Emergency Lighting source of supply.

Does this have to come from the same mcb to which the lighting circuit is connected for which the emergency lighting circuit is to protect? Or can I just supply the E/lighting from the common terminal of the light switch for the ordinary lighting circuit?

  • does not the light switch get fed from the MCB anyway ? It is a bit late and I may have misunderstood  something, but normally the lights and EM lights charging supply for a given room or group of rooms is the same circuit.


  • In general, self contained emergency lights should be supplied from the same circuit that supplies the normal mains lighting in the area.

    The connection may be made at the MCB or at any other suitable point.

    Other arrangements may be suitable in some limited circumstances. For large open areas such as supermarkets or open plan offices it is IMHO acceptable to use a dedicated circuit to supply self contained emergency lights. Any general power cut will still bring the emergency lights on. A tripped MCB one one local circuit WONT operate the emergency lighting, but this should be acceptable if sufficient mains powered lighting is available from those circuits still on. Remember that emergency lighting only gives very low lighting levels, and that mains lighting from a distant part of an open plan area is almost certainly brighter than that from the emergency lights.

    In the case of maintained emergency lights, then the source of supply is less important since they should be lit at all times, either on mains or on battery.

  • Sorry about the confusion. The E/lighting will serve centre stage only, in a main hall, The wings at each side have their own E\lighting systems. Basically there will be two working floodlights for setting up and shall be supplied via their own rcbo. and I am adding a couple of emergency lights to this circuit via the floodlight light switch rather than the dist board.