I want to add a spur from a socket, but it already has a spur
connected.
So can I instead run 2 cables to the new 'spur', and connect one side
of the ring with 30A connector block behind the original socket to one
cable and the other to the original socket.
Thus the new socket will be in the ring, and not a spur after all.

The topology of this sounds fine to me, it's just the use of connector
block behind the socket to extend one of the cables that i'm not sure
about.

cheers,

rob.

cantalou wrote:
So can I instead run 2 cables to the new 'spur', and connect one side
of the ring with 30A connector block behind the original socket to one
cable and the other to the original socket.

As long as it is electrically sound, and the connector block is in
an accessible accessory box (ie, not wrapped in PVC tape and hidden
under the floor). You might be squeezing it with the connector block
in the same accessory box as the socket outlet.

--
JGH

The message

from contains these words:

cantalou wrote:
So can I instead run 2 cables to the new 'spur', and connect one side
of the ring with 30A connector block behind the original socket to one
cable and the other to the original socket.

As long as it is electrically sound, and the connector block is in
an accessible accessory box (ie, not wrapped in PVC tape and hidden
under the floor). You might be squeezing it with the connector block
in the same accessory box as the socket outlet.

I could be misremembering but didn't someone say recently that the rule
isn't that you can't have more than one spur off a socket but that you
can't have more sockets on spurs than there are on the ring. Not
something I would want to attempt though. I have enough trouble getting
the wires into their holes in the first place even without a spur. :-)

The op could try what I have done in the past when extending ring mains.
Repace the double socket with two single sockets in close proximity and
wire the extension between them. Don't get the boxes too close together
or the second socket will be an interference fit on the side of the
first.

--
Roger Chapman

On Fri, 7 Dec 2007 16:32:11 UTC, Roger
wrote:

The message

from contains these words:

cantalou wrote:
So can I instead run 2 cables to the new 'spur', and connect one side
of the ring with 30A connector block behind the original socket to one
cable and the other to the original socket.

As long as it is electrically sound, and the connector block is in
an accessible accessory box (ie, not wrapped in PVC tape and hidden
under the floor). You might be squeezing it with the connector block
in the same accessory box as the socket outlet.

I could be misremembering but didn't someone say recently that the rule
isn't that you can't have more than one spur off a socket but that you
can't have more sockets on spurs than there are on the ring. Not
something I would want to attempt though. I have enough trouble getting
the wires into their holes in the first place even without a spur. :-)

But he isn't prposing to do that. He's proposing to split the ring and
then insert some more cable and the new socket. Hence the joints.

The op could try what I have done in the past when extending ring mains.
Repace the double socket with two single sockets in close proximity and
wire the extension between them. Don't get the boxes too close together
or the second socket will be an interference fit on the side of the
first.

You can always use a surface box that has space for two separate single
sockets. Quite useful if you want extra wiring (and a possible, though
arguably not very good way of housing the choc block in this case, by
using a blanking plate on one side).

--
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
http://www.diybanter.com

The message
from "Bob Eager" contains these words:

I could be misremembering but didn't someone say recently that the rule
isn't that you can't have more than one spur off a socket but that you
can't have more sockets on spurs than there are on the ring. Not
something I would want to attempt though. I have enough trouble getting
the wires into their holes in the first place even without a spur. :-)

But he isn't prposing to do that. He's proposing to split the ring and
then insert some more cable and the new socket. Hence the joints.

But his post started off with:

"I want to add a spur from a socket, but it already has a spur
connected."

I read that as the op accepting that more than one spur from the same
socket is forbidden. How do you see it?

--
Roger Chapman

On Fri, 7 Dec 2007 17:45:54 UTC, Roger
wrote:

The message
from "Bob Eager" contains these words:

I could be misremembering but didn't someone say recently that the rule
isn't that you can't have more than one spur off a socket but that you
can't have more sockets on spurs than there are on the ring. Not
something I would want to attempt though. I have enough trouble getting
the wires into their holes in the first place even without a spur. :-)

But he isn't prposing to do that. He's proposing to split the ring and
then insert some more cable and the new socket. Hence the joints.

