In article ,
John Rumm writes:
J. P. Gilliver (John) wrote:

Would you care to elaborate on that? (Not disagreeing: just curious.)
[]

The design evolving, or being well suited to modern usage?

Changes include increasing the size of the earth wire since the original
spec could leave spurs inadequately protected under fault conditions
with re-wireable fuses. Switching from re-wireable fuses to cartridge
fuses and then MCBs, routine inclusion of RCDs, sleeving of plug pins
etc. Each of these have made improvements along the way. As have better
understanding of cable heating a cooling modes, and the influence the
way they are installed can have.

The other factor, which has been a big one in the UK, but is almost
completely missing in most of the world, has been the competition
between different electrical accessory manufacturers to produce
products which are safer than those from their competitors, in order
to gain a competitive advantage based on increased safety. This has
resulted in steady safety leapfrogging between manufacturers, and
long term, an across the board increase in the quality and ease of
use of electrical accessories.

This was actually pointed out to me by an engineer working for a US
wiring accessory manufacturer, who was very envious of the market in
the UK. He said he can't sell a 75c socket in the US no matter how
good it is, because someone else sells a 50c one, and everyone there
buys on price alone. Contrast that with the UK where manufacturers
such as MK and Crabtree which invest in safety design manage to grab a
larger portion of the market than the dirt cheap low end manufacturers,
because investment in safety sells here.

I wonder if this competitive safety between manufacturers was actually
started by the competition to design what became the 13A plug back in
the 1930's? It does seem to stem from around then in old adverts.
Conversely, if you take a stroll around the electrical isles of Home
Depot (the US equivalent of B&Q), it is like looking back at the wiring
accessories we used to use in the 1930's.

--
Andrew Gabriel
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