What are the different types of Emergency Lighting Systems?

One way of classifying the type of Emergency Lighting System is based on how the emergency light has its power supplied. The emergency light could contain its own power supply, in the form of a battery, and this is referred to as Self Contained or Single Point. Similarly the power could be supplied from a central battery source, where a battery is located somewhere within the premises and the power is supplied to the emergency light via cabling. Generally, the decision to use either a central battery or a self-contained system is likely to be cost determined. If an installation has longevity and low maintenance as priorities, then the higher cost of a central battery may be acceptable on a very large project. Typically, luminaire costs and installation costs are a major consideration, particularly on smaller jobs, and it is this criterion which makes the self-contained luminaire the most popular choice. Self-Contained or Single Point Advantages: The installation is faster and cheaper as additional power cables do not need to be run Standard wiring material can be used, as opposed to fire resistant cables required for central battery source Burn through of the mains cable will automatically satisfy the requirement for the luminaire to be lit Low maintenance costs – periodic testing and general cleaning required Low hardware equipment costs – no requirement for extended wiring, extra ventilation, etc. Greater system integrity as each luminaire is independent of the others System can easily be extended with additional luminaires No special sub-circuit monitoring is required Disadvantages: Environmental conditions may vary across the system, and batteries may be affected by relatively high or low temperatures Battery life...