emergency light circuit

[markymark2406]

I am having conflicting information in regards the right way to wire a emergency light as follows:

I have to put a Flouresent fitting which is fitted with a emergency circuit in case of power failure, i want to have a standard mk switch on the wall with a key switch for testing the emergency circuit, so do i have to run a separate live staight from the MCB to the key switch or can i just link over the live from the live of the standard switch?

 

[breezer]

what will an additional live do?

EL's are supposed to come on when supply removed

 

[Spark123]

I take it that is it just a maintained one? The way I'd go about it is a permanent live to the keyswitch common linked across to the normal switch common. The other side of the keyswitch to the L and the other side of the normal switch to LS.

 

[ricicle]

Is it of the type that is a normal fluorescent light with the mains on and uses an inverter to run one or two tubes from an enclosed battery pack (sustained lighting) in the event of a power failure?
If so you need to break the permanent live that charges the battery pack as this is what changes the light over from mains to battery.

 

[markymark2406]

yes thats right ridicle, the key switch is there for the purpose of breaking the live feed to the inverter on the flouresent fitting as so to produce a emergency light test, so do i take a link from the permanant live on the normal switch or do i take a completlly new live from the board?

 

[tim west]

It should come from the same live that feeds the lighting in the vicinity of the Emergency Light so that if the surrounding lighting fails due to power failure of that particular circuit then there are still lights for safety or escape.

 

[Lectrician]

And to really impress, use a two way switch. L1 feeding the em fitting, and L2 feeding a neon adjacent to the keyswitch. The neon lights when the supply the em is OFF. This is a specification on many jobs these days. Prevents the em from not having its power returned after a duration test.