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A quick one hopefully for some one familiar with the dos and donts.
I'm in the process of pulling cabling to my shed. 16mm swa is pulled ready for connecting. Plan is a 63a mcb consumer unit in the shed running a pair of 16a and a 6a circuit.
So far so straight forward.
As is the swa enters through the garage floor, will then pass through the outer wall of the house and direct to the consumer unit/household supply.
Here in I've a bit of a quandary.
1)Swa 16mm isn't exactly bend friendly so I'm going to need to take at least one brick out of the wall to route it and even then it won't be good. Given the placement of the entry I'd really rather not take out any.
2) a run of sockets in the garage would be a bonus.
The obvious solution is to run 3x16mm 6491 out to the garage then junction it to the swa before that heads out. That will bend much much better, to the point the bend will barely leave the wall before running flat so solves my routing issue.
Given I'd like to run a few sockets in the garage another consumer in there makes sense.
So my question is this.
A) Can I run the 6491 to a three way consumer in the garage. 50a rcd feed for the shed off that effectively daisy chaining them.?
B) do I need to junction the feed for the consumer units rather than daisy chain them?
C)do I actually need to run 2 sets of cables, one for the garage and one for the shed back to the existing household consumer unit?
(a&b are much the same in practical terms as I'm just doing the donkey work & it'll be the proper spark connecting them any how so I'm guessing they will do as appropriate regardless, the significance being how much of what cable I allow and what space I need to leave clear when the electrician does come)
Firstly are you sure it is 16mm? That's some pretty hefty cable. Mine is 6mm. Daisy chaining is fine as long as the protection is set correctly. Mine runs straight from the house consumer unit on a 40A MCB to the (detached) garage. I've got a 5 way consumer unit in there for the sockets and lights. One of the spare ways in the garage consumer unit has another run of 6mm SWA to the little shed where it feeds a socket and the lights (via a fused switch). This could've been 2.5mm SWA but I had plenty of 6mm. You don't need a consumer unit in the shed (or 16mm swa!) for a couple of sockets and some lights.
What size MCB are you going back to in the house consumer unit?
16mm seems overkill for a shed supply - even with a 40a breaker you could probably get away with 4mm.
Is the garage attached to the house? so I don't see an issue with running 6491's to the new consumer unit - just be mindful of the bending radius of the single core cables too.
Yeah, definitely 16mm, it's a 45m run, laid direct. 50a max on that over a 10mm so upped to 16mm. In practice I'll never be pulling close to that but a few big tools etc it adds up pretty quick and I'd really rather not have to dig the thing back out.
Arguably could "get away" with 6mm which should be enough for up to 30a at that sort of distance but there's no point skimping and cutting it fine.
The singles will bend at 50mm ish. Rather a lot better than the 150mm or so for the swa 🙂
We had power to the garage upgraded for the sauna and hot tub. Can't remember the exact spec of the cable but as you can see from the picture it was pretty hefty.
It was fed through the house wall and bent at 90 degrees into a box. That box was then connected to a separate 80 amp RCD which was then connected to the original mans cable. You can see from where the cable comes through the wall to the box what the tightest bend we could manage so it sticks out a little on the outside of the house.
At the garage end we just have another unit like the main one in the picture and run circuits for tub, sauna, circuits, lighting, garden lights etc from there.
Hope some of that might help.
Super ta - though, I have to ask, who installs a sex pond in garage? Isn't the sole purpose to allow you to exhibit your selves and your giggling bunga-bunga party guests to your neighbours?
The cabin is on the back of the garage
And the doors open wide when the sun gets low...
You will need to put the singles into some form of mechanical protection if you want to use that, easier way would be to use twin and earth from the house board to your new garage board then gland your armoured into that
You will need to put the singles into some form of mechanical protection if you want to use that, easier way would be to use twin and earth from the house board
Not to worried about running conduit in honesty, it'll go straight up and over the roof in the loft so won't be in the way and it'll run behind the skirting indoors. I couldn't seem to spot a t&e up to spec but will take a look (much as I know I'm not running them all together there's a few 2kw + tools heaters and so on to run so the numbers add up pretty quickly).
house board to your new garage board then gland your armoured into that
That's perfect though, precisely what I wanted to hear. Ta.
it’ll run behind the skirting indoors
Not allowed in UK regs unless it is properly protected. Still pretty bad practice
Not allowed in UK regs unless it is properly protected. Still pretty bad practice
Didn't realise it was an issue in conduit behind?
Behind skirting is not a prescribed zone so not allowed regardless of what you do to protect cables.
Ah, fair do. Hmm drawing board then me thinks. Not sure quite how to get a line out of the current unit then without actually taking the wall down.
Edit - that said, steel conduit on the face would be physically viable, certainly more so than playing dodge the gas lines in the wall.
Hmmm
Thank you for the pointers.
OP is the house on Protective Multiple Earth wiring?
If so you can within certain limits not run an earth to the outbuilding from the house but use a stake from the remote consumer unit. (This was pointed out to me when I wired our garage up around 15 years ago, saved a fortune in wiring by running 10mm live and neutral in conduit underground and using 10mm earth cabling to a ground stake.
Power rating is easy to test by licking a finger and shoving it in the socket.
13a -Makes you jump backwards exclaiming Bloody Hell that hurt
16a -blows you across the room and you awaken to finding some stranger performing cpr on you
3 phase - You come to and its either some bloke with wings, on in most cases here some bright red guy holding a pitchfork.
As above if your house is a PME system you need to wire any external buildings as a TT system.
This is so you are not introducing any external earthing problems into the house.
As for removing a brick. just drill a hole at a downwards angle from the inside of the building then dig a pit/trench deep and wide enough for the bend radius!
Cant remember the thickness of the cable I used but as above brought it in at an angle through a drilled hole. Into a large "cooker" switch inside the wall to allow me to isolate it from the house then cabled into the main board in the garage. Glanded at each end into a 3 way box.
As above if your house is a PME system you need to wire any external buildings as a TT system.
OP is the house on Protective Multiple Earth wiring
To my knowledge it's not, but I'm doing nothing beyond dragging cables so ensuring that the earthing etc are up to spec will be down to someone who knows what they're doing. If the cable is there and not needed is easy to not use it though.
Regrettably the chap who was going to make the connections (and asked for three core swa) isn't about anymore to do them or he'd probably have picked me up on the cable in conduit behind the skirting too. (and very quickly answered about the acceptability of daisy chaining the consumer units or not)
A TT system only really needs to be considered for outbuildings if there’s a risk something in/around it could have a different potential difference to the earthing in there, so if there’s gas/water/oil supplies etc entering the building