Lighting Circuit Advice

[leevis]

HI
I am planning out the electrics for my extension and need to power the following
1. Main Lights in Kitchen (on a dimmer)
2. Lights in Utility Room
3. Under Plinth Lighting
4. External Lights 1
5. External Lights 2
6. Extractor Fans (1 in Kitchen and 1 in Utility Room)

Not too sure how this works, would this be one feed from the RCD and then split 6 ways?

Not too sure what this is called to research it

 

[Celeronmanuk]

You'll have a lighting circuit already, maybe even two (upstairs/downstairs) you'd extend off this. It's just a radial circuit.

 

[leevis]

This is a brand new build new rcd which all of this. is running off of

 

[securespark]

OK.

But you don't need lighting and fans on separate circuits. Internal lights and fans can be on one circuit External lights if you wish can go on another.

If they are on RCBOs, this means any fault with the external lighting will not bring down any other circuits.

I would not put kitchen lighting on a dimmer. You need bright functional lighting there to minimise the possibility of accidents.

 

[leevis]

The reason for the dimmer is to get the lighting to a decent level and keep it there, I have a suspicion that when it goes live it will be too bright hence the dimmer.

Yes these will be RCBOs

What I am trying to understand is the actual cable rules, the way I see it (in my head) is there will be ONE lighting feed that will then be split SIX ways to accommodate all of this?

 

[securespark]

Lighting is usually a radial circuit, so yes, it would feed one point then run to the others.

Loading comes into the design, as does circuit length, but I can't see either meaning that you would need more than one circuit, unless the extension is large and it would be an advantage to have two circuits in case one fails.
This would mean the extension would not be in complete darkness.

Edited for clarity.

 

[Celeronmanuk]

The reason for the dimmer is to get the lighting to a decent level and keep it there, I have a suspicion that when it goes live it will be too bright hence the dimmer.

Or use fittings with changeable bulbs, e.g. GU10 so you can set the colour temperature and brightness.