# Switchroom lighting-contact relay interface Canonical URL: https://eloragrid.ai/symbols/switchroom-lighting-contact-relay-interface Publisher: Elora Grid Updated: 2026-11-03 Lookup label: SLRI Drawing use: Schematic Reference families: Manufacturer Representation: Functional block Installation focus: switchrooms Input: Lighting relay command Output: Lighting contact operation Links the lighting-control relay to the power contacts serving the selected branch. ## In plain English ### What this block does Links the lighting-control relay to the power contacts serving the selected branch. ### A simple 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 “Lighting relay command” at the input and “Lighting contact operation” at the output. Contact rating depends on the actual lighting load. ### What the drawings help you do Start at the named input: Lighting relay command. Identify its source device or document and the state represented on the drawing. Follow the named output: Lighting contact operation. Cross-reference its destination and separate the command from confirmation that the equipment responded. ### Terms - Input: Lighting relay command - Output: Lighting contact operation - Application reference: An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections. Concept diagram: Lighting relay command → SLRI → Lighting contact operation A reading guide. The entry's original illustration and input/output facts describe this application. - [Indoor substation: lighting, fire and auxiliary services](https://www.electrical-installation.org/enwiki/Indoor_substation) ## What it represents Links the lighting-control relay to the power contacts serving the selected branch. 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 “Lighting relay command” at the input and “Lighting contact operation” at the output. Contact rating depends on the actual lighting load. 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. ## How to read it - Start at the named input: Lighting relay command. Identify its source device or document and the state represented on the drawing. - Follow the named output: Lighting contact operation. Cross-reference its destination and separate the command from confirmation that the equipment responded. - Contact rating depends on the actual lighting load. - 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. ## Information to show or reference - Label the source and connection reference for lighting relay command. - Identify the destination and defined state of lighting contact operation. - Record the equipment or control-document revision supporting this functional block. - Check this application limit in the project design: Contact rating depends on the actual lighting load. ## Important distinction Contact rating depends on the actual lighting load. 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 - Representation: Functional block - Installation focus: Switchrooms - Input / boundary: Lighting relay command - Output / connection: Lighting contact operation - Lookup label: SLRI is a library lookup label, not a standard device designation. ## Public references - [Indoor substation: lighting, fire and auxiliary services](https://www.electrical-installation.org/enwiki/Indoor_substation) — Schneider Electric. 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. ## Graphic scope Independent original educational concept illustration by Elora Grid. Not a certified standards graphic or manufacturer footprint. Unitless; not to scale. Original artwork licence: https://creativecommons.org/licenses/by/4.0/. Publisher material is linked only.