Chapter N

Characteristics of particular sources and loads


Lighting of "building accessible to the public"

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Normal lighting

Regulations governing the minimum requirements for buildings receiving the public in most European countries are as follows:

  • Installations which illuminates areas accessible to the public must be controlled and protected independently from installations providing illumination to other areas
  • Loss of supply on a final lighting circuit (i.e. fuse blown or CB tripped) must not result in total loss of illumination in an area which is capable of accommodating more than 50 persons
  • Protection by Residual Current Devices (RCD) must be divided amongst several devices (i.e. more than on device must be used)

Emergency lighting and other systems

When we refer to emergency lighting, we mean the auxiliary lighting that is triggered when the standard lighting fails.

Emergency lighting is subdivided as follows (EN-1838):

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Emergency lighting and safety signs for escape routes

The emergency lighting and safety signs for escape routes are very important for all those who design emergency systems. Their suitable choice helps improve safety levels and allows emergency situations to be handled better.

Standard EN 1838 ("Lighting applications. Emergency lighting") gives some fundamental concepts concerning what is meant by emergency lighting for escape routes:

"The intention behind lighting escape routes is to allow safe exit by the occupants, providing them with suffi cient visibility and directions on the escape route …"

The concept referred to above is very simple:

The safety signs and escape route lighting must be two separate things.

Functions and operation of the luminaires

The manufacturing specifications are covered by standard EN 60598-2-22, "Particular Requirements - Luminaires for Emergency Lighting", which must be read with EN 60598-1, "Luminaires – Part 1: General Requirements and Tests".

Duration

A basic requirement is to determine the duration required for the emergency lighting. Generally it is 1 hour but some countries may have different duration requirements according to statutory technical standards.

Operation

We should clarify the different types of emergency luminaires:

  • Non-maintained luminaires
    • The lamp will only switch on if there is a fault in the standard lighting
    • The lamp will be powered by the battery during failure
    • The battery will be automatically recharged when the mains power supply is restored
  • Maintained luminaires
    • The lamp can be switched on in continuous mode
    • A power supply unit is required with the mains, especially for powering the lamp, which can be disconnected when the area is not busy
    • The lamp will be powered by the battery during failure.

Design

The integration of emergency lighting with standard lighting must comply strictly with electrical system standards in the design of a building or particular place.

All regulations and laws must be complied with in order to design a system which is up to standard (see Figure N73).

Fig. N73 – The main functions of an emergency lighting system

European standards

The design of emergency lighting systems is regulated by a number of legislative provisions that are updated and implemented from time to time by new documentation published on request by the authorities that deal with European and international technical standards and regulations.

Each country has its own laws and regulations, in addition to technical standards which govern different sectors. Basically they describe the places that must be provided with emergency lighting as well as its technical specifi cations. The designer's job is to ensure that the design project complies with these standards.

EN 1838

A very important document on a European level regarding emergency lighting is the Standard EN 1838, "Lighting applications. Emergency lighting".

This standard presents specifi c requirements and constraints regarding the operation and the function of emergency lighting systems.

CEN and CENELEC standards

With the CEN (Comité Européen de Normalisation) and CENELEC standards (Comité Européen de Normalisation Electrotechnique), we are in a standardised environment of particular interest to the technician and the designer. A number of sections deal with emergencies. An initial distinction should be made between luminaire standards and installation standards.

EN 60598-2-22 and EN-60598-1

Emergency lighting luminaires are subject to European standard EN 60598-2-22, "Particular Requirements - Luminaires for Emergency Lighting", which is an integrative text (of specifi cations and analysis) of the Standard EN-60598-1, Luminaires – "Part 1: General Requirements and Tests".

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