Chip wrote:
On 4 Jul 2005 11:11:49 -0700,it is alleged that
spake thusly in uk.d-i-y:
Safety margin is determined by looking at what in the system causes
safety failures, and how often. Cable rating doesnt come into it. Your
heavy US cables are merely a waste of resources, achieving nothing
afaics.
Dunno, they seem much sturdier against mechanical damage (stripping
etc).
is that one of the big causes of fires though?
Again you miss it. Your systems are overloaded day in day out, not at
the service entrance but at the wall plugs that get too hot, and the
wirenuts that cant reliably maintain their ratings. The result is a
high level of fires.
Wall outlets and plugs don't get hot when they're new, it tends to be
the older ones that are loose that overheat.
ok, so they are a problem.
I never in 5 years in the
US saw wirenuts that couldn't maintain the ratings *when installed
correctly*.
If users routinely cant install them safely, even after over half a
century of use, theyre a safety problem. Whatever the mechanics of it,
they do cause fires, but are still used. Strips of 12 screw connectors
are very cheap here, even if not as cheap as wirenuts. The cost to save
those lives is trivial. Add in the great cost saved in damaged goods,
and the US's use of wirenuts seems to make no real sense.
Most fires are due to overloading extension cords, that is one thing
that really SHOULD be changed, they allow 13 amp rated (16AWG) ext
cords on 20 amp circuits, which is a recipe for disaster, one that all
too often works well:-(
why would that cause disaster, given the large cable safety margins?
and why permit 13A rated cable on 20A circuits?
If what youre saying is accurate, the next question is why.
precisely, here theyre illegal and unheard of. There isnt even a black
market in such junk, its just off the scale. Even the occasional 50
year old install isnt that bad.
As someone else has noted, they are appearing on lighting equipment
and scare the bejesus out of me, the ones that are on light fixtures
make the US backstab connections look secure.
We use them only for low current apps in UK, for which they work
satisfactorily. Trying to put over 10A through them is another matter.
They will only maintain a gas tight connection over a very small
contact area.
NT