Maker Pro
Maker Pro

Re: Internal wiring of USA v UK mains plug

S

Spurious Response

Jan 1, 1970
0
The lack of appropriate machanical stress handling is my biggest rejection of
the American type 130V power plug system, in addition to extremely poor design
of those flat contact receptacles, which wear out very easily, giving poor
contact with all bad things to follow..


Sleeves and pins... blades and wipers. They both sport similar life
spans and contact mating particulars, and neither is a clear winner, and
BOTH are used in higher power commercial scenarios. They are both proven
winners for the industry.

As far as our "130V" (120V actually) 2 and 3 prong plugs and
receptacles not having strain relief... they don't need it. If one
remains within the specs for their use, the outlet/plug combo never sees
any particularly high mechanical stresses placed on it. The bladed type
actually fights mechanical stress in one plane far better than pins do
without harming contact mating integrity over tens of thousands of stress
cycles.
 
E

Eeyore

Jan 1, 1970
0
Wolfi said:
Am 29.06.07 11.50 schrieb Eeyore:

Sure it is!


Here you are wrong.
The Euro plug is a flat, 2 prong, 4mm round contact plug, with pins 17mm
apart, fitting into regular 16A/240V outlets, but meant only for low power
devices. Its current rating usually is only 2,5A and they are widely used for
connecting consumer electronics (where the other end of the cable often is
pluggable too, having the 8-shape socket, if you look at it, with 2 small
receptacles 10 mm apart), small AC/DC power supplies, 240V to 2...24V
transformers and such.

They fit into the round 5mm receptacles of German type 3 contact "Schuko"
sockets, where the plug body actually dives into the outlet cover by some
20mm, allowing it to take on mechanical forces applied to the cable, rather
than having the contacts themselves deal with it.

It is not a standard *Euro* plug and is only suitable for 2.5A

Its proper name is CEE7/16.

Graham
 
D

Dave Plowman (News)

Jan 1, 1970
0
Just the opposite. The Euro plug is not designed that you can travel
across Europe with your 3680W water boiler and plug it in everywhere,
but for all those <= 575W gadgets, people like to have with them, while
they are travelling, but also for devices being fully insolated, hence
mot requiring the protective ground like VCR, TV, RCR, audio
amplifiers, satellite receivers, battery chargers, etc, etc.

You take those with you when you travel? ;-)

But it won't fit a UK outlet due to the shutters - so not a true Euro plug.
 
J

John Larkin

Jan 1, 1970
0
I've replaced a number of two prong outlets in my house (vintage 1928)
because the outlets failed in just the manner described. I don't know
the actual vintage of the particular sockets involved--although it's
pertinent that no two were the same, leading me to believe that they
themselves were later replacements for the originals.

In some cases it was possible to easily rewired with grounded 12/2 romex
from the breaker box. In others, where that was not practical, the
two-prongers were replaced with new outlets--also two prong.

These are still available and should be used if upgrading to a properly
grounded outlet is not done.

In any case, IME the OP's statement is entirely accurate. The
edison-style outlets are either inherently--or at least 'as
implemented'--prone to losing secure contact.


They are about the same as the IEC connector on the other end of most
power cords. No big deal.

I think that the number of deaths from US-style outlets is minute.
Electrocution and electrical fires result mostly from bad/old house
wiring and faulty appliances.

Germany runs about 1 PPM annual risk of death from electrocution, with
the USA closer to 2 PPM. That's not a lot of risk. I recall reading
that the majority of electrocutions in the US are on construction
sites, things like machines and ladders hitting high-voltage lines.

Really, cars are hundreds of times more dangerous than electricity,
and cigarettes 10x again. If Europeans want to save lives, they should
discourage smoking.

John
 
D

Dave Plowman (News)

Jan 1, 1970
0
Really, cars are hundreds of times more dangerous than electricity,
and cigarettes 10x again. If Europeans want to save lives, they should
discourage smoking.

A timely comment. England starts a total smoking ban in enclosed public
spaces and the work place at 0600 on the 1st July. And having used a train
today noted my area service has banned smoking anywhere on their land -
most of the smaller stations are surface with the platforms not enclosed
so don't come under the law.
 
K

krw

Jan 1, 1970
0
There's about 3 different types of receptacles you'll find in a US
residence, the rest on that list are either industrial stuff or obsolete
things you might find in the occasional 1950s or earlier house. Generally
you'll find mostly 15A 120V grounded types, then the clothes dryer will have
a 30A 240V receptacle and the kitchen stove will have a 50A 240V receptacle.
Other high powered items like an electric furnace, water heater, spa, etc
will be hard wired. Sometimes you'll find a 15 or 20A 240V receptacle in the
garage for something like an air compressor or small arc welder but these
are generally added by the homeowner. It's really not very complicated.

There are also outlets used for room air conditioners. I have a 120V
15/20A outlet by one window downstairs and a 240V 20A (IIRC) outlet
for the thru-the-wall AC. Stoves and clothes dryers may also have
either a three pin ungrounded or four pin grounded outlet.
 
