Maintained Lighting. The emergency lights are always on and continue to be lit for up to 3 hours after the power fails, using their back up batteries.
Non Maintained Lighting Only light up once the power has failed and will be lit for 3 hours using backup batteries.
Legal Requirements The need for emergency lighting varies around the country with different fire officers.
The main principles are: Public Functions i.e. where the public pay to enter a venue, maintained lighting is essential.
Private Functions i.e. events not open to the general public, only require non maintained lighting.