],"related":["on-delay-timer-relay","iec-push-button-plan-mark","iec-time-switch-plan-mark"],"artwork":"s28-iec-time-delay-push-switch","publishedOn":"2026-10-28","updatedOn":"2026-10-28","provenance":"independent-public-research","symbolVariant":{"convention":"IEC","form":"Time-delay push 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 Time-delay push switch plan mark mean?","introduction":"A time-delay push switch, often wired to a staircase timer, turns lighting on when pressed and lets it switch off after a set interval. Plans draw a push-button mark at each push position with a small clock or t tag, and show the timer location in the board where one is used.","example":"Several push switches may be wired in parallel to one timer, so the switching line links them all to a common luminaire group. The electrician reads the plan to run a separate push conductor rather than switched-line wiring.","drawings":"The plan symbol does not set the delay period or state whether the timer is in the switch or at the board. The specification should give both.","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":"IEC graphical symbols for diagrams","url":"https://tc3.iec.ch/tc-activity/graphical-symbols-for-diagrams/"},{"label":"Elementary switching devices","url":"https://www.electrical-installation.org/enwiki/Elementary_switching_devices"}],"detail":"Plan mark for a push switch that turns lights on for a set period, commonly used in stairwells and common corridors. A momentary bell push is not connected to lighting; a time-delay push switch starts a lighting timer.","profileId":"reviewed-symbol-20261028"},"url":"https://eloragrid.ai/symbols/iec-time-delay-push-switch","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/iec-time-delay-push-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":"switching-devices","title":"Elementary switching devices","publisher":"Schneider Electric — Electrical Installation Guide","url":"https://www.electrical-installation.org/enwiki/Elementary_switching_devices","type":"manufacturer","scope":"Explains disconnectors, load-break switches, contactors and fuses. The manufacturer diagrams remain at the source.","checkedOn":"2026-10-13","reuse":"link-only","relevance":"Context for functional control switching."}]}