Tam/WB2TT wrote in message
. ..

"N Cook" wrote in message
...
This is someone's graphic of internal wiring of a UK line connector
http://web.onetel.net.uk/~uncletony/...mains-plug.jpg
note the screw down, into captive hollows, for the bared leads , also
the
cord grip and also the internal fuse.
This week I had to wire up a USA mains connector like this one
http://www.maplin.co.uk/images/Full/hl19v.jpg
I could not find an internal pic or graphic but it reminded me of the
internal wiring of UK plugs of 50 years ago, before ROSPA and BS got
involved - , wrap around screw terminals that can easily shed a loose
wire
filament,

I have never seen a house here in the US wired with stranded wire, except
for one built in 1906. Generally #14 solid copper. BTW the 3 wire UK plug
reminds me of what is used on a clothes dryer or stove here. Would you
actually use one of these on a lamp?

Tam

both of them, live and neutral surprisingly close together and
what I find very odd , no cord grip/anchor and no fuse.





We have no choice in the matter, by law, we can use 1,2 or 3 amp fuses
inside these plugs but thats the only choice

The USA cannot have the equivalent of RoSPA (Royal Society for the
Prevention of Accidents), AFAICS none of the USA ones have child preventers
on them unless the mouldings on the wall outlets preclude that eventuality
of small fiongers touching both pins.
The other notable difference is the insulated pins that have been necessary
refinement, again by law, for 20 years or so
You can just see the orange plastic bits extending up the brass pins on the
first pic on this wiki and the black bits on the one lower down on
http://en.wikipedia.org/wiki/BS_1363
....
The phase and neutral pins on modern plugs have insulated bases to prevent
finger contact with pins and also to stop metal sheets (for example, fallen
blind slats) from becoming live if lodged between the wall and a partly
pulled out plug. A downside to this prong insulation is that it may
contribute to damaged sockets not making good contact with the prongs, which
may even melt the latter. No such problems exist with healthy sockets.
....

as an aside someone told me that per million houses there are more house
fires in the USA due to wiring faults than any other country, partly due to
a lot of timber construction and partly due to the higher current for a
given KW of power transfered - is that the case?

SNIP
...
The phase and neutral pins on modern plugs have insulated bases to prevent
finger contact with pins and also to stop metal sheets (for example,
fallen
blind slats) from becoming live if lodged between the wall and a partly
pulled out plug. A downside to this prong insulation is that it may
contribute to damaged sockets not making good contact with the prongs,
which
may even melt the latter. No such problems exist with healthy sockets.
...

as an aside someone told me that per million houses there are more house
fires in the USA due to wiring faults than any other country, partly due
to
a lot of timber construction and partly due to the higher current for a
given KW of power transfered - is that the case?


Have you seen the way they connect their wires? They just twist them
together and put a plastic cap over the bare wires!
Multiply that by double current and it's no wonder they have fires

"TT_Man" wrote in message
...
SNIP
...
The phase and neutral pins on modern plugs have insulated bases to
prevent
finger contact with pins and also to stop metal sheets (for example,
fallen
blind slats) from becoming live if lodged between the wall and a partly
pulled out plug. A downside to this prong insulation is that it may
contribute to damaged sockets not making good contact with the prongs,
which
may even melt the latter. No such problems exist with healthy sockets.
...

as an aside someone told me that per million houses there are more house
fires in the USA due to wiring faults than any other country, partly due
to
a lot of timber construction and partly due to the higher current for a
given KW of power transfered - is that the case?


Have you seen the way they connect their wires? They just twist them
together and put a plastic cap over the bare wires!

They are called wire nuts, and contain a threaded metal insert. Sort of an
inverse of a self tapping screw. I understand the hesitance, but they don't
seem to be a problem

Tam

Multiply that by double current and it's no wonder they have fires

Tam/WB2TT wrote:
someone wrote

Have you seen the way they connect their wires? They just twist them
together and put a plastic cap over the bare wires!

They are called wire nuts, and contain a threaded metal insert. Sort of an
inverse of a self tapping screw. I understand the hesitance, but they don't
seem to be a problem

We used to have a similar thing but made of ceramic, called a scruit
(sp?) (pronounced screw-it) I understand that they may be outlawed these
days.

Ron(UK)

Tam/WB2TT wrote:

"TT_Man" wrote in message


Have you seen the way they connect their wires? They just twist them
together and put a plastic cap over the bare wires!

They are called wire nuts, and contain a threaded metal insert. Sort of an
inverse of a self tapping screw. I understand the hesitance, but they don't
seem to be a problem

I fixed a Weller TCP iron a couple of weeks back that was running cold. A 'wire
nut' inside was loose and a connection to the element had become iffy.

Graham

On 27 jun, 22:56, "TT_Man" wrote:
Have you seen the way they connect their wires? They just twist them
together and put a plastic cap over the bare wires!
Multiply that by double current and it's no wonder they have fires -

Sounds dodgy!

