I just watched another of Tim Hunkin's excellent videos - this one is on connectors:

https://www.youtube.com/watch?v=q43tZ6DjuIE

One of the connectors he deals with is the UK 13A power plug. He claims that it was introduced in about 1947 because of the copper shortage. The reasoning is that there was a post-war housing boom - I expect that a lot of existing houses also needed re-wiring - but that the conventional way of doing this by running a cable from the fuse-box to each separate mains socket was deemed wasteful of copper. So someone invented the ring-main which generally used less cable. The problem was that the ring-main fuses had to be larger and so the system wasn't as safe. The solution was to put a fuse in each plug-top and this made them much larger. Does that sound a reasonable explanation?

In fact I can just recall the old 15 amp 3-pin plugs which preceded them and I don't think they were all that much smaller even though they were fuse-less. In North America they don't seem to worry much about safety given their lower mains voltage, but what about mainland Europe - do they use ring mains with their fuse-less plugs or does each socket have a separate run back to the fuse-box? I have never thought to enquire.


--
Clive Page

On 09/04/2021 19:07, Clive Page wrote:
In North America they don't seem to worry much about safety given their
lower mains voltage,

But lower voltage means higher current for the same use. So they have
proportionally more house fires, due to failing connections carrying
that much higher current, combined with the US favouring timber frame
construction rather than bricks and mortar, compared to UK

--
Global sea level rise to 2100 from curve-fitted existing altimetry data
http://diverse.4mg.com/slr.htm

"N_Cook" wrote in message
...
On 09/04/2021 19:07, Clive Page wrote:
In North America they don't seem to worry much about safety given their
lower mains voltage,

But lower voltage means higher current for the same use. So they have
proportionally more house fires, due to failing connections carrying that
much higher current,

The code system avoids house fires due to electrical faults.

combined with the US favouring timber frame construction rather than
bricks and mortar, compared to UK

Thats the real reason.

On 09/04/2021 19:07, Clive Page wrote:
I just watched another of Tim Hunkin's excellent videos - this one is on
connectors:

https://www.youtube.com/watch?v=q43tZ6DjuIE

One of the connectors he deals with is the UK 13A power plug.Â* He claims
that it was introduced in about 1947 because of the copper shortage.
The reasoning is that there was a post-war housing boom - I expect that
a lot of existing houses also needed re-wiring - but that the
conventional way of doing this by running a cable from the fuse-box to
each separate mains socket was deemed wasteful of copper.Â* So someone
invented the ring-main which generally used less cable.Â* The problem was
that the ring-main fuses had to be larger and so the system wasn't as
safe.Â* The solution was to put a fuse in each plug-top and this made
them much larger.Â* Does that sound a reasonable explanation?

In fact I can just recall the old 15 amp 3-pin plugs which preceded them
and I don't think they were all that much smaller even though they were
fuse-less.Â* In North America they don't seem to worry much about safety
given their lower mains voltage, but what about mainland Europe - do
they use ring mains with their fuse-less plugs or does each socket have
a separate run back to the fuse-box?Â* I have never thought to enquire.



The ring main certainly saved wire as more and more sockets were fitted.
It also gave two paths to each socket - did Hunkin mention that?

The 3-pin round-pin domestic plugs were 15A, 5A and 2A, IIRC.
Volume-wise the 13A is not that different.

The US domestic systems do have 220v capability - so they're not that
different from us.

PA

On 09/04/2021 18:45, Peter Able wrote:
On 09/04/2021 19:07, Clive Page wrote:
I just watched another of Tim Hunkin's excellent videos - this one is
on connectors:

https://www.youtube.com/watch?v=q43tZ6DjuIE

One of the connectors he deals with is the UK 13A power plug.Â* He
claims that it was introduced in about 1947 because of the copper
shortage. The reasoning is that there was a post-war housing boom - I
expect that a lot of existing houses also needed re-wiring - but that
the conventional way of doing this by running a cable from the
fuse-box to each separate mains socket was deemed wasteful of copper.
So someone invented the ring-main which generally used less cable.
The problem was that the ring-main fuses had to be larger and so the
system wasn't as safe.Â* The solution was to put a fuse in each
plug-top and this made them much larger.Â* Does that sound a reasonable
explanation?