W

Wolfi

Jan 1, 1970
0
Am 30.06.07 16.28 schrieb Dave Plowman (News):
You take those with you when you travel? ;-)

therefore I said "... but also for...." ,-)
But it won't fit a UK outlet due to the shutters - so not a true Euro plug.

Yeah well, the 'Islanders' always had to be slightly different from the rest
of the world :)
 
W

Wolfi

Jan 1, 1970
0
Am 30.06.07 14.04 schrieb John Larkin:
Not in my experience. I've owned houses that were first wired in the
early 1900's, and I don't recall ever having a bad wall outlet. Most
of the really old ones have been replaced, not because they failed but
rather because they had to be upgraded to accept a 3-prong plug.

A decent 3-prong molded plug, plugged into even a cheap (79 cent) dual
wall outlet, seems to be perfectly reliable. Our biggest problem is
cats chewing on the cords, some of which seem to be tastier than
others.

It's not necessarily the wall outlet itself I had bad experience with weakened
contacts but much more those extremely poor designed extension cords with
those 3 socket heads. And I also have seen so many messed up cable plugs, due
to the lack of a decent mechanical support from the socket moulding and plug
housing. Those often flaky cheapest style flat contacts bend very easily,
especially if used on power cords connected to class II devices, which do not
require a protective ground.

But also those 3-pin plugs come out of the wall socket quite easily, when a
heavy rubber cable for an air compressor with that weird AWG format, probably
coming close to a wire cross section of some 3.something mm², is connected to
it. Despite the thicker, round third ground pin, the plug comes out very
easily quite a bit, exposing dangerously the 2 spade contacts, so that I
wouldn't want a toddler to be near it to put its tiny fingers across them.
The extremely poor electrical safety is, btw., besides the far below
suboptimal mechanical stability of the whole socket-plug system, my biggest
critic of the US domestic 110V/15A power connector system.

Or think of a vacuum cleaner with roll-up cable, where you bend or even break
the plug contacts quite easily while vacuuming around the room and putting
some tension on the power cord, especially if the stress is applied under an
angle << than 90° from the wall.

Mechanically and under safety aspects it just is an extremely poor and flimsy
design and it doesn't surprise me a bit, that every other report in the news
about a fire breaking out in US houses is claimed due to "electric
wiring/overload/failure", you name it.

It is quite interesting though, that the later added third ground pin isn't of
the same flimsy flat spade type anymore, but with its round 5mm style much
more like the also 5mm Schuko plug pin type.
 
J

James Sweet

Jan 1, 1970
0
John Larkin said:
Not in my experience. I've owned houses that were first wired in the
early 1900's, and I don't recall ever having a bad wall outlet. Most
of the really old ones have been replaced, not because they failed but
rather because they had to be upgraded to accept a 3-prong plug.

Boy I sure have, things got really cheap in the late 70s, about half the
outlets in my 1979 house were bad, of course they also were the cheap
bargain bin home center junk. You can get a pretty good outlet that will
last a long time for about 2 bucks, or you can get a really crappy one that
will wear out for about 75 cents. Guess which goes into most cookie cutter
houses they're building these days?
 
J

James Sweet

Jan 1, 1970
0
There are also outlets used for room air conditioners. I have a 120V
15/20A outlet by one window downstairs and a 240V 20A (IIRC) outlet
for the thru-the-wall AC. Stoves and clothes dryers may also have
either a three pin ungrounded or four pin grounded outlet.


I've heard of those, I don't recall ever actually seeing a 240V window AC
unit though. AC in general is very rare around here and if people have it,
it's normally central. Perhaps 0.1% of the houses have vertical casement
windows that an AC unit will fit in, I suppose that would explain it.
 
J

James Sweet

Jan 1, 1970
0
Eeyore said:
Has meaning current ?

Absolutely not. Any 'oddballs' you have date from roughly before 1960.

Graham

Correct.

We're talking about oddballs in general though right? As I've said, in 99%
of houses, you'll find one type of receptacle in all the standard locations,
and it's the same type that's been used for decades. You'll also find a
dryer outlet and a stove outlet in those houses that are not gas, and
occasionally one of a few different oddballs for specific applications like
air conditioners, compressors, welders, etc, but those are almost always
added later and most houses lack them. I just don't understand why this
would be confusing, it's made sense to me since I was a little kid, it's not
as if we have a random mismash of different types in every room of the
house. Any yahoo can do electrical work if they take some care to be neat
and tidy.
 
W

Wolfi

Jan 1, 1970
0
Am 30.06.07 14.59 schrieb Spurious Response:
Sleeves and pins... blades and wipers. They both sport similar life
spans and contact mating particulars, and neither is a clear winner, and
BOTH are used in higher power commercial scenarios. They are both proven
winners for the industry.

As far as our "130V" (120V actually)

of course, my bad. I was still thinking in terms of my accustomed european
230V system.
2 and 3 prong plugs and
receptacles not having strain relief... they don't need it. If one
remains within the specs for their use, the outlet/plug combo never sees
any particularly high mechanical stresses placed on it.

