Re: [TCML] Consensus on HV cable

["David Rieben" <drieben@xxxxxxxxxxx>]

Hi Joe,

Huh? A 1.0 uFd tank cap? Looks like your math is correct but
that means you would need a transformer (and supply) capable
of  >78 kVA to fully charge such a beast at just standard mains
60 hz frequency (assuming 14.4 kV). You would need even more
power available if you opted to run an ARSG at greater than 120 bps.
Even DC Cox's Big Bruiser coil that was like 16 ft. tall with a 10 ft.
diameter topload that hurled 20 ft.+ sparks only used 0.3 uFd of
tank capacitance and he was not using a very high break rate,
either (probably < 250 bps). http://www.youtube.com/watch?v=-nG1wJFev4s
My Green Monster coil stands right  at 8 ft. tall, including its 12 x 56
topload, is fed by a properly ballasted 14,400 volt, 10 kVA pig and
throws 11 to 13 ft. sparks. It has a 0.1 uFd primary tank capacitor
and I usually get the best results with the ARSG breakrate set at around
350 bps.
http://www.youtube.com/watch?v=GGb-qWIqx7g&p=8616F830A0EB304C&playnext=1&index=40

David Rieben



----- Original Message ----- 
From: "Joe Mastroianni" <joe@xxxxxxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Tuesday, September 14, 2010 12:51 PM
Subject: Re: [TCML] Consensus on HV cable


> Not to pile on here, but just to do some of the calculations for the 
> original question:
>
>  - For a Pole Pig of 14400V output, and 1.0uf tank cap, 60Hz  Ichg= 
> 377*1x10^-6*14400 = 5.43A
>
>  - NEC Table 310-16 suggests ampacity for 10Ga AWG between 30 -40A 
> depending on temp, 60-90 C.
>
> - Inner conductor diameter of RG8/U coax is, depending on type, is between 
> 0.103" to  0.108" copper, stranded or solid, with insulating material of 
> foam polyethylene or teflon.
>
> - Diameter of solid 10Ga AWG copper is 0.102"
>
> - Therefore, using the center conductor only of a length of RG8/U is 
> feasible for a 1uf Tank primary + 14400V pole pig , taking only current 
> into account.
>
> Am I missing something in that brief analysis?
>
> However, I wonder if the group could comment - does it matter if the core 
> insulating material is foam-polyethylene,  or teflon?  Should one consider 
> shorting the shield to the center conductor to avoid creating some sort of 
> distributed capacitive transmission line (though at 60hz, probably not so 
> much of an issue)?
>
> Has anyone actually done this?
>
> Thanks in advance,
>
> Joe
>
>
>
>
> On 9/14/2010 5:46 AM, David Sharpe wrote:
> > David
> >
> > What is output voltage of pole pig?
> > What is size of tank capacitor?
> >
> > Ichg ~ w * C * E  (w= 2*pi*f; 377);  C farads, E volts, Ichg amps
> > Ichg is approximate steady state VAR current
> >
> >   Would size wire to support minimum 2X that value
> >   (see NEC table 310-16 for typical conductor
> >    ampacities).
> >
> > Typical #16 is good for 7.5A continuous which at
> > 12kV is nearly 90kVA delivery to load; insulation
> > to support applied voltage.
> >
> > Regards
> >
> > On Mon, Sep 13, 2010 at 11:49 PM, David Speck<Dave@xxxxxxxxxxxxxxxx> 
> > wrote:
> > >   Esteemed list:
> > >
> > > Is there any consensus on the optimum gauge and insulation of the cable 
> > > that
> > > goes from the HV output terminals of a 10 KVA pole pig to the RSG and 
> > > tank
> > > cap of a 12" x 48" Coil?
> > >
> > > I seem to recall that the inner conductor of RG-8 coax with solid
> > > polyethylene jacket and without the shield was the preferred material.
> > >
> > > Anyone found anything better?
> > >
> > > Thanks,
> > > Dave
> > > _______________________________________________
> > > Tesla mailing list
> > > Tesla@xxxxxxxxxx
> > > http://www.pupman.com/mailman/listinfo/tesla
>
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