Are the present regulations regarding emergency lighting fit for purpose ?

Is this not satisfied by running all the Emergency lighting in maintained mode? I have used this in the past were it has not been possible to comply with the "failure of the local lighting" requirement since the local lighting has been supplied from more than one final circuit.

Yes, maintained emergency lights would solve the problem, but these are now discouraged due to the energy used.

Switched maintained fittings are available, but do not help in the circumstances described since whatever system or device that improperly turned off the main lighting also turns the switched maintained emergency lights to non maintained mode.

The only way I can see to do this is, as Adrian says, to use maintained fittings. However this is very wasteful from an energy stand point and somewhat undermines the point of a full lighting control system which is presumably there, at least in part, to save money/energy.

I can see where you're coming from but I really don't think it warrants re-writing standards.

Unless a proportion of the luminaries are wired outside of the 'control system' & so sacrificed to operate 24/7 I'm not sure how one might satisfy your "fault, failure or mis-application" clause.

I guess you might use some kind of watchdog function to realise that the CPU of your controller has crashed, using this to open the feed to the E-light circuit. That might cover the fault/failure mode. But 'mis-operation' .... are you classifying 'poor programing/setup' as mis-operation?

I have worked in many buildings where the lights would regularly go out if no one was moving around. This was expected and someone would usually standup and wave their hands around to turn the lights on again, it  usually happened in meeting rooms where everyone was siting around a table and not moving around. It was inconvenient but worked where the sensors were sensibly placed. I can see it being a problem if the sensors were not sensibly placed or blocked by furniture. 

ha! I have recently put a normal light switch in the ladies loo at a scout and guide  HQ with that issue. The PIR sensor only covered the area  by the door, so anyone sitting in a cubicle is not 'seen' by the sensor, and gets plunged into darkness after a short interval.
As users indicated strongly that  neither opening the cubicle door and waving nor taking a candle to see by or keep the sensor running was sensible, for now it has a light switch. If the 20 odd watts of loo lights stay on continuously on a meeting night, the cost is lost in the noise of having the heating on as the outside doors open and shut. We may change the switch, (or  use the PIR) to trigger a very long timer, 30 mins or more, as a final solution if anyone complains.

M.

The lights going out in a meeting room or toilet when a PIR times out can be inconvenient, but  unlikely to be dangerous except in rare circumstances.

My concerns refer to much larger areas such an interior fire escape stairway in a multi storey office building, or an entire floor of a large office, or a large open plan sales area in a department store.

In my view this needs to be addressed by changes in regulations, or at least new guidance on the interpretation and application of existing regulations. Despite the energy cost, I would consider maintained emergency lights that are always lit to be the best solution.

An acceptable and energy saving alternative MIGHT BE for these lights to include a presence detector that remains "on" for at least 60 minutes after the last activation. Any such presence detector MUST BE SELF CONTAINED and only applicable to the single light that it controls. Nothing involving signals or data links to any other system is acceptable since that is where the problems start.

The lights going out in a meeting room or toilet when a PIR times out can be inconvenient,

it is however P poor design and that sort of poor design, by association brings those of us who design stuff into disrepute.

Mike

I agree Mike, but we seem to be getting rules, instructions etc. that every single Watt hour must be saved, whatever the consequences. There will be serious accidents or events at some point, it is just a matter of time. I heard the Chancellor on the news just now, saying energy needs to be saved to reduce peoples costs, yet he thinks £5k grants are all that is needed and this will save £400 per year. That might be true for roof insulation if there is none, but is nonsense for low e new windows, and wall insulation. It is all going very wrong somewhere, just look at the alleged costs to insulate and clad a tower block!