Pls help identifying T&E cable size.

[AL_n]

I have some old white-covered twin & earth mains cable with its pos & neg
insulated in red & black.

The red & black wires are both 7-strand, and each individual strand is
about 1mm thick. Where all 7 strands are tightly together, the total
thickness of each pos or neg 7-strand cable is approx 3mm (not including
the red/black insulation).

The earth wire is single-strand and approx 1.5mm thick.

The overall outside dimensions of the cable (the white outer covering) is:

13.5mm wide and 7.5mm thick.

Please tell me what this is in mm-squared terminilogy.

Many thanks indeeed...

Al

[charles]

In article <XnsA4BEA5E8...@130.133.4.11>,

AL_n <fgdf...@fghfghfg.com> wrote:

> I have some old white-covered twin & earth mains cable with its pos & neg
> insulated in red & black.

> The red & black wires are both 7-strand, and each individual strand is
> about 1mm thick. Where all 7 strands are tightly together, the total
> thickness of each pos or neg 7-strand cable is approx 3mm (not including
> the red/black insulation).

> The earth wire is single-strand and approx 1.5mm thick.

> The overall outside dimensions of the cable (the white outer covering) is:

> 13.5mm wide and 7.5mm thick.

It's probably 7/.044 which was rated at 36 A. 4.5mm is the metric
equivalent.

> Please tell me what this is in mm-squared terminilogy.

> Many thanks indeeed...

> Al

--
Please note new email address:
cha...@CandEhope.me.uk

[AL_n]

charles <cha...@charleshope.demon.co.uk> wrote in
news:54d63eda...@charleshope.demon.co.uk:

>> I have some old white-covered twin & earth mains cable with its pos &
>> neg insulated in red & black.
>
>> The red & black wires are both 7-strand, and each individual strand
>> is about 1mm thick. Where all 7 strands are tightly together, the
>> total thickness of each pos or neg 7-strand cable is approx 3mm (not
>> including the red/black insulation).
>
>> The earth wire is single-strand and approx 1.5mm thick.
>
>> The overall outside dimensions of the cable (the white outer
>> covering) is:
>
>> 13.5mm wide and 7.5mm thick.
>
> It's probably 7/.044 which was rated at 36 A. 4.5mm is the metric
> equivalent.

Many thanks for that. Now for the dumb question! What is the max wattage of
electric shower I can use this for? Probably none, right?

Al

[charles]

In article <XnsA4BEB67A...@130.133.4.11>, AL_n

do the maths - 8kW.

[Dave Plowman (News)]

In article <XnsA4BEA5E8...@130.133.4.11>,
AL_n <fgdf...@fghfghfg.com> wrote:

> The red & black wires are both 7-strand, and each individual strand is
> about 1mm thick. Where all 7 strands are tightly together, the total
> thickness of each pos or neg 7-strand cable is approx 3mm (not including
> the red/black insulation).

I'd say probably 7/0.29. That was the old equivalent of 2.5mm ring cable.
But 7/0.44" is also possible - you'd need to measure a strand more
carefully. The 0.29" etc is the diameter IIRC.

--
*Why is the time of day with the slowest traffic called rush hour?

Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.

[AL_n]

charles <cha...@charleshope.demon.co.uk> wrote in
news:54d64674...@charleshope.demon.co.uk:

>> Many thanks for that. Now for the dumb question! What is the max wattage
>> of electric shower I can use this for? Probably none, right?
>
>
> do the maths - 8kW.
>

Thanks; that's encouraging. I'm not challenging your math, but the TLC
cable calculator below says says I'd need 10mm cable for an 8kw shower.
(same for a 7kw one). Perhaps they factor in some overkill to cover
themselves and/or perhaps make more profit? The length of my cable run is
12metres.

Calculator I used is here:

https://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html

TIA

Al

[Dave Plowman (News)]

In article <XnsA4BEBBFB...@130.133.4.11>,

You first need to make *absolutely* sure what the cable you have is. The
13.5mm overall width of the T&E says to me it's more likely 7/0.29. That
was a lot wider than 2.5mm TW&E.

Measure a strand with a digital caliper.

--
*Support bacteria - they're the only culture some people have *

[Bob Minchin]

Dave Plowman (News) wrote:
> In article <XnsA4BEA5E8...@130.133.4.11>,
> AL_n <fgdf...@fghfghfg.com> wrote:
>> The red & black wires are both 7-strand, and each individual strand is
>> about 1mm thick. Where all 7 strands are tightly together, the total
>> thickness of each pos or neg 7-strand cable is approx 3mm (not including
>> the red/black insulation).
>
> I'd say probably 7/0.29. That was the old equivalent of 2.5mm ring cable.
> But 7/0.44" is also possible - you'd need to measure a strand more
> carefully. The 0.29" etc is the diameter IIRC.
>

Erm 0.029" I think you mean.

The problem is the OP said about 1mm and 0.029" is under 3/4mm

Accurate measurements and simple calculation is needed.

[Andrew Mawson]

"Bob Minchin" wrote in message news:mm1lvl$e3l$1...@dont-email.me...

The only 7/ 029 I've worked with was TRS which in that era invariably was
black. O/P iirc is saying a white sheath.

Andrew

[Mike Clarke]

On 19/06/2015 19:17, Andrew Mawson wrote:

> The only 7/ 029 I've worked with was TRS which in that era invariably
> was black. O/P iirc is saying a white sheath.

I've come across plenty of PVC 7/029 in the past, but only grey.

--
Mike Clarke

[charles]

In article <54d64af...@davenoise.co.uk>,

Dave Plowman (News) <da...@davenoise.co.uk> wrote:
> In article <XnsA4BEBBFB...@130.133.4.11>,
> AL_n <fgdf...@fghfghfg.com> wrote:
> > charles <cha...@charleshope.demon.co.uk> wrote in
> > news:54d64674...@charleshope.demon.co.uk:

> > >> Many thanks for that. Now for the dumb question! What is the max wattage
> > >> of electric shower I can use this for? Probably none, right?
> > >
> > >
> > > do the maths - 8kW.
> > >

> > Thanks; that's encouraging. I'm not challenging your math, but the TLC
> > cable calculator below says says I'd need 10mm cable for an 8kw shower.
> > (same for a 7kw one). Perhaps they factor in some overkill to cover
> > themselves and/or perhaps make more profit? The length of my cable run
> > is 12metres.

> > Calculator I used is here:

> > https://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html

> You first need to make *absolutely* sure what the cable you have is. The
> 13.5mm overall width of the T&E says to me it's more likely 7/0.29. That
> was a lot wider than 2.5mm TW&E.