But his post started off with:

"I want to add a spur from a socket, but it already has a spur
connected."

That's what he wanted to do. But he knew he couldn't.

So can I instead run 2 cables to the new 'spur', and connect one side
of the ring with 30A connector block behind the original socket to one
cable and the other to the original socket.

Thus linking it into the ring.

Thus the new socket will be in the ring, and not a spur after all.

--
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
http://www.diybanter.com

"Bob Eager" wrote in message
...
On Fri, 7 Dec 2007 17:45:54 UTC, Roger
wrote:

The message
from "Bob Eager" contains these words:

I could be misremembering but didn't someone say recently that the
rule
isn't that you can't have more than one spur off a socket but that
you
can't have more sockets on spurs than there are on the ring. Not
something I would want to attempt though. I have enough trouble
getting
the wires into their holes in the first place even without a spur.
:-)

But he isn't prposing to do that. He's proposing to split the ring and
then insert some more cable and the new socket. Hence the joints.

But his post started off with:

"I want to add a spur from a socket, but it already has a spur
connected."

That's what he wanted to do. But he knew he couldn't.

Why not?

Two spurs from one point on the ring is acceptable (expected
loading/balancing of the ring and the number of spurs already taken off the
ring may come into play). A spur off a spur is not acceptable.

Adam

On Fri, 7 Dec 2007 18:47:38 UTC, "ARWadsworth"
wrote:

"I want to add a spur from a socket, but it already has a spur
connected."

That's what he wanted to do. But he knew he couldn't.

Why not?

Two spurs from one point on the ring is acceptable (expected
loading/balancing of the ring and the number of spurs already taken off the
ring may come into play). A spur off a spur is not acceptable.

Good point. I was assuming he'd be adding a spur to a spur. However,
getting four cables in there might be 'challenging'!

--
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
http://www.diybanter.com

The message
from "Bob Eager" contains these words:

"I want to add a spur from a socket, but it already has a spur
connected."

That's what he wanted to do. But he knew he couldn't.

Why not?

Two spurs from one point on the ring is acceptable (expected
loading/balancing of the ring and the number of spurs already taken
off the
ring may come into play). A spur off a spur is not acceptable.

Good point. I was assuming he'd be adding a spur to a spur. However,
getting four cables in there might be 'challenging'!

The wording seemed clear enough to me, as did the problem of inserting
all the wires.

--
Roger Chapman

On Fri, 7 Dec 2007 20:37:56 UTC, Roger
wrote:

The message
from "Bob Eager" contains these words:

"I want to add a spur from a socket, but it already has a spur
connected."

That's what he wanted to do. But he knew he couldn't.

Why not?

Two spurs from one point on the ring is acceptable (expected
loading/balancing of the ring and the number of spurs already taken
off the
ring may come into play). A spur off a spur is not acceptable.

Good point. I was assuming he'd be adding a spur to a spur. However,
getting four cables in there might be 'challenging'!

The wording seemed clear enough to me, as did the problem of inserting
all the wires.

Good for you.

--
The information contained in this post is copyright the
poster, and specifically may not be published in, or used by
http://www.diybanter.com

The message
from "Bob Eager" contains these words:

The wording seemed clear enough to me, as did the problem of inserting
all the wires.

Good for you.

But not for you. :-)

--
Roger Chapman

Bob Eager wrote:
On Fri, 7 Dec 2007 18:47:38 UTC, "ARWadsworth"
wrote:

"I want to add a spur from a socket, but it already has a spur
connected."

That's what he wanted to do. But he knew he couldn't.

Why not?

Two spurs from one point on the ring is acceptable (expected
loading/balancing of the ring and the number of spurs already taken
off the ring may come into play). A spur off a spur is not
acceptable.

Good point. I was assuming he'd be adding a spur to a spur. However,
getting four cables in there might be 'challenging'!

