I have fitted a spur to a double socket, however it was a tad tricky
since the conductors were not long enough. Is it 'OK' to hide screw
block connectors in the socket box ? The Muppet who originally fitted
the surface mount dual socket over the original single socket recess
did not manage to connect up the earth cable.. so I can't have made it
any worse !

Simon

wrote in message
...
I have fitted a spur to a double socket, however it was a tad tricky
since the conductors were not long enough. Is it 'OK' to hide screw
block connectors in the socket box ? The Muppet who originally fitted
the surface mount dual socket over the original single socket recess
did not manage to connect up the earth cable.. so I can't have made it
any worse !

Simon

Yes that is fine.

Have you considered

http://www.screwfix.com/prods/12849/...ts/Socket-Conv
erters/Clipsal-Converta-Skt-1G-to-2G-Polycarbonate

as an alternative to a surface mounted double socket?

Adam

wrote in message
...
I have fitted a spur to a double socket, however it was a tad tricky
since the conductors were not long enough. Is it 'OK' to hide screw
block connectors in the socket box ? The Muppet who originally fitted
the surface mount dual socket over the original single socket recess
did not manage to connect up the earth cable.. so I can't have made it
any worse !

Simon


Sockets are normally accessible, so screw connector block can be used in
this situation. But, it all depends on the current rating of the block you
have used / are thinking of using to make all your connections in the
recessed box.

A standard ring mains can carry up to 30 amps, split between two conductors
sized at 2.5 mm each, so equaling 5 mm that should be connected to each
outlet point.

If you are thinking of connecting both of the original ring supplies
together and tapping from them to the original double and then the new
single spur outlet. Then you will need connector block rated for at least
30 amps current loading to be sure it will cope safely with all situations.

Don't think you can get away with the smaller 15 amp rated connectors
because of the space restriction you have in the single back box. You could
be asking for trouble if you do. You could, if you are worrying about the
space, use two sets of 15 amp connectors, but do it safely by connecting one
supply directly to the spur and from there to the double socket and from the
double socket back to the second supply. Thus keeping the full ring supply
to both outlets again.

Two sets of smaller connectors are easier to work with in the small space
provided by a single sized back box. One set of connectors can be placed
neatly at the back of the box, with the other set of connectors placed in a
mirror fashion in front. So leaving more room for the conductors to be
dressed safely within the rest of the space in the back box.

Good luck with the project, anywhoo.

On Nov 1, 10:09*am, "BigWallop"
wrote:
wrote in message

...

I have fitted a spur to a double socket, however it was a tad tricky
since the conductors were not long enough. Is it 'OK' to hide screw
block connectors in the socket box ? The Muppet who originally fitted
the surface mount dual socket over the original single socket recess
did not manage to connect up the earth cable.. so I can't have made it
any worse !

Simon

Sockets are normally accessible, so screw connector block can be used in
this situation. *But, it all depends on the current rating of the block you
have used / are thinking of using to make all your connections in the
recessed box.

A standard ring mains can carry up to 30 amps, split between two conductors
sized at 2.5 mm each, so equaling 5 mm that should be connected to each
outlet point.

If you are thinking of connecting both of the original ring supplies
together and tapping from them to the original double and then the new
single spur outlet. *Then you will need connector block rated for at least
30 amps current loading to be sure it will cope safely with all situations.

Don't think you can get away with the smaller 15 amp rated connectors
because of the space restriction you have in the single back box. *You could
be asking for trouble if you do. *You could, if you are worrying about the
space, use two sets of 15 amp connectors, but do it safely by connecting one
supply directly to the spur and from there to the double socket and from the
double socket back to the second supply. *Thus keeping the full ring supply
to both outlets again.

Two sets of smaller connectors are easier to work with in the small space
provided by a single sized back box. *One set of connectors can be placed
neatly at the back of the box, with the other set of connectors placed in a
mirror fashion in front. *So leaving more room for the conductors to be
dressed safely within the rest of the space in the back box.

