Emergency lighting is required in premises to allow occupants to escape safety in an emergency situation. The requirements under BS 5266: 2016 state that a building must have adequate illumination for escape, and identify firefighting equipment. In the UK, the legislation stipulates that all business premises including offices, factories, recreation, schools, hospitals and entertainment venues – including tents and marquees – must have emergency lighting. If the lighting is artificial (lighting from lamps), then it will be on escape routes showing exit signs, and in open areas 60m2 or greater.
The emergency lighting system must allow for safe movement of occupants walking out of a building, whether during a power cut or evacuation. It will prevent panic during evacuation if the occupants can see the directional signs for escape routes. All escape routes must be illuminated, which includes rooms, corridors, and emergency exit route signage. The signage will be either luminescent or presented by illuminated signs showing directions.
All emergency lighting must be maintained and regularly tested in the same way as other emergency equipment. Each light should be identified and have a location identity for recordkeeping. A record log can then be kept of system tests, defects, any damage to the system and remedial action relating to each light.
The monthly test can be carried out by the responsible person or automated system, and is a short functional test which ensures the light switches on and illuminates correctly. It should be free from damage and clean. The test should be done using the secure device key, commonly called a fish key due to its shape or by a central management system. Switching should be carried out by isolating the maintained live to the emergencies rather than switching off the mains lighting power, which may be hazardous to other occupants. Further information can be found in BS EN 50172 and BS 5366-8.
Emergency Monitoring using DALI
DALI emergency lighting is widely used as a robust and reliable solution that meets safety-critical requirements in buildings throughout the world.
The DALI protocol enables integrated, digital control systems that combine illumination and emergency lighting. Emergency lighting, which provides light when the mains supply fails, is a critical feature that is mandated by various regulations. “Self-contained” means that the battery – which provides power during an emergency – is inside, or placed next to, the luminaire.
In many countries, there is a legal requirement for periodic testing of emergency lighting. DALI enables self-contained emergency tests to be automated, triggered by DALI commands or by an optional timer.
Emergency control gear must implement both a function test and a duration test. The function test is a quick test of the battery, charging circuit, driver/relay and lamp, while the duration test ensures that the battery will be able to operate the lamp for the full rated duration.