It bloody well is! I found such a wiring nightmare whilst dry lining a
kitchen once. Several junction boxes & bits of cable later I got it sorted.


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk
01634 717930
07850 597257

Your proposed solution may be incorrect.

Regs limit the number of connections in a socket to 3
o 2 connections for the ring legs
o 1 connection for 1 socket spur off the ring

You propose a choc-block to keep to 3 connection limit
o The choc block would need to be 30/32A
---- two spurs to 2x 1G sockets can draw 2x 13A = 26A
---- two spurs to 2x 2G sockets can draw 4x 13A = 52A*
---- * obviously limited in the latter by 32A ring CPD
o The cables feeding the choc block must be 30/32A
---- a spur to 2x 1G sockets is 26A or 1x FTE-2.5mm
---- a spur to 2x 2G sockets is 32A or 2x FTE-2.5mm
---- so link the choc-bloc by FTE-4mm or reroute legs
o The choc block & cables take up a lot of space
---- I doubt it would fit even in a 47mm depth box

There are some alternatives.


1. If you only require 13A in total from "two spurs".

a) If your existing socket is 1G (1-gang)...
o Fit a Twin-1G metal backbox in place of the 1G socket
---- it is a single metal box with twin-1G fittings
---- separated by a metal plate which you push out
o Fit a 1G Socket in the one side
---- into which your 2 ring legs connect
o Fit a 1G Fused Outlet (FCU) into other side
---- run 3rd FTE-2.5mm to the socket next to it
---- run as many spurs as you want off this (13A fuse)
o Maintains 3-wires into socket & good workmanship

b) If your existing socket is 2G (2-gang)...
o Fit a 1G metal backbox next to the socket
o Fit a 1G Fused Outlet (FCU) into it
---- run 3rd FTE-2.5mm to the socket next to it
---- run as many spurs as you want off this (13A fuse)
o Maintains 3-wires into socket & good workmanship


2. If you require 13A from each spur, 26A total.

o Fit a Twin 1G metal backbox in place of the 1G socket
---- it is a single metal box with twin-1G fittings
---- separated by a metal plate which you push out
o Fit a 1G Socket in EACH side of the fitting
o Ring leg #1 goes to LH socket, leg #2 to RH socket
---- this separates the original ring
o Link the two sockets by FTE-2.5mm
---- this rejoins the ring
o Spur #1 off LH socket, Spur #2 off RH socket
o Maintains 3-wires into socket & good workmanship

However you may not have sufficient ring leg length.


It can be done similarly with surface mount boxes,
but that may be problematic re ring cable length.


You CAN use a 30A junction box under floorboards:
o The EXISTING socket become a spur
o Your junction box then runs the 2 new spurs as a RING
o You would need to link these 2 new spurs as a RING

The problem is accessibility:
o Accessibility means an area never subject to furniture
o Eg, a landing area, access via hole/floorboard


I would fit a twin-1G box in place of a 1G/2G socket, fit
FCU in one side & 1G skt in other. Then run as many
spurs as you like off the FCU subject to 13A load limit.

Alternatively extend the ring properly - as a ring.

I think I read your question correctly.
--
DB.

In article ,
"The Medway Handyman" writes:
Bob Eager wrote:

Good point. I was assuming he'd be adding a spur to a spur. However,
getting four cables in there might be 'challenging'!

It bloody well is! I found such a wiring nightmare whilst dry lining a
kitchen once. Several junction boxes & bits of cable later I got it sorted.

Some socket makes have larger cable capacities than others.
Depth of back box makes a big difference too when you have
lots of cables or particularly thick cables.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Dorothy Bradbury wrote:
Your proposed solution may be incorrect.

Regs limit the number of connections in a socket to 3
o 2 connections for the ring legs
o 1 connection for 1 socket spur off the ring

SNIP
Interesting.
Could you cite the number(s), please?
(I can't find it in my old (red-cover) version and I'm too mean to buy a new
one until a couple of years after the 17th ed. has been released.)

Dorothy Bradbury wrote:
Your proposed solution may be incorrect.