I've spent time in the US and Japan, and I have to say that those flat
blade sockets are an atrocious design. They suffer sloppy fit problems
very easily . Those countries don't seem to have switched wall sockets
either, which the Uk standard has, so you get more arcing if plugging
in live equipment (which degrades the contacts even further).
The UK plugs are more complex, and expensive, but a damn sight safer
and a lot more sturdy and resist wear better -only ever had to
replace one or two fittings over the years.

I suppose all this is because it is a more recent standard - like the
German PAL TV system - which, since it was introduced later, had the
edge.
-B.

"b" wrote in message
ps.com...
On 27 jun, 22:56, "TT_Man" wrote:
Have you seen the way they connect their wires? They just twist them
together and put a plastic cap over the bare wires!
Multiply that by double current and it's no wonder they have fires -

Sounds dodgy!

I've spent time in the US and Japan, and I have to say that those flat
blade sockets are an atrocious design. They suffer sloppy fit problems
very easily . Those countries don't seem to have switched wall sockets
either, which the Uk standard has, so you get more arcing if plugging
in live equipment (which degrades the contacts even further).
The UK plugs are more complex, and expensive, but a damn sight safer
and a lot more sturdy and resist wear better -only ever had to
replace one or two fittings over the years.

I suppose all this is because it is a more recent standard - like the
German PAL TV system - which, since it was introduced later, had the
edge.
-B.



Done correctly, a quality wire nut is a very secure and long lasting
connection. It's not simply a plastic cap, but a plastic casing over a
threaded springy metal insert which grips the wires very well. I have some
UK terminal blocks, and the problem with them is that there's no mechanical
bond between the wires, the contact point is small, and they can and do work
loose or corrode over time. They generally are ok, but neither method is
greatly superior to the other.

The double current isn't really much of an issue, our large loads are 240V
too, it's handy to have both voltages readily available.

You can get quality US style receptacles, problem is they're expensive so
few houses come with them. I like many things about the UK plugs, but the
thing I don't like is they're *huge* so things like power strips and
multi-gang outlets are really cumbersome.

Having discussed this in length with a friend in the UK, we've both come to
the conclusion that both systems have many advantages and disadvantages and
neither one is a clear winner.

James Sweet wrote in message
news:9hGgi.5824$bj5.164@trndny07...

"b" wrote in message
ps.com...
On 27 jun, 22:56, "TT_Man" wrote:
Have you seen the way they connect their wires? They just twist them
together and put a plastic cap over the bare wires!
Multiply that by double current and it's no wonder they have fires -

Sounds dodgy!

I've spent time in the US and Japan, and I have to say that those flat
blade sockets are an atrocious design. They suffer sloppy fit problems
very easily . Those countries don't seem to have switched wall sockets
either, which the Uk standard has, so you get more arcing if plugging
in live equipment (which degrades the contacts even further).
The UK plugs are more complex, and expensive, but a damn sight safer
and a lot more sturdy and resist wear better -only ever had to
replace one or two fittings over the years.

I suppose all this is because it is a more recent standard - like the
German PAL TV system - which, since it was introduced later, had the
edge.
-B.



Done correctly, a quality wire nut is a very secure and long lasting
connection. It's not simply a plastic cap, but a plastic casing over a
threaded springy metal insert which grips the wires very well. I have some
UK terminal blocks, and the problem with them is that there's no
mechanical
bond between the wires, the contact point is small, and they can and do
work
loose or corrode over time. They generally are ok, but neither method is
greatly superior to the other.

The double current isn't really much of an issue, our large loads are 240V
too, it's handy to have both voltages readily available.

You can get quality US style receptacles, problem is they're expensive so
few houses come with them. I like many things about the UK plugs, but the
thing I don't like is they're *huge* so things like power strips and
multi-gang outlets are really cumbersome.

Having discussed this in length with a friend in the UK, we've both come
to
the conclusion that both systems have many advantages and disadvantages
and
neither one is a clear winner.



Could someone direct me to pics of the 2 different types of plug/socket
system used in the USA to differentiate for medium and high power use, I
didn't even realise 220 or 240V was used residentially anywhere in the USA.

N Cook wrote:
Could someone direct me to pics of the 2 different types of plug/socket
system used in the USA to differentiate for medium and high power use, I
didn't even realise 220 or 240V was used residentially anywhere in the USA.

There are several kinds depending upon the current rating and if 120
volts is used too. Before 1996, the ground pin was also used for neutral
for things like clothes dryers that had a 120 volt motors and timers and
240 volt heaters. I think that practice was stopped in the late 1970's.

In 1996, it became illegal. If your device has a mixture of 120 and 240
volt components, you need to have a four wire plug. I left the U.S. in
1996, so I've never seen them.

The simplest kind is used for air conditioners and is similar to a 120
volt grounded plug, with two flat blades and a rounded ground pin below
them in the middle. The difference is that the flat blades are the same
size and are horizontal instead of vertical.