I don't have any 7/029 clips left (I do have 1/029 though), but 2.5mm clips
are only 10mm across. That's why I suspected 7/044. The stranmg diameter
also seem to agree with .044

[charles]

In article <mm1m7p$f1l$1...@dont-email.me>, Andrew Mawson

No, there was PVC in Imperial sizes. I re-wired my house in in 1964 using
PVC.

[charles]

In article <XnsA4BEBBFB...@130.133.4.11>,
AL_n <fgdf...@fghfghfg.com> wrote:

12m is quite a long cable run for a shower, so yes, you might need a
thicker cable.

[harry]

As the earth wire is single strand, it must be 7/029.
Rated at 20 amps, equivalent to 2.5mm these days.

Commonly used for wiring sockets, usually a ring main

[John Rumm]

On 19/06/2015 16:16, AL_n wrote:
> I have some old white-covered twin & earth mains cable with its pos & neg
> insulated in red & black.
>
> The red & black wires are both 7-strand, and each individual strand is
> about 1mm thick. Where all 7 strands are tightly together, the total
> thickness of each pos or neg 7-strand cable is approx 3mm (not including
> the red/black insulation).
>
> The earth wire is single-strand and approx 1.5mm thick.
>
> The overall outside dimensions of the cable (the white outer covering) is:
>
> 13.5mm wide and 7.5mm thick.

If you go from the overall size, and compare with the figures in the
last column of the table here:

http://wiki.diyfaq.org.uk/index.php?title=Cables#Cable_Sizes

That suggests something around the 6mm^2 mark, or its imperial equal.



--
Cheers,

John.

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

[John Rumm]

While 7/.029" could be treated as roughly equal to 2.5mm^2 these days
(it actually a bit more), its inappropriate to describe it as "20 amps".
The rating will depend on the installation method.

The 14th edition quotes a "clipped direct" rating of 25A, which seems
rather conservative given that's less than the 27A quoted for 2.5mm^2 in
the same circumstances these days.

> Commonly used for wiring sockets, usually a ring main

[spuorg...@gowanhill.com]

On Friday, 19 June 2015 23:21:55 UTC+1, John Rumm wrote:
> The 14th edition quotes a "clipped direct" rating of 25A, which seems
> rather conservative given that's less than the 27A quoted for 2.5mm^2 in
> the same circumstances these days.

But the 14th Edition would assume rewireable fuse, but the current edition assumes MCB and has an optional derating for rewireable fuse?

Owain

[John Rumm]

Indeed, there is a de-rating factor 0.725 allocated for re-wireable
fuses now. Hence my comment about 25A rating being conservative in a
modern setting - the 2.9mm^2 that 7/.029 is approximately in modern
money, would probably have a clipped direct rating of around 34A with
MCB protection.

[AL_n]

John Rumm <see.my.s...@nowhere.null> wrote in
news:RvGdnYUq5ryEGhnI...@brightview.co.uk:

>> 13.5mm wide and 7.5mm thick.
>
> If you go from the overall size, and compare with the figures in the
> last column of the table here:
>
> http://wiki.diyfaq.org.uk/index.php?title=Cables#Cable_Sizes
>
> That suggests something around the 6mm^2 mark, or its imperial equal.

I measured another piece of this cable. I am relying on a tape-measure, not
a micrometer; the OD appears to be to be possibly 7mm x 13.5mm, which is
close to the '6.8 x 13.1' stated as the OD of 6mm^ cable. However, would
the insulation thicknesses be the same in the 1970s/1980s as it is today?

Somewhere buried in my house, I have an imperial micrometer. If I can
somehow manage to find it, I'll be able to measure the exact thicknesses of
the copper wires.

6mm^ certainly does ring a mental bell. ISTR seeing a lot of it in the late
1980s. ISTR using it to run power to a Baby Belling (small) cooker back in
the early 1990s..

Anyway, assuming it is 6mm^, and I use a circuit breaker at the end of my
12m run, I would like to use it to feed a 7.5kw shower.

I have some vague recollection of hearing someone say it was frowned-upon
to connect two or three shorter lengths of this stuff together, when
feeding a high-wattage appliance. It that a hard-and-fast rule, or is it
okay to have a couple or more joints using those round, hard plastic 30A
junction boxes?


Thanks to all for the help.
Al

[Dave Plowman (News)]

In article <mm1lvl$e3l$1...@dont-email.me>,

Bob Minchin <bob.minc...@YOURHATntlworld.com> wrote:
> > I'd say probably 7/0.29. That was the old equivalent of 2.5mm ring cable.
> > But 7/0.44" is also possible - you'd need to measure a strand more
> > carefully. The 0.29" etc is the diameter IIRC.
> >
> Erm 0.029" I think you mean.

I did, sorry.

> The problem is the OP said about 1mm and 0.029" is under 3/4mm

I'd rather an accurate measurement than 'about'

And the overall diameter of the conductor was said to be about 3mm, which
says 7/0.029 to me.

But I don't have any handy to check.

The only way is to measure a single stand *accurately*.

> Accurate measurements and simple calculation is needed.

--
*The more people I meet, the more I like my dog.

[Dave Plowman (News)]

In article <mm1m7p$f1l$1...@dont-email.me>,
Andrew Mawson <andrew@please_remove_me.mawson.org.uk> wrote:

> The only 7/ 029 I've worked with was TRS which in that era invariably
> was black. O/P iirc is saying a white sheath.

7/0.029 came in both grey and white PVC too. If it was older rubber, then
yes, black.

--
*If you can read this, thank a teecher

[Dave Plowman (News)]

In article <54d65012...@charleshope.demon.co.uk>,

charles <cha...@charleshope.demon.co.uk> wrote:
> > You first need to make *absolutely* sure what the cable you have is.
> > The 13.5mm overall width of the T&E says to me it's more likely
> > 7/0.29. That was a lot wider than 2.5mm TW&E.

> I don't have any 7/029 clips left (I do have 1/029 though), but 2.5mm
> clips are only 10mm across.

7/0.029 TW&E was a lot wider than 2.5mm. At first glance it looked more
like the next size up in metric.

> That's why I suspected 7/044. The stranmg
> diameter also seem to agree with .044

--

*I must always remember that I'm unique, just like everyone else. *

[Dave Plowman (News)]

In article <XnsA4BF6947...@130.133.4.11>,

AL_n <fgdf...@fghfghfg.com> wrote:
> I measured another piece of this cable. I am relying on a tape-measure,
> not a micrometer; the OD appears to be to be possibly 7mm x 13.5mm,
> which is close to the '6.8 x 13.1' stated as the OD of 6mm^ cable.
> However, would the insulation thicknesses be the same in the
> 1970s/1980s as it is today?

Simply not the way to measure it. Imperial cable external dimensions were
much larger than the equivalent metric.

