On Sun, 15 Jan 2017 10:04:49 -0800 (PST), trader_4
wrote:

On Sunday, January 15, 2017 at 11:56:35 AM UTC-5, wrote:
On Sun, 15 Jan 2017 08:32:37 -0800 (PST), trader_4
wrote:

James can't even apply Ohm's Law. 18g wire has a resistance of .02 ohms
per meter. Put 20A through it and you get 8 watts. That's 8 watts
distributed along a meter of wire. Actually, I guess it's 8 x 2,
since there are two wires in a lamp cord. But 16W along a meter of
wire is very little heat. Go over 20A and the breaker will open.
And we have the everday experience where if this was a real problem,
houses would be burning down from it and it would be addressed in the
code. Obviously it's not happening. Plus, as I pointed out earlier,
a direct, serious short will greatly exceed 20A, tripping the breaker
quickly, before the wire heats up.

Evidently they have 30ga wire on their 30a ring circuits so they need
fuses in the plugs. I guess the British Empire never colonized a place
with copper ore.

Even if you had 30A running through 18g, you only wind up with 36W over a
one meter lamp cord length.

I guess those guys at NFPA who established the fixture wire standard
understand these things ;-)
If you noticed, the NRTLs stopped listing 18 ga extension cords too.
In a commercial setting most fire marshals will tag any extension cord
or plug strip that does not have a breaker in it and some will only
allow a plug strip if it is for surge protection.