Good luck with the project, anywhoo.

Thanks for help, I think they must be 30A connectors but I will check
this. Is it as well to run a second 2.5mm T&E to the spur connection
box and use 4 terminal connectors then ? Is that what you are saying ?

wrote in message
...
On Nov 1, 10:09 am, "BigWallop"
wrote:
wrote in message

...

snipped

Two sets of smaller connectors are easier to work with in the small space
provided by a single sized back box. One set of connectors can be placed
neatly at the back of the box, with the other set of connectors placed in
a
mirror fashion in front. So leaving more room for the conductors to be
dressed safely within the rest of the space in the back box.

Good luck with the project, anywhoo.

Thanks for help, I think they must be 30A connectors but I will check
this. Is it as well to run a second 2.5mm T&E to the spur connection
box and use 4 terminal connectors then ? Is that what you are saying ?


No. What I mean is. You should have two cables supplying the double
socket. These two cables connect from one socket to the other right round
the house. So all the sockets are literally connect together to form what
is called a ring mains supply.

Looking inside the existing single back box, you see the two cables ( grey
cover) which both have a red and black covered conductor and a bare earth
connecting center conductor.

Connecting them together in 30 amp rated block is fine, but then taking a 4
or 6 mm cable to the double socket, would be the proper way to do it. Then
you can safely take a spur off to the new single outlet.

But an alternative is to connect the first supply cable (grey cover with red
and black inside) in a lower rated 15 amp block and take new 2.5 mm cable to
the new single spur outlet. From the new single spur outlet, take another
piece of 2.5 mm cable back to the double socket. Also from the double
socket, take another piece of 2.5 mm cable and connect it with a separate
block to the second supply cable.

What you are doing is keeping the whole ring mains supply connecting with
all the sockets again, but now including your new spur off. So your spur
will not be a spur, but part of the actual ring mains supply.

If you don't understand any of this explanation, then do it your own way.
But be aware of the limitations of the safe loading on your new spur.

On Nov 1, 11:42*am, "BigWallop"
wrote:
wrote in message

...
On Nov 1, 10:09 am, "BigWallop"
wrote:

wrote in message

...

snipped

Two sets of smaller connectors are easier to work with in the small space
provided by a single sized back box. One set of connectors can be placed
neatly at the back of the box, with the other set of connectors placed in
a
mirror fashion in front. So leaving more room for the conductors to be
dressed safely within the rest of the space in the back box.

Good luck with the project, anywhoo.

Thanks for help, I think they must be 30A connectors but I will check
this. Is it as well to run a second 2.5mm T&E to the spur connection
box and use 4 terminal connectors then ? Is that what you are saying ?

No. *What I mean is. *You should have two cables supplying the double
socket. *These two cables connect from one socket to the other right round
the house. *So all the sockets are literally connect together to form what
is called a ring mains supply.

Looking inside the existing single back box, you see the two cables ( grey
cover) which both have a red and black covered conductor and a bare earth
connecting center conductor.

Connecting them together in 30 amp rated block is fine, but then taking a 4
or 6 mm cable to the double socket, would be the proper way to do it. *Then
you can safely take a spur off to the new single outlet.

But an alternative is to connect the first supply cable (grey cover with red
and black inside) in a lower rated 15 amp block and take new 2.5 mm cable to
the new single spur outlet. *From the new single spur outlet, take another
piece of 2.5 mm cable back to the double socket. *Also from the double
socket, take another piece of 2.5 mm cable and connect it with a separate
block to the second supply cable.

What you are doing is keeping the whole ring mains supply connecting with
all the sockets again, but now including your new spur off. *So your spur
will not be a spur, but part of the actual ring mains supply.

If you don't understand any of this explanation, then do it your own way.
But be aware of the limitations of the safe loading on your new spur.