In fact I can just recall the old 15 amp 3-pin plugs which preceded
them and I don't think they were all that much smaller even though
they were fuse-less.Â* In North America they don't seem to worry much
about safety given their lower mains voltage, but what about mainland
Europe - do they use ring mains with their fuse-less plugs or does
each socket have a separate run back to the fuse-box?Â* I have never
thought to enquire.



The ring main certainly saved wire as more and more sockets were fitted.
It also gave two paths to each socket - did Hunkin mention that?

The 3-pin round-pin domestic plugs were 15A, 5A and 2A, IIRC.
Volume-wise the 13A is not that different.

The US domestic systems do have 220v capability - so they're not that
different from us.

From a pedantic POV, the USA has 120V between live and neutral. It can
also have 240V or 208V depending on the supply. 208V being from 2 legs
of their 3-phase supply.

Fredxx wrote:

From a pedantic POV, the USA has 120V between live and neutral. It can
also have 240V or 208V depending on the supply. 208V being from 2 legs
of their 3-phase supply.


Not wuite, they have 3-phases in the street but their transformers (pole
pigs) have centre tapped secondary so it gives +110V/N/-110V to the
house, most circuits use a single live (hot) to neutral, but heavy duty
stuff like tumble driers use both hots

https://youtu.be/jMmUoZh3Hq4

On 09/04/2021 20:39, Andy Burns wrote:
Fredxx wrote:

Â*From a pedantic POV, the USA has 120V between live and neutral. It
can also have 240V or 208V depending on the supply. 208V being from 2
legs of their 3-phase supply.


Not wuite, they have 3-phases in the street but their transformers (pole
pigs) have centre tapped secondary so it gives +110V/N/-110V to the
house, most circuits use a single live (hot) to neutral, but heavy duty
stuff like tumble driers use both hots

https://youtu.be/jMmUoZh3Hq4

1) First all the guy in the video is correct.

2) The voltage is 120V but also 240V or 208V depending on the supply.

https://en.wikipedia.org/wiki/Mains_electricity
"In the United States[14][15] and Canada,[16] national standards specify
that the nominal voltage at the source should be 120 V and allow a range
of 114 V to 126 V (RMS) (ˆ’5% to +5%). Historically 110 V, 115 V and 117
V have been used at different times and places in North America. Mains
power is sometimes spoken of as 110 V; however, 120 V is the nominal
voltage."

3) 208V or 240V is supplied to homes. 240V split either side of
ground/neutral is the most common but many domestic builds simply supply
2 phases and not every home has it's dedicated transformer. It's
obviously cheaper for a one large transformer supply a block of flats
and houses. Many appliances will have a 208/220/240V label. I can find
very little with Google, but this is an article with an explanation:

https://www.researchgate.net/post/Co...r-110-or-220-V

Obviously: 208 = sqrt(3) * 120

HTH

On 09/04/2021 19:07, Clive Page wrote:
I just watched another of Tim Hunkin's excellent videos - this one is on
connectors:

https://www.youtube.com/watch?v=q43tZ6DjuIE

One of the connectors he deals with is the UK 13A power plug.Â* He claims
that it was introduced in about 1947 because of the copper shortage.
The reasoning is that there was a post-war housing boom - I expect that
a lot of existing houses also needed re-wiring - but that the
conventional way of doing this by running a cable from the fuse-box to
each separate mains socket was deemed wasteful of copper.Â* So someone
invented the ring-main which generally used less cable.Â* The problem was
that the ring-main fuses had to be larger and so the system wasn't as
safe.Â* The solution was to put a fuse in each plug-top and this made
them much larger.Â* Does that sound a reasonable explanation?

In fact I can just recall the old 15 amp 3-pin plugs which preceded them
and I don't think they were all that much smaller even though they were
fuse-less.Â* In North America they don't seem to worry much about safety
given their lower mains voltage, but what about mainland Europe - do
they use ring mains with their fuse-less plugs or does each socket have
a separate run back to the fuse-box?Â* I have never thought to enquire.


A bit slack with the past and present tenses.

8 min 46 sec "so it was extremely safe"

--
Adam

On 09/04/2021 19:07, Clive Page wrote:
In fact I can just recall the old 15 amp 3-pin plugs which preceded them
and I don't think they were all that much smaller even though they were
fuse-less.

They were bigger.

