RE: HV Cables

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Mccauley, Daniel H" <daniel.h.mccauley-at-lmco-dot-com> 


For general tesla coil where voltages are about 14.4kVAC from a pole
transformer or similar, high voltage cables
aren't really necessary as there is always ample room to route cables
and wires to prevent arcing to nearby objects
etc...

However, for higher voltage applications, the best high voltage wire out
there is type RCB wire made by
Rowe Industries.  Its a standard silicone type insulated wire with an
internal conductive silicone layer immediately surrounding the wire
inside.  This internal semi-conductive layer is used to equalize the
voltage gradients around the internal wire prevents corona formation
between the wire and the insulation.  Very expensive, but works
extremely well.  I have a spool of this type of wire rated at 80kV, 8
AWG!  Its 8 AWG and the jacket is about 1" in diameter.  I know a few
people at Richard Hull's commented on this wonderful wire i had in Marx
Generator charge circuit.

Dan


 > Hi all,
 >
 > I am wondering what is the general consensus out there
 > amongst coilers as to
 > what makes the best cable for HV.
 >
 > For some time, I have been using RG-8 coaxial (Thick
 > Ethernet), with the
 > outer braided shield removed.  This has excellent dialectric
 > strength and is
 > rated for more than 35kV.  I believe it is, or has been in
 > the past, been
 > widely used as HV transmission cable?  I managed to get a
 > reasonable length
 > of used cable from an ex-employee when they moved their
 > building trunk cable
 > over from this to fibre.
 >
 > However, the thick, heavy, yellow RG-8 coax is becoming very
 > difficult to
 > obtain and expensive, and I am wondering about alternatives.
 > I have looked
 > through Tesla archives, I did not find much, except that
 > someone mentioned
 > the use of RG213 coaxial, but according to the spec's, this
 > cable is only
 > rated for 3.7kV RMS.  It is also not solid core, but multi-stranded.
 >
 > I have been toying with two ideas:
 > 1) Just buy some Neon cable.
 > 2) Using thick guage enamelled copper, with my own insulation
 > around it (a
 > few layers of heatshrink maybe).
 >
 > I believe, from my research, that for HV, esp. at relatively
 > low current,
 > solid copper conductors are best (comments welcomed).  I have tried
 > multi-stranded copper (high current DC) before for 15kV-at-60mA
 > (NST ouput),
 > but the HV tends to "buzz" inside the cable, and you lose
 > most of the power
 > to what I believe must be coronal losses within the strands
 > of the cable.
 >
 > I am sure this is an old topic, so I apologise for that.
 >
 > All commented welcomed.
 >
 > Rgs
 > Ian
 >
 >
 >