Imperial lighting TW&E 3/0.029 was approx the same outside size as 2.5mm
TW&E.

It's also far more likely to find 7/0.029 cable lying around. Larger stuff
in those days only likely used for an electric cooker - showers were rare
if they even existed.

--
*They told me I had type-A blood, but it was a Type-O.*

[John Rumm]

On 20/06/2015 10:19, AL_n wrote:
> John Rumm <see.my.s...@nowhere.null> wrote in
> news:RvGdnYUq5ryEGhnI...@brightview.co.uk:
>
>>> 13.5mm wide and 7.5mm thick.
>>
>> If you go from the overall size, and compare with the figures in the
>> last column of the table here:
>>
>> http://wiki.diyfaq.org.uk/index.php?title=Cables#Cable_Sizes
>>
>> That suggests something around the 6mm^2 mark, or its imperial equal.
>
>
> I measured another piece of this cable. I am relying on a tape-measure, not
> a micrometer; the OD appears to be to be possibly 7mm x 13.5mm, which is
> close to the '6.8 x 13.1' stated as the OD of 6mm^ cable. However, would
> the insulation thicknesses be the same in the 1970s/1980s as it is today?

For PVC they are likely to be similar - but the overall cable sheath
size was not standardised then or now - so its not a cast iron
guarantee. You will need to get a calliper on the conductors to be sure.

> Somewhere buried in my house, I have an imperial micrometer. If I can
> somehow manage to find it, I'll be able to measure the exact thicknesses of
> the copper wires.

Yup, that's what you need to be certain.

> 6mm^ certainly does ring a mental bell. ISTR seeing a lot of it in the late
> 1980s. ISTR using it to run power to a Baby Belling (small) cooker back in
> the early 1990s..

Yup, its commonly used for cookers, and used to be used for showers when
they were more modest in power than many modern ones.

> Anyway, assuming it is 6mm^, and I use a circuit breaker at the end of my
> 12m run, I would like to use it to feed a 7.5kw shower.

You will need RCD protection now (17th edition rules) as well.

To check any cable for adequacy, run through the procedure described here:

http://wiki.diyfaq.org.uk/index.php?title=Calculating_A_Cable_Size

> I have some vague recollection of hearing someone say it was frowned-upon
> to connect two or three shorter lengths of this stuff together, when
> feeding a high-wattage appliance. It that a hard-and-fast rule, or is it
> okay to have a couple or more joints using those round, hard plastic 30A
> junction boxes?

With high current circuits, you have most risk of heating at the
termination points. So the more you have, the more "risk" if you like.
However if you do the job correctly and make the terminations tightly
(or better still crimp or solder them), there there is no problem
joining cables.

You will have difficulty getting 2 x 6mm^2 into many junction boxes, so
look for one of the high current ones designed for the application.

Something like:

https://www.tlc-direct.co.uk/Products/LB9065.html

may be a better bet.

[Robert]

On 20/06/2015 10:19, AL_n wrote:

If you have some digital kitchen scales, you could always cut off a
fixed length of the 7 strands , weigh it (the copper) and work out the
crossectional area. About 20cms should give enough accuracy to
differentiate 2.5, 4 and 6mm^2 cores ( assuming 1g accuracy on scales).
Copper is 8.96 g cm^-3

[Brian Reay]

My understanding is you should use the 'new colours' for new
installations. If you have the installation checked, and being a shower
you should, then you may have a problem.

I'm not trying to be officious, just helping you avoid potential issues.

We had a new kitchen installed several years back which required some
electrical work, including 'spurs' (new colours) etc. for the induction
hob, double oven and the like, and a new consumer unit. As the existing
wiring has the 'old colours' a there is a note warning that the
installation has 'mixed colours' and the whole installation was checked
under the dreaded 'part P' as part of the contract.

[ARW]

"Brian Reay" <no...@m.com> wrote in message
news:mm3r50$2sd$1...@dont-email.me...

>
>
> My understanding is you should use the 'new colours' for new
> installations.

Correct.

If this is indeed a new installation then one wonders why the OP is asking
the question and is not just fitting 10mm T&E and fitting a higher rated
shower.


I suspect that some of the cable is already in place and the OP wants to
reuse it.


--
Adam

[Brian Reay]

Another point, don't skimp on the shower itself.

We've had cheaper, 7kW or so, showers in the past than they were never
really that good. They worked but you couldn't get a 'hot' shower, and
they were prone to cutting out due to thinking they were too hot. They
were the better end of the 7kW range.

We now have a Mira Advance ATL and can't fault it*. It is 9kW and you
can have it as hot as you are likely to want, with a good flow rate.
They aren't cheap but, in my view, worth the money.

*Well, I saw we can't fault it, my wife doesn't like the blue LEDs but
she has a 'thing' about blue LEDs.

There may be other makes of course, I'm just going by our experience.

[John Rumm]

On 20/06/2015 14:52, Brian Reay wrote:
> On 19/06/15 17:54, AL_n wrote:
>> charles <cha...@charleshope.demon.co.uk> wrote in
>> news:54d63eda...@charleshope.demon.co.uk:
>>
>>>> I have some old white-covered twin & earth mains cable with its pos &
>>>> neg insulated in red & black.
>>>
>>>> The red & black wires are both 7-strand, and each individual strand
>>>> is about 1mm thick. Where all 7 strands are tightly together, the
>>>> total thickness of each pos or neg 7-strand cable is approx 3mm (not
>>>> including the red/black insulation).
>>>
>>>> The earth wire is single-strand and approx 1.5mm thick.
>>>
>>>> The overall outside dimensions of the cable (the white outer
>>>> covering) is:
>>>
>>>> 13.5mm wide and 7.5mm thick.
>>>
>>> It's probably 7/.044 which was rated at 36 A. 4.5mm is the metric
>>> equivalent.
>>
>> Many thanks for that. Now for the dumb question! What is the max
>> wattage of
>> electric shower I can use this for? Probably none, right?
>>
>> Al
>>
>
> My understanding is you should use the 'new colours' for new
> installations. If you have the installation checked, and being a shower
> you should, then you may have a problem.

There is no requirement to replace an existing cable though it its
adequate for the job.

> I'm not trying to be officious, just helping you avoid potential issues.

In the real world its really a non issue IME. Conveyancing solicitors
etc long since lost interest in electrics.

> We had a new kitchen installed several years back which required some
> electrical work, including 'spurs' (new colours) etc. for the induction
> hob, double oven and the like, and a new consumer unit. As the existing
> wiring has the 'old colours' a there is a note warning that the
> installation has 'mixed colours' and the whole installation was checked
> under the dreaded 'part P' as part of the contract.

