{"schemaVersion":1,"slug":"switchroom-normal-lighting-control-branch","name":"Switchroom normal-lighting control branch","kind":"symbol","abbreviation":"SNCB","aliases":["Switchroom lighting and access interfaces","switchrooms Switchroom lighting and access interfaces","switchrooms","Switchrooms","Local lighting command","Normal lighting switched supply"],"category":"installation-communications","drawingTypes":["Schematic"],"referenceFamilies":["Manufacturer"],"summary":"Identifies the control path switching the assigned normal room-lighting circuit.","description":["Identifies the control path switching the assigned normal room-lighting circuit. Lighting and access interfaces coordinate the electrical-room service circuits and their supervision. Normal lighting, emergency illumination and access indication have different power sources and purposes.","In a switchroom, a normal lighting branch may be switched locally while the specified emergency luminaires remain connected to their own backed-up or integral supply. For this reference, the drawing identifies “Local lighting command” at the input and “Normal lighting switched supply” at the output. Emergency lighting can have a separate unswitched supply.","Identify the lighting supply type, controlled circuit and the meaning of any test or failure output. A drawing symbol does not establish illumination levels, emergency duration or an approved egress arrangement. The functional block is an independent explanation of this named application. Equipment-specific ratings, terminal connections and operating conditions must be established in the project documentation."],"readingNotes":["Start at the named input: Local lighting command. Identify its source device or document and the state represented on the drawing.","Follow the named output: Normal lighting switched supply. Cross-reference its destination and separate the command from confirmation that the equipment responded.","Emergency lighting can have a separate unswitched supply.","Identify the lighting supply type, controlled circuit and the meaning of any test or failure output. A drawing symbol does not establish illumination levels, emergency duration or an approved egress arrangement."],"drawingChecklist":["Label the source and connection reference for local lighting command.","Identify the destination and defined state of normal lighting switched supply.","Record the equipment or control-document revision supporting this functional block.","Check this application limit in the project design: Emergency lighting can have a separate unswitched supply."],"distinction":"Emergency lighting can have a separate unswitched supply. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram.","facts":[{"label":"Representation","value":"Functional block"},{"label":"Installation focus","value":"Switchrooms"},{"label":"Input / boundary","value":"Local lighting command"},{"label":"Output / connection","value":"Normal lighting switched supply"},{"label":"Lookup label","value":"SNCB is a library lookup label, not a standard device designation."}],"references":[{"sourceId":"pi26-room-services","relevance":"Public technical context for switchroom lighting and access interfaces. Lighting, emergency lighting, fire provisions and substation auxiliary services. Original cause-and-effect examples require project design. The application text and educational graphic are independently authored; the publisher does not certify this representation."}],"related":["iec-maintained-emergency-luminaire","iec-exit-sign-luminaire","switchroom-emergency-lighting-supply-interface"],"artwork":"pi26-switchroom-normal-lighting-control-branch","publishedOn":"2026-11-03","updatedOn":"2026-11-03","provenance":"independent-public-research","representation":{"type":"functional-block","focus":"switchrooms","family":"room-lighting","input":"Local lighting command","output":"Normal lighting switched supply"},"plainEnglish":{"title":"What this block does","introduction":"Identifies the control path switching the assigned normal room-lighting circuit.","example":"In a switchroom, a normal lighting branch may be switched locally while the specified emergency luminaires remain connected to their own backed-up or integral supply. For this reference, the drawing identifies “Local lighting command” at the input and “Normal lighting switched supply” at the output. Emergency lighting can have a separate unswitched supply.","drawings":"Start at the named input: Local lighting command. Identify its source device or document and the state represented on the drawing. Follow the named output: Normal lighting switched supply. Cross-reference its destination and separate the command from confirmation that the equipment responded.","terms":[{"name":"Input","meaning":"Local lighting command"},{"name":"Output","meaning":"Normal lighting switched supply"},{"name":"Application reference","meaning":"An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections."}],"diagram":"flow","steps":["Local lighting command","SNCB","Normal lighting switched supply"],"caption":"A reading guide. The entry's original illustration and input/output facts describe this application.","sources":[{"label":"Indoor substation: lighting, fire and auxiliary services","url":"https://www.electrical-installation.org/enwiki/Indoor_substation"}],"profileId":"power-installation-room-lighting"},"url":"https://eloragrid.ai/symbols/switchroom-normal-lighting-control-branch","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/switchroom-normal-lighting-control-branch.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"pi26-room-services","publisher":"Schneider Electric","title":"Indoor substation: lighting, fire and auxiliary services","url":"https://www.electrical-installation.org/enwiki/Indoor_substation","scope":"Lighting, emergency lighting, fire provisions and substation auxiliary services. Original cause-and-effect examples require project design.","type":"manufacturer","checkedOn":"2026-11-03","reuse":"link-only","relevance":"Public technical context for switchroom lighting and access interfaces. Lighting, emergency lighting, fire provisions and substation auxiliary services. Original cause-and-effect examples require project design. The application text and educational graphic are independently authored; the publisher does not certify this representation."}]}