How to connect 2 sockets to one 27A cable without ring

[chris2012]

I'm looking at https://www.cef.co.uk/catalogue/product ... nction+box

But I'm not sure how to use it, it looks like theres 2x Neutral connections on either side, so 4 in total, would those 4 terminals
be internally connected?

[themadhippy]

maybe,maybe not, whats wrong with the good ole circular junction box

As an aside if your intending to take a single spur from the ring to run 2 sockets the big book of electrickery rules dont like that,your only allowed 1 double or 1 single socket per unfused spur

[IPA]

It's just a 32 amp connector with two ins and two outs

[chris2012]

I'd be taking a cable from the house fuse box, to the shed, and running a couple of sockets from that, with the junction box, is that ok?

Ah, so that one I linked wouldn't do the job?

With the circular type are you essentially pushing all Neutral wires for example into one of those terminals I assume?

[themadhippy]

i'd be taking a cable from the house fuse box, to the shed, and running a couple of sockets from that, with the junction box, is that ok

If its its own dedicated circuit yes fine,you need to use a 20A fuse if your using 2.5mm cable,if you want to use a 32A fuse then you need to use 4mm cable

With the circular type are you essentially pushing all Neutral wires for example into one of those terminals I assume?

yep

[chris2012]

Awesome cheers, just going to grab one of those circle junction boxes now

[Hogarth]

Couldn't one of your sockets also double as a junction box? That'd give you fewer connections to make. (I'm not an electrician, mind…)

[phil.dadd]

Yeah don't quite understand the point of the junction box, just run a new radial circuit.

[themadhippy]

Yeah don't quite understand the point of the junction box, just run a new radial circuit.

maybe the layout of the sockets makes it more economical to put in a junction box and run 2 short cables instead of 2 long ones

[Aleman]

The 'Proper way to do it would be to run you cable from your house fuse box, to a smaller fuse box in the shed, and then run a ring containing your sockets in the shed from this fuse box.

You probably want 6mm cable to go from the fuse in the house to the fuse box in the shed, then run 2.5mm cable as the ring in the shed. . . . Depending on the cable run you might get away with 4mm but it depends on the resistance and voltage drop, which is a function of length. . . . If you are running exposed or buried cable then you will need armoured cable.

Then you have the issue of what to do with the earth? Do you export it from the house or add new earths??

Get some professional advice . . . and as an aside Part P prevents you personally from doing this work . . . or at least you would need to pay a fortune to the local authority to come out and certify it . . . If you have a Part P certified friend they might certify it for you, but they are then putting their reputation on your ability

[JamesF]

Then you have the issue of what to do with the earth? Do you export it from the house or add new earths??

I've only today read elsewhere that you're not supposed to export the earth. Apparently it should be connected at the house end and insulated from everything at the shed end, where you should have a new earth rod providing the earth for the shed because the actual earth potentials at the house and shed may be different and therefore may be unsafe in the event of an electrical failure.

I've also read that people often still export the earth anyhow

I'm not entirely sure I properly understand all this equipotential bonding stuff though.

James

[themadhippy]

I've only today read elsewhere that you're not supposed to export the earth.

it all depends on the type of earthing arrangement on the incoming supply,if it TNC-S then no exporting the earth outside the equipotential bonding zone

[Pinto]

I was always under the impression there was nothing wrong with exporting the earth on TN-S or TN-CS provided you used a conductor of sufficient size connected to the incoming earth source - eg: 10mm2 - basically treat it as a main bond. The new connection just extends the EPZ to your shed ? Never seen a reg that says no...

TT of course would be a different kettle of onions

[JamesF]

I think our house is TT, but I'm really not sure. I know the transformer in our field is earthed because we get paid rental for the earth cables as well as the pole and we have a local "house" earth that goes into a 100A fuse box where the power comes in that I've never seen open. For all I know there might actually be two phases delivered in there. The transformer is off an 11kV overhead supply prone to tree damage and lightning strikes, so I don't imagine they'd rely on an externally-supplied earth.

James

[Pinto]

Quick and easy check :

Is the entire supply protected by an incoming RCD switch with an earth rod outside ? TT

Does the main earth bond connect to the outer sheath of the suppliers incoming cable ? TN-S

At the incoming head (where the main fuse is) can you see the earth cable enter the head adjacent to the Neutral ? - TN-CS

Edit : Just seen that you have an overhead incomming supply - that usually signifies TT; these days it's pretty much limited to rural, non urban locations. You live in d'country ?