Posted By AlanB
Emergency lighting should not be powered off the mains. They are there in case of power failure as well. Therefore no power = no emergency lights.

However, they can be re-charged off the mains. This is often a much better alternative to using purely replacable batteries, as there is always maintenance required for battery only lights. Ho do you know that battery is not depleated? Rechargable emergency lights off the mains guarantees fully charged emergency lighting, so that if the power does go off, there will be power stored in a mains rechargable battery.

Alan

Posted By Charles Robinson
Simon

Emergency lighting is coverd under British Standards BS 5266
contents as follows
1 scope
2 Definitions
3 Consultation and records
4 Need for emergency lighting
5 Illumination for safe movement
6 Emergency light design
7 Batteries
8 wiring systems and circuit requirments
9 Choice of appropriate emergency lighting systems
10 Emergency lighting design procedure
11 Certificate and log book
12 servicing
appendencies

a Measuring illumination of emergency lightin
b Model completion certificate
c model periodic inspection and test certificate
d model servicing schedual

these systems need daily checks to see if they are charging
6 monthly
and 3 yarly compleat discharge generaly 3 hours after 3 years old this becomes
yearly rechargable batteries general need replacing after 4/5 years but still then require anual compleat discharge due to age of charging circuit and inverter

records of testing are normaly kept with building fire alarm log and can be checked by the fire brigade