Emergency Lighting Design

[telectrix]

using a 2 pole keyswitch, take L through key to L on em. then take sw.l from normal light switch and feed through other pole on k/s to L1 on em. that way the k/s will cut both live feeds to em.and the normal switch will cut the switched L when the lights are turned off.

 

[dazza1981]

Thats what i thought, i never would of thought of doing that...... easy when you know how.
Thanks alot tel

 

[industryspark]

Ahh, i see how you can do it now.

To clarify, a permanent live (lets say straight from lighting circuit mcb) runs through one pole of the keyswitch to supply the fitting permanent live.
Then the live from the normal light functional switch passes through the keyswitch other pole to the sl on the EL. If i feed this live off to the normal lights before it passes through key switch i can remove all power to the EL's whilst keeping the normal lights on.

Correct?

 

[telectrix]

egggsackkly.

 

[dazza1981]

And if you have a perm live and a neutral at your existing light switch it makes it even easier as you can just run a three core from there.
p/l s/l and neutral

 

[industryspark]

Appreciatte the input guys.

Ive been doing plenty of research the last few days regarding the requirments and its a far more indepth subject than one would first think.

The workshops i am installing the E-lights in are lit by discharge fittings (SON/MH) spread across 3 phases ( i.e workshop A has 12 lights, 4 on L1, 4 on L2 and 4 on L3 with a 3 gang gridswitch). I take it im ok supplying all the EL's (for a particular workshop) from just one phase so id then have a 4 gang gridswitch (1 gang for the keyswitch module) with all the EL's say from L3?

Couldnt find anything in BS5266 regarding this today although it seems like the only way it should be done?

Regards

 

[dazza1981]

Wheres telectrix??????? he will know straight away

 

[telectrix]

strictly speaking the em's should be tied to the individual light circuits.your way means that if the lights on L1 and L2 failed, the em's would not activate unless L3 circuit went down.

 

[Tiny Spark]

Appreciatte the input guys.

Ive been doing plenty of research the last few days regarding the requirments and its a far more indepth subject than one would first think.

The workshops i am installing the E-lights in are lit by discharge fittings (SON/MH) spread across 3 phases ( i.e workshop A has 12 lights, 4 on L1, 4 on L2 and 4 on L3 with a 3 gang gridswitch). I take it im ok supplying all the EL's (for a particular workshop) from just one phase so id then have a 4 gang gridswitch (1 gang for the keyswitch module) with all the EL's say from L3?

Couldnt find anything in BS5266 regarding this today although it seems like the only way it should be done?

Regards

If I am understanding you right then what you are suggesting would put a 415v potential in the light fittings if you are running your lights from L1 but have L3 for the Perm supply?

 

[industryspark]

mmm, see the argument telectrix but even if L1 and L2 was lost the EM's would still be on (they are exit sign bulkheads above doorways which is why the client wants them on the whole time the place is 'open' - hence the desire they come on with normal lighting).

So if L1 and L2 are lost the EM's are still on and there would be adequate lighting from the 4 normal fittings of L3 to be able to aid escape aswell.

 

[industryspark]

No Tiny, you misunderstand mate.

L3 would be the only phase with any EL's connected to it.

Regards.

 

[dazza1981]

Is it ok to have 3 phases in that arrangement??? As you would have 3 different points of isolation in one accessorie.
Or does it just require a warning label above the switches.

 

[industryspark]

Its permitted Dazza yeah.

You see it all the time in industrial setups - a 3 gang gridswitch with the 3 gangs each supplied with a different phase and feeding out to fittings from there.

Your correct in that a 400V warning label is required though.

 

[Tiny Spark]

No Tiny, you misunderstand mate.

L3 would be the only phase with any EL's connected to it.

Regards.

Thats ok then, Its a personal hate of mine as I got caught out years ago by someone who used 2 different phases in 1 light fitting!
Air turned blue and I was not a happy bunny....

 

[industryspark]

I can imagine Tiny, ive seen a similar thing with a timed supply to Ambirad heaters........very dangerous and makes you wonder how some 'sparks' manage to sleep at night!

 

[Tiny Spark]

I can imagine Tiny, ive seen a similar thing with a timed supply to Ambirad heaters........very dangerous and makes you wonder how some 'sparks' manage to sleep at night!

He would of slept fine if I got hold of him!! :angry_smile: