Re: arsclist Ground Impedance for Sound Studio

["Doug Pomeroy" <pomeroyaudio@xxxxxxx>]

Richard,

An excellent answer. It's rare to find a clear-sighted 
and straightforward answer which does not try to
grossly oversimplify the reality.

And see Tesla's work for possible "complication"
of what we call "grounding"?

Doug Pomeroy
pomeroyaudio@xxxxxxx
---------
>From: "Richard L. Hess" <arclists@xxxxxxxxxxxxxxx>
>To: ARSCLIST@xxxxxxxxxxxxxxxx
>Subject: Re: arsclist Ground Impedance for Sound Studio
>Date: Thu, Oct 25, 2001, 2:41 PM
>

> At 08:10 AM 10/25/2001 -0400, José Llufrío wrote:
>
> This happens to be an area that I have spent some time studying. In order
> to get you in the correct frame of mind for what follows, remember
> satellites work fine without being grounded. Think about the image of
> geostationary satellites with 22,300 mile long ground conductors! Ok now on
> to what we're trying to do.
>
> When we say grounding, we mean a lot of things. There is bonding
> (connecting everything together to form an equi-potential plane) and
> grounding (connecting that equi-potential plane to the center of the earth).
>
> The actual grounding is really only important so that you don't fry
> yourself as you step from the real world into the facility.
>
> Everything else is bonding. The goal here is to minimize the potential
> difference among all the points that are connected together. The design
> here is very dependent on the power system design and the overall building
> design.
>
> If you have a central computer room using an access floor the #2 copper
> wire grid  (signal reference grid) is a very useful way of achieving a good
> equi-potential plane.
>
> Is RF present? If so, then surface area is more important than cross
> sectional area. Copper strips are often used (and mis-used) as ground
> references.
>
> Don't be afraid of ground loops. In fact, a ring ground around the
> perimeter of the building is often a very good place to start.
>
> I'm sorry there is no one answer, and answering the question of what
> "impedance" ground is only really useful to determine if the power
> utility's circuit breakers will trip if there is a ground fault on the
> incoming feeder.
>
> The most important function of a ground is personnel safety. Bonding helps
> equipment work better.
>
> Also, there are papers for the "pin one problem" that describes common
> impedance sharing. The noise voltage's drop across the common impedance
> becomes superimposed on the signal.
>
> Hope this helps.
>
> Cheers,
>
> Richard