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Ring Final Circuit - spurs only

Discuss Ring Final Circuit - spurs only in the UK Electrical Forum area at ElectriciansForums.net

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I read that it is against the regs that a ring final circuit cannot be just a ring with with spurs off it. In short, a ring must have sockets on it which double up as junctions. I find that hard to believe.
 
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A ring can't have more unfused spurs than it has sockets on the ring.
So if there are 10 sockets on a ring then the maximum number of unfused spurs you can have is 10.

Spurs do not have to be taken from sockets, they can be taken from a suitable joint box or from the origin of the circuit.


As always the above refers to the 'standard circuits' as described in the regulations and supporting publications. If you wish to design your own non-standard circuits then you are free to do so, however you would need to fully document the design (as a courtesy to anyone else who has to work on the installation, as defense should anything go wrong, as defense when an EICR is carried out and the non-standard design is flagged up, etc etc)
 
So, a ring can be just a ring of cable - in effect a busbar. Then on this cable j-boxes with spurs off that.

No, it can't, not as a standard ring final circuit.

As I said, a ring can only have as many unfused spurs as it has sockets connected to the ring.

On your ring of cable with joint boxes, if you intend it to be a standard ring final circuit, you cannot have any spurs as you have no sockets on the ring.
 
What would lead you to design a circuit like this?

If you can get one cable to a socket, then you can get two.
It has no financial benefit, as the cable saving is countered by joint boxes and time making those extra joints.
The extra joints also add another point of possible faults.

In technical terms…. This is how a standard socket is. The joint is the terminals on the back of the socket… the “spur” is the internal metalwork between the terminal and the contacts for the plug pins.
 
Why would you hard wire any appliances?
They are designed to be portable, come with a plug.
Give them a socket.

As I said earlier, extra joint boxes and time to install outweigh the cable cost saving.


Get your replies in now, lads…. Can’t see this thread lasting much longer. 😆
 
Why would you hard wire any appliances?
They are designed to be portable, come with a plug.
Give them a socket.

As I said earlier, extra joint boxes and time to install outweigh the cable cost saving.
The point is a ring without sockets, either with for e.g., having only jboxes or appliances hard wired on the ring. Why the jbooxes are there or why the appliance are hard wired in is not the point. It is a regs point.
 
The point is a ring without sockets, either with for e.g., having only jboxes or appliances hard wired on the ring. Why the jbooxes are there or why the appliance are hard wired in is not the point. It is a regs point.
What about the cost of the joint boxes or are you not going to answer that.
There are plenty of ring final circuits out there which do not incorporate socket outlets.
 
The regs don’t state sockets, they will state points.

The regs concerning unfused spurs comes from the load on the spur not being too much for the cable between the ring and the point.
How that cable is joined into the ring is immaterial. Joint box, or back of another point.


That is from memory, as it’s Sunday and I can’t be bothered to look for my book.
 
The regs don’t state sockets, they will state points.

The regs concerning unfused spurs comes from the load on the spur not being too much for the cable between the ring and the point.
How that cable is joined into the ring is immaterial. Joint box, or back of another point.


That is from memory, as it’s Sunday and I can’t be bothered to look for my book.

Sockets are not for permanently used appliances. They are to be plugged in and out. Permanently wired in appliance need to be hard wired. And that in theory includes a 24/7/365 fridge.
 
Any fridge is on 24/7/365, but still comes with a plug fitted.
But there is nothing wrong with hardwiring them into a switch fuse.... its just not standard
Basically, if its stuck to the wall, it doesnt come with a plug..... if its portable... it does.
And portable does include large, american style fridge freezers.

Either way, whether an appliance is plugged in or not isn't part of the original question.

Which, if i understand it, was

"can you just have a ring circuit, with no points on the ring itself, but unfused spurs coming off the ring, with points on the end of each spur"

And a very early answer was "yes, but it would be non-standard"
There's nothing in the regs to say you cant.
 
Was common place back in the 70s often known as a 'spider ring' all ran around to circular junction boxes with radials to each accessory it isn't anything new. Some dwellings had the ring final on the upper floor with accessories connected with spurred radial drops to the lower floor.
 
A ring can't have more unfused spurs than it has sockets on the ring.
So if there are 10 sockets on a ring then the maximum number of unfused spurs you can have is 10.
I used to believe this too. I don't know if it was included in the 15th or 16th edition, but there's no mention of it in BS7671:2018+Amd2:2022 (at least as far as I can see).
 
Sockets are not for permanently used appliances. They are to be plugged in and out. Permanently wired in appliance need to be hard wired. And that in theory includes a 24/7/365 fridge.

And then, when the homeowner needs a new fridge, he has to get a sparky out to disconnect the old one and reconnect the new one.

Makes perfect sense to use a plug, especially since it will come with a pre fitted one.
 
Just a thought on this. A ring with jboxes only. The jboxes supply only one socket via a cable approx 2 to 3 metres long. Big saving on cable.

Assuming the average ring circuit has 10 sockets on it and you save 3m of cable per socket that's a saving of 30m of cable.
At current prices that could be about £25 saved.

Depending on your preference for joint boxes they could realistically cost you £25.
Then you need to consider the additional time involved.

Other considerations are best practice, it is generally accepted that best practice is to avoid unnecessary joints in cables, every joint being a potential point of failure.

Also you need to consider maintainence and fault finding, it is going to be a lot harder to fault find a ring circuit where you can't readily get to the ring itself.
 

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