Bill

In article ,
williamwright wrote:
On 09/04/2021 19:07, Clive Page wrote:
In fact I can just recall the old 15 amp 3-pin plugs which preceded them
and I don't think they were all that much smaller even though they were
fuse-less.

They were bigger.

Bill

They are bigger. Still used in theatres.
^^^

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

On 09/04/2021 21:28, charles wrote:
In article ,
williamwright wrote:
On 09/04/2021 19:07, Clive Page wrote:
In fact I can just recall the old 15 amp 3-pin plugs which preceded them
and I don't think they were all that much smaller even though they were
fuse-less.

They were bigger.

Bill

They are bigger. Still used in theatres.
^^^



The reason for that is if a plug had a fuse in it and it blew during a
live performance, it was not a quick or safe job to get a maintenance
man out to climb into the suspended walkways in the dark, find the plug,
unplug it, take it apart, replace fuse, reassemble the plug, plug it
back in and vacate the suspended walkways.

instead, the arrangement was a wall of MCBs or fuses immediately after
the lighting power thyristors controlled by the lighting desk.

They were on the wall in the same room as the lighting engineer.... so
if a circuit pops, the lighting engineer had to reset/replace the
MCB/fuse there and then instead.

In article ,
SH wrote:
They are bigger. Still used in theatres.
^^^



The reason for that is if a plug had a fuse in it and it blew during a
live performance, it was not a quick or safe job to get a maintenance
man out to climb into the suspended walkways in the dark, find the plug,
unplug it, take it apart, replace fuse, reassemble the plug, plug it
back in and vacate the suspended walkways.

Err, theatre lighting doesn't use a ring main. Most usually a radial with
dimmer control. You don't want such circuits confused with a GP mains
supply - hence different connectors.

--
*Isn't it a bit unnerving that doctors call what they do "practice?"

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

"Dave Plowman (News)" wrote in message
...
In article ,
SH wrote:
They are bigger. Still used in theatres.
^^^



The reason for that is if a plug had a fuse in it and it blew during a
live performance, it was not a quick or safe job to get a maintenance
man out to climb into the suspended walkways in the dark, find the plug,
unplug it, take it apart, replace fuse, reassemble the plug, plug it
back in and vacate the suspended walkways.

Err, theatre lighting doesn't use a ring main. Most usually a radial with
dimmer control. You don't want such circuits confused with a GP mains
supply - hence different connectors.

Ah, I wasn't sure whether lighting circuits in theatres were spurs (with
only one route from the supply to the lamps) or a ring (with two alternative
routes from the supply to the lamps). Either way, they are fused at the
lighting board rather than the plug, and usually the supply goes via a
variable resistor or triac dimmer and switches so several circuits can be
switched on/off or dimmed in synchrony.

I remember working as a lighting operator for school plays, perched 10 feet
above one side of the stage on a gantry with a row of about 10 vertical
wire-wound dimmers which could be switched between lighting circuits - eg
we'd put all the lights that we wanted to dim in sync on adjacent dimmers so
a 2-, 3- or 4-dimmer length of wood could be used to move all the dimmers in
sync. Once that effect was over, we'd switch circuits to other dimmers to
put ones for another synchronous effect on adjacent dimmers. The fuses were
per dimmer rather than per lighting circuit, so if a fuse blew, you switched
the circuit to another dimmer while you rewired the blown fuse. I remember
the "blackout" switch that killed all lights everywhere when a total
instantaneous blackout was needed: it was a surprisingly small insignificant
switch which operated a humungous relay nearby which always made a loud
clonk.

The big daddy dimmer was the one for the house lights. That was a flat box
about 3 feet square with load of ventilation holes all over it and a big
wheel on the front that made a loud screeching noise as the contacts moved
over the wire-wound coil. The instruction there was the move it smoothly,
quickly and fully from one end to the other, not leaving it half-on or
almost-but-not-quite off/on for any longer than necessary because it got
very hot. I think there were 24 house lights, each with a 500 W bulb shaped
like a very large 60 W bulb, so that was 12 kW that had to be dimmed - hence
the need to go from off to on as quickly as possible, because the wire-wound
coil didn't like 12 kW passed through it.


