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A lack of lighting in a building during an emergency could lead to sudden darkness and possible harm to the occupants, either through panic or physical danger… In the event of an emergency, does your building have the necessary light fittings and signs to allow your employees to safely evacuate?

In this NEW series, we introduce you to emergency lighting. In the first instalment, we start by giving an overview of what emergency lighting is, and touch on the reasons for having this in your workplace.

What is Emergency Lighting?

It is lighting that is required for an emergency when the main power supply is disrupted, and the normal electrical illumination fails. The loss of mains electricity can be a result of a fire or a power cut.

Emergency lighting is required to operate fully automatically as well as provide illumination at a sufficiently high level. This enables all occupants to evacuate the premises in a safe and according manner. Emergency lighting is a general term which is sub-divided into emergency escape lighting and standby lighting.

1. Emergency Escape Lighting

This is the part of an emergency lighting system that provides the necessary lighting for the safety of people that are leaving a location or attempting to terminate a potentially dangerous process beforehand. Escape route lighting, open area lighting and high-risk task area lighting make up the emergency escape lighting system.

2. Standby Lighting

According to SANS 10114, standby lighting is the non-mandatory part of an emergency lighting system that is provided to enable normal activities to continue unchanged.

What is the need for Emergency Lighting?

Emergency lighting is necessary for the following reasons:

1. Instant Effect - Emergency lighting is continuously powered by a battery-powered system hence the effects are immediate, preventing initial confusion or waiting for the lights to turn back on.

2. Help Fire Responders - Emergency lighting assists fire responders to reach their target as soon as possible, especially if they are not familiar with the layout of the building. It will also highlight the safest route to take and reach those who need assistance.

3.  Minimise Panic - A well-lit exit route will enable the building occupants to identify and follow the necessary exit lights so that they can escape the building in a timely and sensible manner. A panic that is initiated by darkness with the addition of smoke-filled corridors can cause stampedes, and confusion which can lead to an increase in injuries, or even a fatality.

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                          Figure 1 : How an Emergency Lighting System Operates

Emergency Lighting Technologies

The 2 types of technologies that exist for emergency lighting systems are the self-contained (SC) system and the central battery system (CBS).

A self-contained emergency luminaire has its own battery to provide the required power. Under normal conditions, the battery will remain on a permanent charge by the mains lighting circuit until the power supply is lost and the battery takes over. Components of the SC luminaire such as the battery, light source, control unit and any test or monitoring equipment are located in the luminaire housing itself, or in a directly adjacent enclosure.

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Fig 2: Self-Contained Luminaire System

A central battery system supplies power to emergency luminaires that have no onboard battery. These luminaires draw power from one centralized battery in the building that is supported by a charger, change-over devices and alarms should mains lighting fail.  In some CBS installations, several Low Power Supply systems (LPS) are distributed in the building to serve only individual floors or fire protection sections. 

Fig 3: Central Battery System Used to power Luminaires
Fig 3: Central Battery System Used to power Luminaires

 

In the next article of the series, we touch on the different types of technologies that exist for emergency lighting systems, the types of lights used and the importance of it in terms of building requirements and legislation.

 

Resources:

1. READ about the importance of escape route lighting and markings

2. CHAT to us for an emergency lighting solution for your facility

3. SUBSCRIBE to receive these mails straight to your inbox

 

Sources:

https://www.firesafe.org.uk/emergency-lighting/