If worried, say you are happy for the purchaser to have inspection done
at their expense, under the understanding that there will be no price
reduction or remedial action taken regardless of the outcome! Its a
sellers market at the moment ;-)

[charles]

In article <mm3r50$2sd$1...@dont-email.me>, Brian Reay <no...@m.com> wrote:
> On 19/06/15 17:54, AL_n wrote:
> > charles <cha...@charleshope.demon.co.uk> wrote in
> > news:54d63eda...@charleshope.demon.co.uk:
> >
> >>> I have some old white-covered twin & earth mains cable with its pos &
> >>> neg insulated in red & black.
> >>
> >>> The red & black wires are both 7-strand, and each individual strand
> >>> is about 1mm thick. Where all 7 strands are tightly together, the
> >>> total thickness of each pos or neg 7-strand cable is approx 3mm (not
> >>> including the red/black insulation).
> >>
> >>> The earth wire is single-strand and approx 1.5mm thick.
> >>
> >>> The overall outside dimensions of the cable (the white outer
> >>> covering) is:
> >>
> >>> 13.5mm wide and 7.5mm thick.
> >>
> >> It's probably 7/.044 which was rated at 36 A. 4.5mm is the metric
> >> equivalent.
> >
> > Many thanks for that. Now for the dumb question! What is the max
> > wattage of electric shower I can use this for? Probably none, right?
> >
> > Al
> >

> My understanding is you should use the 'new colours' for new
> installations. If you have the installation checked, and being a shower
> you should, then you may have a problem.

I understand that if you mark the ends with the new colours then it is
permissable to use cable to the old spec.

[AL_n]

Robert <rob...@invalid.invalid> wrote in news:cul7urFs2q1U1
@mid.individual.net:

>>
> If you have some digital kitchen scales, you could always cut off a
> fixed length of the 7 strands , weigh it (the copper) and work out the
> crossectional area. About 20cms should give enough accuracy to
> differentiate 2.5, 4 and 6mm^2 cores ( assuming 1g accuracy on scales).
> Copper is 8.96 g cm^-3

Thanks for the tip. I cut off 200mm off one of the 7-strand wires, and
after stripping, it weighs 11g (to the nearest g, I guess since it doesn't
register decimals). That was using an electronic letter scale. I checked
the reading on a second electronic letter scale, and got the same reading.

Unfortunately math is one of my worst subjects and I can't get my head
around the formula to calculate what I need to know. Can anyone tell me
what the cable is now?

Al

[AL_n]

John Rumm <see.my.s...@nowhere.null> wrote in news:qNKdnfS-
8pueERjInZ2d...@brightview.co.uk:

> If worried, say you are happy for the purchaser to have inspection done
> at their expense, under the understanding that there will be no price
> reduction or remedial action taken regardless of the outcome! Its a
> sellers market at the moment ;-)

I must remember that one; I like it!

Al

[AL_n]

"ARW" <adamwa...@blueyonder.co.uk> wrote in news:mm3s4o$6m8$1@dont-
email.me:

> I suspect that some of the cable is already in place and the OP wants to
> reuse it.

Good deduction! Actually, the whole house is wired in matching white-
covered, red+black inner cables, so at least it'll all be cosistent. :)

Al

[BruceB]

In article <mm3r50$2sd$1...@dont-email.me>, no...@m.com says...

> My understanding is you should use the 'new colours' for new
> installations. If you have the installation checked, and being a shower
> you should, then you may have a problem.
>
> I'm not trying to be officious, just helping you avoid potential issues.
>

Provided the cable is sleeved with the correct colour at its
terminations, then it meets current regulations (514.3.2).

[Andy Burns]

AL_n wrote:

> I cut off 200mm off one of the 7-strand wires, and after stripping,

> it weighs 11g Can anyone tell me what the cable is now?

Seems equivalent to 6mm^2

<http://www.wolframalpha.com/input/?i=11+grams+%2F+200mm+%2F+density+of+copper>

[AL_n]

Andy Burns <usenet....@adslpipe.co.uk> wrote in
news:w4edneZmwNB0NhjI...@brightview.co.uk:

>> I cut off 200mm off one of the 7-strand wires, and after stripping,
>> it weighs 11g Can anyone tell me what the cable is now?
>
> Seems equivalent to 6mm^2

Many thanks!

Al

[AL_n]

Brian Reay <no...@m.com> wrote in news:mm3s84$6m0$1...@dont-email.me:

> Another point, don't skimp on the shower itself.
>
> We've had cheaper, 7kW or so, showers in the past than they were never
> really that good. They worked but you couldn't get a 'hot' shower, and
> they were prone to cutting out due to thinking they were too hot. They
> were the better end of the 7kW range.

Thanks for the tip. I'll be sure to keep the guarantee, whatever I get.
Then if it gives me any gyp I can take it back. I feel sure that a 7.5Kw
will be adequate, as I always prefer a modest water flow from a shower.
That's partly because the shower will be over a bath with a shower curtain,
and I don't like any ovespray getting onto the floor etc.

Al

[Tough Guy no. 1265]

Voltage drop for 240V is negligible. It's how well insulated the run is that matters, not the length.

--
Mary had a little lamb, it walked into a pylon. 10,000 volts went up its arse, and turned its wool to nylon.

[Tough Guy no. 1265]

The only problem with having mixed colours is when you have 3 phase in the building. Black can be live or neutral. And I saw the consequences - 40 broken computers and a fair bit of a stink when they got 2 phase given to them. Fixed them all by replacing the capacitors though, which the insurance company didn't think of.

--
Love conquers all, except in tennis.

[Charles Hope]

In article <op.x0jj1...@red.lan>, Tough Guy no. 1265 <n...@spam.com>
wrote:

The voltage drop will be the same for any voltage - it's dependant on
current. Insulation doesn't affect voltage drop.

[Tough Guy no. 1265]

As a percentage, the voltage drop is lower. If you had the same current at 12 volts, you could lose a sixth of the voltage with only 2 volts missing. 238 volts would be fine.

--
People who don't like their beliefs being laughed at shouldn't have such funny beliefs

[spuorg...@gowanhill.com]

On Saturday, 20 June 2015 16:51:34 UTC+1, John Rumm wrote:
> Its a sellers market at the moment ;-)

I wish :-(

Owain

[John Rumm]

Might be a different storey in jock land... ;-)

[Robert]

Yes agree spot on.
Rough calc is:

11grams divide by 9 g/cm^3 = 1.2 cm^3 (cubic cms) = 1200 mm^3
1200 mm^3 divide by 200mm = 6 mm^2 cable.

Errors: even if 2g out on weight wouldnt take cable much below 5mm^2
which I dont think exists.

