Wiring up new external security lights

[myxiplx]

Hi,

I'm in the process of re-wiring my house, I'm going to have everything checked by a qualified electrician before I turn things on, but I'd like to get it right first time if I can and I have a few questions about how I should add external lights.

I'm planning to add two external security lights outside the front door. The plan will be to wire these to a 3 gang two way switch, where two of the switches control the stair lights, and the third the outside lights.

From reading these forums, I'm planning to run the outside lighting from a 6A MCB on the RCD side of the CU. Is this the right way to do this? Do I need any other kind of protection on the circuit?

There will only be .5m or so of cable outside the house, but I'm guessing I still need to use external cable. Can anyone recommend what I need to be looking for, can I just walk into an electronics shop and ask for a couple of meters of 1mm external lighting cable?

Finally, am I safe to mix internal & external lighting in one switch, and can this be a standard switch? I was hoping to use http://www.screwfix.com/app/sfd/cat/pro.jsp?ts=18263&id=19422.

many thanks,

Ross

 

[plugwash]

you shouldn't have multiple cuircuits in one box

and outside lighting should be rcd protected

i would use a dedicated cuircuit for the 3 lights that are switched from that switch

this should be fed from a 6A rcbo in the non rcd side of the CU or a 6A mcb in the rcd side of the CU preferablly the former as it means you won't be in the dark when the rcd in your CU trips

 

[myxiplx]

Hmm, I guess I can see why 2 circuits in one box might be bad... BZZZZ!!! *thud*

Seriously though, thanks for the advice. Rather than run those internal lights from a separate circuit though, I think I'll just have a separate switch for the outside lights. That way, if I buy a 6A RCBO, I can label that 'outside lights' and keep things simple inside the CU.

Any advice on the cable I should use for this? Can I get away with standard 1mm indoor cable if I run it straight through the brickwork into the back of the ouside light fitting?

If I can get away with this, should I consider sealing the light fitting / hole against moisture?

Ross

 

[plugwash]

if its not exposed outside at all (ie you go straight into the back of the light) then normal twin and earth is fine

but you should use PVC conduit through the wall to protect from present/future cavity wall insulation

 

[myxiplx]

Lovely, I'd read that about conduit in the past, but would have forgotten without the reminder.

Many thanks for all your help.