--- title: "Emergency lighting and escape lighting" subject: "Industrial Power Distribution and Illumination" chapter: 9 key: "semester_6/industrial_power_distribution_and_illumination:emergency-escape-lighting" source: https://www.bctengineer.com/q/semester_6/industrial_power_distribution_and_illumination/emergency-escape-lighting site: BCT Engineering --- # Emergency lighting and escape lighting Industrial Power Distribution and Illumination · Chapter 9: Emergency and Backup Supply Systems - Asked in: 2078 Chaitra, 1+3 marks - Video: [Emergency Lighting Design Guide](https://www.youtube.com/watch?v=crUjqnvhn5Y) — Nelca Roco, Lighting Design - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_6/industrial_power_distribution_and_illumination/emergency-escape-lighting - Whole chapter: https://www.bctengineer.com/md/semester_6/industrial_power_distribution_and_illumination/chapter-9 ## Question What is an emergency lighting system? Explain about escape lighting system for escape routes. ## Short answer An emergency lighting system automatically activates from an independent source when normal supply fails. Escape lighting provides at least 1 lux on escape routes, with 50% illumination within 5 seconds, 1-3 hour duration, luminaires at exits, turns, stairs, and fire equipment, using self-contained or central battery systems. ## Answer #### Emergency lighting system An **emergency lighting system** is lighting supplied from an independent source (battery or generator) that switches on **automatically** when the normal supply fails, so people can see to escape or to finish critical tasks safely. It has three types: **escape lighting**, **standby lighting** (to continue normal work) and **high-risk task area lighting**. #### Escape lighting for escape routes Escape lighting makes sure that escape routes can be **identified and used safely** at all times. - **Illuminance:** at least about **1 lux** along the centre line of the escape route (0.5 lux for open areas), with a uniformity (max:min) not more than 40:1. - **Response time:** 50% of the level within 5 s and full level within 60 s. - **Duration:** usually 1 h minimum; 3 h for premises occupied at night or where immediate re-occupation is likely. - **Luminaire positions:** near every exit door, at changes of direction, at stair landings (each flight should get direct light), near fire-fighting equipment and alarm call points, at changes of floor level, outside final exits. - **Exit signs:** illuminated "EXIT" and directional signs visible from any point on the route. - **Supply:** self-contained luminaires with their own batteries, or a central battery system with fire-resistant wiring. - **Maintenance:** monthly function test and yearly full-duration test. ```text [Room]──►corridor──►stairs──►EXIT ● ● ● ● (emergency luminaires at doors, turns, stairs and final exit) ``` ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. What minimum illuminance is required on the centre line of an escape route? A. About 1 lux B. About 100 lux C. About 10 lux D. 0 lux Answer: A. 1 lux on the centre line, 0.5 lux for open areas. (Key point: Illuminance) 2. What is the response time requirement? A. Full level within 0.5 s B. 50% of the level within 5 s and full level within 60 s C. Full level after 10 minutes D. 50% within 5 minutes Answer: B. Emergency lighting must come up quickly. (Key point: Response time) 3. What minimum duration is required, and when is 3 h needed? A. 10 minutes; 1 h at night B. 3 h always C. 1 h minimum; 3 h where premises are occupied at night or quickly re-occupied D. 24 h always Answer: C. Duration is usually 1 h, extended to 3 h for sleeping or immediate re-occupation. (Key point: Duration) 4. Where should escape luminaires be placed? A. Only in the middle of long corridors B. Only outside the building C. Only in offices D. Near exits, changes of direction, stair landings, fire equipment and alarm call points Answer: D. They mark hazards and routes at key points. 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