The school also had a lecture theatre with a modern triac dimmer system in
the projection booth and ceiling-mounted lights. But it had no proscenium
arch and no wings, so all the fancy lighting couldn't be used for a stage
play where actors had to enter or exit. The only way to do it was to open
one of the fire doors either side of the "stage" and have the actors enter
from outside in the playground.

What intrigued me about the lecture theatre was that the fluorescent tubes
could be dimmed from very dim to fully bright - they couldn't dim right to
extinction so there was a sudden switch-off once they got very dim. But I'm
not sure how you dim fluorescents while maintaining the striking voltage.
Did they feed them with a crude square wave that remained above the striking
voltage for an gradually-decreasing portion of each mains cycle, a bit like
you'd dim LEDs?

In article , Dave Plowman (News)
wrote:
In article , SH
wrote:
They are bigger. Still used in theatres. ^^^



The reason for that is if a plug had a fuse in it and it blew during a
live performance, it was not a quick or safe job to get a maintenance
man out to climb into the suspended walkways in the dark, find the
plug, unplug it, take it apart, replace fuse, reassemble the plug,
plug it back in and vacate the suspended walkways.

Err, theatre lighting doesn't use a ring main. Most usually a radial with
dimmer control. You don't want such circuits confused with a GP mains
supply - hence different connectors.

yes, but the reason is you don't want a fuse in some remote part of the rig.

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

On 09/04/2021 21:28, charles wrote:


They were bigger.

Bill

They are bigger. Still used in theatres.
^^^


You wouldn't want to be climbing up into the lighting gantry at the
interval to change a fuse.

Bill

On 09/04/2021 20:26, williamwright wrote:
On 09/04/2021 19:07, Clive Page wrote:
In fact I can just recall the old 15 amp 3-pin plugs which preceded
them and I don't think they were all that much smaller even though
they were fuse-less.

They were bigger.

Bill

And a lot more robust.
--
Cheers,
Roger

williamwright wrote:

On 09/04/2021 19:07, Clive Page wrote:
In fact I can just recall the old 15 amp 3-pin plugs which preceded them
and I don't think they were all that much smaller even though they were
fuse-less.

They were bigger.

Does anyone remember this monstrosity?

https://www.plugsocketmuseum.nl/Fitall1.html

Chris
--
Chris J Dixon Nottingham UK
@ChrisJDixon1

Plant amazing Acers.

Chris J Dixon formulated the question :
williamwright wrote:

On 09/04/2021 19:07, Clive Page wrote:
In fact I can just recall the old 15 amp 3-pin plugs which preceded them
and I don't think they were all that much smaller even though they were
fuse-less.

They were bigger.

Does anyone remember this monstrosity?

https://www.plugsocketmuseum.nl/Fitall1.html

Chris

Yep, I used to have one, wired to a 13amp socket - in the days when you
were faced with a variety of plugs.

In article , Chris J Dixon
wrote:
williamwright wrote:

On 09/04/2021 19:07, Clive Page wrote:
In fact I can just recall the old 15 amp 3-pin plugs which preceded
them and I don't think they were all that much smaller even though
they were fuse-less.

They were bigger.

Does anyone remember this monstrosity?

https://www.plugsocketmuseum.nl/Fitall1.html

Chris

Yes

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

On Saturday, 10 April 2021 at 08:32:19 UTC+1, charles wrote:
In article , Chris J Dixon
wrote:
williamwright wrote:

On 09/04/2021 19:07, Clive Page wrote:
In fact I can just recall the old 15 amp 3-pin plugs which preceded
them and I don't think they were all that much smaller even though
they were fuse-less.

They were bigger.

Does anyone remember this monstrosity?

https://www.plugsocketmuseum.nl/Fitall1.html

Chris
Yes
--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

How about these,

https://www.plugsocketmuseum.nl/Wylex1.html

A flat I moved into in the early seventies had sockets for these, the plugs were a bugger to find. I think the landlord used them deliberately and sold spares to tenants to enable them to cob together leads in order to use standard square pin plugs on personal electrical equipment. I think he limited the number issued so the system could not be overloaded.

Richard

In article ,
Tricky Dicky wrote:
On Saturday, 10 April 2021 at 08:32:19 UTC+1, charles wrote:
In article , Chris J Dixon
wrote:
williamwright wrote:

On 09/04/2021 19:07, Clive Page wrote:
In fact I can just recall the old 15 amp 3-pin plugs which preceded
them and I don't think they were all that much smaller even though
they were fuse-less.