Regs limit the number of connections in a socket to 3
o 2 connections for the ring legs
o 1 connection for 1 socket spur off the ring

Could you cite the number(s), please?

1stly, Implied...

OSG 16th, p153, Appx8.
"A non-fused spur feeds only 1 single/twin/multiple outlet
or 1 permanently connected equipment. Such a spur is
connected to a circuit at the terminals of a socket outlet
or junction box or at the origin of the circuit in the DB".

No regulation is cited, which suggests Guidance.
In order to meet the Guidance meens 3 connections.


2ndly, Physically...
o Skt terminals physically limited to 3x 4mm CSA conductors
o Socket terminals may physically accept 4x 2.5mm CSA conductors


The OSG guidance can be read as merely existing to prevent a
chain of spurs off 1 socket fed by FTE-2.5mm with 32A CPD.
It comes down to interpretation - by an Inspector on the day :-)

Frankly, telephone the tech support of the socket maker.
If they say it can physically accept the number of wires then
you are complying with their instructions of acceptable usage.

They will probably advise a 32-35mm depth backbox though.
So the implementation may require physical change anyway.
--
DB.

Andrew Gabriel wrote:
In article ,
"The Medway Handyman" writes:
Bob Eager wrote:
Good point. I was assuming he'd be adding a spur to a spur. However,
getting four cables in there might be 'challenging'!
It bloody well is! I found such a wiring nightmare whilst dry lining a
kitchen once. Several junction boxes & bits of cable later I got it sorted.

Some socket makes have larger cable capacities than others.
Depth of back box makes a big difference too when you have
lots of cables or particularly thick cables.

The TLC Ultimate range sockets have plenty of terminal space for 4 wires...

The other trick to get more backbox depth is to use a spacer:

http://cpc.farnell.com/jsp/Electrica...sp?sku=PL08925

(order codes PL08924 and PL08925)

These surface mount over the sunken backbox and give you an extra 10mm
of depth to play with, without changing the appearance of the socket in
the way a complete surface mounting pattress would - it still looks
flush mounted.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Dorothy Bradbury wrote:
Dorothy Bradbury wrote:
Your proposed solution may be incorrect.

Regs limit the number of connections in a socket to 3
o 2 connections for the ring legs
o 1 connection for 1 socket spur off the ring
Could you cite the number(s), please?

I don't believe there is one. You can have two spurs from the same
location if required (point load and balance issues aside)


1stly, Implied...

OSG 16th, p153, Appx8.
"A non-fused spur feeds only 1 single/twin/multiple outlet
or 1 permanently connected equipment. Such a spur is
connected to a circuit at the terminals of a socket outlet
or junction box or at the origin of the circuit in the DB".

This does not really have anything to do with the number of spurs at a
single connection point, only that a unfused spur should only feed a
single socket of flex connection unit etc.

No regulation is cited, which suggests Guidance.
In order to meet the Guidance meens 3 connections.


2ndly, Physically...
o Skt terminals physically limited to 3x 4mm CSA conductors
o Socket terminals may physically accept 4x 2.5mm CSA conductors

Given 2.5mm^2 is the normal cable of choice, 4 wires ought to be doable
on most sockets. Some are very much better designed for this than
others. You will note that most junction boxes also have 4 cable entry
holes.

They will probably advise a 32-35mm depth backbox though.
So the implementation may require physical change anyway.

or a spacer under the socket.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"Andrew Gabriel" andrew@a17 wrote in message
...
In article ,
"The Medway Handyman" writes:
Bob Eager wrote:

Good point. I was assuming he'd be adding a spur to a spur. However,
getting four cables in there might be 'challenging'!

It bloody well is! I found such a wiring nightmare whilst dry lining a
kitchen once. Several junction boxes & bits of cable later I got it
sorted.


Some socket makes have larger cable capacities than others.

So you have met my girlfriend.

Depth of back box makes a big difference too when you have
lots of cables or particularly thick cables.

I cannot comment about the depth of the backbox.

Adam

PS Sorry