[Prev][Next][Index][Thread]

Re: Grounding Question

In a message dated 96-03-06 11:41:31 EST, you write:

> I am installing a grounding system for my coil (15kv, 60ma).  I intend
>to eventually use this coil as a transmitting coil, and then further
>down the road as a magnifier.  I was going to go pick up some 10"
>grounding rods.  I have heard that 2 was all I needed, but should I get
>more if I intend to use this as a transmitter?  I'm not really concerned
>about the magnifier part now, that's way down, I'd be willing to
>build/modify the grounding system then if it was required.

Josh,  I think 10" rods are a little short.  I used two 8.0 ft copper rods
for this power level and higher with no problem.  Three rods of this type
would be a good system.
>
>  Now, as for connecting this all.  Is grounding strap better than
>grounding wire?  Until I heard people talking about grounding strap
>here, I was going to get grounding wire (the kind that would be used to
>ground a house with metal-siding).

Solid flat 3.0" wide aluminum or copper sheeting (like aluminum flashing)
seems to be the best choice.
>
>  Now comes the part of connecting the components to the grounding
>system.  In previous coils, I had made a "Grounding Bar" (as I called
>it), which was a small bar (6" long) I picked up at the hardware store,
>and stuck bolts & nuts in it (to connect various components).  Then I
>connected this grounding bar to the RF ground.  Is this a bad idea?  It
>seemed to work ok, but my previous coils were smaller than the one I am
>building now (6").

I would connect the ground rods directly to the base of the secondary with
one continuous piece of flashing.  Then I would connect the other grounds
into that piece with bolts somewhere close to the base of the coil.
>
>  What type of wire would be BEST for connecting components (such as
>transformer) to the grounding bar (or whatever else you guys suggest I
>use instead).  I had intended to use grounding strap for the secondary
>coil, but I wasn't sure if I should use strap/grounding wire for stuff
>like the xfmer, saftey gap, etc., or if I should use HV wire.

I have all my grounds like the transformer, safety gap, etc. connected to the
RF ground with 12 gauge solid copper wire.  Something larger wouldn't hurt
anything.
>
>  One last question about the safety gap.  When everything is properly
>tuned, how often should this gap spark?  I can get it to spark from
>never to constantly by varying the distance of it.  I didn't notice any
>affect on the coil with various distances, but again, my previous coils
>were pretty bad.  I want to do this coil right.

With everything properly tuned, the safety gaps should not be firing, or only
occassionally.  I have mine set at 1/2" on each side.

Ed Sonderman
>
>Josh W. Perfetto