I remember walking into an electronics store in SoHo (in Lyle Street?)
around 1983 and talking to the owner for a while. We got on to discussing
the differences in power cords and he showed me the 240 volt cords
they sent to the U.S. He was surprised that I was familar with them.

He also showed me a catalog from a U.S. company called Herbach and Rademan
that sold surplus electronics. He imported items from them. It was
my turn to be surprised, I lived less than 2 miles from them and was
a frequent customer. :-)

By 1989, the store was gone, it had become a Chinese grocery. In 2001 I
was given a stack of U.K. radio magazines and an article about the
store was in one of them. It was written by the nephew of the man
I spoke to. Unfortunatley he had no pictures of the store near the
end, and although I took many photographs of London that trip, I
never thought to take one of the store or his uncle. :-(


Geoff.
--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

"N Cook" wrote in message
...
James Sweet wrote in message
news:9hGgi.5824$bj5.164@trndny07...

"b" wrote in message
ps.com...
On 27 jun, 22:56, "TT_Man" wrote:

Could someone direct me to pics of the 2 different types of plug/socket
system used in the USA to differentiate for medium and high power use, I
didn't even realise 220 or 240V was used residentially anywhere in the
USA.


Electric clothes dryer, stoves/ovens, and permanently installed air
conditioners are only available in 240 V versions. Also, larger sizes of
electric space heaters. The first three are probably more likely to be wired
in directly to a junction box than to use a plug/socket. There are several
incompatible types of 240 V plugs. All are huge, bigger than the UK plug,
and expensive.
Tam

On Thu, 28 Jun 2007 07:45:50 +0100, N Cook wrote:

Could someone direct me to pics of the 2 different types of plug/socket
system used in the USA to differentiate for medium and high power use, I
didn't even realise 220 or 240V was used residentially anywhere in the USA.

http://www.voltec-industries.com/nema_chart.html
https://www.hubbellnet.com/max_htm/t...EMA/front.html
http://nooutage.com/nema_configurations.htm

Hope This Helps!
Rich

"N Cook" wrote in
:

Could someone direct me to pics of the 2 different types of
plug/socket system used in the USA to differentiate for medium and
high power use, I didn't even realise 220 or 240V was used
residentially anywhere in the USA.



http://nooutage.com/nema_configurations.htm

Some are used only in industrial and commercial situations though.

Not shown is the NEMA 10-xx configuration, which is used for the
aformentioned 120/240V appliances that use a neutral for chassis grounding
and as a return for internal 120V loads. They basically have angled hot
prongs with a straight or L shaped neutral prong (appropriately sized for
the load). FWIW, the NEMA 10-15 plug is exactly the same as a typical
Australian plug, less safety features.

On 28 jun, 05:53, "James Sweet" wrote:
"b" wrote in message

ps.com...





On 27 jun, 22:56, "TT_Man" wrote:
Have you seen the way they connect their wires? They just twist them
together and put a plastic cap over the bare wires!
Multiply that by double current and it's no wonder they have fires -

Sounds dodgy!

I've spent time in the US and Japan, and I have to say that those flat
blade sockets are an atrocious design. They suffer sloppy fit problems
very easily . Those countries don't seem to have switched wall sockets
either, which the Uk standard has, so you get more arcing if plugging
in live equipment (which degrades the contacts even further).
The UK plugs are more complex, and expensive, but a damn sight safer
and a lot more sturdy and resist wear better -only ever had to
replace one or two fittings over the years.

I suppose all this is because it is a more recent standard - like the
German PAL TV system - which, since it was introduced later, had the
edge.
-B.

Done correctly, a quality wire nut is a very secure and long lasting
connection. It's not simply a plastic cap, but a plastic casing over a
threaded springy metal insert which grips the wires very well. I have some
UK terminal blocks, and the problem with them is that there's no mechanical
bond between the wires, the contact point is small, and they can and do work
loose or corrode over time. They generally are ok, but neither method is
greatly superior to the other.

The double current isn't really much of an issue, our large loads are 240V
too, it's handy to have both voltages readily available.

You can get quality US style receptacles, problem is they're expensive so
few houses come with them. I like many things about the UK plugs, but the
thing I don't like is they're *huge* so things like power strips and
multi-gang outlets are really cumbersome.

Having discussed this in length with a friend in the UK, we've both come to
the conclusion that both systems have many advantages and disadvantages and
neither one is a clear winner.- Ocultar texto de la cita -

- Mostrar texto de la cita -

Leaving aside the joining wires/terminal blocks issue, on the subject
of the plugs and sockets, the UK one to me is superior in many ways.
1. fused plugs.
2. cord grip in plugs
3. screw terminals in plugs -no wrapping wires.
4. ALL receptacles and plugs have earth pin.
5. 3 prong design means a better fit (they don't waggle about at all)
6. much thicker pins - handle more current, do not bend, and seem to
resist arcing damage better.
7. switched sockets
......etc.

