Note for Guidance

The Fire Safety Advice Centre

Emergency Lighting

Introduction.

Emergency lighting is a self-descriptive term and is lighting for an emergency situation when the main power supply fails. The loss of mains electricity could be the result of a fire or a power cut and the normal lighting supplies fail. This may lead to sudden darkness and a possible danger to the 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 persons of all ages to evacuate the premises safely. Most new buildings now have emergency lighting installed during construction, the design and type of equipment is normally specified by the relevant local authority, architect or consultant.

The British Standard provides the emergency lighting designer with laid down guide lines which form the general basis for the designer to work to. British Standard BS 5266: Part 1: 2005 includes in its scope residential hotels, clubs, hospitals, nursing homes, schools and colleges, licensed premises, offices, museums, shops, multi-storey dwellings etc. Although this standard recommends the types and durations of emergency lighting systems relating to each category of premise it should be remembered that the standards are minimum safe standards for the types of premises and that a higher standard may be needed for a particular installation.

Type of system

Most emergency lighting schemes fall into one of the following categories:-

• Non-maintained - The emergency light units only illuminate in the event of a mains failure.
• Maintained - The emergency light units are illuminated at all times using the same lamps for both normal and emergency operation.
• Sustained - The emergency light units are fitted with two lamps or two sets of lamps. One of which operates on mains 240V AC supply, the other which operates from the battery supply in the event of mains failure. It is basically a non-maintained system with the addition of mains lamps which should be illuminated whenever the premises are occupied.

The type of system and emergency duration is often expressed in abbreviated form as per the following examples:-

• M3 - Maintained System, emergency duration 3 hours.
• NM2 - Non-maintained System, emergency duration 2 hours.
• S1 - Sustained System, emergency duration 1 hour.

Emergency Luminaire's

An emergency luminaire will either be of the self-contained type, i.e. with all components integral to the luminaire body (battery, charging circuit, mains ballast etc). Or "slave" to a central battery system where only the lamp (and an inverter if fluorescent) is located within the luminaire body and the supply on power failure is fed from some centralised point.
The majority of systems installed in the United Kingdom are of the self-contained type, but both options have their own advantages and disadvantages.

Emergency Power Supplies

Central Battery Source

Advantages

• Maintenance and routine testing is easier with only one location to consider;
• Superior battery life, between 5 and 25 years dependant upon type;
• Environmentally stable in a protected environment, luminaire able to operate at relatively high or low ambient temperatures;
• Large batteries are cheaper per unit of power and luminaire are usually less expensive.

Disadvantages:

• High capital equipment costs;
• High installation and wiring costs with essential MICC or Pirelli FP200 type cable to each slave luminaire;
• Poor system integrity - failure of battery or wiring circuit can disable a large part of the system;
• Requirement for 'battery room' to house cells and charger circuits etc, may also require ventilation of acid gases;
• Localised mains failure may not trigger operation of emergency lighting in that area.
• Voltage drop on luminaire wired furthest from the central battery could become a problem.

Self Contained - Single Point

Advantages:

• Speedy and low cost installation;
• Standard wiring material may be used (failure of mains supply due to cable burning through will automatically satisfy the requirement for a luminaire to be lit);
• Low maintenance costs - periodic test and general cleaning only required;
• Low hardware equipment costs – no requirement for extended wiring,special ventilation etc.
• Greater system integrity with each luminaire independent of the other;
• System can easily be extended with additional luminaire's;
• No special sub-circuit monitoring requirements.

Disadvantages:

• Limited environmental operating range (batteries may be adversely affected by a relatively high ambient temperature);
• Battery life is limited to between 2 and 4 years dependant upon application;
• Testing requires isolation and observation of luminaire's on an individual basis.

In general then,the decision to use either a central battery or a self-contained system is likely to be cost dominated. If an installation has longevity and low maintenance as priorities, then the higher cost of central battery may be acceptable on a very large project. Usually, luminaire and installation costs will be a major consideration, particularly on smaller jobs, and it is this criterion which makes the self-contained luminaire the most popular choice.

How much light?

BS5266 recommends the provision of a horizontal illumination at floor level on the centre line of a defined escape route (permanently unobstructed) not less than 0.2 lux and 0.5 lux minimum for anti panic areas to exclude 0.5 metre border around the room. In addition, for escape routes of up to 2m wide, 50% of the route width should be lit to a minimum of 0.1 lux. Wider escape routes can be treated as a number of 2m wide bands. The actual degree of illumination should be closely related to the nature of both the premises and its occupants with special consideration being given to old person’s homes, hospitals, crowded areas such as pubs, discos and supermarkets, and to whether or not the premises are residential.

