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Internal wiring of USA v UK mains plug

D

DJ Delorie

Eeyore said:
Why would you need more than one type ?

Most of them are the usual 15 amp outlets (||). Some (in my workshop)
are 15/20 outlets, with the extra slot for 20A-only cords(+|). I have
one 30A twist-lock outlet in my generator, too.

I don't think I've ever seen the 20A-only plug on anything though.
Have they gone the way of the $2 bill?
 
K

krw

Most of them are the usual 15 amp outlets (||). Some (in my workshop)
are 15/20 outlets, with the extra slot for 20A-only cords(+|). I have
one 30A twist-lock outlet in my generator, too.

I don't think I've ever seen the 20A-only plug on anything though.

I've seen them on air conditioners. I put one on a bathroom kick-
board heater (2kW).
Have they gone the way of the $2 bill?

They're still around too. ;-)
 
K

krw

[email protected] (Geoffrey S. Mendelson) wrote in


In new installations maybe. There are still many hundreds of thousands of
two prong recepticals still installed, or incorectly refitted to three
prong recepticals.
Two-prong receptacles may be replaced by three-prong as long as there
is a GFCI on the circuit. It's common to replace the first outlet on
the chain with a GFCI outlet. The grounds don't have to be
connected, but according to code it has to be marked as ungrounded.
I agree that many are incorrectly retrofitted (no GFCI).
 
N

N Cook

Dave Plowman (News) said:
If like UK wiring of that age, rubberised cloth. Which crumbles away. Uk
wiring was often lead sheathed and inside the sheath the insulation can be
perfect. But the ends exposed to air etc not.

--
*If only you'd use your powers for good instead of evil.

Dave Plowman [email protected] London SW
To e-mail, change noise into sound.


The lead was the earthing conductor and at most points, of a tight bend, the
lead would fail a few years after the bending at installation.
 
N

N Cook

D

Dave Plowman (News)

The lead was the earthing conductor and at most points, of a tight bend,
the lead would fail a few years after the bending at installation.

The entire lighting circuit in my house was wired in lead when I bought
it. And there was no sign of this at all. Nor can I think of a reason why
it would - unless subject to continuous flexing. In which case the
conductors would fail too.
 
G

Geoffrey S. Mendelson

Also there are 2 very similar types of 2 pin plug which sometimes
causes confusion. The modern EU ones cant fit a UK socket, the pins
are too fat and too closely spaced. Forcing doesnt work. There are
also historic French plugs that look similar and do fit our sockets
with a bit of fiddling, but very rarely does one see one of those used
over here. They have 4mm pins. I dont think I've seen one in over 20
years.

The current EU standard is a 2 pin plug that looks like the one you have
not seen in 20 years. The grounded version is the same with a third
pin of the same diameter, but slightly longer between them but below.

The two "fat" round pins, were only used in some parts of Europe and
does not fit in the U.K. outlets.

According to an answer to a previous post, modern U.K. outlets have
shutters which are opened by inserting the ground pin. This is to
prevent the two round pin plugs going in on their own, albeit with
a little force.

I know the adaptors of which you spoke, I have several. They take a
two pin "euro" plug and clamp onto them. They have to be installed
with a screwdriver, so they are not for casual useage and won't
fall out halfway when pulled, like the simple two pin U.S. to "euro"
plug adaptors.

I recently bought a rice cooker made in the U.S. for export. It had
sat unused for years. It was 220 volt, but had a U.S. plug with one
of those simple adaptors on it. Since I consider the chance of it
staying together while I unplugged it near zero, as soon as I tested
it to make sure it worked, off came the plug and a three pin "euro"
plug went on it. The third pin is of no real use, the cord is only
two wire.

However, I've seen enough of them to know that I am in the very
small minority. Most people just use the adaptors and be done with
it. I assume the smarter but less handy ones tape them together.

Geoff.
 
G

Geoffrey S. Mendelson

Eeyore said:
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.
 
E

Eeyore

Geoffrey S. Mendelson said:
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
 
D

Dave Plowman (News)

Eeyore wrote:
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.
 
D

Dave Plowman (News)

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

Eh? Even with final circuit rings there were at least three types of
sockets. Normal, D&S (round pins where the live was a removable fuse) and
Walsall gauge. Same as 13 amp but the pins at 90 degrees. The last two
often used by councils on housing estates. Gawd knows why. Some official
with a bee in his bonnet. Or saving pennies.

Then plenty of the old types still in use. 3,5 and 15 amp round pin. In
both 2 and three pin. Then there were some oddities with flat pins.

US visitors used to laugh at our variety of sockets, domestically. Now we
have only one, and they have the variety...
 
E

Eeyore

Dave Plowman (News) said:
Eh? Even with final circuit rings there were at least three types of
sockets. Normal, D&S (round pins where the live was a removable fuse) and
Walsall gauge. Same as 13 amp but the pins at 90 degrees. The last two
often used by councils on housing estates. Gawd knows why. Some official
with a bee in his bonnet. Or saving pennies.

Then plenty of the old types still in use. 3,5 and 15 amp round pin. In
both 2 and three pin. Then there were some oddities with flat pins.

The 2 and 3 pin 2, 5 and 15A plugs were all part of a single standard.
http://en.wikipedia.org/wiki/BS_546

Never seen any flat pin jobbies.

As for Walsall gauge I've only ever seen that in the tube. Did councils really
fit them ?

Graham
 
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=en&q=knob+and+tube+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
 
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