The US /japan one only has the advantage of compact size, personally I
can live with a bigger plug if it means better performance. I couldn't
care less about cosmetic aspects!

just my tuppence' worth. -B.

b wrote:
Leaving aside the joining wires/terminal blocks issue, on the subject
of the plugs and sockets, the UK one to me is superior in many ways.
1. fused plugs.

Ok, I'll conceed that one, but only 50%, after all, how many people
put a 16amp fuse on a .5mm cord?

2. cord grip in plugs

You can get them in the U.S. I occasionaly use them here for 120
volt equipment (I brought a few items with me) and had a friend
bring me some LEVITON (high quality plugs) from the U.S. They
ave execelent grips on them.

3. screw terminals in plugs -no wrapping wires.

The Leviton plugs have them too. I'm not sure they are an advantage,
the gripping area is the area of the screw shaft,not the circumfrence
times the area of the wire surface, a lot smaller.

4. ALL receptacles and plugs have earth pin.

Cut me a break. Since around 1960 all of the outlets in the U.S. have
grounds. In the U.K. you can buy appliances with 2 condoctor cords
with two plug pins that can usually be forced into U.K. outlets.
They are supposed to be for export to the E.U. but they are sold.

Many of the appliances sold here come that way too, but I must be
the only person who cuts them off and puts three pin plugs with large
grips on them. I also write the name of the appliance on its plug.

It does not make an difference electricaly, the appliances come with
two conductor cords and I don't replace them.

5. 3 prong design means a better fit (they don't waggle about at all)

See above.

6. much thicker pins - handle more current, do not bend, and seem to
resist arcing damage better.

That's a big problem here. Many appliances use 15-16 amps (at 230 volts)
and come with the smaller round plugs which are rated at 16 amps, but
not for continuous duty. When we moved into this appartment, all of the
outlets had burnt "hot" pins because the previous tenants plugged
high current heaters into them.

I replaced the outlet for our oven with an airconditioner plug, which
except for the round pins looks like a U.K. plug. It's no longer
used we replaced it with a gas oven.

7. switched sockets

Maybe. only good if they are not at floor level.

One advantage we have here in Israel is that all new construction
requires a GFI on all outlets. Usually it's BEFORE the main
circuit breaker.


.....etc.

The US /japan one only has the advantage of compact size, personally I
can live with a bigger plug if it means better performance. I couldn't
care less about cosmetic aspects!

As someone said earlier, it depends upon how much you pay. If you
buy cheap junk, you get cheap junk. :-)

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

b wrote in
ups.com:
Leaving aside the joining wires/terminal blocks issue, on the subject
of the plugs and sockets, the UK one to me is superior in many ways.
1. fused plugs.
Not really needed, but could be a hazard due to mis-fusing.

FWIW, some lighting (especially holiday lighting) has fused plugs.

2. cord grip in plugs

Good aftermarket or factory moulded plugs have grips.

3. screw terminals in plugs -no wrapping wires.

As I said, good plugs don't have them, and wires can be twisted anti-
clockwise to wrap around screws.

4. ALL receptacles and plugs have earth pin.

That is a plus. As is the shuttered recepticals, the reason for the
earth pin on everything.

5. 3 prong design means a better fit (they don't waggle about at all)

I can't complain there. It is just easier to deal with two prong moulded
plugs, and they don't hold that bad in a decent recepticle.

6. much thicker pins - handle more current, do not bend, and seem to
resist arcing damage better.

In theory they could handle more, but are only limited to 13A by design.
the standard US plug design can do up to 20A.

7. switched sockets

Another plus for the UK (and Aussie) system.
.....etc.

The US /japan one only has the advantage of compact size, personally I
can live with a bigger plug if it means better performance. I couldn't
care less about cosmetic aspects!

just my tuppence' worth. -B.

On Wed, 27 Jun 2007 19:57:19 -0700, b wrote:
On 27 jun, 22:56, "TT_Man" wrote:
Have you seen the way they connect their wires? They just twist them
together and put a plastic cap over the bare wires!
Multiply that by double current and it's no wonder they have fires -
Sounds dodgy!
I've spent time in the US and Japan, and I have to say that those flat
blade sockets are an atrocious design. They suffer sloppy fit problems
very easily . Those countries don't seem to have switched wall sockets
either, which the Uk standard has, so you get more arcing if plugging
in live equipment

In the US, we know better than to do stupid crap like plugging in live
equipment.

Good Luck!
Rich

On 28 Jun, 23:12, Richard The Dreaded Libertarian
wrote:
On Wed, 27 Jun 2007 19:57:19 -0700, b wrote:
On 27 jun, 22:56, "TT_Man" wrote

I've spent time in the US and Japan, and I have to say that those flat
blade sockets are an atrocious design. They suffer sloppy fit problems
very easily . Those countries don't seem to have switched wall sockets
either, which the Uk standard has, so you get more arcing if plugging
in live equipment

In the US, we know better than to do stupid crap like plugging in live
equipment.

