Re: Ground Rods & Secondary Leads: How long is too long??

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Esondrmn-at-aol-dot-com>

In a message dated 10/28/02 8:48:30 PM Pacific Standard Time, 
tesla-at-pupman-dot-com writes:


>What is a respectable length for a ground lead off the secondary coil?
>
>What is too long? What's the max I could expect to make it and not
>suffer decreased performance? I planned to go from 22ga magnet wire to
>some glass/ptfe coated 12ga nickel plate stranded probably shielded in
>1/8 wall silicone tubing. Excessive, but it'll never go bad!!!
>
>What's the shortest rod I can get away with? I have fairly damp soil, so
>I wouldn't think I'd have to go too horribly deep. I've watched the list
>and somewhere between 3-5' seems to be the norm, but I also saw the
>posts about the dog leash screw which would seem plausible in really
>moist soil!
>
>I can drive a grounding rod into several places, but I only want to
>drive in one, so I'd like to make it as central as possible to all spots
>I intend to run. If a really short screw-type thing would work, then my
>only real concern is actual distance from the "ground".
>
>Thanks,
>
>Ken


Ken,

You will probably get as many different opinions as you get answers on this 
question.  In my opinion, it depends on the system.  Smaller, lower powered 
systems can get by with less.  Larger, higher powered systems need a more 
robust ground and shorter connections.  My 3" diameter coil using a 12 
kv  60 ma transformer uses one eight foot ground rod about 15 feet away and 
is connected to the coil with two parallel #12 solid copper wires.  My 6" 
coil running with a 14.4 kv distribution transformer at 7kva uses a large 
ground system with three eight foot ground rods inter-connected by copper 
flashing.  The coil is operated about two feet from this ground system and 
is connected to it by a 5" wide piece of copper flashing.

Ed Sonderman