I was poking around under the floor of my mother's house sorting out the wiring and I found that a socket that wasn't working was wired with twin & earth cable with the normal grey PVC outer but the live and neutral were 3 stranded multicore rather than the more normal single core. The conductors (including the earth) were silver/gray rather than copper.

Does this cable date back to the time when copper prices went very high? What kind of metal was used instead. Pretty certain it wasn't aluminum.

Tim

Tim Downie wrote:

I was poking around under the floor of my mother's house sorting out the
wiring and I found that a socket that wasn't working was wired with twin &
earth cable with the normal grey PVC outer but the live and neutral were 3
stranded multicore rather than the more normal single core. The
conductors (including the earth) were silver/gray rather than copper.

Does this cable date back to the time when copper prices went very high?
What kind of metal was used instead. Pretty certain it wasn't aluminum.

Sounds like 3/029 or 3/036 tinned copper which was quite common in the 60's
prior to metrication. That's 3 strands, each 0.029 or 0.036 inch diameter.
I expect you'll see copper if you scrape the surface. They were rated at 10
and 15 amp each so I wouldn't have expected them to be used for a ring main
but might have originally been a radial circuit feeding the old style 5A or
15A round pin plugs. The standard cable for ring mains was 7/029.

--
Mike Clarke

On 9 Dec,
"Tim Downie" wrote:

I was poking around under the floor of my mother's house sorting out the
wiring and I found that a socket that wasn't working was wired with twin &
earth cable with the normal grey PVC outer but the live and neutral were 3
stranded multicore rather than the more normal single core. The conductors
(including the earth) were silver/gray rather than copper.

Does this cable date back to the time when copper prices went very high?
What kind of metal was used instead. Pretty certain it wasn't aluminum.

more likely 3/029, which is an imperial size, and tinned copper conductors.
7/029 (2.9mm^2) was what was required for 30A ring circuits so it would be
about 1.25mm^2 and not really up to standard.

--
B Thumbs
Change lycos to yahoo to reply

In article ,
Tim Downie wrote:
I was poking around under the floor of my mother's house sorting out the
wiring and I found that a socket that wasn't working was wired with twin
& earth cable with the normal grey PVC outer but the live and neutral
were 3 stranded multicore rather than the more normal single core. The
conductors (including the earth) were silver/gray rather than copper.

Does this cable date back to the time when copper prices went very high?
What kind of metal was used instead. Pretty certain it wasn't aluminum.

That is the predecessor of 1.5mm from before metrication. 3 strands of
0.029". Normally used for lighting or 5 amp sockets. 7/0.029 was the
equivalent to 2.5mm.
It was usually tin coated hence the bright appearance. Rather like good
quality flex is.

Since it is PVC, rather than rubber, it could still be in satisfactory
condition. But note the ratings above.

--
*Why doesn't glue stick to the inside of the bottle?

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

On Dec 9, 10:26*pm, "Tim Downie" wrote:
I was poking around under the floor of my mother's house sorting out the wiring and I found that a socket that wasn't working was wired with twin & earth cable with the normal grey PVC outer but the live and neutral were 3 stranded multicore rather than the more normal single core. *The conductors (including the earth) were silver/gray rather than copper.

Does this cable date back to the time when copper prices went very high? What kind of metal was used instead. *Pretty certain it wasn't aluminum.

Tim


As people have said, its older than that.
http://wiki.diyfaq.org.uk/index.php?...c_Mains_Cables

When you say wired with, if its just a single cable feeding a single
socket then it should be adequate. But if there are 2 cables to the
socket, either there are sockets daisy chained or its part of a ring
circuit, and in either case the cable is well below what's required
for a 30A circuit.

If it does turn out you have a 30A fused circuit wired with 10A or 15A
cable, replacing the fuse with 10 or 15A would be a good idea - but if
the circuit feeds the kitchen, it may be inadequate.

Some details of regs are of quite minor importance, but running 30A
plus through 10A cable really isnt a good plan. It might do it, but
its a fire risk.


NT

Dave Plowman (News) wrote:
In article ,
Tim Downie wrote:
I was poking around under the floor of my mother's house sorting out
the wiring and I found that a socket that wasn't working was wired
with twin & earth cable with the normal grey PVC outer but the live
and neutral were 3 stranded multicore rather than the more normal
single core. The conductors (including the earth) were silver/gray
rather than copper.

Does this cable date back to the time when copper prices went very
high? What kind of metal was used instead. Pretty certain it wasn't
aluminum.

That is the predecessor of 1.5mm from before metrication. 3 strands of
0.029". Normally used for lighting or 5 amp sockets. 7/0.029 was the
equivalent to 2.5mm.
It was usually tin coated hence the bright appearance. Rather like
good quality flex is.

Since it is PVC, rather than rubber, it could still be in satisfactory
condition. But note the ratings above.

Thanks to all for the info. It was a single spurred socket that was wired
up with the above cable at the socket end but the other end was hanging free
near a junction box under the floor. Oddly, a new bit of 2.5mm cable had
been loosely attached (looking like it was waiting to be pulled through) but
the job never completed.

In the end all I had to do was complete the aborted job using the new cable
and wire the spur into the junction box. (The existing ring was in 2.5mm).

Tim