New garage supply

M

Martin606

-
Hi
I am wishing to get power to my garage. I live in a terraced new build house and the garage is about 20m away from the house but the cable run will need to be about 60m. I will be installing a 40A 2 way distribution board to provide lighting and socket outlets.
I have calculated that I will need to use 10mm cable to allow for volt drop due to the length of the cable run.
Can someone please assist with the following queries.
The house DB is at the front of the house so I will need to take a feed from a spare gang on this through the first floor to the rear garden.
I believe the correct way would be to run SWA in a trench to the garage.
1. Is it ok to run normal 10mm cable internally and convert to SWA on the wall outside?
2. As an alternative is it ok to run 10mm cable in conduit on the fence line?
3. As another alternative, is it ok to run 10mm cable from a socket outlet as a spur at the rear of the house rather than from the house distribution board?
4. Is it even possible or allowable to spur off a socket outlet to get power to the garage?
Thanks.
 
Sort by date Sort by votes
Are you an Electrician, do you have any electrical experience? your first two questions, are easy to answer yes the SWA should be installed in a trench, and it is OK to run 10mm twin and cpc in the house and change to SWA in an appropriate IP rated enclosure, I say yes, to the 10mm but how have you arrived at this size of cable?

I don't like the idea of running anything along the fence line.

Assuming the Ring Final Circuit you intend to spur from is wired in 2.5mm cable it would be pointless running the supply to your Garage in 10mm cable, that would be for both question 3 and 4.

The next things to take into consideration is what is the Earthing system in your house? will there be any other services in your Garage water, gas, oil etc because if there is you will need to consider bonding these services, hence you may have to run a separate bonding conductor, assuming of course, the Steele wire used as armoring isn't big enough to act as a main earth conductor and a bonding conductor.
 
Upvote 0 Downvote
Hi Pete
Thanks for your reply.
I have arrived at the cable size as follows
Max load X cable length X volt drop per metre/1000
40a X 60 X 4.4/1000
This gives volt drop of 10.56V which is within the accepted volt drop of 5%(11.5V)
I arrived at the cable size of 10mm by assuming max load at the garage DB OF 40A.
Is this correct?
Am I right in my assumption that it is correct to use 10mm in a trench rather than the fence line?
Am I also right to assume that it is not acceptable to spur off the final ring circuit in these circumstances.
Thanks
Martin
 
Upvote 0 Downvote
If you spur from the ring final you will have to fit a 13A fuse connection unit which restricts you to 13A, this would probably be adequate with a lighting and socket radial in the garage.
The other way I would definitely trench the cable, why 60m if garage is 20m from the house.
 
Upvote 0 Downvote
The house is a mid terrace and the garage is in a block 20m away.
The cable would need to be run around the garden and down a path to prevent it going across the neighbours garden hence the run would be 60m. Hence I came to the 10mm sizing
 
Upvote 0 Downvote
Hi Martin - just checking, but when you say 'down a path' is this piece of land on your title? (A shared path may not be yours to dig up for example).
 
Upvote 0 Downvote
Martin606 said:
Hi Pete
Thanks for your reply.
I have arrived at the cable size as follows
Max load X cable length X volt drop per metre/1000
40a X 60 X 4.4/1000
This gives volt drop of 10.56V which is within the accepted volt drop of 5%(11.5V)
I arrived at the cable size of 10mm by assuming max load at the garage DB OF 40A.
Is this correct?
Am I right in my assumption that it is correct to use 10mm in a trench rather than the fence line?
Am I also right to assume that it is not acceptable to spur off the final ring circuit in these circumstances.
Thanks
Martin
Click to expand...
You don't appear to have used any correction factors in your cable calcs..
 
Upvote 0 Downvote
I am aware of part P and am aware that it would need to be my land. Not that much of a tin hat thanks Murdock.
A little more help than criticism would have been nice after all this is a forum for assistance?
 
