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Re: Internal wiring of USA v UK mains plug

G

Gary Tait

b said:
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.
 
G

Gary Tait

[email protected] (Geoffrey S. Mendelson) wrote in
Cut me a break. Since around 1960 all of the outlets in the U.S. have
grounds.

In new installations maybe. There are still many hundreds of thousands of
two prong recepticals still installed, or incorectly refitted to three
prong recepticals.
 
G

Gary Tait

No you can't - legally. With the exception of shavers or toothbrushes
etc designed to fit a transformer isolated bathroom outlet, everything
must be fitted with a '13 amp' plug with a suitable fuse.

The appliances have a two prong cord, but a 13A plug with a dummy ground
pin (to open the shutters in the receptical). With the exception of those
that are inteded to be plugged into the batheroom shaver outlet, and those
sold in the black/grey market
 
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
 
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