I am attaching a spuron the plugs circuit to add a double plug. This
spur will run ..tv..sky box and DVD player.
Does the spur wire have to be the same "type" as the the triple earth
wire on the circuit ?

Mike P

On Tue, 11 Dec 2007 13:21:25 +0000, Mike P mike@askme wrote:

I am attaching a spuron the plugs circuit to add a double plug. This
spur will run ..tv..sky box and DVD player.
Does the spur wire have to be the same "type" as the the triple earth
wire on the circuit ?

Mike P

Are you sure you should be adding a spur when you are asking such a
question?
The wire you refer to ( It is actually called cable ) is not "triple
earth" .It is " twin and earth" ,a live and neutral conductor and a
bare earth conductor which should be sleeved in earth sleeving at the
connections . The cable will be 2.5mm size so use this size cable for
the spur .
Have a read here

http://www.diynot.com/pages/el/el012.php#a0
Stuart

On Tue, 11 Dec 2007 13:32:43 +0000, Stuart B wrote:

... On Tue, 11 Dec 2007 13:21:25 +0000, Mike P mike@askme wrote:
...
... I am attaching a spuron the plugs circuit to add a double plug. This
... spur will run ..tv..sky box and DVD player.
... Does the spur wire have to be the same "type" as the the triple earth
... wire on the circuit ?
...
... Mike P
...
... Are you sure you should be adding a spur when you are asking such a
... question?
... The wire you refer to ( It is actually called cable ) is not "triple
... earth" .It is " twin and earth" ,a live and neutral conductor and a
... bare earth conductor which should be sleeved in earth sleeving at the
... connections . The cable will be 2.5mm size so use this size cable for
... the spur .
... Have a read here
...
... http://www.diynot.com/pages/el/el012.php#a0
... Stuart

Thanks ... terminology is a problem for us all.
I do sleeve all the earth wires I come across. This is an old house
where bare earths are the norm.

Mike P

. The cable will be 2.5mm size so use this size cable for
the spur .
Stuart

As a general rule yes but it may be larger.

..

On Tue, 11 Dec 2007 23:33:57 -0800 (PST), ac1951
wrote:

...
...
... . The cable will be 2.5mm size so use this size cable for
... the spur .
... Stuart
...
... As a general rule yes but it may be larger.
...
... .

The circuit cable is larger. It has 3 coiled earth wires for a start.
I spurred off with a 30amp junction box using 2.5mm.
Why should the cable all be the same size?

Mike P

On Wed, 12 Dec 2007 08:17:53 +0000 someone who may be Mike P
mike@askme wrote this:-

The circuit cable is larger. It has 3 coiled earth wires for a start.
I spurred off with a 30amp junction box using 2.5mm.

Personally I would have found out why the cable is larger than
expected and how much larger it is.

There are a number of possibilities, a radial socket circuit and
someone "borrowing" a circuit that once fed a cooker or shower are
the more likely possibilities.

Electric wiring in houses is not always as easy as it appears. An
expert is someone who knows how little they know about something.
Over-confidence is best avoided with something that can kill,
whether by direct means or indirect means like fire.

No matter the bluster about terminology, I agree with Stuart, "Are
you sure you should be adding a spur when you are asking such a
question?"


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54

In article ,
Mike P mike@askme wrote:
The circuit cable is larger. It has 3 coiled earth wires for a start.
I spurred off with a 30amp junction box using 2.5mm.
Why should the cable all be the same size?

It sounds like you've got old cable called 7/0.29. There will be 7 strands
of 0.29" twisted together for the live and neutral and 3 of 0.29" for the
earth. That is the old standard ring main cable replaced by single strand
2.5mm TW&E about 40 years ago when such things went metric. If it has PVC
insulation it should still be fit for further service. If earlier it could
be rubber and likely to need replacing.

--
*Who is this General Failure chap anyway - and why is he reading my HD? *

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

On Wed, 12 Dec 2007 10:26:59 +0000 (GMT), "Dave Plowman (News)"
wrote:

... In article ,
... Mike P mike@askme wrote:
... The circuit cable is larger. It has 3 coiled earth wires for a start.
... I spurred off with a 30amp junction box using 2.5mm.
... Why should the cable all be the same size?
...
... It sounds like you've got old cable called 7/0.29.
snipped

What you describe, is what I have and it is pvc covered.
I have no concern about the cooker feed as it has its own direct
supply.
To all who feel concerned this is as far as I go with electrics.
Though I did move the central heating thermostat to another room.

This saga all arose because wifey got me a junction box from the HB
shed, as I did not have the time to go to the local trade leccy.
For some inexplicable reason I was reading the instructions that came
with it, as I swigged a cup of coffee.
It stated that the spur cable should be the same size as the circuit
cable .. which made my 6m of 2.5 somewhat redundant !
Hence the questions.