Typical emergency lighting units

Siting of luminaire's/signs

Having decided on your basic system, consideration should now be given to the siting of the lighting units and signs within the particular premises involved. This will then form the basis on which your selection of equipment can be made.

Lighting units and signs should be sited so as to clearly show the exit routes leading to the final exits from the premises. Where the exit route or final exit is not readily identifiable a sign should be utilized rather than a lighting unit. Particular attention should be paid to individual stairways, changes in level, corridor intersections, changes in direction, the outside of each final exit, control/plant rooms, lifts, toilet areas over 8m2 (although in some peoples opinion all toilets of public access and especially those for the disabled should have emergency lighting). Access to fire alarm call points, fire fighting equipment, should be clearly illuminated.

In general, if common sense is used when siting the luminaire and signs to cover these areas, then the completed scheme will meet most requirements.

Note. Detailed computer point calculations or luminaire manufacturers spacing tables should be used.

Areas to be covered

There is legislation, guides, British and European standards that require emergency lighting to be installed and the ares it should cover. An emergency escape lighting system should normally cover the following ares,

• each exit door;
• escape routes;
• intersections of corridors;
• outside each final exit and on external escape routes;
• emergency escape signs;
• stairways so that each flight receives adequate light;
• changes in floor level;
• windowless rooms and toilet accommodation exceeding 8m2;
• firefighting equipment;
• fire alarm call points;
• equipment that would need to be shut down in an emergency;
• lifts and areas in premises greater than 60m2.

It is not necessary to provide individual lights (luminaire) for each item above, but there should be a sufficient overall level of light to allow them to be visible and usable.

Servicing and testing

To test an emergency lighting system you need to simulate a mains power failure on the normal lighting circuit or circuits or individual luminaire's. This will force the emergency lighting system to operated and use the battery supply. This can be done manually or automatically.

Manual Testing

You can achieve a simulated mains failure by providing a switch to isolate all lighting circuits or individual circuits or individual luminaire's. If manual testing is utilised, the following points should be considered:

In a non maintained system and a single switch is used for the whole building or a separate switch used for each circuit. This means when you simulate the mains failure you have to walk the whole system to check all emergency luminaire are operating correctly.When you restore the mains supply you have to walk it again to check that they are recharging. If all luminaire's 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 should be logged.

Automatic Testing

If the costs of an engineer time and the disruption caused by manual testing are excessive, automatic systems should be considered. Different formats are available to match particular site requirements.

The following is an overview of one manufacturers automatic system and is typical of the systems available. It consists of a main control panel plus one remote unit per luminaire. The remote units report back to the main panel using the mains wiring in the premises so no extra wiring is required.

The main panel can control up to 500 luminaire's and each remote unit can be configured to be maintained or non-maintained, three hour or one hour type and the frequency of tests can also be set. In addition, restrictions on when testing may be carried out can be imposed with regard to a user specified time window, an input from a twilight sensor or an input from an alarm panel (so that luminaire's will be tested when the alarm is set and the premises empty).

All activities are logged at the main panel and can be printed on the system printer either continuously or on user request. Thus a hard copy of when each unit was tested is always available together with log entries when either user or engineer modes are used.

The log can have a 1000 entry capability and is battery backed. The system information (set-up details for both the overall system and for individual remote units) is stored in EEPROM which is therefore preserved even if the battery fails.

An additional serial port is available which could be connected via a modem to a central station. Software for this port is available on request.

General

BS EN 50172:2004/ BS 5266-8:2004 Emergency escape lighting systems. Specifies the minimum provision and testing of emergency lighting for different premises. Also additional information on servicing can be found in BS 5266 - Part 1 - 2005 Emergency lighting - section 13 servicing.

The system should include adequate facilities for testing 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 caliber and reliability of staff available to do the testing
• The level of difficulty in performing the test
• Discharge tests need to be done outside normal working hours. In buildings that are permanently occupied the test should be phased so only alternate luminaire are tested.

When automatic testing devices are used the information shall be recorded monthly and annually. For all other systems, the tests shall be carried out as described below and the results recorded.

Regular servicing is essential. The occupier/owner of the premises shall appoint a competent person to supervise servicing of the system. This person shall be given sufficient authority to ensure the carrying out of any work necessary to maintain the system in correct operation.

Routine inspections and tests

Where national regulations do not apply, the following shall be met.

Because of the possibility of a failure of the normal lighting supply occurring shortly after a period of testing of the emergency lighting system or during the subsequent recharge period, all full duration tests shall wherever possible be undertaken just before a time of low risk to allow for battery recharge. Alternatively, suitable temporary arrangements shall be made until the batteries have been recharged.