Upvote 0 Downvote
another ting to bear in mind as regards cost and ease of installation is.... depending on the load, you could possibly run 10mm T/E through the house into an adaptable box at the back of the house, then reduce the cable size for SWA, caclulating VD on the 10mm then on the SWA. OCPD selected to suit the SWA, of course.just a thought.
 
Upvote 0 Downvote
Martin606 said:
I am aware of part P and am aware that it would need to be my land. Not that much of a tin hat thanks Murdock.
A little more help than criticism would have been nice after all this is a forum for assistance?
Click to expand...

We do help on this forum. It also helps if you answer our questions. You didn't like to answer the one about of you are an electrician.
The reply to this can help us tailor our replies so that they are suitable to the OP.
You might be someone who knows nothing about new circuits, testing and proper installation and just reads bits on the web.
 
Upvote 0 Downvote
westward10 said:
If you spur from the ring final you will have to fit a 13A fuse connection unit which restricts you to 13A, this would probably be adequate with a lighting and socket radial in the garage.
The other way I would definitely trench the cable, why 60m if garage is 20m from the house.
Click to expand...
 
Upvote 0 Downvote
westward10 said:
If you spur from the ring final you will have to fit a 13A fuse connection unit which restricts you to 13A, this would probably be adequate with a lighting and socket radial in the garage.
The other way I would definitely trench the cable, why 60m if garage is 20m from the house.
Click to expand...
Why cant you just split the ringmain better still if you have a spare fuse run a new ringmain into your garage make sure everything that needs earthing such as bonding is done then if you need lighting put a fused spur with 3 amp fuse for your lighting 3 amp is ample
 
Upvote 0 Downvote
Che Guevara said:
Why cant you just split the ringmain better still if you have a spare fuse run a new ringmain into your garage make sure everything that needs earthing such as bonding is done then if you need lighting put a fused spur with 3 amp fuse for your lighting 3 amp is ample
Click to expand...
It has a run of 60 odd meters between the house and garage.
 
Last edited:
Upvote 0 Downvote
Che Guevara said:
Why cant you just split the ringmain better still if you have a spare fuse run a new ringmain into your garage make sure everything that needs earthing such as bonding is done then if you need lighting put a fused spur with 3 amp fuse for your lighting 3 amp is ample
Click to expand...
Westy wash yer mouth out "ring main" indeed:eek:
 
Upvote 0 Downvote
There's a chap (on another forum), who's been doing his own electrics. When I've tried to explain, perhaps he should not be doing this, he replied he was going to install another RING MAIN, if members were interested. I thought of you Pete :eek:
 
Upvote 0 Downvote
Midwest said:
There's a chap (on another forum), who's been doing his own electrics. When I've tried to explain, perhaps he should not be doing this, he replied he was going to install another RING MAIN, if members were interested. I thought of you Pete :eek:
Click to expand...
BLASPHEMY BLASPHEMY
 
Upvote 0 Downvote

Similar threads

G
UK Running an additional armoured cable to outdoor building.
Replies
4
Views
429
EricMark
EricMark
B
3 phase cable advice for novice
Replies
4
Views
277
bdo2123
B

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Green 2 Go Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses Heating 2 Go
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

Advert

YOUR Unread Posts

Daily, weekly or monthly email

Receive a daily, weekly, or monthly email containing a digest of new and recently updated threads.

Thread starter

M

Martin606

-
Joined
Location
Wellington

Thread Information

Title
New garage supply
Prefix
N/A
Forum
UK Electrical Forum
Start date
Last reply date
Replies
33
Unsolved
--

Thread Tags

Tags Tags
cable garage house new supply

Advert

Thread statistics

Created
Martin606,
Last reply from
telectrix,
Replies
33
Views
3,591

Advert

TrueNAS JBOD Storage Server

Tilers | UK Tiling Forum | Tilers Forums | Find a Tiler
UK Tiling Forum by Tilers Forums UK
Plumbers Forums | Plumbing Advice | Gas Forum
Back
Top