>
> >I strongly challenge this assertion. I know of no mechanism within the
realm
> >of classical EM field theory to account for this. I am assuming you are
> >referring to the normal force that would accompany two current-carrying
> >conductors which are in parallel proximity to each other.
> >
> Have you ever been to a welding shop and observed what happens to
> arc-welder cables when an arc is struck? I have and I saw the cables
> jump about on the floor.
Yea verily, Rich!
In my past life I did high current trip testing on 480 volt circuit
breakers. 50,000 amps was not unusual but even much lower currents would
make welding cables jump off of the floor.
I remember experimenting with a fairly large 480/120 3 phase lighting
transformer, with a dead short on the secondary and 208 volts applied to the
primary via a pretty large motor control contactor and momentary push
button. It was a "hit the button while peaking around the corner" type of
experiment. We were able to draw about 2000 amps momentarily on the
secondary which really made a set of welding cables jump.
In my experience, a single conductor doesn't need any other conductor near
it to display mechanical force when high current is applied. The self
inductance of the cable and resulting cemf produce sufficient magnetic
reaction to make the cable jump if it is not secured. Very interesting to
look at the Z of a 4/0 welding cable...
I've often found that if our engineering theories couldn't explain what
appeared to take place in reality, then we needed to look deeper into the
matter.
73, Jeff - K1LE - CT
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