Decking lights and shed supply

[brucelee]

Hi all

I would be grateful if someone could give me some pointers on decking lighting

My Brother has had a large shed /workshop built

I have dug a trench 600mm to the shedabout 34m approx and installed 6mm 3 core swa in ducting to supply 4 metalclad double sockets using singles in conduit and 2 vapourproof fittings again in 1.5mm singles in conduit and a outside bulkhead over the door

i worked the volt drop out of the swa and its 5.2v this is using 21A as load for 20A for socket circuit 20Acb and 1 amp for the lighting protected by 6a CB
the length of runs for the sockets and lighting is approx 10m
the volt drop on the sockets is approx 3.6v so added to the swa volt drop gives 8.8v
the volt drop on the lighting is 1.2 rounded up so 6.4v just under the 6.9v max
I wanted to use 10 mm swa for the volt drop reasons above and also in case my brother wanted to add which he has now decided to do

He now wants me to wire a outside socket of the radial sockets so means altering the conduit and the singles i already installed and also on the outside a fcu to supply a large decking area with decking spotlightsappox 20 of them and also 4 which will be on a vertical wooden wall at the back of the decking

the house is a TN-C-S system and needs a lot of improvment to the existing wiring and CCUs

Now I know i shouldnt have let him talk me into getting jsut a 6mm lol even though we got 33 metres for £80 and the 10mm was more like double

can someone give me advice on best types of lighting to use ELV with transformers thinking 12v and places to buy etc

will the Volt drop be an issue if supplied from the shed either by another seperate SWA to the decking or swa from a external FCU or should i directly supply the decking lights from the house using either another seperate swa or from the conservatory were there is double sockets but these are already spurred of the House ring with a 13 a fcu in the lounge

Sorry its not more detailed but this is a first for me installing decking lighting lol it wasnt invented when i started lol

any help and advice appreciated greatly

cheers

 

[Snapester]

I think the volt drop would be fine for lighting 11.5v have you worked it out from origin? I think supplying from shed would be ok. What was the Zs from the shed did you not think about exporting the earth?

 

[brucelee]

Hi mate cheers for the reply
I have calculated the volt drop from the origin to the shed ccu and then added the Vd of each circuit in the shed in turn the swa calculated volt drop is 5.2v

the Zs from the shed i havnt measured yet as the swa isnt connected yet only ran it in thursday after digging for 3 days lol
jsut trying to weigh up wether to supply the decking lights from house or the new shed ccu
the Ze at origin is 0.09ohms and the swa calculated R1 +R2 is 0.21 the measured R1+R2 of the lighting final circuit was 0.27 so 0.09+0.21+0.27= 0.57
and the sockets R1+R2 will be around 0.27 also taking into account 1.2 correction factor for increase in resistance due to operating temp so again 0.57 this will be including the alteration to take into account the extra few metres for the outside socket he now wants
then either i culd install a waterproff FCU at side of it and run a 2.5mm or 1.5mm swa to the decking
Or just take it direct from the spare way in the CCU in the shed

or run another seperate swa direct from 1 of the spare ways in the house


there are no extraneous conductive parts in the shed all wood no other services or metal steelwork and i have run a 3 core so the 6mm earthing will suffice and then earth the armour at one end also so no need for a seperate earthing rod for the shed jsut use the 6mm 3rd core as my CPC back to the MET in the house

just need some ideas for the types of lighting that would suit best a fellow forum member says transformer with 12v output

 

[johnboy6083]

I wouldn't worry about the vd mate to be honest. It's very unlikely that you will ever load the sockets upto 20a, and it is mv per a, per m. Sounds like your doing a good job for your bro, hope he sorts you out for it!

 

[brucelee]

Hi mate cheers for reply

mate he best do after all the digging i have done lol
have to sort his CCUs and that also loads of bits in the house

I havnt installed decking lights before so unsure what type to get and wether to go with elv transformer etc can you get kits with say 10 in each kit
I am thinking 20 on the decking floor and then he wants 4 light points on the rear wooden wall he has built angled down to shine on the decking

will have to have a look about to see whats best

anybody recommend what lights to use please

 

[Des 56]

Bruce,seems your doing a fine job

There are a range of drive over/decking lights on the TLC website,its not worth me posting a link,the forum wont permit
There are also some on the Meteor sponser site hereMeteor Electrical Wholesaler |Trade Electrical Supplies | Free Delivery UK and Ireland

When you chose,let us know how good/bad, I have some to install in a couple of weeks and like you no past experience of these to rely on

 

[brucelee]

Trying mate always do just lack experience fitting decking lights mate they didnt have them when i started lol it was 500w flood in the borders we used to use lol for showhomes

think i will run a swa from the shed under ground either fed direct of the ccu or from a 13A fcu on the outside of the shed to a waterproof enclosure and then house the transformers in here

its a first for me mate so just trying to ensure i buy the right typer then not messing about getting them replaced lol

I have given my brother a load of trade catologues to look through
But he is hard work i told him i wanted some ducting for the swa from hosue to shed he tried to get some Got the Brown waste pipe for drains but no couplers or obtuse angles lol and was 3 inch tell he works for a big crane company everything big in his world lol

I went and bought some 40mm waste pipe with couplers which you can glue
as i couldnt get a continous ducting pipe like we used to have on site it was on a large drum jsut continous black pvc pping about 40 or 50mm si settled on the waste pipe on Tels recommendation lol

 

[Des 56]

Nothing wrong with some waste pipe,its probably over the top for your install,but I recently had some of this laid for a install where the various driveway supplies will go in at a later date
http://www.cirrustrading.co.uk/Backup/images/Twinwall Duct.pdf

 

[telectrix]

wonder when the colour of ducting is going to be harmonized to brown/blue.

 

[brucelee]

Nothing wrong with some waste pipe,its probably over the top for your install,but I recently had some of this laid for a install where the various driveway supplies will go in at a later date
http://www.cirrustrading.co.uk/Backup/images/Twinwall Duct.pdf

Cheers Des i was looking for something like this
On site the groundworkers used to install something similar but smooth faced jsut like large PVC continous pipe black abouit 50mm for SWA under drive to garage
the hassle i have had trying to find something it was on Tels advice i got the 40mm waste pipe with the push fit connectors you can glue with polypipe adhesive

anyway i have saved the link for future reference

I have done the first trench laid the ducting installed the swa and have dug the second trench from shed to decking today
600mm deep
My brother i think wants the small LED 12v 2 sets of 10 so jsut looking around for some reasonably priced but good quality sets

He is still undecided on the 4 lights he wants on the rear wall which is basically vertical decking

cheers for info mate

 

[brucelee]

need a weatherproof enclosure also to house the sockets in as they are supplied via 3 pin plugs and the transformer nuilt into the plug which makes it to large for a weatherproof socket

some of the sets i have looked at look like they wont last long