My mother has a single socket under her kitchen worktop which she
currently has both the dishwasher and washing machine plugged into via
a 13amp multisocket. Obviously if she turns both on at once the fuse
blows in the multisocket, so she doesn't. I've just made an
exploratory investigation to see if I could change the single for a
double to make things a bit easier. I'm assuming it would be safe
enough to run two 13amp appliances from a double socket on a standard
ring main, am I right?

Anyway, she evidently doesn't have a standard ring main. Rather than
finding the two cables I was hoping for going into the socket, there is
only one. The outer sheath has been cut back so far that I can't see
it. The three cores (?) are stranded, but are substantially thicker
than the usual 2.5mm twin and earth, I would guess they are 4mm. They
are sheathed in PVC, the earth is plain green and the other two are
grey. From what my mother can remember the wiring there dates back to
the early 80s.

What I'm asking your collective wisdoms is what this is and whether I
can safely put a double socket on it which will draw 26amps
(sometimes). I'm guessing it's a radial circuit, but I await your
thoughts.

Many thanks,

Martin

On 25 Oct 2005 03:15:16 -0700, "Martin Pentreath"
wrote:

My mother has a single socket under her kitchen worktop which she
currently has both the dishwasher and washing machine plugged into via
a 13amp multisocket. Obviously if she turns both on at once the fuse
blows in the multisocket, so she doesn't. I've just made an
exploratory investigation to see if I could change the single for a
double to make things a bit easier. I'm assuming it would be safe
enough to run two 13amp appliances from a double socket on a standard
ring main, am I right?

Anyway, she evidently doesn't have a standard ring main. Rather than
finding the two cables I was hoping for going into the socket, there is
only one. The outer sheath has been cut back so far that I can't see
it. The three cores (?) are stranded, but are substantially thicker
than the usual 2.5mm twin and earth, I would guess they are 4mm. They
are sheathed in PVC, the earth is plain green and the other two are
grey. From what my mother can remember the wiring there dates back to
the early 80s.

What I'm asking your collective wisdoms is what this is and whether I
can safely put a double socket on it which will draw 26amps
(sometimes). I'm guessing it's a radial circuit, but I await your
thoughts.

I'd suggest erring on the side of caution until you know where the
other end goes. For all you know it could be terminated in a plug-top
plugged into a hidden socket somewhere..

sponix

Slight amendment: the earth is stranded, the other two are solid
copper.

I do know that the wiring was originally done by a pro, so it would
have been done to the regs of the day (and I think we can rule out the
other end being plugged into a mystery socket).

In article .com,
Martin Pentreath wrote:
Anyway, she evidently doesn't have a standard ring main. Rather than
finding the two cables I was hoping for going into the socket, there is
only one. The outer sheath has been cut back so far that I can't see
it. The three cores (?) are stranded, but are substantially thicker
than the usual 2.5mm twin and earth, I would guess they are 4mm. They
are sheathed in PVC, the earth is plain green and the other two are
grey. From what my mother can remember the wiring there dates back to
the early 80s.

If all the conductors are stranded likely 7/0.29 which was 'ring' cable
before metric. It's usually tin plated, so doesn't look like copper. The
L&N will have seven strands, the earth three. Would date back to the early
'70s at best.

--
*I don't know what your problem is, but I'll bet it's hard to pronounce

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

"Martin Pentreath" wrote in message
oups.com...
My mother has a single socket under her kitchen worktop which she
currently has both the dishwasher and washing machine plugged into via
a 13amp multisocket. Obviously if she turns both on at once the fuse
blows in the multisocket, so she doesn't. I've just made an
exploratory investigation to see if I could change the single for a
double to make things a bit easier. I'm assuming it would be safe
enough to run two 13amp appliances from a double socket on a standard
ring main, am I right?

Anyway, she evidently doesn't have a standard ring main. Rather than
finding the two cables I was hoping for going into the socket, there is
only one. The outer sheath has been cut back so far that I can't see
it. The three cores (?) are stranded, but are substantially thicker
than the usual 2.5mm twin and earth, I would guess they are 4mm. They
are sheathed in PVC, the earth is plain green and the other two are
grey. From what my mother can remember the wiring there dates back to
the early 80s.

