Jim Michaels wrote:
On 4 Jul 2005 11:11:49 -0700, wrote:

UK Ten 100watt lamps at 240V equal 4.166 amps on circuit rated at 6
amps with 1mm wire.

US Five 100 watt lamps at 120V equals 4.166 amps on 15amp rated
circuit with 14gauge (2.08mm) wire.

In this example the US system has a massively greater safety margin.

Your analysis is too simplistic. The load current / cable rating is not
something that causes any significant number of fires in either case,
it is a nonissue in reality.

Agreed, There are not many electrical fires due to fixed wiring.

that is not correct.


Also I assume you realise 1mm2 is capable of much more than 6A, it is
merely fused at 5A or MCBed at 6A.

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.

Just a reasonable engineering safety margin.

reasonable safety margin on wire sizes has been addrssed already. I
cant help thinking youre perhaps not keeping up.


the problem is simply theyre
designed to have a higher incidence of faults.

Ridiculous.

hardly, look at the stats, and the practices that are known to cause
fires. Or dont.


We may have more old or poorly maintained installations but safety has
always been a primary concern.

Given what we've read in this thread, that conclusion is simply
impossible to draw.


Simply a system with more smaller circuits each with an equal or
greater degree of safety margin.

Youre not understanding safety margin. Size of cable has nothing to do
with it, once the cables big enough not to overload. Ours are big
enough and much more. Yours are even bigger, but for what? Its just
poor engineering.

Look up safety margin.

That doesnt answer the q at all. Im perfectly familiar with safety
margins, and UK has more than big enough margins in its cable sizes. US
cables are not large for that reason.


this provides 48kW of power. This is a
home with gas space heating, gas water heating, gas clothes drying,,
and often gas cooking.
Even with our maniacal excess it would be hard to overload such a
system to the point of combustion.

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,

???????

thats news?

and the
wirenuts that cant reliably maintain their ratings.

???????

The result is a
high level of fires.

???????

thats news too??

I think time to end this discussion. Good luck.


NT