24 Nov
2014
24 Nov
'14
5:39 a.m.
On Sun, Nov 23, 2014 at 02:12:15PM -0800, Brent Hilpert wrote:
[...]
The ring system in Britain with fuses in the plugs
provides a safety factor
of appropriately limited current at the wall. On the other hand, in NA the
vast majority of in-wall house wiring is done with #14 wire(15A circuits),
which is a lot easier to work than whichever gauge Britain uses for 25A or
32A circuits.
Actually, we use the same gauge, except it's in metric :) Or to give actual
figures, 32A ring circuits typically use 2.5mm^2 cable, whereas #14 is
approximately 2.1mm^2. It's stiffer than 13A mains flex, but easy enough to
work with.
The ring circuit provides two paths back to the fuse box, so the whole circuit
can in theory carry twice the current. In practice, of course, the paths don't
have equal resistance so the current will not be shared equally. This
especially applies when one path has infinite resistance due to some muppet
cocking up the installation, as a quick continuity test won't detect it.
The benefit of the North American split-phase system
vs EU/Britain
Point of order: The UK is part of the EU; and 230V is not pecular to the EU but
standard across the world with the notable exceptions of North America and
Japan. Japan is also very much the poster child of how not to design an
electricity distribution network.
is you have the energy & copper-efficiency of 240V
available for heavy
appliances, but you have the safety factor throughout the house of never
having more than 120V between you and earth.
We have the safety factor of not using those lethal NEMA plugs that expose the
user to 120V in the first place.