What I'm asking your collective wisdoms is what this is and whether I
can safely put a double socket on it which will draw 26amps
(sometimes). I'm guessing it's a radial circuit, but I await your
thoughts.

Many thanks,

Martin


IF it is copper (check) and IF it is a correctly wired radial (check that it
isn't something like sponix says). Then you can fit a double. IF it is 4mm
copper flat twin/earth then it is rated at 26A max. current carrying
capacity (table 4D5A)

Martin Pentreath wrote:
My mother has a single socket under her kitchen worktop which she
currently has both the dishwasher and washing machine plugged into via
a 13amp multisocket. Obviously if she turns both on at once the fuse
blows in the multisocket, so she doesn't. I've just made an
exploratory investigation to see if I could change the single for a
double to make things a bit easier. I'm assuming it would be safe
enough to run two 13amp appliances from a double socket on a standard
ring main, am I right?

Anyway, she evidently doesn't have a standard ring main. Rather than
finding the two cables I was hoping for going into the socket, there
is only one. The outer sheath has been cut back so far that I can't
see it. The three cores (?) are stranded, but are substantially
thicker than the usual 2.5mm twin and earth, I would guess they are
4mm. They are sheathed in PVC, the earth is plain green and the other
two are grey. From what my mother can remember the wiring there dates
back to the early 80s.

What I'm asking your collective wisdoms is what this is and whether I
can safely put a double socket on it which will draw 26amps
(sometimes). I'm guessing it's a radial circuit, but I await your
thoughts.

Many thanks,

Martin

Ahem! whats the fuse rating in the multi adaptor? and have you checked to
see if there is a fuse spare in the CU to see if the socket is on its own
fuse?

--
Sir Benjamin Middlethwaite

"Dave Plowman (News)" wrote in message

If all the conductors are stranded likely 7/0.29 which was 'ring' cable
before metric. It's usually tin plated, so doesn't look like copper. The
L&N will have seven strands, the earth three. Would date back to the early
'70s at best.
I think it's actually 7/.029 inch strand dia, the next size up being 7/.036.
If you have a micrometer youi can check the dia of the strands they should
be 29 thou or 36 thou or even 44thou. I cannot remember the current carrying
capacity but someone might have some old tables available.
Regards
Tom

On Tue, 25 Oct 2005 12:17:57 +0100, "Bob Watkinson"
wrote:

IF it is copper (check)

Oh! Just had a thought..

I remember reading somewhere about an aluminium mains wiring system
that was used in the 50s/60s. It's not aluminium wire is it?

Problems occured as the ends of the wires corroded at the point they
were secured by the brass terminals. The corrosion would cause high
resistance, overheating and potentially fire.

From what I can gather installations using aluminium wire were fairly
rare, but there must be some of it left out there to this day.

sponix

s--p--o--n--i--x wrote:
"Bob Watkinson" wrote:
IF it is copper (check)

I remember reading somewhere about an aluminium mains wiring system
that was used in the 50s/60s. It's not aluminium wire is it?

No.

On Tue, 25 Oct 2005 14:05:52 +0100, Chris Bacon
wrote:

s--p--o--n--i--x wrote:
"Bob Watkinson" wrote:
IF it is copper (check)

I remember reading somewhere about an aluminium mains wiring system
that was used in the 50s/60s. It's not aluminium wire is it?

No.

How do you know?

sponix

In article ,
Tom wrote:
If all the conductors are stranded likely 7/0.29 which was 'ring'
cable before metric. It's usually tin plated, so doesn't look like
copper. The L&N will have seven strands, the earth three. Would date
back to the early '70s at best.

I think it's actually 7/.029 inch strand dia,

You're absolutely correct. Sorry for the typo. 7/0.29 would be a pretty
healthy cable. ;-)

--
*Half the people in the world are below average.

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

s--p--o--n--i--x wrote:

How do you know?

Good question (aluminium was used for a while).

