This performs the same function as a key-switch, isolating the fitting from its permanent live supply and thereby simulating a power failure. L SW is the normal mains supply. A normal light switch, or sensor, would usually be on this circuit to enable the end-user to have control over the light fitting in normal operating mode. L SW is always to be wired so that any switching of L PERM will disconnect L SW too, but any switching of L SW will not affect L PERM. As I understand it the EL light units that (should) have LEDs on them, the LEDs are illuminated when in normal 'charging' mode but go out when in EL mode?

It supplies the power that keeps the emergency batteries charged. That’s why it must not be affected by any switching of L SW. Our experienced testers conduct over 14,000 emergency lighting tests every year in properties across the UK. They test and inspect all units to ensure they’re functioning correctly. Pre-service audit

Pre-service audit

UK fire safety legislation states that emergency lighting is required in buildings to provide light if normal lighting fails during a fire. Self-test has several benefits. First, it saves the labour of manual testing. Secondly, it removes the risk that routine monthly or annual testing is overlooked. Details of the testing and commissioning carried out on the emergency lighting system, including dates and the results of the tests. It can take up to 24 hours for batteries on emergency lighting systems to recharge after a full discharge test. For businesses, testing should be planned around periods of non-occupancy – like over the weekend. In full-time tenanted buildings, other strategies may be necessary to ensure that systems work around testing times.

Now the refurbishment on the ground floor seems to be wired up in the 'new' way - does not extinguish power to mains. There are different types of emergency lighting; it can be maintained, non-maintained, or combined. Often there are choices with how long they remain on after a power failure. Maintained Emergency Lighting Details of the emergency lighting system, including its location, components, and the type of system installed. Confirmation that the emergency lighting system has been designed and installed to meet the specific requirements of the building and its occupants.The name of the person or organization responsible for the maintenance and testing of the emergency lighting system. If you have a central battery system, then most of the above still applies to you. Drop the incoming power to the battery and do the same walk tests. Make a note of any failures etc. However you need to test the whole system all at once. By testing the whole system at once, you are ensuring that the battery can power all the emergency lights for a full 3 hour duration. If you only tested in zones then the battery would not get a full and proper test.