Em Lighting key switches!

[Crosswire]

OK,
Settle this once and for all please chaps.

When keying off emergency lights, should you switch;

1) just one pole (e.g. the permanent live)
2) two poles ( e.g. both switched and permanent lives)

or

3) three poles ( both lives and neutral also (as some key switches have two poles) ) ?


Thanks

 

[lloyd1980]

Anyway,
back to original point - seeing as no-one has disagreed can I safely assume that only the permanent live is to be switched via an key switch for testing purposes?

yes you switch the perminant live

the emergency lights have a perminant live feeding them so the battery packs charge, you switch this to cut the power to them and the battery will kick in

switch the permiant live,
if you switched the switch live, they wouldnt work properly and you should never swicth the neutral

 

[lloyd1980]

Anyway,
back to original point - seeing as no-one has disagreed can I safely assume that only the permanent live is to be switched via an key switch for testing purposes?

yes you switch the perminant live

the emergency lights have a perminant live feeding them so the battery packs charge, you switch this to cut the power to them and the battery will kick in

switch the permiant live,
if you switched the switch live, they wouldnt work properly and you should never switch the neutral

unless you get jobs from MY HAMMER in which case anything goes!!!

 

[sean123]

i use black as permanent feed and brown as switch wire

also if you use crabtree klik roses ( which i use all the time) the pre wired plug tops for the 4 pin kliks have brown in the L terminal and black in the A terminal,

so then it all matches each other up.

 

[wattsup]

the sw live and and perm live are both brown, imho...the switch live tagged for id only. I've always used dp key switches, cuts both supply and sw/l....thats how i've allus done it.

when red was red, line, the same, all lives were red, switched or otherwise...tagged with yellow ferrals/tape for id only.

Only deviations were 3-phase, if on yellow phase for instance, yellow feeds and yellow sw tagged...bloody black? switch wires.Brussels needs bombing -

 

[wattsup]

you should never switch the neutral....lol
no YOU SHOULDN'T

many em lighting circuits are double pole, in fact some key switches say N in, N out, L in, L out ...just in case
Some switch both perm live and the s/w, again dp


I best not try to explain why sometimes dp em key switches are used

 

[wattsup]

AND no, you do not only switch the perm live, the key switch cuts all power including sw's to the fitting, or sometimes a complete circuit and importantly line/s and neutral. If a large circuit you will need a contactor.

 

[sean123]

the sw live and and perm live are both brown, imho...the switch live tagged for id only. I've always used dp key switches, cuts both supply and sw/l....thats how i've allus done it.

when red was red, line, the same, all lives were red, switched or otherwise...tagged with yellow ferrals/tape for id only.

Only deviations were 3-phase, if on yellow phase for instance, yellow feeds and yellow sw tagged...bloody black? switch wires.Brussels needs bombing -

we are talkin about 3 core cable which has black grey and brown, if wiring in singles then yes permanent live or not it would be brown. but if using 3 core cable which colour to use a permanent brown or black? thats the debate .

 

[Risteard]

we are talkin about 3 core cable which has black grey and brown, if wiring in singles then yes permanent live or not it would be brown. but if using 3 core cable which colour to use a permanent brown or black? thats the debate .

But either way it has to be reidentified brown.

 

[sean123]

But either way it has to be reidentified brown.

well yea of course it does, its just that the original debate was when using 3 core cable which out of black or brown do you use as the permanent live.

 

[SEC-Tom]

 

[Adam W]

i use black as permanent feed and brown as switch wire

also if you use crabtree klik roses ( which i use all the time) the pre wired plug tops for the 4 pin kliks have brown in the L terminal and black in the A terminal,

so then it all matches each other up.

That's my reason for doing it; while I agree with the 'switch principle' (as in using sleeved blue as switched line) this is the way manufacturers have decided it is done and it is easier to go with the flow than against the grain - sure you could rewire all the plugs for the sake of making a point, but I'd rather just accept that that's the way it's done.

 

[pennywise]

That's my reason for doing it; while I agree with the 'switch principle' (as in using sleeved blue as switched line) this is the way manufacturers have decided it is done and it is easier to go with the flow than against the grain - sure you could rewire all the plugs for the sake of making a point, but I'd rather just accept that that's the way it's done.

Wish mine came pre-wired

 

[Adam W]

AND no, you do not only switch the perm live, the key switch cuts all power including sw's to the fitting, or sometimes a complete circuit and importantly line/s and neutral. If a large circuit you will need a contactor.

You can do it like that, or you could just switch the permanent live so all the non-emergency lights stay on when you do the emergency lighting test and the people working in the office don't start freaking out because all the lights have gone off.

 

[Crosswire]

You can do it like that, or you could just switch the permanent live so all the non-emergency lights stay on when you do the emergency lighting test and the people working in the office don't start freaking out because all the lights have gone off.

This is the main point, and I agree. However if you don't do this you won't know if the the emergencies give adequate lighting in the event of a power cut.

Damned if you etc....

Think I'll stick to just permanents and save myself the grief

(P.S. You should never switch ONLY the neutral. If you break ALL live conducters (including neutral) the switch is now an isolator).

 

[Adam W]

if you don't do this you won't know if the the emergencies give adequate lighting in the event of a power cut.

I would argue that that is the job of the designer - in most situations as far as the guy testing the emergency lights is concerned he just needs to look out for the lights coming on where the LEDs have gone out, then check the LEDs have come on again when power is restored.