OK! so to be /safe/ I will replace the bit of 2.5mm I put between the
ring main and the socket with 6mm and it will be OK assuming they are
30 A connectors . Thanks for that.

wrote in message
...
I have fitted a spur to a double socket, however it was a tad tricky
since the conductors were not long enough. Is it 'OK' to hide screw
block connectors in the socket box ? The Muppet who originally fitted
the surface mount dual socket over the original single socket recess
did not manage to connect up the earth cable.. so I can't have made it
any worse !

If you have a crimping tool then just crimp some wire on the make them
longer.
Its easier than screw terminals but they are OK for what you are doing if
you use ones that are big enough.

BigWallop wrote:

No. What I mean is. You should have two cables supplying the double
socket. These two cables connect from one socket to the other right round
the house. So all the sockets are literally connect together to form what
is called a ring mains supply.

"Ring final circuit" is the proper name really. (ring mains are not used
in domestic wiring)

Connecting them together in 30 amp rated block is fine, but then taking a 4
or 6 mm cable to the double socket, would be the proper way to do it. Then
you can safely take a spur off to the new single outlet.

Extending both existing sets of wires to allow them to reach the
existing socket is the way to go. The spur can then be safely taken from
the socket terminals.

But an alternative is to connect the first supply cable (grey cover with red
and black inside) in a lower rated 15 amp block and take new 2.5 mm cable to

15A connectors are not suitable. The current in any single cable in a
ring circuit can exceed that.

the new single spur outlet. From the new single spur outlet, take another
piece of 2.5 mm cable back to the double socket. Also from the double
socket, take another piece of 2.5 mm cable and connect it with a separate
block to the second supply cable.

What you are doing is keeping the whole ring mains supply connecting with
all the sockets again, but now including your new spur off. So your spur
will not be a spur, but part of the actual ring mains supply.

Generally its usually simpler to crimp a connection to one of the
existing cables when joining new socket(s) into an existing ring in this
way since the connectors are physically much smaller. Otherwise you can
run out of box space with four cables to terminate.

http://wiki.diyfaq.org.uk/index.php?...Cable_crimping

If you don't understand any of this explanation, then do it your own way.
But be aware of the limitations of the safe loading on your new spur.

There are no limitations of loading on a spur that you need to keep in
mind really. If the spur is unfused then it can supply at most one
single socket. That in itself limits the maximum load. (for more than
one double socket you would require a fused spur - an hence a total load
limit of 13A imposed by the fused connection unit).

--
Cheers,

John.

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

On 2 Nov, 01:32, John Rumm wrote:
BigWallop wrote:
No. *What I mean is. *You should have two cables supplying the double
socket. *These two cables connect from one socket to the other right round
the house.

*snip

But be aware of the limitations of the safe loading on your new spur.

There are no limitations of loading on a spur that you need to keep in
mind really. If the spur is unfused then it can supply at most one
single socket. That in itself limits the maximum load. (for more than
one double socket you would require a fused spur - an hence a total load
limit of 13A imposed by the fused connection unit).

This maybe needs clarification.

The rules SFAIUI are that a single spur - normally in 2.5mmsq cable,
unless its route etc dictates a larger size - can feed only one
fitting, but that fitting can contain either a single 13 A outlet or a
pair (ie double) of outlets.

This is because a double 13A socket is counted as a single 13A fitting
for assessing circuit loading (or at least was in the 16th IEE regs).

To feed more than one fitting on a spur, a fused connection unit must
be wired into the spur. This may be placed anywhere along the spur
before the first fitting. The fuse rating may be up to 20A, (but is
often only 13A) as 20 A is the limit current for 2.5mmsq cable.

