Everything you need to know about Emergency lighting systems

Everything you need to know about Emergency lighting systems

Jul 16, 2021 4:46:00 PM

What is an emergency lighting

Emergency lighting is the lighting that is activated as a result of a malfunction in the general artificial lighting. The following systems may be used as replacement power supplies: single batteries, group batteries, central batteries, generating sets or a specially protected mains power supply.



Why do we need an emergency lighting

Mainly because for different reasons the Power supply systems may fail at any point of time, In serious situations it may be necessary for people Safety to leave buildings and for rescue or civil defense crew to come inside. for that an emergency light is an essential requirement for safety in buildings. Also, it allows  Easy identification of fire-fighting and safety equipment

What are the minimum requirements for an emergency lighting design? 

The minimum requirements for emergency lighting as defined in European standard EN 1838 are:

The emergency light should be at least two times brighter than the moon in a cloudless sky. the moonlight at a cloudless night is 0.01 Lux, a full moon lux is 0.25Lux, for anti-panic light it requires 0.5 Lux and the safety light level is 1 Lux. Also, there should be a sufficient number of emergency signs to illuminate the escape route


Types of Emergency lighting


  1. Safety lighting

Safety lighting must provide for a minimum brightness level to avoid panic in buildings and to allow for hazardous procedures to be completed and equipment to be turned off safely. Escape routes and safety devices must be clearly recognisable, thus enabling people to leave the premises quickly. Safety lighting breaks down into anti-panic lighting, escape route lighting and safety lighting for high-risk workplaces.



  1. Secondary lighting

Secondary lighting provides light in places where power failures will not cause any hazard, but where nevertheless work needs to be continued. For a limited period of time, it will assume the function of general lighting.



  1. Anti-panic lighting

Anti-panic lighting is meant to avoid panic in case of a power failure and to enable the people in the building to clearly recognize escape routes. The required illuminance level in the defined area is at least 0.5 lux.



  1. Escape route lighting

Escape route lighting allows for safety devices to be recognized clearly and used safely. Escape routes must be illuminated across a width of 2 m. In doing so, an illuminance level of at least 1 lux along the centerline for a path width of one meter must be guaranteed.


According to the EN 1838 standard, the ratio of highest to lowest illuminance must not exceed 40:1 for anti-panic and escape route lighting. The required illuminance level must be reached after no longer than 60 seconds. 50 percent of the illuminance level, however, must be reached already after 5 seconds. The rated service time is at least one hour.



  1. Emergency lighting for high-risk workplaces

Emergency lighting for high-risk workplaces must reach 10 percent of the illuminance level required for the respective tasks or at least 15 lux after a maximum switch-on delay of 0.5 seconds. The ratio between highest and lowest illuminance must not exceed 10:1.

Requirements for safety lighting


  1. Uniformity

The ratio of the maximum to the minimum illuminance shall not be greater than 40:1.


Fig.: Example of lighting for an escape route (Emax : Emin =< 40 : 1 lx)



  1. Safety lighting for escape routes

The safety lighting for escape routes is that part of safety lighting that enables escape facilities to be effectively identified and safely used.


Illuminance

Emin = 1 lx

(minimum horizontal illuminance at floor level)

Uniformity

Emax : Emin =< 40 : 1 lx

Colour rendering

Ra >= 40

Rated service time for escape routes

1 hour

Switch-on delay

50 % of the required illuminance level within 5 seconds, 100 % within 60 seconds

Escape routes up to 2 m in width

_ At least 1 lx along the central axis

_ 0,5 lx over at least half the width


The measurement is taken 2 cm above the floor; only the direct light from the safety or combination luminaire is taken into consideration.





Fig.: Example of horizontal illumination of escape routes



  1. Anti-panic lighting

Anti-panic lighting is that part of safety lighting that serves to avoid panic and provide illumination to allow people to reach a place where an escape route can be reliably identified.


Illuminance

E (horizontal at floor level) >= 0.5 lx

(Marginal areas with a width of 0.5 m are not taken into consideration)

Uniformity

Emax : Emin =< 40 : 1 lx

Colour rendering

Ra >= 40

Rated service time for escape routes

1 hour

Switch-on delay

50 % of the required illuminance level within 5 seconds, 100 % within 60 seconds



  1. Hazardous workplaces

There are special requirements that relate to potentially hazardous work processes and situations. Proper shut-down procedures are needed for the safety of operators and all other occupants of the premises, for example in places where machines are running, in laboratories handling hazardous and in control rooms.


Illuminance

Emin = 10 % of the level needed for the task or at least > 15 lx

Uniformity

Emax : Emin =< 10 : 1 lx

Colour rendering

Ra >= 40

Rated service time for escape routes

For as long as the hazard persists

Switch-on delay

0.5 seconds




Types of Emergency lighting systems 


Single battery system:


  • Consists of a maintenance-free battery, charging and monitoring equipment

  • Supplies backlit safety signs, standard luminaires or other safety equipment


Group battery system:


  • Limited output

  • Consists of a battery, charging and monitoring equipment


Central battery system:


  • Battery system without output restrictions

  • Consists of a battery, charging and monitoring equipment

  • Supplies the necessary safety equipment


Safety power unit:


  • Supplies the safety equipment with electrical energy no later than 15 seconds after failure of the general lighting system

  • Additional measures may be needed to achieve the minimum illuminance within the prescribed period, such as further safety power sources


High-speed standby generating set:


  • Supplies the safety equipment with electrical energy no later than 0.5 seconds after failure of the general lighting system

  • Built-in energy buffer (battery) for short-term supplies to loads and if necessary for quickly starting up the generating set


Instant standby generating set:


  • Supplies the safety equipment with electrical energy immediately on failure of the general lighting system with no interruption

  • Built-in energy buffer (battery) for short-term supplies to loads and if necessary for quickly starting up the generating set

  • There may be a temporary frequency deviation on transition from the electric motor to the power engine


Two independent systems:


  • If one system fails the other ensures that power supply is continuo

  • Energy suppliers must prevent the simultaneous failure of both supply systems

  • Two systems are deemed to be independent if they are decoupled from each other up to a voltage level of 110 kV





Emergency lighting standards and guidelines 


EN 50172

Emergency escape lighting systems

EN 1838

Lighting applications – emergency lighting


Emergency signs safety and performance standards


EN 60 598-2-22

Emergency luminaires

EN 61 347-2-7

Safety requirements for DC supplied ballasts for emergency lighting

EN 61347-2-13

Lamp control gear - Part 2-13: Particular requirements for d.c. or a.c. supplied electronic control gear for LED modules

EN 62384

DC or AC supplied electronic control gear for LED modules - Performance requirements

EN 60 925

Performance requirements for DC supplied ballasts for emergency lighting