Emergency lighting is battery powered lighting which will switch on and illuminate when the power is cut from the mains. This is usually for the people inside a building to find their way out in a safe manner.
Traditional emergency lighting is either an internal or external bulkhead fitting. These usually have a polycarbonate body and tray which house all the components and will operate for approximately three hours without any mains power, recharging when the mains power has been restored. Another popular type of emergency light is the illuminated fire exit sign which lights up to show you where the main exits are. LED emergency lighting is now starting to become very popular thanks to its energy saving benefits.
When looking for the emergency lighting fitting you require, you are likely to come across the terms 'maintained' and 'non-maintained':
Maintained fittings are ones which can be operated with a lighting controller (such as a switch) and can be left permanently on or can just operate when there is a power cut.
Non maintained fittings will not illuminate unless there is a power cut.