Accuracy could be improved by stripping other core and checking the
combined weight. Should of course be twice one core but would show up
any zeroing errors on scales.
Apologies for maths and experimental error lesson !!

[ARW]

"charles" <cha...@charleshope.demon.co.uk> wrote in message
news:54d6cd90...@charleshope.demon.co.uk...

There is no requirement to oversleeve old colours when being reused.

--
Adam

[ARW]

"charles" <cha...@charleshope.demon.co.uk> wrote in message

news:54d65185...@charleshope.demon.co.uk...
> In article <XnsA4BEBBFB...@130.133.4.11>,

> AL_n <fgdf...@fghfghfg.com> wrote:
>> charles <cha...@charleshope.demon.co.uk> wrote in

>> news:54d64674...@charleshope.demon.co.uk:

>
>> >> Many thanks for that. Now for the dumb question! What is the max
>> >> wattage
>> >> of electric shower I can use this for? Probably none, right?
>> >
>> >

>> > do the maths - 8kW.
>> >
>
>> Thanks; that's encouraging. I'm not challenging your math, but the TLC
>> cable calculator below says says I'd need 10mm cable for an 8kw shower.
>> (same for a 7kw one). Perhaps they factor in some overkill to cover
>> themselves and/or perhaps make more profit? The length of my cable run is
>> 12metres.
>
>> Calculator I used is here:
>
>> https://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html
>
> 12m is quite a long cable run for a shower, so yes, you might need a
> thicker cable.

I would not be bothered by the distance but by the CCC due to the
installation method.



--
Adam

[ARW]

"AL_n" <fgdf...@fghfghfg.com> wrote in message
news:XnsA4BEBBFB...@130.133.4.11...

> charles <cha...@charleshope.demon.co.uk> wrote in
> news:54d64674...@charleshope.demon.co.uk:
>
>>> Many thanks for that. Now for the dumb question! What is the max wattage
>>> of electric shower I can use this for? Probably none, right?
>>
>>
>> do the maths - 8kW.
>>
>
> Thanks; that's encouraging. I'm not challenging your math, but the TLC
> cable calculator below says says I'd need 10mm cable for an 8kw shower.
> (same for a 7kw one). Perhaps they factor in some overkill to cover
> themselves and/or perhaps make more profit? The length of my cable run is
> 12metres.
>
> Calculator I used is here:
>
> https://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html
>

And the cable size is dependant on the installation method.

Re do the calc with a cable clipped to a wall and you can use 4.0mm T&E for
a 8kW shower



--
Adam

[Dave Plowman (News)]

In article <mm60q1$u1s$1...@dont-email.me>,

ARW <adamwa...@blueyonder.co.uk> wrote:
> > I understand that if you mark the ends with the new colours then it is
> > permissable to use cable to the old spec.


> There is no requirement to oversleeve old colours when being reused.

Is it allowed to use ancient cable such as this for what appears to be a
new part of an installation? Didn't the size of the ECC increase even
during the lifespan of metric? So any modern calculators etc ain't going
to be accurate?

--
*In "Casablanca", Humphrey Bogart never said "Play it again, Sam" *

[ARW]

"Dave Plowman (News)" <da...@davenoise.co.uk> wrote in message
news:54d730e...@davenoise.co.uk...

> In article <mm60q1$u1s$1...@dont-email.me>,
> ARW <adamwa...@blueyonder.co.uk> wrote:
>> > I understand that if you mark the ends with the new colours then it is
>> > permissable to use cable to the old spec.
>
>
>> There is no requirement to oversleeve old colours when being reused.
>
> Is it allowed to use ancient cable such as this for what appears to be a
> new part of an installation? Didn't the size of the ECC increase even
> during the lifespan of metric? So any modern calculators etc ain't going
> to be accurate?

You are no longer supposed to install cables that use the old colours
(imperial or metric). You can certainly re-use ones that are already
installed as part of an alteration.

ECC = cpc :-)

It makes no difference that the cables are imperial as you would do the
calculations for the sizes you have - with a pen and paper if required -
"Please Sir can I use a calculator for the square root bit of the
calculation?"

As RCD protection will almost certainly be required for the OPs circuit then
a smaller cpc is irrelevant in this case. The RCD protects the cpc.

Regarding the increased size of cpcs in modern cables it is worth noting
that 2.5mmT&E did have it's cpc increased from 1.0mm to 1.5mm - I am not
aware of any other metric cables being changed. However this is probably due
to a ring circuit design fault (ie the one circuit that by default nearly
always uses 2.5mm T&E).

A final ring circuit that used the maximum length of 2.5mmT&E allowable for
voltage drop could not pass the adiabatic calculation with a 1.0mm cpc when
the protective device was a 30A rewireable fuse (the BS3036 ones).

Cheers

--
Adam

[Dave Plowman (News)]

In article <mm6c7q$5ha$1...@dont-email.me>,

ARW <adamwa...@blueyonder.co.uk> wrote:
> > Is it allowed to use ancient cable such as this for what appears to be
> > a new part of an installation? Didn't the size of the ECC increase
> > even during the lifespan of metric? So any modern calculators etc
> > ain't going to be accurate?


> You are no longer supposed to install cables that use the old colours
> (imperial or metric). You can certainly re-use ones that are already
> installed as part of an alteration.

> ECC = cpc :-)

> It makes no difference that the cables are imperial as you would do the
> calculations for the sizes you have - with a pen and paper if required -
> "Please Sir can I use a calculator for the square root bit of the
> calculation?"

Snag is the OP seems incapable of measuring a cable strand accurately -
and talked about using the TLC calculator.

> As RCD protection will almost certainly be required for the OPs circuit
> then a smaller cpc is irrelevant in this case. The RCD protects the cpc.

If you can be certain he'll use an RCD.

> Regarding the increased size of cpcs in modern cables it is worth noting
> that 2.5mmT&E did have it's cpc increased from 1.0mm to 1.5mm - I am
> not aware of any other metric cables being changed. However this is
> probably due to a ring circuit design fault (ie the one circuit that by
> default nearly always uses 2.5mm T&E).


> A final ring circuit that used the maximum length of 2.5mmT&E allowable
> for voltage drop could not pass the adiabatic calculation with a 1.0mm
> cpc when the protective device was a 30A rewireable fuse (the BS3036
> ones).

Yup - that makes sense. Nudged my few remaining memory cells. ;-)

--
*Honk if you love peace and quiet.

[Mike Clarke]

On 21/06/2015 10:30, Robert wrote:

> Yes agree spot on.
> Rough calc is:
>
> 11grams divide by 9 g/cm^3 = 1.2 cm^3 (cubic cms) = 1200 mm^3
> 1200 mm^3 divide by 200mm = 6 mm^2 cable.