Mike P

On Dec 11, 1:49 pm, Mike P mike@askme wrote:
On Tue, 11 Dec 2007 13:32:43 +0000, Stuart B wrote:

.. On Tue, 11 Dec 2007 13:21:25 +0000, Mike P mike@askme wrote:
..
.. I am attaching a spuron the plugs circuit to add a double plug. This
.. spur will run ..tv..sky box and DVD player.
.. Does the spur wire have to be the same "type" as the the triple earth
.. wire on the circuit ?
..
.. Mike P
..
.. Are you sure you should be adding a spur when you are asking such a
.. question?
.. The wire you refer to ( It is actually called cable ) is not "triple
.. earth" .It is " twin and earth" ,a live and neutral conductor and a
.. bare earth conductor which should be sleeved in earth sleeving at the
.. connections . The cable will be 2.5mm size so use this size cable for
.. the spur .
.. Have a read here
..
.. http://www.diynot.com/pages/el/el012.php#a0
.. Stuart

Thanks ... terminology is a problem for us all.

Is it?

MBQ

In article ,
Mike P mike@askme wrote:
On Wed, 12 Dec 2007 10:26:59 +0000 (GMT), "Dave Plowman (News)"
wrote:

.. In article , .. Mike
P mike@askme wrote: .. The circuit cable is larger. It has 3 coiled
earth wires for a start. .. I spurred off with a 30amp junction box
using 2.5mm. .. Why should the cable all be the same size? .. ..
It sounds like you've got old cable called 7/0.29. snipped

What you describe, is what I have and it is pvc covered.

Should be ok for many a year yet, then.

I have no concern about the cooker feed as it has its own direct supply.

Eh? Is this a red herring? ;-)


To all
who feel concerned this is as far as I go with electrics. Though I did
move the central heating thermostat to another room.

This saga all arose because wifey got me a junction box from the HB
shed, as I did not have the time to go to the local trade leccy. For
some inexplicable reason I was reading the instructions that came with
it, as I swigged a cup of coffee. It stated that the spur cable should
be the same size as the circuit cable .. which made my 6m of 2.5
somewhat redundant ! Hence the questions.

All they're saying is that it should have the same current handling
capacity as the ring main cable - which means in effect the same type. In
your case you're simply using the modern equivalent. The reason for this
is it's not the power the socket may take - in your case only small if AV
stuff - but to maintain a suitably low earth conductor impedance so the
breaker will trip quickly in event of a fault in the wiring to the socket.

What may have confused many was saying you had a triple earth wire. What
you really meant was a stranded type which uses three strands twisted
together instead of the modern single strand variety.

--
*Most people have more than the average number of legs*

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

The message
from "Dave Plowman (News)" contains these words:

In article ,
Mike P mike@askme wrote:
The circuit cable is larger. It has 3 coiled earth wires for a start.
I spurred off with a 30amp junction box using 2.5mm.
Why should the cable all be the same size?

It sounds like you've got old cable called 7/0.29. There will be 7 strands
of 0.29" twisted together for the live and neutral and 3 of 0.29" for the
earth. That is the old standard ring main cable replaced by single strand
2.5mm TW&E about 40 years ago when such things went metric. If it has PVC
insulation it should still be fit for further service. If earlier it could
be rubber and likely to need replacing.

Hmm.............. While it was general to use 7/.036 for ring main work
before metrication, that would have had 7/.029 for the ecc.

If the OP's cable has three strands to the ecc, then it was probably
indeed 7/.029 which would have 3/.036 for the ecc.
(IEE Regs, 13th Edition)

In article ,
Appin wrote:
It sounds like you've got old cable called 7/0.29. There will be 7
strands of 0.29" twisted together for the live and neutral and 3 of
0.29" for the earth. That is the old standard ring main cable replaced
by single strand 2.5mm TW&E about 40 years ago when such things went
metric. If it has PVC insulation it should still be fit for further
service. If earlier it could be rubber and likely to need replacing.

Hmm.............. While it was general to use 7/.036 for ring main work
before metrication, that would have had 7/.029 for the ecc.

I've never seen 7/0.36 used for a ring main. Rather overkill and there
would be problems wiring it to the sockets where there was a spur.

If the OP's cable has three strands to the ecc, then it was probably
indeed 7/.029 which would have 3/.036 for the ecc.
(IEE Regs, 13th Edition)

That could be - it's a bit before my time. The stuff I've seen looked
rather like the same size strand used on all conductors.

--
*When a clock is hungry it goes back four seconds*

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

On Thu, 13 Dec 2007 17:03:13 +0000 (GMT), "Dave Plowman (News)"
wrote:

snip
...
... I've never seen 7/0.36 used for a ring main. Rather overkill and there
... would be problems wiring it to the sockets where there was a spur.
/snip

Right again .... The terminals were at bursting point .. hence I
opted for a junction box.

Mike P

In article ,
Mike P mike@askme wrote:
On Thu, 13 Dec 2007 17:03:13 +0000 (GMT), "Dave Plowman (News)"
wrote:

snip .. .. I've never seen 7/0.36 used for a ring main. Rather
overkill and there .. would be problems wiring it to the sockets where
there was a spur. /snip

Right again .... The terminals were at bursting point .. hence I
opted for a junction box.

Are the fittings more modern than the wiring? I've a feeling 'metric' ones
have smaller holes than the old ones.

--
*Heart attacks... God's revenge for eating his animal friends

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