Ring main consisting of only spurs

[Accessless]

Hi, this is my first time on this forum so I hope I'm in the correct section.

I've come across a strange socket wiring set up in my own home. I was baffled at first as to how at the consumer unit I had a ring main set up (2x 2.5 T&E fused at 32A) but radial setup at each socket (1 cable).

What appears to have been installed is a ring of junction boxes with every socket spurred off of this ring. This was obviously done to replace the house's previous wiring whilst utilising the existing conduit routes (only space for 1 cable).

I know that this is not acceptable by today's standards so my question is: Was this ever an acceptable method? Judging by the occasional use of green earth sleeving (if not left bare) this was done in the 70's.

 

[westward10]

This isn't uncommon and is given various monicas. One is by way of a ring final on the upper level with radials to the lower level or by a ring final to junction boxes and then radials to each point of utilisation.

 

[Octopus]

Very common in late 1960’s and 1970’s houses ..... the give away is normally very low end to end R2 readings

 

[Dillb]

This isn't uncommon and is given various monicas. One is by way of a ring final on the upper level with radials to the lower level or by a ring final to junction boxes and then radials to each point of utilisation.

2.5 radial feeding more than one current using point on a 32 amp OCPD isnt acceptable unless its MIMS

 

[westward10]

2.5 radial feeding more than one current using point on a 32 amp OCPD isnt acceptable unless its MIMS

They are only feeding one point, it isn't uncommon they are often called spider rings.

 

[Dillb]

They are only feeding one point, it isn't uncommon they are often called spider rings.

Ahh yes, my mistake, thought it was 2 legs feeding a JB each which then spurred off to several sockets. I am blurry eyed from too much Barley, hops, yeast and water

Edit: if I could vote my own post dumb I would so feel free too

 

[Spoon]

They are only feeding one point, it isn't uncommon they are often called spider rings.

Is this so that the downstairs sockets are on a ring and the upstairs are all spared from the downstairs circuit, rather than having 2 circuits?

 

[westward10]

Is this so that the downstairs sockets are on a ring and the upstairs are all spared from the downstairs circuit, rather than having 2 circuits?

Yes but bit is more common for the upper level to be a ring final with the lower level radials from it.

 

[Spoon]

Yes but bit is more common for the upper level to be a ring final with the lower level radials from it.

Out of curiosity, why the ring on the upper level?

 

[westward10]

Out of curiosity, why the ring on the upper level?

Less cable usage I would guess if installed in the ceiling void, if the ring final was downstairs you have a longer double drop to each socket than the upper level.

 

[Gavin John Hyde]

Ahh yes, my mistake, thought it was 2 legs feeding a JB each which then spurred off to several sockets. I am blurry eyed from too much Barley, hops, yeast and water

Edit: if I could vote my own post dumb I would so feel free too

I have rated your post a winner for your honesty and repentance...

 

[Deleted member 26818]

Them spider rings are a bugger if you want to add a few extra sockets.

 

[Intoelectrics]

Them spider rings are a bugger if you want to add a few extra sockets.

I never understood the mentality of doing a spider ring? The little bit of cable saving and little bit of easier cable run doesn't in my my mind outweigh the use of so many JB's. Its just asking for trouble if you ask me.
My old man often says "they don't make them like they used to" I often reply with "thank god they don't!" (which really winds him up)

Even though I know what he means, you often come across things that should really stay in the "good old days", spider rings being a classic example!

 

[Pete999]

Out of curiosity, why the ring on the upper level?

Probably due to the ground floor being a solid floor, far easier to run the ring in the first floor, drop down to sockets on the ground floor as spurs,and the sockets on the first floor are part of the ring. That's how we used to do it in the olden days, 7/029 twin and earth, lots of 30 Amp JBs.

 

[Octopus]

Such circuits with imperial cable and spur drops off the upstairs sockets are fun unless you have sockets that can accept 3 x 4 mm cable

 

[Pete999]

Such circuits with imperial cable and spur drops off the upstairs sockets are fun unless you have sockets that can accept 3 x 4 mm cable

Why 3 times 4mm2?

 

[Pete999]

Probably due to the ground floor being a solid floor, far easier to run the ring in the first floor, drop down to sockets on the ground floor as spurs,and the sockets on the first floor are part of the ring. That's how we used to do it in the olden days, 7/029 twin and earth, lots of 30 Amp JBs.

Of course nowadays you would need poncy MF joint boxes, whereas many of today' s Domestic Guys aren't taught how to make off a proper JB, just bung the cables in a MF JB. No sign of a platform between the joists to keep the JB stable, or cable clips for that matter, art has gone from our trade, bung it in, glue the flooring down, and forget the joint, cuz it's MF, until, da da Murphy's law comes into play, if you don't know Murphy's law, " what can go wrong, will go wrong"

 

[Pete999]

Probably due to the ground floor being a solid floor, far easier to run the ring in the first floor, drop down to sockets on the ground floor as spurs,and the sockets on the first floor are part of the ring. That's how we used to do it in the olden days, 7/029 twin and earth, lots of 30 Amp JBs.

Of course nowadays you would need poncy MF joint boxes, whereas many of today' s Domestic Guys aren't taught how to make off a proper JB, just bung the cables in a MF JB. No sign of a platform between the joists to keep the JB stable, or cable clips for that matter, art has gone from our trade, bung it in, glue the flooring down, and forget the joint, cuz it's MF, until, da da Murphy's law comes into play, if you don't know Murphy's law, " what can go wrong, will go wrong"

 

[Deleted member 26818]

Have seen these in Warner type flats, where the circuit only supplies the upstairs flat (as far as I am aware).
Landlord wanted to lease to the Local Council and had to add a couple of extra sockets.
Wanted as little disruption as possible.

 

[Octopus]

Why 3 times 4mm2?

Old imperial cable has a greater cross section than 2.5 mm cable

An "old" installation with a ring around the top floor and spurs down to the socket below means each socket will have 3 cables

Therefore the sockets need to accommodate 3 x 4mm cables .... as they are very unlikely to accept 3 x imperial cables ...