The following minimum inspections and tests shall be carried out at the intervals recommended below. The regulating authority may require specific tests.

Daily

Indicators of central power supply shall be visually inspected for correct operation.

NOTE. This is a visual inspection of indicators to identify that the system is in a ready condition and does not require a test of operation.

Monthly

If automatic testing devices are used, the results of the short duration tests shall be recorded.

For all other systems the tests shall be carried out as follows:

a) Switch each luminaire and each internally illuminated exit sign to emergency mode so it uses the battery. This simulates a failure of the supply of the normal lighting and continue for a period sufficient to ensure that each lamp is illuminated.

At the end of this test period, the supply to the normal lighting should be restored and any indicator lamp or device checked to ensure that it is showing that the normal supply has been restored.

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

b) For central battery systems, the correct operation of system monitors shall be checked.

c) For generating sets, refer to the requirement of ISO 8528-12.

Annually

If automatic testing devices are used, the results of the full rated duration test shall be recorded.

For all other systems the following tests made:

a) each luminaire and internally illuminated sign shall be tested as per monthly test but for its full rated duration in accordance with the manufacturer's information;

b) the supply of the normal lighting shall be restored and any indicator lamp or device checked to
ensure that it is showing that normal supply has been restored. The charging arrangements should
be checked for proper functioning;

c) the date of the test and its results shall be recorded in the system logbook;

d) For generating sets, refer to the requirements of ISO 8528-12.

Commissioning Certificate

BS5266 and the European Standard both require written declarations of compliance to be available on site for inspection. These consist of

1. Installation quality.
   IEE regulations must have been conformed with and non-maintained fittings fed from the main circuit of the normal lighting system, as required in BS 5266
2. Photometric performance.
   Evidence of compliance with light levels has to be supplied by the system designer.
3. Declaration of a satisfactory test of operation.
   A log of all system tests and results must be maintained. System log books, with commissioning forms, testing forms and instructions should be provided by the installer.

On completion of the installation of the emergency lighting system, or part thereof, a completion
certificate should be supplied by the installer to the occupier/owner of the premises. The Building Control Department should insist upon a copy of this certificate which will be retained with the Building Regulations Authority.

Maintenance

Finally, to ensure that the system remains at full operational status, essential servicing should be defined. This normally would 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.

Summary of guidance covering emergency lighting.

British Standard 5266 - Emergency Lighting

Emergency lighting is now covered by a series of interdependent standards which can be seen as forming a hierarchy as shown below.

Base guidance document
BS 5266-1- 2005 Emergency lighting-Part 1: Code of practice for emergency lighting of premises. Gives general rules and guidance on the provision and operation of emergency lighting in most premises other than dwellings

System standards
BS EN 1838:1999/ BS 5266-7:1999 Lighting applications - Emergency lighting. Specifies the illumination to be provided by emergency lighting (including luminance, duration and colour)
BS EN 50172:2004/ BS 5266-8:2004 Emergency escape lighting systems - Specifies the minimum provision and testing of emergency lighting for different premises

Product standards
BS EN 60598-1: 2008 Luminaire's. General requirements and tests. Check out the 60598 series for particular requirements.
BS EN 62034:2006 Automatic test systems for battery powered emergency escape lighting . Specifies a test system for battery powered emergency lighting
BS EN 50171:2001 Central power supply systems. Specifies central power supply systems for luminaire for emergency lighting

Check out your local reference library or purchase copies from BSI Online insert the BS number to see what standards are available and their titles. These links may not be inclusive but do indicate the some of the standards that are available.

Regulatory Reform (Fire Safety) Order

The Regulatory Reform (Fire Safety) Order guides has a "Section 5 Further guidance on emergency escape lighting" which will provide you with additional relevant information. Check out The Regulatory Reform (Fire Safety) Order guides

Approved Document "B"

Check out Approved Document "B"

This handout provides a general overview and basic information on this topic. It may not apply to everyone, consequently to find out if this guide applies to you and to get more information on this subject, study all the relevant legislation, guides and British/European Standards. Also you should seek advice from an expert on the subject or your local Fire Safety Officer or Fire Safety Professional.

I would be much obliged if you would sign the guestbook and make your comments about the web site. Also include your constructive criticism on the site and inform me if any information which is out of date so I can research it to bring it up todate. This will enable me to improve the site and make it more relevant to its users.

Merseyside Fire Liaison Panel. Permission is granted to print and photocopy this material for nonprofit educational uses.

[Index]

This page was last checked and modified on Friday, 23 July, 2010 20:15