Yes, the sums look right but this doesn't fit in with the OP's
description of it having a single core cpc approx 1.5mm dia.

Looking at imperial cables in table 5 of my old 13th edition regs the
largest cable with a single core cpc is 3/036 but this can't be the case
here because we have 7 strand conductors.

A 1.5mm diameter conductor would have a cross section area of 1.77 mm^2
or 0.0027 in^2. This is close to the area of 0.003 in^2 required for a
cpc in 7/029 but I don't know if 7/029 with a single core earth ever
existed.

As others have said the only safe way will be to measure the conductor
sizes accurately to see if they match any of the standard sizes.

--
Mike Clarke

[AL_n]

Mike Clarke <uceb...@milibyte.co.uk> wrote in
news:z9mdncDtOaozQxvI...@brightview.co.uk:

If there are any psychic peeps reading this, please tell me where I put my
micrometer! I did compare my piece of stripped 7-core with the clean-cut
end of some 6mm T&E in Wickes today. It looks almost identical. It's
possible that my imperial 7-core is a few thou thicker. It's definitely not
thinner.

One thing that puzzled me a bit is that while the TLC site says that 7.5KW
is the most powerful shower you should run with 6mm^ cable, the blurb on
the side of a Wickes' shower box says it "recommends" using 10mm^ on
anything more than a 8.5kW shower. That seems to imply that I could use 6mm
cable for an 8.5kw shower. Any comments on that?

Al

[AL_n]

"AL_n" <fgdf...@fghfghfg.com> wrote in
news:XnsA4C0C826...@130.133.4.11:

>
> One thing that puzzled me a bit is that while the TLC site says that
> 7.5KW is the most powerful shower you should run with 6mm^ cable, the
> blurb on the side of a Wickes' shower box says it "recommends" using
> 10mm^ on anything more than a 8.5kW shower. That seems to imply that I
> could use 6mm cable for an 8.5kw shower. Any comments on that?

PS....

The table shown at the lnk below says much the same.

http://www.gainsboroughshowers.co.uk/Site-Information/Cable-Size-Chart/

So it looks like I could install an 8.5kw shower, assuming it's 6mm cable.
Anyone agree?

Al

[ARW]

"AL_n" <fgdf...@fghfghfg.com> wrote in message

news:XnsA4C0C9FD...@130.133.4.11...

You could install a 10500W shower with 6mm cable if you did it properly.

The gainsborough link is not worth a toss.

--
Adam

[Andy Burns]

AL_n wrote:

> while the TLC site says that 7.5KW
> is the most powerful shower you should run with 6mm^ cable, the blurb on
> the side of a Wickes' shower box says it "recommends" using 10mm^ on
> anything more than a 8.5kW shower. That seems to imply that I could use 6mm
> cable for an 8.5kw shower. Any comments on that?

Depends, if everything was "ideal" you could even get away with 4mm^2
for 8.5kW. You've already told us the length, but not the fixing method
or any other factors that might require de-rating the cable (running in
or through insulation, grouping with other cables, etc) does it have
fuse or MCB, does it have RCD


Are you re-using an installed cable as some have asked, or hoping to use
some old cable you have knocking about? As there's still doubt whether
what you have is approx 6mm^2 or not, you could buy 10mm^2 cable for
under £2/m and give yourself a wider choice of shower ...

[AL_n]

Andy Burns <usenet....@adslpipe.co.uk> wrote in

news:EtKdnWUWYfKTkRrI...@brightview.co.uk:

> cable for under œ2/m and give yourself a wider choice of shower ...


I've only been able to find 10mm cable for about £40 for 12m... If I can
get it for £2/m I might just do that.

The cable runs from the shower, up plastic trunking to the loft. It then
runs accross the loft (loose) and then down some plastic trunking to the
consumer unit which is an old type fuse box fitted with circuit-breakers.
It does not have RCD.

Al

[AL_n]

"ARW" <adamwa...@blueyonder.co.uk> wrote in news:mm71mf$vdp$1@dont-
email.me:

> You could install a 10500W shower with 6mm cable if you did it properly.

I must say, I just read some electrician saying he has "installed loads of
9.5kw showers on 6mm cable, and never had a problem".

Al

[Andy Burns]

AL_n wrote:

> I've only been able to find 10mm cable for about £40 for 12m... If I can
> get it for £2/m I might just do that.

<http://discount-electrical.co.uk/product.php/385718266>

P&P extra, of course.

[ARW]

"AL_n" <fgdf...@fghfghfg.com> wrote in message

news:XnsA4C0D0EA...@130.133.4.11...

> Andy Burns <usenet....@adslpipe.co.uk> wrote in
> news:EtKdnWUWYfKTkRrI...@brightview.co.uk:
>
>>> while the TLC site says that 7.5KW
>>> is the most powerful shower you should run with 6mm^ cable, the blurb
>>> on the side of a Wickes' shower box says it "recommends" using 10mm^
>>> on anything more than a 8.5kW shower. That seems to imply that I
>>> could use 6mm cable for an 8.5kw shower. Any comments on that?
>>
>> Depends, if everything was "ideal" you could even get away with 4mm^2
>> for 8.5kW. You've already told us the length, but not the fixing
>> method or any other factors that might require de-rating the cable
>> (running in or through insulation, grouping with other cables, etc)
>> does it have fuse or MCB, does it have RCD
>>
>>
>> Are you re-using an installed cable as some have asked, or hoping to
>> use some old cable you have knocking about? As there's still doubt
>> whether what you have is approx 6mm^2 or not, you could buy 10mm^2

>> cable for under o2/m and give yourself a wider choice of shower ...

>
>
> I've only been able to find 10mm cable for about £40 for 12m... If I can
> get it for £2/m I might just do that.
>
> The cable runs from the shower, up plastic trunking to the loft. It then
> runs accross the loft (loose) and then down some plastic trunking to the
> consumer unit which is an old type fuse box fitted with circuit-breakers.



> It does not have RCD.

^^^^^^^^^^^^^^^^^^^
That stops you fitting an electric shower.


--
Adam

[Charles Hope]

In article <mm73nl$7u3$1...@dont-email.me>,

But you can add a "stand alone" RCD.

[AL_n]

"ARW" <adamwa...@blueyonder.co.uk> wrote in news:mm73nl$7u3$1@dont-
email.me:

> That stops you fitting an electric shower.

Well, I could swap the consumer unit for a MCB one, I suppose - or simply
add a shower mcb unit just for the shower, yes?

[ARW]

"Charles Hope" <Cha...@candehope.me.uk> wrote in message
news:54d75d13...@charleshope.demon.co.uk...

It's going to get messy if you want to meet the 17th edition regs.

