>This can be easily explained, the welding cables are subject to the earths
>magnetic field and any other localised magnetic fields, that's why they jump
>about.
Tubes are immune to Earth's magnetic field ?
>The question is, would this happen in a shielded enclosure (amp
>chassis) and with the magnitude of current flowing in the grid during a
>fault condition? I am still sceptical. One thing's for sure, something
>happens, but what?
Good question. What is the fusing current of #28 Cu ? It must be at
least 15A, and yet the 3-500Z cathode/filament is theoretically not
capable of such a preak emission.
>
Any ideas, Conrad?
>-----Original Message-----
>From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]On
>Behalf Of Jeffrey Madore
>Sent: 07 February 2003 04:24
>To: 2; MorgusMagnificen@aol.com; AMPS
>Subject: Re: [Amps] Re: Voodoo "EMF' forces from grid current pulses
>
>
>
>>
>> >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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>
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>
- R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K,
www.vcnet.com/measures.
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