Sorry to ask this but we are having a bit of a barney here...

Does emergency lighting regardless of maintained or non-maintained have to be wired so that in the result of power fail they illuminate?

Hi Steve

Surely emergency lighting that does not illuminate in a power failure is just lighting?!!

Ian

The answer to your question is yes. However, short of not wiring it at all, it would not be possible to wire an emergency unit in such a way that it did not come on at power fail.

What is the type of premises you referring to, and what are the activities being undertaken?

Extract from the Section 5 Further guidance on emergency escape lighting of the Fire Safety-Risk Assessment Guide for Offices & Shops:-
https://www.gov.uk/gover...1/fsra-offices-shops.pdf

The primary purpose of emergency escape lighting is to illuminate escape routes but it also illuminates other safety equipment.

The size and type of your premises and the risk to the occupants will determine the complexityof the emergency escape lighting required. Borrowed lighting may be suitable in small premises where the light is from a dependable source, e.g. street lamps, and it will adequately illuminate escape routes. Where borrowed lighting is not suitable, then a number of torches, in strategic positions, can be considered.

Single ‘stand-alone’ escape lighting units may be sufficient in small premises and these can sometimes be combined with exit or directional signs (Figure 54). The level of general illumination should not be significantly reduced by the sign.

In larger more complex premises a more comprehensive system of fixed automatic escape lighting is likely to be needed. This will be particularly true in premises with extensive basements or where there are significant numbers of staff or members of the public.

However, you "insurer" that covers fires may have specific requirements that are over & above the official guidance

Em lights best fed from local circuits and unless on a phase-fail system. Exit lighting does add something in the mix.

Never from their own circuit as they will only come on when that circuit fails...and not the local lighting

If we can go back to the original question and clear up for those that don't know -

Maintained lighting is designed to be lit continuously and will continue to work even in the event of a power failure. This allows the unit to double as a standard light fitting but still supply the necessary backup in the event of a power outage.

Non-maintained emergency lighting is designed to turn on in the event of a power failure, day-to-day it just looks like the lamp might have blown. It is linked into the building’s lighting circuitry and reacts to a power failure ensuring emergency exit routes remain illuminated.

Both types require a battery hook-up in order to work in emergency situations.

I'm not sure why anyone would pay for materials and labour to install non-maintained. If I fork out for this, then maintenance and testing, I want it to work in general, not just when I have to get out of the building in a hurry. Possibly thinking "It's so worth it".

Your maintenance person/ team should really be doing a monthly function test, it's just to see if the lamp and battery work at all, rather than the annual full function test for 3 hours. This too should be recorded in the log book. There could be a key switch or a localised socket which just takes a 'fish key' http://uk.rs-online.com/...00490/?origin=PSF_428090|acc
to cut the lighting power in that area and do the test.

Paul, the point i was making is that maintained em lights are always on.
A supply for this could come from any permanent supply, not just a local lighting circuit as you would with non maintained fittings

Having just spent 4k on batteries on one of my central inverter units, I fully agree,thankfully mine supplying all 96 fittings are wired in white pyro.
Shall we say a proper job.

There seems to be some confusion about how a maintained light operates. It has two mains inputs, one is powered continuously when the supply is present, charges the battery and senses when the mains fails.
The second "maintained" input is typically wired to a light switch and turns the (mains powered) light on and off in the normal way. The emergency function will always operate on mains failure, regardless of whether the maintained input is on or off.
It is (of course) different in France where they have a thing called "rest mode" whereby a light that has automatically come on in emergency mode can be switched off.
John (engineer at Menvier before the Americans bought it)

No tony. not quite.
As Mebo says, again ignoring France,.
A maintained light will only operate as you describe IF it is wired in that manner.
An M/3 light according to the old designations has 2 line inputs that must be from the same phase, and a single neutral conductor, thus realistically to comply with BS7671 both supplies must be fed from the same source circuit.
(The current designation would be X1***180, where the * characters provide explicit functions.
The "trade" still refer to them in general as M3 & NM3.

The point that it seems both myself and Mebo are trying to make is that never mind how they are installed and functioning, what they are called etc. they are different designs that can be wired in different ways electrically to provide different functionality.

Some right, some wrong.

I often fit maintained 3 hr emergency lights (for a public sector client) which are not fed from the local lighting circuit, and in the event of failure of the local lighting circuit, they have to be manually energised to provide illumination.
They are not always illuminated.
These lights are NOT to comply with BS5266 the FRA or any statute requirements.
However, in the event of failure of their supply circuit they illuminate, as it is the failure of the circuit from which they are supplied we need to provide "assistance" with.

tony.

A non-maintained fitting will have only one line supply.
A maintained fitting will have two.

It is not my descriptions that are difficult, they exactly describe the electrical design of the fittings.
IF you can't comprehend the difference in the electrical design of a maintained and non-maintained fitting, then perhaps you should not comment?
There is NOTHING basic about electrical installations, done wrong they can kill and injure people and seriously damage property.
A maintained fitting requires two line supplies to function correctly end of story.

How many designs and installations of emergency lights have you undertaken exactly?
Do you REALLY understand how they function and are designed, and should be installed.

Your comment, that you will comment no more, to me seems to admit, that you are out of your depth?

Please all, if you don't, really, understand electrical systems, then you should not be "supervising" & "influencing" them on a level that it seems many people are.