I am all for DIY as long as it is done safely. Nothing the OP has posted so
far suggests that the electrical installation will be safe.

Let's start off with the main bonding - the first thing to be checked before
starting a shower installation (or indeed a shower swap)

--
Adam

[ARW]

"AL_n" <fgdf...@fghfghfg.com> wrote in message

news:XnsA4C0D45C...@130.133.4.11...

It's RCD that you need

--
Adam

[John Rumm]

On 20/06/2015 14:00, John Rumm wrote:

> You will have difficulty getting 2 x 6mm^2 into many junction boxes, so
> look for one of the high current ones designed for the application.
>
> Something like:
>
> https://www.tlc-direct.co.uk/Products/LB9065.html
>
> may be a better bet.

Or better still:

https://www.tlc-direct.co.uk/Products/AAJB60.html

(could not find that one on my first search - thanks to Adam for the
pointer!)

[AL_n]

"ARW" <adamwa...@blueyonder.co.uk> wrote in
news:mm75qj$g04$1...@dont-email.me:

>> Well, I could swap the consumer unit for a MCB one, I suppose - or
>> simply add a shower mcb unit just for the shower, yes?
>
>
> It's RCD that you need

Sorry; that's what I meant.

[ARW]

"John Rumm" <see.my.s...@nowhere.null> wrote in message
news:_uqdncil36JqhhrI...@brightview.co.uk...

> On 20/06/2015 14:00, John Rumm wrote:
>
>> You will have difficulty getting 2 x 6mm^2 into many junction boxes, so
>> look for one of the high current ones designed for the application.
>>
>> Something like:
>>
>> https://www.tlc-direct.co.uk/Products/LB9065.html
>>
>> may be a better bet.
>
> Or better still:
>
> https://www.tlc-direct.co.uk/Products/AAJB60.html
>
> (could not find that one on my first search - thanks to Adam for the
> pointer!)

The best thing is that they have clamps for the cable.



--
Adam

[tony sayer]

In article <mm71mf$vdp$1...@dont-email.me>, ARW <adamwadsworth@blueyonder.c
o.uk> scribeth thus

In fact the best thing you could install is a proper power shower and
just enjoy it :)

Best thing we ever did chucking the Electric ones!.


--
Tony Sayer

[AL_n]

"ARW" <adamwa...@blueyonder.co.uk> wrote in
news:mm74m0$bhm$1...@dont-email.me:

> Let's start off with the main bonding - the first thing to be checked
> before starting a shower installation (or indeed a shower swap)

The house's copper gas supply pipe is bonded at the consumer unit. The
internal copper water pipes are bonded at the boiler which was recently
installed by British Gas engineers. The water pipe to the shower will be
plastic. It appears to be a TN-CS electric supply which installed in 1991.
I've nerver experienced any issues with the mains circuit.

[AL_n]

tony sayer <to...@bancom.co.uk> wrote in news:yo0pLcHn...@bancom.co.uk:

>
> In fact the best thing you could install is a proper power shower and
> just enjoy it :)
>
> Best thing we ever did chucking the Electric ones!.

In my case, I wouldn't like a power shower because I have a combi boiler,
so every time I draw hot tapwater, the central heating cuts out. That's not
a problem in Summer, but in winter, it can be uncomfortable as the bathroom
grows cold pretty quickly when the central heating is cut off.

I've always likes electric showers, (Perfect water temperature, instantly,
etc) I've never had a problem with them - apart from one failing after
about ten years of use.

Al

[AL_n]

John Rumm <see.my.s...@nowhere.null> wrote in news:
_uqdncil36JqhhrI...@brightview.co.uk:

>> https://www.tlc-direct.co.uk/Products/LB9065.html
>>
>> may be a better bet.
>
> Or better still:
>
> https://www.tlc-direct.co.uk/Products/AAJB60.html
>
> (could not find that one on my first search - thanks to Adam for the
> pointer!)

Thanks for that. It turns out I will only need to make one join, so that's
good.

Al

[John Rumm]

On 21/06/2015 13:56, ARW wrote:

> A final ring circuit that used the maximum length of 2.5mmT&E allowable
> for voltage drop could not pass the adiabatic calculation with a 1.0mm
> cpc when the protective device was a 30A rewireable fuse (the BS3036 ones).

If memory serves the circuit could pass, but any spur from it could fail...

[John Rumm]

On 21/06/2015 20:30, AL_n wrote:

> The cable runs from the shower, up plastic trunking to the loft. It then

Is this plastic trunking mounted on the surface of the wall, or buried
in it?

> runs accross the loft (loose) and then down some plastic trunking to the
> consumer unit which is an old type fuse box fitted with circuit-breakers.
> It does not have RCD.

And the trunking there.. surface or buried?

Is your main equipotential bonding to current standards?

http://wiki.diyfaq.org.uk/index.php?title=Earthing_and_Bonding

[AL_n]

John Rumm <see.my.s...@nowhere.null> wrote in

news:i6adncKhCc788BrI...@brightview.co.uk:

>> The cable runs from the shower, up plastic trunking to the loft. It
>> then
>
> Is this plastic trunking mounted on the surface of the wall, or buried
> in it?

The trunking is mounted on the surface of the wall, inside the house.

>> runs accross the loft (loose) and then down some plastic trunking to
>> the consumer unit which is an old type fuse box fitted with
>> circuit-breakers. It does not have RCD.
>
> And the trunking there.. surface or buried?

There is no trunking in the loft; the cable lies on the top of the glass
fibre loft insulation.

> Is your main equipotential bonding to current standards?

I guess so, because a central heating system was installed a couple of
years ago, by well-trained British Gas engineers. I noticed they took a lot
of pains to make sure the bonding of their work was done properly. The
house's gas inlet pipe is also bonded directly to the CU's green+yellow
earth cable, whose overall thickness is 6mm. Where it is connected to the
gas mains supply pipe, there is an aluminium tag with a red stripe, saying
"Safety Electrical Connection Do Not Remove".

I guess it's all in order, but can I check the integrity of the earthing
and bonding somehow, say with a multi-meter?

Al

[tony sayer]

In article <XnsA4C0DE5D...@130.133.4.11>, AL_n
<fgdf...@fghfghfg.com> scribeth thus

>tony sayer <to...@bancom.co.uk> wrote in news:yo0pLcHn...@bancom.co.uk:
>
>>
>> In fact the best thing you could install is a proper power shower and
>> just enjoy it :)
>>
>> Best thing we ever did chucking the Electric ones!.
>
>In my case, I wouldn't like a power shower because I have a combi boiler,
>so every time I draw hot tapwater, the central heating cuts out. That's not
>a problem in Summer, but in winter, it can be uncomfortable as the bathroom
>grows cold pretty quickly when the central heating is cut off.
>

Simples chuck the combi;!..

