In our latest Emergency Lighting Q&A of the week we want to find out why do self-contained emergency fixtures in Europe last for one hour while in the UK they last for three hours?
Emergency lighting legislation is stronger in the UK than in some European countries and although the overall European standard (BS EN 1838:2013, lighting applications — emergency lighting) calls for a minimum of one hour duration, the UK guidance document (BS 5266-1 Emergency lighting –Part 1: Code of practice for the emergency lighting of premises) states:
'A minimum duration of three hours should be used for emergency lighting if premises are not expected to be evacuated immediately in the event of a supply failure, such as sleeping accommodation or places of entertainment, or if the premises are expected to be reoccupied when the supply is restored without waiting for batteries to recharge.
A minimum duration of one hour should be used only if the premises are expected to be evacuated immediately on supply failure and not reoccupied until full capacity has been restored to the batteries.'
This guidance document, along with various local legislation, means that three hour emergencies are standard in the UK. Anyone meeting the three hour duration complies totally with the requirements and it means that premises can be reoccupied shortly after a mains failure as there will still be some emergency coverage meeting the minimum requirements.
With a one hour system even a five minute failure may mean you no longer meet the minimum one hour requirement and the building cannot therefore be reoccupied until the batteries have been fully recharged.
You find a full library of our emergency lighting questions and answers here.