Emergency Lighting

Emergency lighting is lighting for an emergency situation when the main power supply is cut and normal electrical illumination fails.  The loss of mains electricity could be the result of a fire or a power cut. Without emergency lighting this could lead to sudden darkness and possible danger to occupants, either through physical danger or panic.

Emergency lighting is normally required to operate fully automatically and give illumination of a sufficiently high level to enable all occupants to evacuate the premises safely. Most new buildings have emergency lighting installed during construction; the design and type of equipment being specified by the architect in accordance with current Building Regulations and any local authority requirements.

The British Standard provides the emergency lighting designer with clear guidelines to work to. BS 5266-1 relates not only to hotels, clubs, hospitals, nursing homes, schools and colleges, licensed premises, offices, museums, shops but also multi-storey dwellings. Although the standard recommends the types and backup durations for each category of premises, it should be remembered that standards define a minimum requirement and that a higher specification may be required for a particular application.

Maintenance

Finally, to ensure that the system remains fully operational, essential servicing should be specified. This would usually be performed as part of the testing routine, but in the case of consumable items such as replacement lamps, spares should be provided for immediate use.

Servicing and testing

To test an emergency lighting system, a mains power failure on the normal lighting circuit / circuits or individual luminaries must be simulated. This will force the emergency lighting system to operate via the battery supply. This test can be carried out manually or automatically.

Manual testing

A simulated mains failure can be achieved by providing a switch to isolate all lighting circuits / individual circuits / individual luminaires. If manual testing is utilised, the following points should be considered:

In a system with a single switch for the whole building or a large circuit, after simulating the mains failure it is necessary for the tester to walk the whole building or circuit, to check all emergency luminaire are operating correctly. After restoring the mains supply, the whole building or circuit must be walked again, to check that the emergency lights are recharging.

If the emergency luminaires are individually switched, only a single walk around the building will be needed. However, the test switches could spoil the decor of the building and they must be of a type that is tamper proof. After the tests, it is recommended that the performance of the system is logged in the fire safety logbook.

Monthly emergency lighting tests

All emergency lighting systems must be tested monthly. The test is a short functional test in accordance with BS EN 50172 / BS 5266-8.

The period of simulated failure should be sufficient for the purpose of this test while minimising damage to the system components, e.g. lamps. During this period, all luminaires and signs shall be checked to ensure that they are present, clean and functioning correctly.

Annual emergency lighting tests

A test for the full rated duration of the emergency lights (e.g. 3 hours) must be carried out. The emergency lights must still be working at the end of this test.

The result of the monthly and annual tests must be recorded and, if failures are detected, these must be remedied as soon as possible.

It is common for fire alarm servicing companies to carry out the annual emergency light ‘drain’ test at the same time as they carry out fire alarm system maintenance, as this fills the waiting time of the ‘drain’ test with useful activity.