Good Luck!
Rich

Are you really saying no-one ever unplugs things withoutout turning
them off first? I really doubt it.


NT

wrote in news:1183330881.790940.287160
@n2g2000hse.googlegroups.com:

Are you really saying no-one ever unplugs things withoutout turning
them off first? I really doubt it.


Some equipment simply has no off switch..

On Jun 27, 4:56 pm, "TT_Man" wrote:

as an aside someone told me that per million houses there are more house
fires in the USA due to wiring faults than any other country, partly due
to
a lot of timber construction and partly due to the higher current for a
given KW of power transfered - is that the case?

Have you seen the way they connect their wires? They just twist them
together and put a plastic cap over the bare wires!
Multiply that by double current and it's no wonder they have fires -

Well, much of the "fires" due to faulty wiring are because we have
*had* wiring as a general condition in most houses since the early
1900s, so after 100 years or so it gets a little tired, and when
overloaded can fail. Of course, 100 years ago, y'all had very nice
green lawns and gorgeous buildings.... but little electricity other
than the very wealthy. Other fires are due to just plain idiocy on the
part of users, such that would occur here, there or anywhere else.
Very damned few fires are caused by properly utilized wiring even if
100 years old.

As to wire-nuts, what would you propose? Per the code, they must be
enclosed, the expectation is that the wires are first twisted
together, then the nut is attached, and the internal threaded section
is spring-loaded. Are you seriously telling me that wire-nuts are not
permitted in your country?

De gustibus non est disputandum. Electricity has been working for us
over here a good deal longer than it has been working for you over
there. The typical poor-man's rowhouse (900 sf, 100 sm) in
Philadelphia has been wired since 1913. Parts of NYC have been wired
since the late 1800s...

On the other hand, there is something to be said for observing the
experiences of others for 50 years or so before taking the plunge...
Cell phones are a similar item. The US started Analog, only slowly
went digital because of legacy issues, Europe dropped the first nearly
10 years of teething, the Middle East and third-world went right to
Tri-band....

Peter Wieck
Wyncote, PA

In article .com,
wrote:
Well, much of the "fires" due to faulty wiring are because we have
*had* wiring as a general condition in most houses since the early
1900s, so after 100 years or so it gets a little tired, and when
overloaded can fail. Of course, 100 years ago, y'all had very nice
green lawns and gorgeous buildings.... but little electricity other
than the very wealthy.

You're not saying there is 100 year old wiring still in use?

--
*Why is it considered necessary to screw down the lid of a coffin?

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

Dave Plowman (News) wrote:


You're not saying there is 100 year old wiring still in use?

No, he IS saying it is in use. Some of it has been replaced, but not
all of it.

Geoff.
--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

In article ,
Geoffrey S. Mendelson wrote:
You're not saying there is 100 year old wiring still in use?

No, he IS saying it is in use. Some of it has been replaced, but not
all of it.

I'm amazed. It presumably has some form of rubber insulation which will
have crumbled away years ago.

--
*Errors have been made. Others will be blamed.

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

On Jun 28, 2:09 pm, (Geoffrey S. Mendelson) wrote:

No, he IS saying it is in use. Some of it has been replaced, but not
all of it.

Exactly that. The precise term is "Knob and Tube", The insulation is
a mixture of silk, rubber and asphaltic tar that remains quite stable
under most conditions, although it becomes brittle at temperature
extremes (hot and cold). One would think from the ingredients that the
insulation would burn from a sideways glance... not so at all.

I worked my way through college as an old-house electrician and ran
across scads of the stuff. Some of the original lighting circuits (but
nothing else) in our house are still operating from K&T wiring
installed in 1906. The house was built in 1890, originally piped with
gas for lighting.

http://images.google.com/images?hl=e...e+wiring&gbv=2

Will show you it in-situ.

If you keep in mind that the conductors are typically separated by
some distance, and where they penetrate boxes, walls and turn
corners, there is either a ceramic insulator (knob) or ceramic/
additional woven silk/asphalt/rubber (tube), as long as the copper
itself is not raised to ignition-point temperatures it is quite safe.

With reference to the NEC, it may be maintained but not installed-as-
new.

And an unbelievable amount of flea-market wind-chimes are made from
old ceramic tubes....

Peter Wieck
Wyncote, PA

On Thu, 28 Jun 2007 18:34:19 +0100, "Dave Plowman (News)"
wrote:

In article .com,
wrote:
Well, much of the "fires" due to faulty wiring are because we have
*had* wiring as a general condition in most houses since the early
1900s, so after 100 years or so it gets a little tired, and when
overloaded can fail. Of course, 100 years ago, y'all had very nice
green lawns and gorgeous buildings.... but little electricity other
than the very wealthy.

You're not saying there is 100 year old wiring still in use?

