Recommended Lighting circuit method

[padstar]

I am having my house rewired and am currently positioning back boxes and conduit runs for the electrician to wire and terminate. He is a friend doing me a favor so i am left with the messy work so that he can use his time doing the proper stuff.

I asked what he wanted for the lighting circuit (down lights throughout) and he has said that he can loop at the switch or in a JB and did i have a preference? I understand the theory behind both but wondered is 1 better than the other? I don't mind what he does as long as the lights work..

 

[AndyPRK]

well if you are having down lights / fancy lights and may want smart switches in future, loop at the switch

 

[padstar]

Thanks Andy. Is the reasoning for this just that it can all be changed from the switch point at a later date rather than having to lift boards or go in the loft?

I guess for my containment then its exactly the same as i was doing but i just need to run a 2nd 20mm conduit to each switch box for to accommodate 3 cables being pulled through rather than 1.

 

[AndyPRK]

smart switches require a neutral at the switch.

and its an easier way to wire, without hidden junction boxes in the floor


If you really are using round conduit, how about using single cables rather than twin and earth. Discuss with your electrican. You should only need 1 pipe then

 

[padstar]

Just using round conduit for the drops from ceiling to switch. Easy enough to put 2 in at the same time. Is that unusual?

If i run 2 conduits that should allow for the looped "feed in" and "feed out" to run down/up 1 and the feed to the light fitting up the other. He is skiing this week and i wanted to get it all in ready for him next week. Can give him a call to check if you think 2 conduits is overkill. Its only about £15 of material so for the entire house so i hadnt wanted to bother him over it to check.

 

[padstar]

I also have 3 drums of 1.5mm twin and earth in the garage so if its no issue doing it that way it will save him buying the material.

 

[AndyPRK]

if the conduit is just going up the wall and stopping then 2 should be fine.

There maybe some regulation that requires the conduit to be earthed ?

 

[Simon35]

...

 

[padstar]

Are 35mm back boxes deep enough for all switching options are should I go 47mm for any reason

 

[Risteard]

if the conduit is just going up the wall and stopping then 2 should be fine.

There maybe some regulation that requires the conduit to be earthed ?

I would presume that the conduit drops are PVC.

Light gauge will give more room for the cables too.

 

[AndyPRK]

35mm is plenty

 

[securespark]

I guess to meet the spacing factor with at least 3 x 1.5 T&E cables, you would need 2 x 20mm drops to each switch.

 

[padstar]

2 drops of pvc conduit to each switch using 35mm back boxes. Sparks coming round tomorrow to have a look and confirm they are happy with how it’s being installed