Opinions on this lighting layout

[LiamPope]

Hi there,

Reading up on the subject I'm quite liking the loop in at the switch lighting wiring method. Easy to add extra lights and to use light fittings not intended to accommodate the loop. Also, whilst my bungalow loft is curently beautifully accessible, I'm thinking about a loft conversion in the future so having no JBs all over the place seems like a good thing to achieve now.

I'll be using T&E, i.e. neutrals in the switches, so my only concern is the number of cables in switch drops. In a 1 gang I'll have three - loop in, loop out and light fitting, but in a two gang there'll be 4, and in my two gang hall/bathroom switch I'll have an additional 3&E up to the fan isolator! All doable as I've used 35mm boxes throughout and can make wall chases as wide as need be to clip all the cables side by side.

I was thinking of a slight hybrid of wiring styles though. From CU to a main junction box that will always be accessable (even after loft conversion) - something like this ashley http://www.tlc-direct.co.uk/Products/ASJ701.html, one for each of my lighting circuits. From there I'd then run individual feeds to each switch (4 each circuit), then to the fittings as the loop in at switch method. This would do away with the loop out from each switch and reduce my cables in the drops by one. Also it'd get rid of the main drawback of the loop in at switch method - that you can't expand the circuit without digging out a switch drop, or putting a jb in the roof. I'd be able to just add another feed to one of my main JBs.

Anyone see any problems? Any reason I dont see it done this way other than it using probably more cable than other methods?

Cheers,

Liam

 

[ericmark]

Terminals like these

can use link bars across the top like this

and if you are going to do it that way many as well do it right.
But I would not use that method as it will not be what anyone will expect and it will cause problems at a later date better keeping to normal method.

 

[holmslaw]

..

 

[ColJack]

I like it....

I've got my lounge light wired up in binary..

2 switches on the wall, 3 arm light rewired so that 2 are on 1 switch and 1 on the other..

that way I can "dim" the lounge lights without the need for a dimmer.. ( all 3 for working, 2 for watching TV and just the 1 for that romantic vibe.. )

 

[sparkyspike]

my only concern is the number of cables in switch drops. In a 1 gang I'll have three - loop in, loop out and light fitting, but in a two gang there'll be 4, and in my two gang hall/bathroom switch I'll have an additional 3&E up to the fan isolator! All doable as I've used 35mm boxes throughout and can make wall chases as wide as need be to clip all the cables side by side.

Why are you concerned about having four cables at the switch? It's no problem normally, especially if you're using 35mm bacboxes. Also, with the loop at the switch, you can run 3C+E cable to each lighting point, giving you extra options in the future.

 

[LiamPope]

Lol! Looks like there's some considerable creativity allowed in lighting circuits then. And as ericmark suggests - ought to keep future sparks on their toes! I better make the most of it until the 18th Edition puts an end to it .

Cheers,

Liam

 

[davelx]

Lol! Looks like there's some considerable creativity allowed in lighting circuits then. And as ericmark suggests - ought to keep future sparks on their toes! I better make the most of it until the 18th Edition puts an end to it .

Cheers,

Liam

AFAICS the regs place no restrictions on the circuit configurations you can use. They provide a number of "conventional" circuits and constraints around them and if you use them you generally don't have to do any design calculations.

However, if you are prepared to do the full design & documentation work, you can do whatever you like provided that the resulting circuit characteristics meet the regs.