non maintained emergency lights wired in fp

[coxy84]

iv seen this done a few times, non maintained emergency lights wired in fp fed via key switch via its own 6a mcb,

now it is my thinking that this is wrong, if there was a fire and the normal lighting had failed then em lights wired in fp wouldnt energise due to the increased fire resistance provided by the fp cable maintaining mains voltage.

opinions please

 

[telectrix]

personally, i would supply the em's from the local lighting so that if the lighting failed, the em's would activate. no problem with FP though.

 

[coxy84]

agreed i would take the supply from the local lighting, but surely there is no need for fp to be used then?

 

[millwall ken]

personally, i would supply the em's from the local lighting so that if the lighting failed, the em's would activate. no problem with FP though.

Same here.

 

[Dayo]

Its definately wrong, emergency lights must be fed off the local lighting circuit, bs5266

 

[johnboy6083]

agreed. if the lights were sustained, ie fed from central UPS or genny then they should be wired in fire resistant cable either MICC or FP. other than that, maintained and non maintained lights should be fed from normal supplies in normal cable.

 

[telectrix]

but there's nothing wrong with wiring in FP. it just costs more. IMO.

 

[Amp David]

Its definately wrong, emergency lights must be fed off the local lighting circuit, bs5266

Does BS5266 require the emergency lights to be fed via a key switch for testing, or is ok to loop through the standard light switch to give them a permenant feed and use the MCB to de energize to check they are working?

 

[Knobhead]

Turning the MCB off isn’t a good idea, you loose the general lighting in the area while you wander around checking the emergency lights. I can see that going down a bundle with an office manager.
Use a key switch.

 

[Amp David]

Thankyou Tony.

Understand what you are saying. Is it best to position the keyswitches near to the DB or switches or does it even matter?

 

[Martin Bradley]

to interupt the supply of the Em lights, so local to the bank of lights under test would be best as you can then see.

 

[somersetsparks]

Quite common for em. lights to be on there own circuit however most would be switched by contactor from an interface off of the fire alarm

 

[Knobhead]

Quite common for em. lights to be on there own circuit however most would be switched by contactor from an interface off of the fire alarm

OK look at this scenario the MCB trips but there’s no fire, everyone’s in the dark. Fire alarm operation of emergency exit lights makes sense.

 

[somersetsparks]

Tis a good point well made, I suppose the reason a lot of these places have a system like this is due to the Em. lights being added at a later date, maybe the same time as a fire alarm system.
Well I still think the central battery systems are better for larger installs anyway!