My previous house, a Victorian built in 1892, had gas pipes leading to
all the lighting fixtures, capped off, and exposed knob-and-tube
wiring in the attic. Junctions were twisted and taped, hanging in
mid-air. I assume the original wiring was intended for lighting, and
over the years, as more loads were added, it became less suited. I had
a few joints open up, and eventually rewired it with Romex, with all
joints inside proper metal junction boxes. There's still a lot of
ancient fabric-insulated, twisted-junction knob-and-tube stuff around.

http://www.oldhouseweb.com/stories/Detailed/10327.shtml

http://www.knobandtubewiring.com/knob%20and%20tube.gif

It's common to see a fuse box, designed for 5 or 10-amp screw-in
fuses, to be full of 30's.


Around here, knob-and-tube was succeded by mandatory rigid steel
conduit and later, roughly 1960 maybe, Romex. Commercial buildings
must still use conduit, rigid metal pipe or the flexible MX stuff.
There is no requirement that old construction be upgraded, unless a
major remodel is done.


John

" wrote:
De gustibus non est disputandum. Electricity has been working for us
over here a good deal longer than it has been working for you over
there. The typical poor-man's rowhouse (900 sf, 100 sm) in
Philadelphia has been wired since 1913. Parts of NYC have been wired
since the late 1800s...

My "rich man's" rowhouse built in 1916 in Philly, which was quite deteriorated
by 1975 when I moved in had a meterboard marked "Philadelphia Electric
Company 1925" on it. I call it a "rich man's" house because it
was 1200 square feet, had a basement, hardwood floors and
some expensive (at the time) finishing touches.

When I moved in it had 25 amp 240 volt service with a four circuit fuse box.
I upgraded it to a 16 circuit fusebox and later had the whole thing replaced
with 200 amp service.

To follow the Philly theme, Willingboro, New Jersey (originaly Levittown)
houses were wired with aluminum wire because of a copper miner's stike in
South America. By the 1970's the wires broke inside the walls, arced over
and caught fire.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

" wrote:

Well, much of the "fires" due to faulty wiring are because we have
*had* wiring as a general condition in most houses since the early
1900s, so after 100 years or so it gets a little tired, and when
overloaded can fail. Of course, 100 years ago, y'all had very nice
green lawns and gorgeous buildings.... but little electricity other
than the very wealthy.

I'd like to see some supporting data for that litle outburst.

Graham

On Thu, 28 Jun 2007 22:27:15 GMT, Eeyore
wrote:



" wrote:

Well, much of the "fires" due to faulty wiring are because we have
*had* wiring as a general condition in most houses since the early
1900s, so after 100 years or so it gets a little tired, and when
overloaded can fail. Of course, 100 years ago, y'all had very nice
green lawns and gorgeous buildings.... but little electricity other
than the very wealthy.

I'd like to see some supporting data for that litle outburst.

---
It's not up to him to provide supporting data. If you want to
refute it, get off your fat, pompous ass and provide evidence to the
contrary.


--
JF

John Fields wrote:

Eeyorewrote:
" wrote:

Well, much of the "fires" due to faulty wiring are because we have
*had* wiring as a general condition in most houses since the early
1900s, so after 100 years or so it gets a little tired, and when
overloaded can fail. Of course, 100 years ago, y'all had very nice
green lawns and gorgeous buildings.... but little electricity other
than the very wealthy.

I'd like to see some supporting data for that litle outburst.

---
It's not up to him to provide supporting data. If you want to
refute it, get off your fat, pompous ass and provide evidence to the
contrary.

Go **** a pig.

Graham

Eeyore wrote:

I'd like to see some supporting data for that litle outburst.

As late as the 1960's London had FOUR different electrical systems with
different voltages and plugs. As late as 1989 I bought a clock radio
in London that did not have a plug on it. You had to buy one that
matched your outlets.

As lightbulbs were mostly the same size around the world a friend of
mine who traveled, carried an adapator that screwed into a lamp
socket and had a standard U.S. outlet instead of the bulb.

I have one that is like that but it has another lamp socket
on the top and two "euro" two pin outlets. I assume that they
are highly illegal in the U.K. now.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

"Geoffrey S. Mendelson" wrote:

Eeyore wrote:

I'd like to see some supporting data for that litle outburst.

As late as the 1960's London had FOUR different electrical systems with
different voltages and plugs.

I'd be very surprised about that. I can only think of 2 different plug
standards. What's your source ?

Graham

In article ,
Geoffrey S. Mendelson wrote:
Eeyore wrote:

I'd like to see some supporting data for that litle outburst.

As late as the 1960's London had FOUR different electrical systems with
different voltages and plugs.

Are you sure about that? There were several different socket outlets still
in use - 3, 5 and 15 amp all in either two or three pin. As well as some
odd types as an alternative to the common 13 amp plug - notably D&S and
Walsall gauge, sometimes used in council housing estates. But I think the
voltage was standardised some time before then.

As late as 1989 I bought a clock radio
in London that did not have a plug on it. You had to buy one that
matched your outlets.

Yes the requirement for a fitted 13 amp plug hasn't always been.