They were bigger.

Does anyone remember this monstrosity?

https://www.plugsocketmuseum.nl/Fitall1.html

Chris
Yes
--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

How about these,

https://www.plugsocketmuseum.nl/Wylex1.html

A flat I moved into in the early seventies had sockets for these, the
plugs were a bugger to find. I think the landlord used them deliberately
and sold spares to tenants to enable them to cob together leads in order
to use standard square pin plugs on personal electrical equipment. I
think he limited the number issued so the system could not be overloaded.

They look very much like the ones the NSHEB introduced.
The D&S mentioned on that page were adopted at TV Centre for 'technical
supplies"; stopped the cleaner plugging in a vacuum cleaner. They were
probably used in some mansion blocks in central London since Selfridges
used to sell the fuses.

--
from KT24 in Surrey, England
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

On 10/04/2021 07:56, Chris J Dixon wrote:
williamwright wrote:

On 09/04/2021 19:07, Clive Page wrote:
In fact I can just recall the old 15 amp 3-pin plugs which preceded them
and I don't think they were all that much smaller even though they were
fuse-less.

They were bigger.

Does anyone remember this monstrosity?

https://www.plugsocketmuseum.nl/Fitall1.html

Yes they were yummy.

--
Max Demian

On 09/04/2021 19:07, Clive Page wrote:
I just watched another of Tim Hunkin's excellent videos - this one is on
connectors:

https://www.youtube.com/watch?v=q43tZ6DjuIE

One of the connectors he deals with is the UK 13A power plug.Â* He claims
that it was introduced in about 1947 because of the copper shortage.
The reasoning is that there was a post-war housing boom - I expect that
a lot of existing houses also needed re-wiring - but that the
conventional way of doing this by running a cable from the fuse-box to
each separate mains socket was deemed wasteful of copper.Â* So someone
invented the ring-main which generally used less cable.Â* The problem was
that the ring-main fuses had to be larger and so the system wasn't as
safe.Â* The solution was to put a fuse in each plug-top and this made
them much larger.Â* Does that sound a reasonable explanation?

Apart from the fuse making it larger part - Then that is the thrust of
it. A ring can serve lots of sockets with less cable and is easier to
wire if you need a high power delivery. It could also be cobbled
together from two existing 15A radials, and be far more versatile than
the sum of the parts. The modern implementation of the ring turning out
to be very well suited to modern applications (i.e. loads of sockets and
load of small loads)

In fact I can just recall the old 15 amp 3-pin plugs which preceded them
and I don't think they were all that much smaller even though they were
fuse-less.

Indeed - if anything they are larger.

In North America they don't seem to worry much about safety
given their lower mains voltage,

They don't but ought to (the number of electrocutions there per year are
staggering compared to ours!)

but what about mainland Europe - do
they use ring mains with their fuse-less plugs or does each socket have
a separate run back to the fuse-box?Â* I have never thought to enquire.

Most places use lots of radials serving just a few sockets, with the MCB
sized to offer both fault and overload protection to all of the circuit,
right up to the appliance.

(contra you our design where the MCB[1] offers fault and overload
protection for the ring circuit as far as the sockets, but the plug fuse
extends fault protection up to the inlet of the appliance).

[1] in conjunction with some design rules.

--
Cheers,

John.

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

On 10/04/2021 01:04, John Rumm wrote:
In North America they don't seem to worry much about safety given
their lower mains voltage,

They don't but ought to (the number of electrocutions there per year are
staggering compared to ours!)

Not all of them accidental.

Bill

On Sat, 10 Apr 2021 01:04:28 +0100, John Rumm wrote:

On 09/04/2021 19:07, Clive Page wrote:
I just watched another of Tim Hunkin's excellent videos - this one is
on connectors:

https://www.youtube.com/watch?v=q43tZ6DjuIE

One of the connectors he deals with is the UK 13A power plug.Â* He
claims that it was introduced in about 1947 because of the copper
shortage.
The reasoning is that there was a post-war housing boom - I expect that
a lot of existing houses also needed re-wiring - but that the
conventional way of doing this by running a cable from the fuse-box to
each separate mains socket was deemed wasteful of copper.Â* So someone
invented the ring-main which generally used less cable.Â* The problem
was that the ring-main fuses had to be larger and so the system wasn't
as safe.Â* The solution was to put a fuse in each plug-top and this made
them much larger.Â* Does that sound a reasonable explanation?