>I've always likes electric showers, (Perfect water temperature, instantly,
>etc) I've never had a problem with them - apart from one failing after
>about ten years of use.

Never had problems with someone else drawing water off elsewhere thus
changing the water feed pressure and the temp taking time to respond?..
>
>
>Al

--
Tony Sayer

.

[Vir Campestris]

On 21/06/2015 21:49, AL_n wrote:
> In my case, I wouldn't like a power shower because I have a combi boiler,
> so every time I draw hot tapwater, the central heating cuts out. That's not
> a problem in Summer, but in winter, it can be uncomfortable as the bathroom
> grows cold pretty quickly when the central heating is cut off.

Ah that's the problem. You need a hot water tank. The boiler can then
heat more water at its leisure.

You can also use the immersion on days the boiler is having a sulk.

Andy

[Andy Wade]

On 21/06/2015 16:56, Mike Clarke wrote:
> On 21/06/2015 10:30, Robert wrote:
>
>> Yes agree spot on.
>> Rough calc is:
>>
>> 11grams divide by 9 g/cm^3 = 1.2 cm^3 (cubic cms) = 1200 mm^3
>> 1200 mm^3 divide by 200mm = 6 mm^2 cable.
>
> Yes, the sums look right but this doesn't fit in with the OP's
> description of it having a single core cpc approx 1.5mm dia.

Why? The CPC in 6 mm^2 metric T&E is usually single strand 2.5 mm^2
(~1.78 mm dia).

I'm not sure why everybody's assumed that the OP's cable is imperial.
Are the conductors tinned copper or plain? IIRC imperial PVC cable to
BS 2004 continued to use tinned conductors (originally necessary with
rubber insulation). Plain copper only appeared at metrication, with the
introduction of BS 6004, c. 1969.

--
Andy

[Jim x321x]

Andy Wade <spamb...@maxwell.myzen.co.uk> wrote in news:curemjFfli9U1
@mid.individual.net:

The wires within the cables in question look like copper through and
through. They are not coated in any silvery-looking metal such as tin.
The cables definitely look more recent than 1969, and are the same colour
of cables used to wire the entire house which was built in or around 1990.

Jim

[Andy Burns]

Jim x321x wrote:

> Andy Wade wrote:
>
>> Are the conductors tinned copper or plain?
>

> The wires within the cables in question look like copper through and
> through.

Confused ... is jim x321x the same person as AL_n? If so why do you
refer to yourself in the 3rd person as "someone" in the fuse box thread?

[Andy Wade]

On 23/06/2015 10:00, Jim x321x wrote:

> The wires within the cables in question look like copper through and
> through. They are not coated in any silvery-looking metal such as tin.
> The cables definitely look more recent than 1969, and are the same colour
> of cables used to wire the entire house which was built in or around 1990.

I'd put money on it being 6 mm^2 then. '10-mil' would have a 7-strand
CPC. It could be '4-mil', but that size is much less commonly used,
especially in houses. If the CPC is the same size as the single strand
line & neutral conductors of 2.5 T&E, then it is 6 mm^2.

If you look at the sheath carefully you'll likely find that it's
embossed at intervals with the manufacturer's name, year of manufacture,
and sometimes the size.

--
Andy

[Dave Plowman (News)]

In article <curemj...@mid.individual.net>,

Andy Wade <spamb...@maxwell.myzen.co.uk> wrote:
> I'm not sure why everybody's assumed that the OP's cable is imperial.
> Are the conductors tinned copper or plain? IIRC imperial PVC cable to
> BS 2004 continued to use tinned conductors (originally necessary with
> rubber insulation). Plain copper only appeared at metrication, with the
> introduction of BS 6004, c. 1969.

Plain copper PVC imperial was around. I've seen it.

There was also stranded metric 2.5mm - made IIRC in singles for conduit
use. But may have been made as a special in TW&E for say a particular
council - they could have odd ideas. And it's not expensive to have
special cable made provided you order enough.

--
*Is it true that cannibals don't eat clowns because they taste funny?

Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.

[ARW]

"AL_n" <fgdf...@fghfghfg.com> wrote in message

news:XnsA4C0DC98...@130.133.4.11...

Is 1991 also the year the house was built?

--
Adam

[AL_n]

"ARW" <adamwa...@blueyonder.co.uk> wrote in
news:mmc4ub$2in$1...@dont-email.me:

>> The house's copper gas supply pipe is bonded at the consumer unit.
>> The internal copper water pipes are bonded at the boiler which was
>> recently installed by British Gas engineers. The water pipe to the
>> shower will be plastic. It appears to be a TN-CS electric supply
>> which installed in 1991. I've nerver experienced any issues with the
>> mains circuit.
>
>
> Is 1991 also the year the house was built?

A large extension was built onto the older part of the building, and the
extension, which contains the CU was wired at that time. The older,
original part of the house was probably rewired at the same time, because
all the wiring throughout is white-covered T&E with red and black inners.

Al

[Jim x321x]

"AL_n" <fgdf...@fghfghfg.com> wrote in
news:XnsA4C2C34F...@130.133.4.11:

>> Is 1991 also the year the house was built?
>
> A large extension was built onto the older part of the building, and
> the extension, which contains the CU was wired at that time. The
> older, original part of the house was probably rewired at the same
> time, because all the wiring throughout is white-covered T&E with red
> and black inners.
>
> Al

What he said..

Jim

[Andy Wade]

On 23/06/2015 13:00, Dave Plowman (News) wrote:

> Plain copper PVC imperial was around. I've seen it.

Yes, you're right. I dug out an old copy of BS 2004:1961, amended 1963
& '65, price 10/- ! In the introductory notes it's clear that from 1955
tinning was the preferred standard, with plain copper permissible if
specified by the purchaser. By the 60s that was the other was round -
plain annealed copper as the default, with options for (i) aluminium
(sizes 7/.064 [*] and smaller not acceptable for installations subject
to the IEE regs) and (ii) plain or tinned hard-drawn copper.

> There was also stranded metric 2.5mm - made IIRC in singles for conduit
> use. But may have been made as a special in TW&E for say a particular
> council - they could have odd ideas.

Those variations are all permitted in BS 6004, so are not non-standard,
just less common :~). Stranded 2.5 singles are quite common - much
easier to pull-in thro' twisty or crowded conduit runs.

> And it's not expensive to have> special cable made provided you order enough.

Where "enough" is an MOQ of th order of 5 or 10 km, IME. That's a lot
of DIY wiring...


[*] 7/.064 was the standard size for domestic meter tails in those days.

--
Andy