Emergency Lighting Services.

 Legal Requirements

Design Objective

BS 5266, when referring to the provision of Escape Lighting in section 4.2, requires that when the supply to all or part of the normal lighting in occupied premises fails, escape lighting is required to fulfil the following function:

1. To indicate clearly and unambiguously the escape routes.
2. To provide illumination along such routes to allow safe movement towards and through the exits provided.
3. To ensure that fire alarm call points and fire fighting equipment provided along escape routes can be readily located.
4. To permit operations concerned with safety measures.

BS 5266-1 recommends that discussions should be held prior to commencing the design, to establish the areas to be covered, the method of operation, the testing regime and the most suitable type of system. These discussions should include the owner or occupier of the premises, the system designer, the installer, the supplier of the equipment and the fire authority. Note: BS5266 will be revised during 2004 following the publication of EN50172.

Other Requirements

In addition to fire safety legislation, some workplaces require a licence from the Local Authority, including theatres and cinemas, sport stadiums and premises for public entertainment, music, dancing, gambling and the sale of alcohol. Other premises must be registered with the Local Authority and be inspected by the Fire Authority, including nursing homes, children's homes, residential care homes and independent schools. Both licensed and registered premises have to pass a fire inspection to confirm that they have systems complying with BS 5266-1 for the emergency lighting and BS 5839 for fire equipment. Records of a system are now essential to maintain the validity of approvals and licences

There are seven main stages to consider when designing Emergency lighting 

STAGE 1 - LOCATE LUMINAIRES AT MANDATORY “POINTS OF EMPHASIS” Initial design is conducted by situating luminaires to reveal specific hazards and highlight safety equipment and signs, in addition to providing illumination to assist safe travel along the escape route. This should be performed regardless of whether it is an emergency escape route or an open (anti-panic) area. Only when this is accomplished should the type of luminaire or its light output be considered. BS5266 Pt 7: 1999 requires that the luminaires sited at points of emphasis must comply with BS EN 60598-2-22. Specific locations where a luminaire must be provided are:
At each exit door All safety exit signs Outside and near each final exit Near stairs so that each tread receives direct light At each change of direction Near each first aid post Near any other change of floor level At each intersection of corridors At each piece of fire fighting equipment and call point
Note - the term near means within 2 metres measured horizontally

STAGE 2 - ENSURE THAT EXIT SIGNS ARE OF CORRECT FORMAT AND SIZE Section 4.1 of BS5266 Pt 7 states that “Signs which are provided at all exits intended to be used in an emergency and along escape routes shall be illuminated to indicate unambiguously the route of escape to a point of safety”. Where direct sight of an emergency exit is not possible, an illuminated directional sign (or series of signs) shall be provided to assist progression towards the emergency exit.
• Sign formats should not be mixed     BS2560: 1975 Old-style signs now obsolete. Should have been replaced by December 1998     BS 5499 Pt 1 Signs are still acceptable, if they are already in the building     European Signs Directive Format This came into force on 1st April 1996, under The Signs Directive If there is any doubt as to the most appropriate format of sign, guidance should be obtained from the local Fire Authority.
• Maximum viewing distances
For all format of safety signs the maximum viewing distances and luminance conditions are given in BS 5266 pt7/EN 1838 Signs can be either internally illuminated, such as exit boxes or edge lit emergency luminaires with a screened sign that have a controlled illuminance, or painted signs with an external emergency light illuminating them. Maximum viewing distances are: Internally illuminated signs - 200 x the panel height Externally illuminated signs - 100 x the panel height  • Illumination requirements       The sign must conform to the colours of ISO 3864, which defines that exit and first aid signs must be white with green as the contrast colour. The ratio of luminance of the white colour to the green colour must be between 5:1 and 15:1. The minimum luminance of any 10mm patch area on the sign must be greater than 2cd/m² and the ratio of maximum to minimum luminance shall be less than 10:1 for either colour Note: Internally illuminated exit signs are pre-tested to ensure they meet these requirements, provided that they comply with EN 60598-2-22. If the sign is designed to be externally illuminated, considerable care must be taken by the system designer to see that these conditions are met. Even though an emergency luminaire must be sited within 2 metres from the sign (see stage 1) calculations should still be made to check that the sign is adequately illuminated.

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STAGE 3 - LOCATE LUMINAIRES AT THE FOLLOWING ESSENTIAL AREAS IN THE BUILDINGS Locate luminaires at the following essential areas in the buildings. These locations are not part of the escape route but because of their risk they require protection by emergency lighting.
a) Lift cars - although only in exceptional circumstances will they be part of the escape route, do present a problem in that the public may be trapped in them in the event of a supply failure. b) Toilets - all toilets for the disabled and facilities exceeding 8m2 floor area or without borrowed lights. c) Escalators - to enable users to get off them safely.       d) Motor generator, control or plant rooms - require battery supplied emergency lighting to assist any maintenance or operating personnel in the event of failure. e) Covered car parks - the normal pedestrian routes should be provided with non-maintained luminaires of at least 1 hour duration.