No-one has yet suggested investigating the type, rating and labelling
(if any) of the fuse (or circuit breaker, although that sounds unlikely)
protecting the wiring to this socket. That could give a clue to the
type of circuit we're dealing with.

--
Andy

s--p--o--n--i--x wrote:
Chris Bacon wrote:
s--p--o--n--i--x wrote:
"Bob Watkinson" wrote:

IF it is copper (check)

I remember reading somewhere about an aluminium mains wiring system
that was used in the 50s/60s. It's not aluminium wire is it?

No.

How do you know?

I would have replied to A. Wade's contribution, but he's messed
up the quoting. So: "Because "stranded" aluminium wiring wasn't
used in situations like the OP mentions, or in such small sizes,
and it wasn't used in the early '80s". That's about it, really.

On Tue, 25 Oct 2005 14:59:55 +0100, Andy Wade
wrote:

| s--p--o--n--i--x wrote:
|
| How do you know?
|
| Good question (aluminium was used for a while).
|
| No-one has yet suggested investigating the type, rating and labelling
| (if any) of the fuse (or circuit breaker, although that sounds unlikely)
| protecting the wiring to this socket. That could give a clue to the
| type of circuit we're dealing with.

My guess would be a spur off a ring, IIRC In the old 7/029 days you were
allowed 2 * 13 amp sockets on a spur.
--
Dave Fawthrop dave hyphenologist co uk
The London suicide bombers killed innocent commuters.
Animal rights terrorists and activists kill innocent patients.

Chris Bacon wrote:

So: "Because "stranded" aluminium wiring wasn't used in
situations like the OP mentions, or in such small sizes,

I think you'll find it was used for small sizes for a while, from the
late 60s to early 70s. Aluminium twin & earth appeared when the price
of copper shot up and its use ended when it was 'banned', having caused
a lot of trouble.

Aluminium is still allowed in house wiring, but only for sizes of 16
mm^2 and above.

and it wasn't used in the early '80s". That's about it, really.

Yes, the small sizes had gone by then.

--
Andy

Martin Pentreath wrote:

What I'm asking your collective wisdoms is what this is and whether I
can safely put a double socket on it which will draw 26amps
(sometimes). I'm guessing it's a radial circuit, but I await your
thoughts.

I'm fairly sure that double sockets are rated for 13A total - not 26A total.

At least, every one I've seen has been marked Max. load 13A on the back.

M

I'd suggest erring on the side of caution until you know where the
other end goes. For all you know it could be terminated in a plug-top
plugged into a hidden socket somewhere..




FFS DON'T MENTION PLUG TOPS!!!!! I mentioned it once, but I think I have
got away with it ;-)


--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG

Martin Pentreath wrote:

My mother has a single socket under her kitchen worktop which she
currently has both the dishwasher and washing machine plugged into via
a 13amp multisocket. Obviously if she turns both on at once the fuse
blows in the multisocket, so she doesn't. I've just made an
exploratory investigation to see if I could change the single for a
double to make things a bit easier. I'm assuming it would be safe
enough to run two 13amp appliances from a double socket on a standard
ring main, am I right?

Anyway, she evidently doesn't have a standard ring main. Rather than
finding the two cables I was hoping for going into the socket, there is
only one. The outer sheath has been cut back so far that I can't see
it. The three cores (?) are stranded, but are substantially thicker
than the usual 2.5mm twin and earth, I would guess they are 4mm. They
are sheathed in PVC, the earth is plain green and the other two are
grey. From what my mother can remember the wiring there dates back to
the early 80s.

What I'm asking your collective wisdoms is what this is and whether I
can safely put a double socket on it which will draw 26amps
(sometimes). I'm guessing it's a radial circuit, but I await your
thoughts.

Many thanks,

Martin


The cables thick enough, just check what it connects to at is other end
is ok first.

BTW ali ring & lighting cable was being installed in the 80s. Whether
it was legal I dont know, but I know it was on retail sale.


NT

Mark wrote:

I'm fairly sure that double sockets are rated for 13A total - not 26A
total.

BS 1363 requires them to be tested at 20 A and, in the absence of any
specific manufacturer's information to the contrary, that should be
considered to be the effective rating.

