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| Authored by: Winter on Wednesday, December 12 2012 @ 08:50 AM EST |
"I clearly remember the UK delegation made it a make or break
point..."
To counter a wrong impression that might come up:
I got this from coverage in the papers at the time. I was not present at the
negotiations.
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Some say the sun rises in the east, some say it rises in the west; the truth
lies probably somewhere in between.[ Reply to This | Parent | # ]
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| Authored by: Wol on Wednesday, December 12 2012 @ 04:31 PM EST |
Actually, you miss several other very important points!
One thing the UK setup does is FAIL SAFE. This is JUST NOT TRUE elsewhere in
Europe.
Tiger has mentioned this elsewhere, but a French plug that REQUIRES an earth
will happily go into an unearthed socket. Huh!?!?!
If something goes wrong and your French earth goes live, there are exposed
connectors that will give you a shock. I don't know what else is dangerous about
the French system, but that's enough to be scary.
We have some glitches with the implementation of our system, but it is ALMOST
IMPOSSIBLE for someone to be shocked by the English system. One of the nice
things about the UK plug-and-socket design today is you can't (at least not
without a lot of difficulty) get access improperly to any live components in the
socket. You NEED the earth pin on your plug to open up access to live and
neutral. Kids can't stick metal objects into the socket and get a shock. Lose
the earth pin from your plug, and the plug will not fit the socket.
Cheers,
Wol[ Reply to This | Parent | # ]
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| Authored by: Anonymous on Thursday, December 13 2012 @ 09:19 AM EST |
If you triple the current-carrying capability in a circuit, you will only triple
the power, as long as the voltage remains constant. Remember, P = E * I.
Also, increasing current-carrying capability from 13 A to 30 A will not even
triple the current; it will only increase it to about 2.3 times as much.[ Reply to This | Parent | # ]
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| Authored by: Alan(UK) on Thursday, December 13 2012 @ 02:04 PM EST |
I am beginning to wonder if the 13A plug/ring main is beginning to become
dated.
I would presume that originally the idea was that one ring would suffice for a
small house; individual loads would be small, apart from an electric fire, and
distributed around the ring. Modern usage has changed considerably; a house
needs several rings and the load, in say a kitchen, could all be bunched at one
end.
The plug-top fuse is a special design to protect the appliance lead in the event
of a short-circuit. Again things have changed a lot; we have reduced the
original 2A, 3A, 5A, 7A, 10A, and 13A values to just 3A and 13A mainly. This is
partly due to cable improvements but mainly because the appliances are made in
China to suit countries where the only protection is a 16A circuit breaker. For
the UK they just fit a cheap 13A plug - not even bothering to tighten all the
screws. Nice molded-on 13A plugs (not needing to be dismantled for inspection)
are now an exception.
The ring main itself is now expected to meet a higher standard; just testing it
is difficult. The concession to allow unfused spurs off the ring has been
tightened to forbid the fitting of two single sockets on a spur because it would
be easy to replace them with double ones. Even so, it is only too easy to
grossly overload the system: On an unfused spur a piece of 20A cable is
protected with a 32A circuit breaker, the double 13A socket is itself not rated
for two 13A loads simultaneously; but when a fused extension lead is plugged
into each socket, it is easy to add loads to both, well above the rating of the
13A fuse in the plug of each extension lead (the fuse is not designed to protect
against overload). The total load could be increased until the 32A breaker
trips. The result would be one very hot double socket - not good.
Splitting the ring into two radial circuits, each with a 20A circuit breaker
would solve some of the problems, including testing, though the 13A fuse then
becomes rather useless.
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Microsoft is nailing up its own coffin from the inside.[ Reply to This | Parent | # ]
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