As lightbulbs were mostly the same size around the world a friend of
mine who traveled, carried an adapator that screwed into a lamp
socket and had a standard U.S. outlet instead of the bulb.

Heh heh - in the UK the bayonet fitting is the common one for GS bulbs.

I have one that is like that but it has another lamp socket
on the top and two "euro" two pin outlets. I assume that they
are highly illegal in the U.K. now.

Perhaps the majority of the sort of things you'd want to plug in to that
are now double insulated so require no earth.

--
*A dog's not just for Christmas, it's alright on a Friday night too*

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

" wrote in news:1183051231.753923.312880
@k29g2000hsd.googlegroups.com:

As to wire-nuts, what would you propose?

Choc-Blocs or Wagos.

"N Cook" wrote in message
...
Tam/WB2TT wrote in message
. ..

"N Cook" wrote in message
...
This is someone's graphic of internal wiring of a UK line connector
http://web.onetel.net.uk/~uncletony/...mains-plug.jpg
note the screw down, into captive hollows, for the bared leads , also
the
cord grip and also the internal fuse.
This week I had to wire up a USA mains connector like this one
http://www.maplin.co.uk/images/Full/hl19v.jpg
I could not find an internal pic or graphic but it reminded me of the
internal wiring of UK plugs of 50 years ago, before ROSPA and BS got
involved - , wrap around screw terminals that can easily shed a loose
wire
filament,

I have never seen a house here in the US wired with stranded wire, except
for one built in 1906. Generally #14 solid copper. BTW the 3 wire UK plug
reminds me of what is used on a clothes dryer or stove here. Would you
actually use one of these on a lamp?

Tam

both of them, live and neutral surprisingly close together and
what I find very odd , no cord grip/anchor and no fuse.





We have no choice in the matter, by law, we can use 1,2 or 3 amp fuses
inside these plugs but thats the only choice

The USA cannot have the equivalent of RoSPA (Royal Society for the
Prevention of Accidents), AFAICS none of the USA ones have child
preventers
on them unless the mouldings on the wall outlets preclude that eventuality
of small fiongers touching both pins.
The other notable difference is the insulated pins that have been
necessary
refinement, again by law, for 20 years or so
You can just see the orange plastic bits extending up the brass pins on
the
first pic on this wiki and the black bits on the one lower down on
http://en.wikipedia.org/wiki/BS_1363
...
The phase and neutral pins on modern plugs have insulated bases to prevent
finger contact with pins and also to stop metal sheets (for example,
fallen
blind slats) from becoming live if lodged between the wall and a partly
pulled out plug. A downside to this prong insulation is that it may
contribute to damaged sockets not making good contact with the prongs,
which
may even melt the latter. No such problems exist with healthy sockets.
...

as an aside someone told me that per million houses there are more house
fires in the USA due to wiring faults than any other country, partly due
to
a lot of timber construction and partly due to the higher current for a
given KW of power transfered - is that the case?

All heavy loads are connected across 240 Volts. 120 is basically used for
things that can be moved from room to room. There seem to be two main causes
for electrical fires in the US. One the improper use of extension cords; for
example, a 10 foot length of 5 amp wire with a refrigerator and microwave
plugged in at the far end. This comes about because older houses and
apartments tend to have an insufficient number of wall outlets. Two, there
was some problem with houses built about 30 years ago that uses aluminum
wire; these require special connection methods. When a home owner replaces a
switch or an outlet with a standard device, you have problems. Most home
owners here tend to do their own electrical repairs.

I think there is an inherent safety factor in a system where neither side of
a 240V circuit is more than 120 V above earth potential. Never heard of a
person being electrocuted who was not standing, or otherwise submerged, in
water. This costs money. For instance the wiring to an electric clothes
dryer will have two 20 Amp hot wires, a 20 Amp neutral wire (from center tap
of transformer), and a 20 amp earth ground wire connected to a cold water
pipe or ground rod. In some localities, the neutral and ground wires can be
tied together at the appliance. I think the only reason for the heavy
neutral and ground wires is to make sure the circuit breaker trip in case of
a short. As recently as about 20 years ago, a much smaller earth ground wire
was used.

The electric use meter must be more expensive than an unbalanced single
phase one.

Tam

"Tam/WB2TT" wrote in
:

For instance the wiring to an electric clothes
dryer will have two 20 Amp hot wires, a 20 Amp neutral wire (from
center tap of transformer), and a 20 amp earth ground wire connected
to a cold water pipe or ground rod.

Actually a typical US clothes dryer uses a 120/240V 30A circuit.
And the ground wire always connects back to the services neutral, where
things are grounded with rods and/or plumbing.

In some localities, the neutral
and ground wires can be tied together at the appliance.

They way is was, is that it was permitted to run just a grounded
conductor (neutral) to the appliance, and bond that to the case.

Since 1996 or so, that has been prohibited, so separate neutral and
grounding conductors must be supplied to a 120/240V appliance.