Apart from the fuse making it larger part - Then that is the thrust of
it. A ring can serve lots of sockets with less cable and is easier to
wire if you need a high power delivery. It could also be cobbled
together from two existing 15A radials, and be far more versatile than
the sum of the parts. The modern implementation of the ring turning out
to be very well suited to modern applications (i.e. loads of sockets and
load of small loads)

In fact I can just recall the old 15 amp 3-pin plugs which preceded
them and I don't think they were all that much smaller even though they
were fuse-less.

Indeed - if anything they are larger.

In North America they don't seem to worry much about safety given their
lower mains voltage,

They don't but ought to (the number of electrocutions there per year are
staggering compared to ours!)

but what about mainland Europe - do they use ring mains with their
fuse-less plugs or does each socket have a separate run back to the
fuse-box?Â* I have never thought to enquire.

Most places use lots of radials serving just a few sockets, with the MCB
sized to offer both fault and overload protection to all of the circuit,
right up to the appliance.

(contra you our design where the MCB[1] offers fault and overload
protection for the ring circuit as far as the sockets, but the plug fuse
extends fault protection up to the inlet of the appliance).

[1] in conjunction with some design rules.

When I was young we had DC mains and the cooker control box had fused
15amp and 5 amp round pin sockets. The switches were the two pole rotary
type. All my experiments were done, using an ex WD rotary transformer used
in reverse, to get ~28volts DC.

Well Europe seems to be a mess of different plugs and ad hoc installed extra
bits all over the place.
I bet there are standards, but whether there is compliance is a whole other
thing.

Brian

--

This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Clive Page" wrote in message
...
I just watched another of Tim Hunkin's excellent videos - this one is on
connectors:

https://www.youtube.com/watch?v=q43tZ6DjuIE

One of the connectors he deals with is the UK 13A power plug. He claims
that it was introduced in about 1947 because of the copper shortage. The
reasoning is that there was a post-war housing boom - I expect that a lot
of existing houses also needed re-wiring - but that the conventional way
of doing this by running a cable from the fuse-box to each separate mains
socket was deemed wasteful of copper. So someone invented the ring-main
which generally used less cable. The problem was that the ring-main fuses
had to be larger and so the system wasn't as safe. The solution was to
put a fuse in each plug-top and this made them much larger. Does that
sound a reasonable explanation?

In fact I can just recall the old 15 amp 3-pin plugs which preceded them
and I don't think they were all that much smaller even though they were
fuse-less. In North America they don't seem to worry much about safety
given their lower mains voltage, but what about mainland Europe - do they
use ring mains with their fuse-less plugs or does each socket have a
separate run back to the fuse-box? I have never thought to enquire.


--
Clive Page

Might I just say that although this house was built in 1939, it was built
using 13 amp sockets on the old rubber and fabric covered wires, including
earth. I could not say if it was ring main or not, or much else but I can
tell you that the lights did not have unstitched lives in the rose. There
were also a smattering of 2 pin 5a sockets as well, apparently wired to the
one lighting circuit. All the 13 amp sockets were on one circuit. Of course
the old consumer unit used wire fuses, and was made of metal.

We had the place rewired in the 70s and then we had split upstairs and
downstairs circuits, all the sockets were raised up above the skirting and
all were on ring mains, but oddly, the bar fires in the bedrooms were on
the lighting circuit, not the socket one. In one case it was spurred off
the ring though as it was basically an afterthought.

Apart from the colours being wrong for today and the old circuit breakers
instead of the more sophisticated fault protection of today, its in very
good condition still.
Brian

--

This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
Note this Signature is meaningless.!
"Clive Page" wrote in message
...
I just watched another of Tim Hunkin's excellent videos - this one is on
connectors:

https://www.youtube.com/watch?v=q43tZ6DjuIE

One of the connectors he deals with is the UK 13A power plug. He claims
that it was introduced in about 1947 because of the copper shortage. The
reasoning is that there was a post-war housing boom - I expect that a lot
of existing houses also needed re-wiring - but that the conventional way
of doing this by running a cable from the fuse-box to each separate mains
socket was deemed wasteful of copper. So someone invented the ring-main
which generally used less cable. The problem was that the ring-main fuses
had to be larger and so the system wasn't as safe. The solution was to
put a fuse in each plug-top and this made them much larger. Does that
sound a reasonable explanation?

