{"schemaVersion":1,"slug":"iec-socket-outlet-with-interlocked-switch","name":"Socket outlet with interlocked switch","kind":"symbol","abbreviation":"SOI","aliases":["interlocked socket outlet","switch-interlocked outlet","mechanically interlocked socket"],"category":"installation-communications","drawingTypes":["GA"],"referenceFamilies":["IEC"],"summary":"Plan mark for an outlet whose switch is mechanically interlocked so a plug cannot be inserted or withdrawn while live.","description":["Interlocked socket outlets are used for industrial plugs, welding outlets, portable plant supplies and higher-current three-phase outlets. The interlock forces the user to switch off before the plug can be removed or inserted, which prevents drawing an arc at the pins. The plan mark adds a switch stroke and a small interlock bar to the outlet form.","On industrial layouts the symbol is often paired with a current rating and pole count written beside it, for example 32 A 5-pin. The estimator should expect a heavier enclosure, sometimes with an integral fuse or circuit breaker, and the installer should expect a surface-mounted accessory rather than a flush plate.","The interlock mark does not confirm the presence of overcurrent or residual-current protection inside the unit. Check the schedule for combination units that include a breaker or RCD."],"readingNotes":["Check the rating text: interlocked outlets are usually specified by current, poles and IP rating together.","Do not confuse the interlock bar with the protective earth bar on a domestic outlet."],"drawingChecklist":["State current rating, pole count and plug standard.","State whether overcurrent or residual-current protection is integral.","Note IP rating and mounting surface."],"distinction":"A simple switched outlet allows the plug to be withdrawn while energised; the interlocked form mechanically prevents it.","facts":[{"label":"Typical location","value":"Workshops, plant rooms and outdoor plant supply points"},{"label":"Added information","value":"Plug cannot move while the switch is on"},{"label":"Exact standard graphic","value":"Not reproduced here; confirm the form against IEC 60617 and the project legend"}],"references":[{"sourceId":"iec-diagrams","relevance":"IEC committee context for graphical symbols used in diagrams and installation documents; not a source of reproduced artwork."},{"sourceId":"switching-devices","relevance":"Explains elementary switching functions such as isolation, control and functional switching."},{"sourceId":"iec-public-receptacles","relevance":"Public receptacle family in an IEC-oriented CAD library, useful for comparing schematic receptacle forms with plan marks."}],"related":["iec-switched-socket-outlet","iec-three-phase-socket-outlet","switch-disconnector"],"artwork":"s28-iec-socket-outlet-with-interlocked-switch","publishedOn":"2026-10-28","updatedOn":"2026-10-28","provenance":"independent-public-research","symbolVariant":{"convention":"IEC","form":"Socket outlet with interlocked 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 Socket outlet with interlocked switch mean?","introduction":"Interlocked socket outlets are used for industrial plugs, welding outlets, portable plant supplies and higher-current three-phase outlets. The interlock forces the user to switch off before the plug can be removed or inserted, which prevents drawing an arc at the pins. The plan mark adds a switch stroke and a small interlock bar to the outlet form.","example":"On industrial layouts the symbol is often paired with a current rating and pole count written beside it, for example 32 A 5-pin. The estimator should expect a heavier enclosure, sometimes with an integral fuse or circuit breaker, and the installer should expect a surface-mounted accessory rather than a flush plate.","drawings":"The interlock mark does not confirm the presence of overcurrent or residual-current protection inside the unit. Check the schedule for combination units that include a breaker or RCD.","terms":[{"name":"Phase","meaning":"One of the related AC waveforms in a power system."},{"name":"Rating","meaning":"A value stating the conditions for which equipment is specified."},{"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"},{"label":"Autodesk IEC-60617 preview: Single and duplex power-receptacle forms","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-7DAEDB03-74FC-47A2-9C50-9164297AA5A3.htm"}],"detail":"Plan mark for an outlet whose switch is mechanically interlocked so a plug cannot be inserted or withdrawn while live. A simple switched outlet allows the plug to be withdrawn while supplied with operating power; the interlocked form mechanically prevents it.","profileId":"reviewed-symbol-20261028"},"url":"https://eloragrid.ai/symbols/iec-socket-outlet-with-interlocked-switch","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/iec-socket-outlet-with-interlocked-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 committee context for graphical symbols used in diagrams and installation documents; not a source of reproduced artwork."},{"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":"Explains elementary switching functions such as isolation, control and functional switching."},{"id":"iec-public-receptacles","title":"Autodesk IEC-60617 preview: Single and duplex power-receptacle forms","publisher":"Autodesk","url":"https://help.autodesk.com/cloudhelp/2021/ENU/AutoCAD-Electrical/files/GUID-7DAEDB03-74FC-47A2-9C50-9164297AA5A3.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 receptacle family in an IEC-oriented CAD library, useful for comparing schematic receptacle forms with plan marks."}]}