Having seen plenty of badly bent contact blades on vacuum, TV set, computer &
monitor, power drill and other shop devices' power cords, I strongly disagree.
Stuff is moved around, either in use or in off state and suddenly the power
cord limits the mobility range. Depending on what kind of bull is pulling on
the other end and he rarely does perpendicular to the wall with the outlet,
those spades bend, simply because there is *no* strain relief *at all* in the
US style socket/plug combo.
The bladed type
actually fights mechanical stress in one plane far better than pins do
without harming contact mating integrity over tens of thousands of stress
cycles.

I can't comment on that, since I don't have reliable data, but simply asked,
what about the other plain? And it also is much easier to have a slotted pipe
type receptacle, with a steel tape spring surrounding it to guarantee,
constant, long-term contact pressure for a round, mechanically sound, 5mm pin,
which gives solid, equal contact all around its circumference.

I think it has a good reason that the later added third ground pin for the US
system isn't of flat spade shape anymore, but strangely a round one now with,
who would have thought it, 5mm like in the Schuko system as well ;-)
 
W

Wolfi

Jan 1, 1970
0
Am 30.06.07 15.01 schrieb Eeyore:
It is not a standard *Euro* plug and is only suitable for 2.5A

What is your definition of "standard"?
The Euro plug was specifically developed already 1963 for insulated, class II,
low power devices up to max. 2.5A, to fit universally all over Europe with the
exception of the British BS1363 sockets. And it was adopted by the IEC in 1975
as plug C5 and as European standard EN 50075 in July 1990.
http://en.wikipedia.org/wiki/Europlug
Its proper name is CEE7/16.

The European standard plug for higher currents is CEE7/17 contour plug, but
also only for insulated devices, not requiring a ground contact.
http://de.wikipedia.org/wiki/Konturenstecker


The regular grounded Schuko plug system, CEE 7/4 and CEE7/7 is used as primary
electrical system in the following countries:

* Afghanistan
* Andorra
* Deutschland
* Estland
* Finnland
* Griechenland
* Indonesien
* Island
* Italien / San Marino / Vatikanstaat (nicht norm, aber verwendet)
* Kroatien
* Lettland
* Litauen
* Niederlande
* Norwegen
* Österreich
* Portugal
* Rumänien
* Rußland
* Schweden
* Slowenien
* Spanien
* Südkorea
* Ukraine
* Ungarn

Among others, these countries are using the CEE 7/7 compatible, „french“ system:

* Belgien
* Frankreich und ein Teil der ehemaligen Kolonien
* Monaco
* Polen
* Slowakei
* Tschechien
* Tunesien

So I would say, this rather long list of countries, stretching from the
Atlantic to the Pacific and from the polar circle down to Africa, qualifies it
as a "European standard" as well.
Still not "European" enough?
http://de.wikipedia.org/wiki/Schukostecker
 
D

Dave Plowman (News)

Jan 1, 1970
0
Yeah well, the 'Islanders' always had to be slightly different from the
rest of the world :)

But part of the EU so officially 'Euro'. Of course a Euro plug will fit a
UK 'shaver' outlet.
 
B

bz

Jan 1, 1970
0
In some cases it was possible to easily rewired with grounded 12/2 romex
from the breaker box. In others, where that was not practical, the
two-prongers were replaced with new outlets--also two prong.

These are still available and should be used if upgrading to a properly
grounded outlet is not done.

If an earth ground is not available, a GFI outlet should be installed at
the beginning of the run and 3 prong outlets along the rest of the run.

The GFI will trip if a ground fault is present.

The outlets should be marked to indicate that a GFI is installed and that
no earth ground is present.

I believe that this is much safer than using 2 prong outlets and meets
code.



--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

[email protected] remove ch100-5 to avoid spam trap
 
[email protected] wrote in @q69g2000hsb.googlegroups.com:
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.

Right, things are different here then (UK). Its mostly the upper class
with grand buildings that keep running historic installations. The
less wealthy usually rent rather than own, and laws are much more
stringent than those applying to privately owned dwellings. Capitalism
backwards.


NT
 
K

krw

Jan 1, 1970
0
I've heard of those, I don't recall ever actually seeing a 240V window AC
unit though. AC in general is very rare around here and if people have it,
it's normally central. Perhaps 0.1% of the houses have vertical casement
windows that an AC unit will fit in, I suppose that would explain it.

I have (vertical) "casement" windows that are difficult to find
window units for (even uglier to install). I also have two "window"
units installed through the wall. One is a 25KBTU unit on a 240V 20A
circuit, IIRC. The other is 7.5KBTU on a normal 120V 20A (15A outlet)
circuit.

We normally only have two weeks of weather where an AC us useful
(mine have run a total of 20 hours so far this year) so central AC is
a bit expensive.
 
F

Fred Abse

Jan 1, 1970
0
"SchuKo", from german "SchutzKontakt"

I never knew that, thanks.

I can bore the guys at the office with something else, now :)
 
Top