In fact I can just recall the old 15 amp 3-pin plugs which preceded them
and I don't think they were all that much smaller even though they were
fuse-less. In North America they don't seem to worry much about safety
given their lower mains voltage, but what about mainland Europe - do they
use ring mains with their fuse-less plugs or does each socket have a
separate run back to the fuse-box? I have never thought to enquire.


--
Clive Page

In article ,
Brian Gaff \(Sofa\) wrote:
Might I just say that although this house was built in 1939, it was
built using 13 amp sockets on the old rubber and fabric covered wires,
including earth.

Pretty certain 13 amp was a post war thing, Brian. But it could have taken
a long time to build your house. ;-)

--
*A plateau is a high form of flattery*

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

Well, All I can tell you is that people moved in in 1942 according though
the searches. The sockets were made of a very brittle brown bakelite
substance and we had to change them in 1956 when we moved in as some had
clearly overheated due to loose screw syndrome. I did go into several of the
houses along this terrace back around 58 or so and remember, being a nerd
back then too, that they all had 13 amp square shuttered pin sockets, so
unless somebody did the whole block at once, then they must have been here
since just before the war.
I guess its possible that some damage was done during the war needing some
work to them all, but no mention on the search. I was still a child but
loved things electrical back then as well.


I'm not going to do loads of research on tit but there were a couple of
socket adaptors left here when we moved in, one was for a large round pin
socket the others were several small three pin sockets on a box shaped 13a
adaptor. None of these adaptors were fused and of cours no plug back then
had shrouded pins and some of the sockets shutters were jammed open, one
assumes to poke wires in with the usual lethal consequences no doubt.
Another device that was left in the cupboard under the stairs was an
electric iron terminated in a bayonet plug that went into a light fitting.
of Brian

--

This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please
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"Dave Plowman (News)" wrote in message
...
In article ,
Brian Gaff \(Sofa\) wrote:
Might I just say that although this house was built in 1939, it was
built using 13 amp sockets on the old rubber and fabric covered wires,
including earth.

Pretty certain 13 amp was a post war thing, Brian. But it could have taken
a long time to build your house. ;-)

--
*A plateau is a high form of flattery*

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

In article ,
Brian Gaff \(Sofa\) wrote:
Well, All I can tell you is that people moved in in 1942 according
though the searches. The sockets were made of a very brittle brown
bakelite substance and we had to change them in 1956 when we moved in as
some had clearly overheated due to loose screw syndrome. I did go into
several of the houses along this terrace back around 58 or so and
remember, being a nerd back then too, that they all had 13 amp square
shuttered pin sockets, so unless somebody did the whole block at once,
then they must have been here since just before the war. I guess its
possible that some damage was done during the war needing some work to
them all, but no mention on the search. I was still a child but loved
things electrical back then as well.


I'm not going to do loads of research on tit but there were a couple of
socket adaptors left here when we moved in, one was for a large round
pin socket the others were several small three pin sockets on a box
shaped 13a adaptor. None of these adaptors were fused and of cours no
plug back then had shrouded pins and some of the sockets shutters were
jammed open, one assumes to poke wires in with the usual lethal
consequences no doubt. Another device that was left in the cupboard
under the stairs was an electric iron terminated in a bayonet plug that
went into a light fitting. of Brian

According to Wiki, a committee was convened in 1942 to look into the ring
main idea. But no information when production of the sockets and plugs
actually started. My guess is factories would be busy with other things
until near the end of the war.

--
*Your kid may be an honours student, but you're still an idiot.

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

On 11/04/2021 09:50, Brian Gaff (Sofa) wrote:
Well, All I can tell you is that people moved in in 1942 according though
the searches. The sockets were made of a very brittle brown bakelite
substance and we had to change them in 1956 when we moved in as some had
clearly overheated due to loose screw syndrome. I did go into several of the
houses along this terrace back around 58 or so and remember, being a nerd
back then too, that they all had 13 amp square shuttered pin sockets, so
unless somebody did the whole block at once, then they must have been here
since just before the war.

The BS1363 13A plug and socket were not introduced until 1947.