The wiring rules in BS 7671 & the OSG also assume 20 A max. load on a
double skt - e.g. an unfused ring spur in 2.5 mm^2 cable (cable rating
= 20 A) may feed one double skt.

At least, every one I've seen has been marked Max. load 13A on the back.

That's per socket. If you ask MK, for example, they will tell you that
their double skts are rated at 26 A "provided that the supply wiring is
suitable for that current."

--
Andy

Dave Plowman (News) wrote:
Martin Pentreath wrote:
Anyway, she evidently doesn't have a standard ring main. Rather than
finding the two cables I was hoping for going into the socket, there is
only one. The outer sheath has been cut back so far that I can't see
it. The three cores (?) are stranded, but are substantially thicker
than the usual 2.5mm twin and earth

If all the conductors are stranded likely 7/0.29 which was 'ring' cable
before metric. It's usually tin plated, so doesn't look like copper. The
L&N will have seven strands, the earth three. Would date back to the early
'70s at best.

Yes, i've got some of that in my 1950's house, and some earthless grey
twin core on the upstairs lights.

Thankfully someone knowledgeable has already had a stab at most of the
ring mains before I got to them, as they're all modern wiring.

Cheers

Paul.

On Tue, 25 Oct 2005 18:10:55 +0100, Andy Wade
wrote:

Chris Bacon wrote:

So: "Because "stranded" aluminium wiring wasn't used in
situations like the OP mentions, or in such small sizes,

I think you'll find it was used for small sizes for a while, from the
late 60s to early 70s.

afaik Rhodesia stopped the export of copper. As 99% of the UKs copper
came from Rhodesia at the time aluminium was used for wiring instead.

sponix

"s p o n i x" wrote in message
...
On Tue, 25 Oct 2005 18:10:55 +0100, Andy Wade
wrote:

Chris Bacon wrote:

So: "Because "stranded" aluminium wiring wasn't used in
situations like the OP mentions, or in such small sizes,

I think you'll find it was used for small sizes for a while, from the
late 60s to early 70s.

afaik Rhodesia stopped the export of copper. As 99% of the UKs copper
came from Rhodesia at the time aluminium was used for wiring instead.


There was a brief period when unofficial aluminium conductor cable in
domestic sizes was on sale. This had serious corrosion heating problems with
terminations and for a while copperclad aluminium was being sold. The copper
coating overcame the corrosion problem but suffered from creep due to the
softer underlying metal and it fell from favour.
Aluminium is approved for use even now but only in larger sizes where the
conductors are big enough to have some mechanical strength and suitable
terminating techniques can be applied

wrote:

On 25 Oct,
Andy Wade wrote:


Aluminium is still allowed in house wiring, but only for sizes of 16
mm^2 and above.


It's known to cause problems in the supply co. cables, where there is a leak
in the outer sheath, and water gets in to corrode (and eventually sever) the
conductors.

Better tell the power companies then! Most new HV overhead line
conductors are all aluminium, the earlier ones being aluminium over a
steel core - they are greased though!






--

On Tue, 25 Oct 2005 22:14:17 +0100, Owain
wrote:

Martin Pentreath wrote:
My mother has a single socket under her kitchen worktop which she
currently has both the dishwasher and washing machine plugged into via
a 13amp multisocket.
Anyway, she evidently doesn't have a standard ring main. Rather than
finding the two cables I was hoping for going into the socket, there is
only one. The outer sheath has been cut back so far that I can't see
it. The three cores (?) are stranded, but are substantially thicker
than the usual 2.5mm twin and earth, I would guess they are 4mm. They
are sheathed in PVC, the earth is plain green and the other two are
grey. From what my mother can remember the wiring there dates back to
the early 80s.

Check your consumer unit. You might find it's an unused cooker circuit,
especially if your mother has a gas cooker.
Snip

On this housing estate built in the '70s each house was provided with
a gas point and an electric cooker point in the kitchen. If the buyer
opted for a gas cooker the electric cooker cable was terminated on a
13A socket (with suitable fuse in the CU of course). Sounds likely
that this is what you have and converting to a double would be ideal.