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STAGE 4 - ESCAPE ROUTE LIGHTING When the points of emphasis have been covered, it is essential to provide any additional luminaires to ensure that minimum illuminance levels are met to enable the routes to be used safely. In addition, every compartment on the escape route must have at least two luminaires, to provide some light in the event of luminaire failure.
• Light Level Requirements BS 5266 Pt 7: 1999 (EN1838) calls for a minimum of 1 lux anywhere on the centre line of the escape route for normal risks. A uniformity ratio of 40:1 maximum to minimum must not be exceeded. This illuminance must be provided for the full duration and life of the system. 50% of the illuminance must be available within 5 seconds and the full value within 60 seconds of supply failure. Note: The UK has an “A deviation” which continues to allow a 0.2 lux minimum value for routes that will be permanently unobstructed. It should be noted that this puts a heavy burden on the user to ensure routes are kept clear even in an emergency. For this reason it is recommended that the 1 lux level should always be used. • Photometric Design Emergency Escape Routes The use of spacing tables or a suitable computer program provides the information to determine whether luminaires are needed in addition to those for the points of emphasis (see data section), to provide the minimum required level of illumination on the escape routes. To ensure that the design will meet the required levels at all times the data is de-rated, as required by the standard, to cover the following factors: i. Reduction in light as the battery voltage reduces during discharge. ii. Aging of lamps in maintained circuits iii. The effects of dirt (Spacing tables use a figure of 80%).
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STAGE 5 - OPEN (ANTI-PANIC) CORE AREAS Areas larger than 60m², open areas with an escape route passing through them, or hazards identified by the building risk assessment all require emergency lighting. The current standard is easy to design for and to verify, promoting systems that provide good uniformity rather than ones that use a few large output luminaires. • Light Level Requirements BS5266 Pt 7/EN1838 - 4.3 calls for 0.5 lux minimum of the empty core area, which excludes a border of 0.5m of the perimeter of the area. Spacing tables or a suitable computer program provide simple and accurate data that can easily be used. The spacing tables for 0.5 lux are de-rated on the same basis as those for escape routes. They can also be used as a guide for initial selection of the location of luminaires when using a computer program • Spacing data Specific data is available for self-contained dedicated emergency luminaires. If using standard mains luminaires fitted with an emergency conversion kit, typical data is also shown in the spacing table document. The data details the polar distribution for common types of luminaires, from which a suitable match should be selected. The factors considered should be the shape of the polar curve and the scale, which is shown by the nadir intensity. Alternatively, a computer program can be used and the light outputs of the appropriate kit can be used with the actual distribution data of the luminaire chosen.
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STAGE 6 - HIGH RISK TASK AREA LIGHTING BS5266 Part 10: 2008 provides guidance on the method of assessing the requirements for emergency lighting to High Risk  areas, with recommendations for a number of selective examples such as kitchens, Plant Rooms Refuges, First Aid Rooms and fire control equipment. Typically the recommended illumination level is 15 Lux on to the task either horizontal or vertical. DESIGN PROCEDURES Reaching the light levels needed would normally be achieved by using a conversion of the normal luminaire, or by using a tungsten projector unit. If conversion units are selected, a direct ratio can be obtained by the Ballast Lumen Factor (BLF). i.e. to achieve 10% of normal use either: - Emergency units with a BLF of 10% are needed for each fitting in the area - Emergency units with a BLF of 20% are needed for every other fitting - Emergency units with a BLF of 100% are needed for one in 10fittings Care is needed to ensure that a reasonably uniform distribution is achieved by whatever combination of luminaire and conversion kit used. If tungsten projector units are selected, a co-efficient of utilisation calculation has to be performed for the required value.
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STAGE 7 - CONTROL Non-maintained luminaires must be activated by failure of supply to the normal lighting. They must therefore be connected an unswitched live taken from the local normal lighting final circuit. Once the design has been completed it becomes apparent that the performance of the luminaire depends as much on the light distribution as it does the light output available. Consequently it becomes essential that luminaire types specified for a particular design do not get changed without a re-appraisal of the photometric design.
TESTING AND LOG BOOK The Fire Precautions (Workplace) Regulations 1997 require that appropriate testing is performed to maintain compliance of the system. The system should include adequate facilities for testing and recording the system condition. These need to be appropriate for the specific site and should be considered as part of the system design. Discussions with the user or system designer should identify: - The calibre and reliability of staff available to do the testing - The level of difficulty in performing the test - If discharge tests need to be done outside normal working hours, or phased so only alternate luminaires are tested in buildings that are permanently occupied The testing requirements in the code of practice are: • Function test All emergency luminaires should be tested be breaking the supply to them and checking that they operate satisfactorily. The supply must then be restored and the charging indicators must be seen to be operating correctly. This test must be performed at least once per month and the results logged • Discharge test The luminaires must be tested for their full rated duration period and checked for satisfactory operation. The supply must then be restored and the charging indicators rechecked. This test must be performed at least annually and the results logged Note: BS 5266-1: 2005 allows a one hour test to be performed as an alternative every six months for the first 3 years of the system, but the guidance document to the Fire Precaution Regulations calls for the annual test at all stages of equipment life. MANUAL TESTING If manual testing is utilised, the following points should be considered: - Is a single switch to be used? Unless the whole building is to be switched off, a separate switch should be used for each final circuit. As the feed to non-maintained circuits must be taken from the switch this will probably mean that the building will have to be walked around twice, once to check the luminaires and once to check that they are recharging - Are luminaires to be individually switched? In practice, only a single walk around the building will be needed. However, the test switches could spoil the décor of the building and they must be of a type that is tamper proof. After the tests, the performance of the luminaires must be logged.

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