I think the
only reason for the heavy neutral and ground wires is to make sure the
circuit breaker trip in case of a short. As recently as about 20 years
ago, a much smaller earth ground wire was used.

For the safety ground, yes. For neutral it is assumed, to the terminals
in the appliance, that the appliance could draw the full current on the
neutral.

The electric use meter must be more expensive than an unbalanced
single phase one.

If you mean the US ones, 2-wire 120/240 ones are the norm, so are made
in quantity enough not to be expensive.


Tam

On Thu, 28 Jun 2007 01:45:44 GMT, Gary Tait
wrote:

"Tam/WB2TT" wrote in
:

For instance the wiring to an electric clothes
dryer will have two 20 Amp hot wires, a 20 Amp neutral wire (from
center tap of transformer), and a 20 amp earth ground wire connected
to a cold water pipe or ground rod.

Actually a typical US clothes dryer uses a 120/240V 30A circuit.
And the ground wire always connects back to the services neutral, where
things are grounded with rods and/or plumbing.

In some localities, the neutral
and ground wires can be tied together at the appliance.

They way is was, is that it was permitted to run just a grounded
conductor (neutral) to the appliance, and bond that to the case.

Since 1996 or so, that has been prohibited, so separate neutral and
grounding conductors must be supplied to a 120/240V appliance.

I think the
only reason for the heavy neutral and ground wires is to make sure the
circuit breaker trip in case of a short. As recently as about 20 years
ago, a much smaller earth ground wire was used.

For the safety ground, yes. For neutral it is assumed, to the terminals
in the appliance, that the appliance could draw the full current on the
neutral.

The electric use meter must be more expensive than an unbalanced
single phase one.

If you mean the US ones, 2-wire 120/240 ones are the norm, so are made
in quantity enough not to be expensive.


Most US electric meters, at least the electromechanical kind, have one
voltage coil (240 volts, l-l) and two current coils, one in each of
the 120 volt phases. That computes power based on an assumption of
voltage symmetry, usually a reasonable bet.

John

On 27 Jun, 22:05, "Tam/WB2TT" wrote:

I think there is an inherent safety factor in a system where neither side of
a 240V circuit is more than 120 V above earth potential. Never heard of a
person being electrocuted who was not standing, or otherwise submerged, in
water. This costs money.

Its a known deal that 240v is safer than 120 for 2 main reasons.
1. The main killer is not electrocution, it is fire.
2. 240v gives much better discrimination between normal and fault
loads. IOW faults have less chance of tripping a breaker in time on
120v circuits.


NT

wrote in message
ups.com...
On 27 Jun, 22:05, "Tam/WB2TT" wrote:

I think there is an inherent safety factor in a system where neither side
of
a 240V circuit is more than 120 V above earth potential. Never heard of a
person being electrocuted who was not standing, or otherwise submerged,
in
water. This costs money.

Its a known deal that 240v is safer than 120 for 2 main reasons.
1. The main killer is not electrocution, it is fire.

That is a sociologic/economic. not technical issue.


2. 240v gives much better discrimination between normal and fault
loads. IOW faults have less chance of tripping a breaker in time on
120v circuits.

I don't know what your load is. The US load per branch circuit is 1800 W,
before the circuit breaker in the box will trip. I think a GFI will trip at
10 microamps.

Tam

NT

Tam/WB2TT wrote:

I think a GFI will trip at 10 microamps.

!!!!!

Graham

On 29 Jun, 00:14, "Tam/WB2TT" wrote:
wrote in message
ups.com...

Its a known deal that 240v is safer than 120 for 2 main reasons.
1. The main killer is not electrocution, it is fire.

That is a sociologic/economic. not technical issue.

I dont see how. Cooking fire risks certainly differ by socio-economic
group, but I dont think electrical fire risks vary much. Things are
perhaps different in the US.


2. 240v gives much better discrimination between normal and fault
loads. IOW faults have less chance of tripping a breaker in time on
120v circuits.

I don't know what your load is. The US load per branch circuit is 1800 W,
before the circuit breaker in the box will trip. I think a GFI will trip at
10 microamps.

20mA is the typical figure for our standard 30mA RCDs, but most fire
causing faults are not detected by RCD, and most properties dont have
an RCD.

But that is a separate issue to fault current discriminaiton.


NT

wrote in news:1183141239.957620.211930
@q69g2000hsb.googlegroups.com:

On 29 Jun, 00:14, "Tam/WB2TT" wrote:
wrote in message
ups.com...

Its a known deal that 240v is safer than 120 for 2 main reasons.
1. The main killer is not electrocution, it is fire.

That is a sociologic/economic. not technical issue.

I dont see how. Cooking fire risks certainly differ by socio-economic
group, but I dont think electrical fire risks vary much. Things are
perhaps different in the US.


The way I see it:

The lower classes see thmselves more as DIYers, even if they are bad at
it.
The lower classes generally cannot afford to have out of date electrical
upgraded to modern standards, so try to bodge what they have to
something they feel is useable, sometimes with disasterous results.