"Doctor Drivel" wrote in message
enews.net...

"Pete C" wrote in message
...
On Wed, 27 Jul 2005 09:58:48 +0100, Gerd Busker
wrote:

The fundamental difference between "continental" installations
and UK
installations is that here in the UK the plug is fused. This
allows for
higher
capacity circuits (such as 30A rings) as you have some degree of
over
current protection in the plug.

In Spain, or the Netherlands, there is no fuse in the plug, so
you will
need
to reduce the circuit rating to keep things safe. In NL most
circuits
are
fused at 16A.

There's not /that/ much difference between a 30A ring and 2 16A
radials. MCB's are cheap these days, also rings are harder to
fault
find and the ring can get a break in it.

Anyway a 13A plug fuse can take 26A for up to 30 mins before
breaking,
I'm sure a 16A MCB can do better than that.

When comparing both ring and radial, IMO the ring just gets it. A
radial
can have a break in it as well as a ring, and if there is a break
in a
radial you know about it sooner, whereas a ring can be fed from the
backend
and the fault goes undetected. A ring has two paths back to the CU
(very
important for safety).

And a very dangerous way of over-loading a single 2.5mm length of
cable, the most dangerous fault that could be caused by a break in a
radial is a break to the earth - anything else will cause the circuit
to fail and unusable.


The fuse in the plug tips it for me regarding the British system.
Others
can introduce these on radials for extra protection, but they
haven't. The
British have for 60 years. There is nothing more annoying when an
appliance
trips out the whole house,

Which won't happen on a modern radial circuit [1], at worst you are
going to take out the room, OTOH a fault can and has taken out a
whole house were a ring circuit is in use...

[1] forget how they might have been wired 60 years ago.

when a fuse could have just dropped out the
faulty appliance. Rings for over 50 plus years have proven to be
very safe.
Installation cost is low too. The British wiring regs are regarded
as the
best, and safest, in the world, and I would go along with that.
BTW, and
rings are not mandatory.


How come that anyone is left alive in the US or other countries that
use radials, the problem is not the circuit but those who miss use
them - as is the case with any circuit.