Garden lighting help

[Dec1815]

Hi guys been a while,

I have a customer asking for quite a large outdoor lighting and power installation

It is going to have a kitchen area built which they want 3 x double sockets and 6 spotlights with a switch

the kitchen will also have a gas cooker

A shed with 2 double sockets and a pendant with a switch

around 20 lights around the full garden which are switched by separate switches half on one half on another

I suggested taking a 6mm swa from the mains inside the house to the shed putting a board in the shed and feeding everything in the garden from there

the customer didn’t seem to like this idea so was wondering if there was any other options to feed this

 

[westward10]

Which thread do you want running this one or your other identical one.

 

[Dec1815]

Which thread do you want running this one or your other identical one.

This one please

 

[brianmoooore]

I doubt that the customer is in any way interested in where the garden lights are fed from, just where they are switched from.
What's the problem in feeding the lights from the house?

 

[Dec1815]

I doubt that the customer is in any way interested in where the garden lights are fed from, just where they are switched from.
What's the problem in feeding the lights from the house?

I was thinking of drilling through the back of a switch for the lights and back of a socket for the sockets but thought adding an addition 31 lights and 5 sockets may be abit excessive and better practise to put on there own circuit seeing as they are positioned outside not in the house

maybe I’m overthinking it

 

[brianmoooore]

I'd stick with the SWA to the garage, direct from the consumer unit ,or preferably a separate switch/fuse adjacent to it for better discrimination. There should be no RCD protection at this end.
You don't say what type of garden lights they require, but with this quantity of lights, some thought needs to be given to the inrush current when they're switched on, to ensure that the switches are up to the job, and that the MCB doesn't flip out on the magnetic. It's possible you may have to go to a C curve MCB, which will affect the loop impedance for the light wiring, so this should also be taken into consideration

 

[Dec1815]

I'd stick with the SWA to the garage, direct from the consumer unit ,or preferably a separate switch/fuse adjacent to it for better discrimination. There should be no RCD protection at this end.
You don't say what type of garden lights they require, but with this quantity of lights, some thought needs to be given to the inrush current when they're switched on, to ensure that the switches are up to the job, and that the MCB doesn't flip out on the magnetic. It's possible you may have to go to a C curve MCB, which will affect the loop impedance for the light wiring, so this should also be taken into consideration

You agree coming from the mains to the shed would be better practise

They are led some are spot lights some are spike lights and some are up down lights

thank you for responses

I find it always helps getting a second opinion

 

[Dustydazzler]

My personal preference woukd be like you say a dedicated supply to the shed and install an rcbo board there to feed the various socket and light circuits.
you could run individual smaller armoured cables back to the house, but that’s a lot of faffing as they might require different routes back...

 

[SJD]

Does the OP know why the customer doesn't like the idea of a supply to the shed, with everything supplied from a small board there?

Some objection to the supply cable presence or installation?
Perception this would be unduly costly?
Some other reason?

 

[Dec1815]

Does the OP know why the customer doesn't like the idea of a supply to the shed, with everything supplied from a small board there?

Some objection to the supply cable presence or installation?
Perception this would be unduly costly?
Some other reason?

it would require digging up the front garden and path at side of the house which they didn’t really want to do plus it would be costly as the mains to the shed is over 50m

 

[SJD]

it would require digging up the front garden and path at side of the house which they didn’t really want to do plus it would be costly as the mains to the shed is over 50m

Sounds like the intake / consumer unit is at the front of the house, and you need to get to the supply to the rear? Does the cable have to be buried? I installed a workshop supply last year where the SWA was cleated to the wall of the house front & side, and only underground for the last bit in the rear garden. Cable mostly low down and unobtrusive in that case.

 

[Dec1815]

Sounds like the intake / consumer unit is at the front of the house, and you need to get to the supply to the rear? Does the cable have to be buried? I installed a workshop supply last year where the SWA was cleated to the wall of the house front & side, and only underground for the last bit in the rear garden. Cable mostly low down and unobtrusive in that case.

Yes that’s correct they do want the cable buried yes however I may be able to persuade them to have it clipped

the main issue for them is the cost the customer is retired engineer so thinks the need for a dedicated supply is unnecessary

he wants us to tap into the downstairs ring and lights by drilling out through the back of a socket and switch

 

[Dec1815]

My personal preference woukd be like you say a dedicated supply to the shed and install an rcbo board there to feed the various socket and light circuits.
you could run individual smaller armoured cables back to the house, but that’s a lot of faffing as they might require different routes back...

Yes I agree a lot of faffing but this is what the customer prefers would you see no issue with running cables from the back of an internal socket and switch ?

thanks for your response

 

[Dustydazzler]

Yes I agree a lot of faffing but this is what the customer prefers would you see no issue with running cables from the back of an internal socket and switch ?

thanks for your response

You will have to drill through from inside to the outside and mount some external boxes on the wall to terminate your swa cables into to. Its certainly do-able.

 

[Dec1815]

You will have to drill through from inside to the outside and mount some external boxes on the wall to terminate your swa cables into to. Its certainly do-able.
Yes that was what I was thinking

my only concern would be just how much extra load I’m adding and no isolation between the internal lights and exterior lights but if the customer prefers this way it can be done

 

[brianmoooore]

Some checks to be made first, as to what kind of circuit the existing socket is on.
A few years down the line, the customer will undoubtedly regret not having done the job properly in the first place. Seen it many times.