Two tentative suggestions which came to mind when I read the OP:

(a) dig out the old metal backing box & replace it with a 45mm deep
one to give more room for a cable connector (which needs wrapping
insulation tape or some other isolation from the other contents of the
metal box & socket)

(b) replace the existing socket from which the spur is being taken by
2 separate sockets (both could be either single or double) in line
with the ring cable to provide spare connection cable from the ring.
Make sure the spur cable is aligned in one of the safe vertical/
horizontal zones of the new sockets & connect up, joining the 2 new
sockets with a short extra length of 2.5mm sq cable.

If it were my problem I would probably have used (b) as the end result
doesn't look botched & it gives more socket outlets of which I find I
never have enough.

HTH

In article ,
John Rumm wrote:
But an alternative is to connect the first supply cable (grey cover
with red and black inside) in a lower rated 15 amp block and take new
2.5 mm cable to

15A connectors are not suitable. The current in any single cable in a
ring circuit can exceed that.

Be interested to know just how a 15 amp connector block differs from the
terminals found in a 13 amp socket?

The diameter of the hole is similar as are the fixing screws. If the
cables being jointed are overlapped over the entire length of the
connector so both screws grip both I'd say they'll make an excellent
connection well up to handling any current the cable can.

--
*I pretend to work. - they pretend to pay me.

Dave Plowman London SW
To e-mail, change noise into sound.

jim wrote:

But be aware of the limitations of the safe loading on your new spur.

There are no limitations of loading on a spur that you need to keep in
mind really. If the spur is unfused then it can supply at most one
single socket. That in itself limits the maximum load. (for more than
one double socket you would require a fused spur - an hence a total load
limit of 13A imposed by the fused connection unit).

This maybe needs clarification.

The rules SFAIUI are that a single spur - normally in 2.5mmsq cable,
unless its route etc dictates a larger size - can feed only one
fitting, but that fitting can contain either a single 13 A outlet or a
pair (ie double) of outlets.

Yup, sorry I was trying to word "a single double socket" IYSWIM, and got
something that failed quite admirably ;-)

This is because a double 13A socket is counted as a single 13A fitting
for assessing circuit loading (or at least was in the 16th IEE regs).

I was under the impression that is was usually counted as 20A rather
than 13A...

To feed more than one fitting on a spur, a fused connection unit must
be wired into the spur. This may be placed anywhere along the spur
before the first fitting. The fuse rating may be up to 20A, (but is
often only 13A) as 20 A is the limit current for 2.5mmsq cable.

Depends on the installation method somewhat - 20A is toward the lower
end (i.e. de-rated by several factors).


--
Cheers,

John.

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

Dave Plowman (News) wrote:
In article ,
John Rumm wrote:
But an alternative is to connect the first supply cable (grey cover
with red and black inside) in a lower rated 15 amp block and take new
2.5 mm cable to

15A connectors are not suitable. The current in any single cable in a
ring circuit can exceed that.

Be interested to know just how a 15 amp connector block differs from the
terminals found in a 13 amp socket?

They will be tested to different specs at the least. However the quality
of socket terminations does vary greatly. Some do seem only just up to it.

(the TLC "ultimate" ones being my current favourite - nice large open
square terminals that come with the screws already open, nicely colour
coded for old and new wires, shallow depth fitting, decent earth
terminations (x2) etc. And they are an attractive design as well)

The diameter of the hole is similar as are the fixing screws. If the
cables being jointed are overlapped over the entire length of the
connector so both screws grip both I'd say they'll make an excellent
connection well up to handling any current the cable can.

The terminal current rating almost certainly assumes you are not
overlapping the wires...



--
Cheers,

John.

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

In article ,
John Rumm wrote:
The diameter of the hole is similar as are the fixing screws. If the
cables being jointed are overlapped over the entire length of the
connector so both screws grip both I'd say they'll make an excellent
connection well up to handling any current the cable can.

The terminal current rating almost certainly assumes you are not
overlapping the wires...

Indeed. But there's no reason not to when simply extending a wire.

--
*The average person falls asleep in seven minutes *

Dave Plowman London SW
To e-mail, change noise into sound.