Typically, the supply to ‘stay put’ emergency lighting is derived, as with emergency escape lighting, from the local mains lighting supply. The emergency lighting will be triggered by the failure either of the supply to the building, or of local lighting circuits.
However, there may be situations in which the occupants of an unaffected building are advised to stay put, perhaps due to a terrorist incident in a nearby street. The normal mains lighting would in this case be available, meaning that the emergency lighting – including the stay put lighting – will not activate. In such a situation it may be necessary to use some form of audible system as a means of informing occupants.
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